Glossary of terms
After-birth
The placenta and associated membranes passed from
the uterus after birth of the child. The placenta usually follows shortly
after the baby. However, if it does not come on its own the doctor may
have to remove it by other means, as complications may arise if it is not
expelled. The fetal membranes - the chorion is the outer one and the
amnion is the inner one - envelope the embryo and contain the amniotic
fluid.
Alpha-fetoprotein screen (AFP)
A plasma protein normally produced by the fetus' liver. AFP
eventually finds its way into the mother's blood and the amniotic
fluid. When too much or too little AFP enters the mother's
blood stream it can be a sign of fetal problems, such as birth defects.
High AFP levels in the mother's blood indicates an increased risk of
fetal spina bifida, anencephaly, or other
malformations. Low AFP levels are associated with an increased risk of Down
syndrome (trisomy 21) and other chromosomal problems. Measuring the
AFP level is not sufficiently accurate in screening for Downs- AFP testing
should be combined with other tests. Don't assume your child has Down
syndrome or spina bifida just because you had an abnormal AFP test result.
The AFP test assesses risk, it does not diagnose disease. Unfortunately,
many abnormal test results are falsely abnormal and do not reflect a
problem with the fetus or mother. If the AFP test is abnormal, additional
testing should be performed.
Amniocentesis
Sometimes called an 'amnio', this minor surgical diagnostic test
allows the doctor to obtain a sample of the amniotic fluid. The amniotic
fluid is then analyzed to look for genetic characteristics of the baby or
to check on the maturity of the unborn baby’s lungs. The amniocentesis
is a common way to obtain material for genetic and other testing of the
baby. The doctor inserts a long, thin, hollow needle thru the mother's
abdomen into the uterus and amniotic fluid. Usually the doctor uses
ultrasound imaging to guide the needle. The small amount of fluid removed
should not affect the baby. The risk of complications from the procedure
is low, but, as with any procedure, complications can occur. Be sure to
consult with your doctor before the procedure is performed.
Amniocentesis helps the doctor estimate the baby's lung maturity.
Because babies often 'breathe' amniotic fluid in and out of their lungs
inside the womb, the amniotic fluid is chemically similar to the fluid
within their lungs. As their lungs mature, the chemical composition
changes. These changes can be measured from the amniotic fluid and used to
estimate the maturity of the lungs.
Amnion
The thin, transparent inner membrane (the chorion
is the outer layer) that constitutes the amniotic membranes. These
membranes contain the amniotic fluid and
form a protective layer for the baby insulating him/her from bacteria in
the vagina. Rupture of this sac exposes the child to bacteria in the
vagina and increases the risk of infection if the infant is not delivered
within about 18 hours. Labor usually starts shortly after or before
rupture of the amniotic membranes.
Amniotic fluid
Amniotic fluid is fluid inside the membrane that forms a sac around the
embryo and later the fetus. The fetus and the placenta produce the
amniotic fluid. This buoyant fluid helps the fetus grow uniformly, helps
the bones and muscles develop, and allows the baby to move within the
uterus. Babies breathe this fluid in and out of their lungs in the womb
helping the lungs to grow as well. It also keeps the amnion
(membrane) from sticking to the fetus.
Having too little or too much amniotic fluid can signal a problem with
the fetus or the mother. A mild decrease in amniotic fluid is common late
in pregnancy. Too much amniotic fluid may cause the uterus to enlarge,
which may result in premature labor. Excess fluid occurs in maternal
diabetes, twins and some other conditions. Fetal problems that may also
result in excess fluid are esophageal atresia (blockage of the esophagus
that prevents effective swallowing) which prevents the amniotic fluid from
passing to the stomach and intestines for absorption.
Amniotomy
Amniotomy - Intentional rupturing of the amniotic sac to hasten or induce
labor. This procedure is also done to check for meconium
or to allow the doctor to use an internal
fetal monitor. Although an amniotomy can speed up labor, its
disadvantages are that it can rarely lead to umbilical cord
compression, and it eliminates the barrier that protects the fetus
from bacteria in the birth canal. Some doctors frequently perform an
amniotomy and some do not.
Analgesic
Refers to any medication that relieves pain while allowing the patient to
remain conscious.
Anencephaly
Birth defect characterized by failure of the brain and skull to form
properly. Parts of the brain and the skull may be missing. This is one of
several neural tube defects (NTDs). The neural tube is an embryonic
structure in the developing fetus that forms the spinal cord and brain.
Anencephaly occurs when the upper end of the neural tube (the rostral
neuropore) fails to close in the embryo's fourth week of life. This is a
fatal malformation and these children usually die within a few days of
delivery. The risk of anencephaly and other NTD's can be reduced by taking
appropriate amounts of folic acid before conception and throughout
pregnancy.
Anterior
Means in front of, usually with reference to the front part of the body.
Often used in association with the term' anterior presentation' or 'occiput
anterior' (OA). Usually, babies are born with the back of the head or
occiput pointed up or slightly to the left or right side. It is as if the
child was looking at the floor during emergence from the birth canal. This
is the best position in most cases since it allows the child to negotiate
more easily the turns required to get thru the mother's pelvis and
birth canal. If the baby presents in the birth canal with the occiput
anterior and to the left it is called an LOA (left occiput anterior)
presentation. If the occiput is anterior and to the right, it is
calledROA (right occiput anterior).
Apgar score
A numerical summary of a newborn's condition at birth based on the five
signs noted in the table. The score is measured at 1 and 5
minutes. Additional measurements are made every five minutes
thereafter if the score is <7 at five minutes until the score reaches 7
or greater. Prematurely born infants generally have lower scores than full
term infants. The Apgar score does not predict future development
with accuracy. The score was developed by Virginia Apgar and represents a
rough estimate of the condition of the infant at birth.
Asymptomatic
Without symptoms.
Back labor
Some women have labor pains that are concentrated in their
back. This is more common when the baby is presenting in the birth
canal with the occiput posterior (OP) with the baby looking up rather than
down as in the occiput anterior (OA) position.
Bilirubin
Yellow chemical that is a normal waste product from the breakdown of
haemoglobin and other similar body components. The placenta clears
bilirubin from the fetus' blood, but after delivery this task belongs to
the infant. It usually takes a week or more for the newborn's liver to
adjust to its new work load. When bilirubin accumulates, it makes the skin
and eyes look yellow, a condition called jaundice. A little jaundice can
be expected in all newborns. If the jaundice is higher than usual, it can
usually be treated with phototherapy (special lights). If the level of
bilirubin gets extremely high, brain injury is a risk. With modern
treatment techniques such as phototherapy, such dangers rarely occur.
Phototherapy is so effective in helping the liver excrete bilirubin that
elevated levels are rarely a problem. Prematurely born infants may have
elevated levels of bilirubin for several weeks.
Biophysical
profile
A series of measurements made to evaluate the fetus' condition before
delivery. The biophysical profile is similar to the Apgar system, but
performed before delivery. Ultrasound observations are made for at least
30 minutes. The score is based on the findings in the table below.
Birth canal
The tunnel comprised of the vagina and cervix,
thru which the infant must pass from the uterus during birth.
Bloody show
As the cervix dilates, blood and the cervical mucous
plug (from the cervical canal) pass from the vagina. The bloody show
is a classic indicator of beginning or progressing labor.
Bradycardia
An abnormally low heart rate. When referring to the fetal heart rate (FHR)
tracing in labor, abnormally low heart rates can signal problems with the
fetus before delivery. The FHR is often monitored for abnormalities of
the heart rate. Fetal bradycardia episodes are sometimes called FHR
decelerations. Some types of FHR decelerations are common during labor.
Others suggest fetal stress and demand further evaluation or
intervention. Sometimes the FHR not only dips down, it stays down and does
not return to its usual level. This is an ominous situation that demands
immediate delivery. FHR decelerations or bradycardia episodes come in
three types.
- Early decelerations are normal and common. These decelerations are
called early because they occur early during a uterine contraction.
These FHR decelerations usually occur after labor is well established
(4-7 cm of cervical dilatation). The FHR rarely goes below 100 beats
per minute. The cause of these decelerations is head compression
during uterine contractions.
- Late decelerations cause more concern. They are called late because
they first appear at or after the peak of the uterine contraction. The
FHR improves only after the contraction has stopped. These FHR
decelerations may be mild or severe based on how low the FHR goes and
how long it takes for the FHR to recover. It is thought to be caused
by reduced blood flow to the uterus and placenta during
a contraction.
- Variable decelerations are a common type of FHR deceleration in
labor and are caused by umbilical cord compression. Up to 80% of
fetuses will have variable decelerations during labor. The
significance of the these decelerations depends on how low the heart
rate drops and how long the episode lasts. When referring to a newborn
baby bradycardia is usually associated with apnea or cessation of
breathing. Apnea and bradycardia spells are most common in
prematurely born infants. During these spells the infant will stop
breathing for at least 15 seconds and the heart rate will start to
slow. Gentle touching or other stimulation almost always restarts the
breathing and increases the heart rate. Medications (theophylline or
caffeine) are often used to treat these spells in newborn babies.
Apnea of prematurity does not cause sudden infant death syndrome
(SIDS). However, prematurely born babies are at greater risk for SIDS,
just because they are prematurely born. The exact reasons why
premature babies have a higher risk of SIDS is not known.
Braxton-Hicks contractions
Periodic contractions of the uterus that do not represent true labor.
These contractions may begin as early as the first trimester, are
irregular, usually painless, and of low intensity. They can be confused
with labor. Toward the end of the third trimester, the contractions
become more frequent and intense.
Breech presentation
When babies are aligned in the uterus to come out buttocks first, as
opposed to head first--the way most babies come out of the uterus --it is
called a breech presentation. The head is the largest part of a full term
baby's body. Therefore, delivery of the buttocks first may not adequately
open up the birth canal enough for the head to pass thru. The head may
then get stuck in the birth canal, leaving the infant and mother in a
precarious situation. Most babies with a breech presentation are
delivered by caesarean section. On
occasion the infant can be turned around so that he is lined up to come
out head first.
Caesarean section
Delivery of the baby thru an incision in the abdominal and uterine
walls when delivery thru the birth canal is impossible or dangerous.
This procedure was performed as early as 715 BC and can be lifesaving for
both the infant and the mother in certain situations. However, elective
caesarean sections (those scheduled in advance and performed before a
woman goes into labor) when performed before term are a significant cause
of medical problems in the baby. If a caesarean section is performed
before the infant's lungs have completely matured, the infant may have
serious respiratory problems. Elective caesarean sections would normally
be performed only if there is good evidence that fetus has mature lungs.
Women should be evaluated using methods to make sure that the fetus'
lungs are mature. The criteria are as follows:
- Fetal heart tones should have been documented for 20 weeks by
non-electronic fetoscope or for 30 weeks by
Doppler.
- It has been 36 weeks since a positive serum or urine chorionic
gonadotropin pregnancy test was performed by a reliable laboratory.
- An ultrasound measurement of the
crown-rump length, obtained at 6-11 weeks, supports a gestational
age of at least 39 weeks.
- An ultrasound, obtained at 12-20 weeks confirms the gestational age
of at least 39 weeks determined by clinical history and physical
examination.
An alternative method to assure fetal lung maturity is toperform an amniocentesis
and measure chemicals in the amniotic fluid. The concentrations of these
chemicals are a good reflection of lung maturity status.
Caput succedaneum (caput)
A spongy swelling and accumulation of fluid in scalp tissues of infants
born vaginally. This occurs because the baby's head, in normal
presentation, is under much pressure in the birth canal, This pressure on
the skin of the scalp causes accumulation of soft tissue fluid. Although
it may look serious, it usually disappears within a few days.
Cephalopelvic disproportion
The most common reason for doing a caesarean
section. Sometimes the infant's head is larger than the mother's
pelvis, thru which the head must pass in a vaginal delivery. Therefore,
the safest way to deliver the infant is to do so by caesarean section.
There are several ways to estimate fetal size and pelvic size. Physical
exam and ultrasound are very useful in evaluating cephalopelvic
disproportion.
Cervical gel
This usually refers to a prostaglandin medication that is prepared in a
gel-like material. It is placed on the cervix to
hasten cervical dilatation in preparation for delivery.
Cervical incompetence
Inability of the cervix to remain closed during pregnancy. The properly
functioning cervix will be tightly closed until labor to keep the fetus
safely inside the uterus. Some women have a cervix that does not stay
closed and opens up in the second or early third trimester. This can
result in miscarriage of the pregnancy or
premature delivery of the baby. To avoid premature delivery with an
incompetent uterus the cervix may be stitched up or the mother may be
confined to bed. The reason for many of these cases is not known. However
women who were exposed to diethylstilbestrol
(DES) as a fetus or those who have had removal or cauterization of
cervical tissue may be at increased risk for this.
Cervicitis
Inflammation of the cervix.
Cervix
The lower portion of the uterus. The cervix is the
part of the uterus that keeps the fetus from
falling out of the uterus. During labor, the cervix thins and dilates to
permit passage of the infant out of the uterus and into the vagina.
Chorioamnionitis
Infection, of the chorionic and amniotic membranes
caused by bacteria. These membranes enclose the amniotic
fluid and when infection is present in the membranes, the mother and
fetus are at increased risk for severe infection. When chorioamnionitis
occurs, delivery of the fetus should be undertaken without delay. The
infection is very difficult to treat without delivery of the fetus.
Chorioamnionitis can also cause premature
labor.
Chorion
The outermost layer of the two fetal membranes, which envelope the
growing fetus and serves as a protective barrier to the fetus against
infection.
Chorionic villus sampling
A prenatal diagnostic test, done at 8-10 weeks of pregnancy to asses the
fetus' chromosomes. The advantage of this test over amniocentesis
is that (CVS) can be done earlier in gestation than the
amniocentesis. However, the risks to the fetus are greater than with
amniocentesis. Chorionic villi are a part of the placenta but contain
fetal tissue. A needle is inserted into the chorionic villi of the
placenta and a small amount of tissue is removed and sent for analysis.
The placenta can be approached either thru the cervix or thru the
mother's abdominal wall.
Chromosome problem
Also called chromosomal malformations, anomalies, or defects. This refers
to abnormalities in the number or organization of chromosomes. A common
example is trisomy 21 or Down syndrome,
in which there is an extra chromosome number 21. This extra chromosome
results in a constellation of abnormalities that is usually recognizable
at birth and consistent from one patient with Down syndrome to another.
Circumcision
Removal of the prepuce or foreskin covering the penis. There has been a
lot of controversy about this procedure in the past few years. Some
believe that it is medically beneficial while others disagree. There are
repeated studies showing that urinary tract infections are less common in
circumcised boys. However, urinary tract infections are relatively rare in
boys anyway. There have also been studies of sexual function in
circumcised and uncircumcised males with very few differences found
between the two groups. In some populations, circumcision reduces the risk
of contracting AIDS. Penile cancer (also a very rare disease) is also
less common among circumcised men.
Contraction
Almost always refers to the contracting of the muscles of the uterus
during labor. The uterus contracts in an effort to expel the fetus into
and out of the birth canal. Contractions are usually a sign of labor,
although they can occur before labor, see Braxton
Hicks contractions.
Contraction stress test
A test of uteroplacental function. Uterine contractions are initiated with
pitocin and the fetal response to the contractions
is analyzed as a measure of fetal well being.
Cord blood banking
Storage of blood from the umbilical cord.
Blood in the umbilical cord is rich in blood cells that are able to
replenish the bone marrow. Freezing cord blood cells immediately after
delivery preserves these cells should the baby need a bone marrow
transplant in the future. It is not now clear that this should be done or
how useful these cord blood specimens will be in the future. The potential
usefulness of cord blood is the object of much ongoing research.
Cord compression
Squeezing of the umbilical cord during
pregnancy, labor or delivery. Pressure on the umbilical cord reduces
blood flow from the placenta to the fetus. If prolonged pressure is
applied, it can produce a dangerously low level of oxygen in the fetus.
Crowning
The stage in childbirth when the top of the infant's head becomes visible
at the vaginal opening.
Delivery room
The room where the delivery occurs. In the past pregnant women routinely
labored in one room and then were moved to a delivery room where the baby
was actually delivered. Following delivery, the mother would then be
moved to a recovery room. To prevent these cumbersome moves, many
hospitals have now changed to a combination labor, delivery and recovery
room (called the LDRP). This prevents having to move the mother to another
room at the height of labor pains, just before delivery.
Demerol
Meperidine hydrochloride (Demerol), either alone or in combination with
promethazine hydrochloride (Phenergan), has the advantage of a history of
extensive use in labor. Common dosing is 50 to 100 mg of meperidine and
25 to 50 mg of promethazine IM every 3 to 4 hours. Both medications can be
given IV, but at reduced dosages of 25 to 50 mg of meperidine (diluted to
10 mg/mL) and 25 mg of promethazine. Since metabolic by-products of
meperidine may have half-lives of 8 to 21 hours and will accumulate in
patients with renal impairment and in their premature fetuses and
neonates, the risk-benefit ratio requires re-evaluation before repeated
dosing. The manufacturers recommend giving no more than 100 mg of
promethazine during 24 hours of labor.
Diethylstilbestrol (DES)
A synthetic, non-steroidal estrogen that was prescribed to many women
up until the early 1970s. It was thought to prevent or treat problems with
pregnancy. However, female fetuses who were exposed to DES
developed serious problems in their reproductive organs when
they became adults. About 1/4th of exposed women develop anatomical
problems with their cervix or vagina. Examples of these are underdeveloped
cervix, small uterine cavities and abnormal fallopian tubes. These women
are also more likely to have ectopic
pregnancy, preterm labor, miscarriage
and incompetent cervix. Women whose
mothers took DES during pregnancy should mention this fact to their
obstetrician so that potential problems can be identified and treated.
Dilation
Opening up, enlargement of a tubular structure. This usually refers to the
cervical dilation that occurs during labor. The opening of the cervix
must go from essentially 0 centimeters to about 10 centimeters, the usual
size required for the baby to pass thru the cervix,
which forms part of the birth canal. The first stage of labor is that
part of labor during which the cervix dilates up to 10 cm or is
completely dilated. This usually takes several hours and is shorter with
subsequent pregnancies.
Doppler ultrasound
A special form of ultrasound that uses sound waves to measure the velocity
of blood flow. Doppler ultrasound can be used to listen to the fetal
heart beat, examine the fetal heart for defects, and estimate placental
blood flow.
Down syndrome
A condition that has a specific set of characteristics found in
children who have an extra number 21 chromosome. Another name for this
condition is trisomy 21. Characteristic findings are widely spaced first
and second toes, a single hand (simian) crease, short fingers, a fold of
tissue (epicanthal fold) across the inner aspect of the eye (near the
nose), eyes that slant upward, decreased muscle tone, flattened back
portion of the head, and a protruding tongue. The only way to make the
diagnosis with certainty is to perform a chromosomal analysis either
before birth (chorionic villus
sampling or amniocentesis) or after birth
(blood or tissue chromosomal analysis). The range of outcomes for these
children is quite broad and many function quite well, although very few
have normal intelligence.
The risk of a healthy woman having a child with Down's syndrome
increases with maternal age, as follows:.
Age Risk of Down’s syndrome
- 25 years 1 in 1300
- 30 years 1 in 900
- 35 years 1 in 350
- 40 years 1 in 100
- 45 years 1 in 25
- 49 years 1 in 12
Dystocia
Literally, it means difficult labor and practically means abnormally slow
progress of labor. The word comes from the Greek 'dys' meaning
'difficult, painful, disordered, abnormal' and 'tokos' meaning
'birth'. Four potential factors may cause difficult labor
characterized by abnormally slow progress. They may occur separately or
together.
- Uterine contractions may be either too weak or too uncoordinated to
open up the cervix. There may also be inadequate pushing with
voluntary muscles during the second stage of labor.
- The baby may be lined up wrong to easily pass thru the birth
canal. Alternatively, there may be other problems with the baby that
also retard passage of the baby thru the birth canal.
- The maternal bony pelvis may be too narrow to allow the baby to pass
thru the birth canal.
- Abnormalities of the birth canal other than those of the bony pelvis
may obstruct fetal descent.
The most common cause of dystocia is a small bony pelvis and/or
insufficiently strong and coordinated uterine contractions.
Ectopic pregnancy
Pregnancy in which the embryo develops outside of the uterus.
Normally, conception occurs not in the uterus but in the fallopian tubes.
The fertilized egg then moves down into the uterus where it should implant
in the lining of the uterus. When the embryo implants anywhere else other
than the uterine lining it is called an ectopic pregnancy. As the embryo
grows outside of the uterus it is usually in a confined space, such as the
fallopian tube. Eventually, the embryo enlarges the tube to the point of
rupturing the fallopian tube, which causes hemorrhaging. This
hemorrhaging can be so severe as to cause shock and death. Surgery is
required to remove the misplaced, embryo. The embryo itself is usually
normal and would have continued to develop normally had it implanted in
the uterus, rather than the fallopian tube or other abnormal location.
Losing a child thru an ectopic pregnancy can be very emotionally
traumatizing. A woman who has lost a pregnancy due to ectopic location
needs the same support as women who have lost pregnancies thru
miscarriage and other causes.
Ectopic (in the wrong place) pregnancy is the leading cause of maternal
mortality in the first trimester and is a true emergency. Fortunately, the
incidence remains very low. Symptoms of ectopic pregnancy include
abdominal pain, missing a normal period, intermittent or scanty vaginal
bleeding, shoulder pain, weakness, dizziness, and fainting. Significant
abdominal pain (anywhere in the abdomen) in the first trimester should be
reported to your doctor.
Effacement
Thinning of the cervix that occurs in preparation
for childbirth. The cervical canal shortens from 2 cm to paper thin edges
and the canal itself disappears. Only the external opening of the uterus
remains of what was the cervix. The edges of the internal opening of the
cervix are drawn upward several centimeters to become a part of the lower
uterine segment. When the cervix becomes as thin as the adjacent lower
uterine segment, it is considered to be completely effaced.
Electronic fetal monitor
An electronic device that is used to monitor the heart rate of the fetus
before delivery. The electronic fetal monitor is usually used in labor
and can identify fetal problems before delivery. There is some evidence
that monitoring the fetal heart rate electronically may increase the rate
of caesarean delivery. Most obstetricians believe that it identifies
serious fetal problems earlier than other methods, thus improving
outcome. Another method for monitoring the fetus' health during labor is
listening to the fetal heart beat with a special fetal stethoscope or
Doppler ultrasound device at regular intervals. There are two types of
fetal monitors:
- External, which are attached to the mother's abdomen.
- Internal, which attach to the infant's scalp inside the uterus.
Engagement
Refers to the point in labor/delivery at which the baby's head, or other
presenting part (buttocks in a breech presentation), begins to descend
thru (engage) the pelvic canal.
Epidural
The epidural is situated over the durra matter. The durra is a tough,
fibrous, whitish membrane; the outermost of the 3 membranes covering the
brain and spinal cord. The extradural is located outside of the durra
matter.
Epidural block
An anesthetic technique that reduces pain during childbirth without
altering the mother's level of consciousness. This type of regional
anesthesia is often given during labor to relieve the pain of
contractions and delivery. A needle is inserted thru the skin of the
back into the epidural space. Anesthetic is then injected around the
spinal cord anaesthetizing the nerves of the lower part of the body. A
well-placed epidural block provides excellent pain relief. A
potential disadvantage is a reduction in a woman's ability to push the
baby out of the birth canal. Some people feel that the use of an epidural
block may increase the likelihood of a caesarean
section. The epidural block may also lower a woman's blood pressure,
affecting blood flow to the baby. However, in the hands of alert,
experienced personnel, the risks of an epidural are low.
Episiotomy
A minor surgical procedure which widens the birth canal by cutting the
introitus (vaginal opening). Episiotomy is performed to prevent the
jagged, less controlled tearing of the introital tissue during the
stretching associated with delivery. The routine use of an episiotomy may
cause more problems than it solves and has been linked to increased rectal
tearing. It is a painful procedure that may predispose to infections and
other complications. An episiotomy may be very helpful when forceps or
vacuum extraction are used and with breech presentations. Talk to your
doctor about whether you might need one. The use of episiotomies has
decreased in the past few years.
External cephalic version
Turning the baby so that the head is pointed down toward the pelvic inlet.
In most pregnancies, babies orient themselves with the head down toward
the pelvis in preparation for labor and delivery by about the 34th week.
If the baby is oriented with the head up or lying with the back toward the
pelvis, labor is more complicated and a caesarean
delivery is more likely. Your doctor may try to turn the baby before
delivery- this is called an external version. The doctor will try to turn
the baby so that the head is down, pointing toward the pelvis. This is
done with pressure on the baby applied thru the mother's abdomen.
External cephalic version reduces the necessity of a caesarean section,
but is not indicated in every case of breech
presentation. Ask your doctor more about version to see if this
procedure is appropriate for you. There are both risks and benefits from
this procedure.
Fetoscopy
Use of a special, fiber optic, tubular telescope to look at the fetus
while it is still in the mother's uterus. Use of this scope requires a
tiny incision in the mother's abdominal wall so that the telescope can be
passed into the uterus to directly view the fetus. Technically, listening
to the fetal heart rate with a fetoscope, a special type of stethoscope
is also fetoscopy.
Fetal distress
Problems with the unborn child during labor. Sometimes during labor and
delivery the fetus may not get enough oxygen from the placenta and may
become 'distressed'. When this happens, the fetal heart rate may show
patterns consistent with oxygen deprivation. These patterns can been seen
on the fetal heart rate monitor. They alert the obstetrician that further
investigation or intervention is needed to assure the fetus' well-being.
Fetal monitoring
Monitoring of the baby before birth. This usually refers to monitoring of
the fetal heart beat. There are two ways to do this. Before the mother's
membranes have ruptured (water has broken) a belt containing a receiver
similar to an ultrasound can be strapped to her
abdomen and used to monitor the fetal heart rate and uterine
contractions. After the membranes have ruptured and the cervix
has dilated, an internal monitor can be attached directly to the baby's
scalp. There are other tests that can be used to monitor the fetus during
and before labor such as ultrasound, scalp pH measurements, and
others.
Fetal presentation
The part of the fetus that enters the birth canal first. When the head
enters the birth canal it is called a vertex presentation. When the
buttocks present first it is called a breech
presentation. There are several methods used to diagnose fetal
presentation: abdominal palpitation, vaginal examination, locating the
fetal heart beat on the abdomen, and ultrasound scans. At or near term
96% of babies are in a vertex position, 3.5% are in a breech presentation,
0.3% in a face presentation, and 0.4% are in a shoulder presentation.
About 2/3 of vertex presenting babies are in a left occiput anterior (See Anterior.)
and 1/3 are in a right occiput anterior position. Up to 14% of babies
are in a breech presentation until the 29th-32nd week of gestation. Many
of these babies change to a vertex presentation birth.
Fetus
The name given to the embryo after the 8th week. Technically this
name should be used until the baby is completely outside of the mother's
body.
Fontanelle
Soft spots found between the cranial bones of the newborn’s skull. There
are two fontanelles that are usually examined in the newborn period, the
anterior and the posterior fontanelles.
Footling presentation
Presentation with the feet entering the birth canal ahead of any other
part of the body. This may occur with two feet (double footling) or a
single foot (single footling). Most often one leg is extended while the
other is flexed at the knee. It is usually safer to deliver this kind
of baby by a Caesarean section early in
labor or before labor begins rather than vaginally. If a footling breech
is delivered vaginally, there is a risk that the head may not easily
thru the birth canal.
Forceps delivery
A delivery in which forceps are used to help assist the baby from the birth
canal. Forceps are a two-bladed instrument that could be compared to a
pair of kitchen tongs in design. Forceps have the additional feature that
the two blades are easily taken apart to facilitate placement on the baby
within the birth canal. After placing the two blades on the baby's
head, the doctor reconnects the two blades and then uses the forceps to
apply traction to the infant, assisting delivery. The forceps are not
sharp, but they firmly grasp the baby's head. Forceps may be used for
several different reasons: to shorten the second stage of labor, end an
abnormally long second stage, when the fetal heart rate suggests
problems, when the mother suffers from cardiac disease, or whenever the
health of the mother and baby are declining and a speedy delivery is
required. Although once used often, they are almost never used now.
Gestational age
Baby’s age in weeks from the first day of the mother’s last
menstrual period before delivery. The duration of a pregnancy is measured
by gestational age. Gestational age is basically a measure of the length
of time that a baby spends in the womb. It is generally calculated as the
time from the first day of the last menstrual period to the day of birth.
Conception occurs on about day 14 after the first day of the last
menstrual period. However, this date is not usually known. The first day
of the last menstrual period usually is known. Therefore the beginning
date for the pregnancy is the first day of the last menstrual period.
A normal gestation lasts 40 weeks or 280 days. If delivery occurs
before 37 weeks gestation, the baby is considered prematurely born. By
this definition, about 11% of all babies are born prematurely. Irregular
menstrual periods or first trimester vaginal bleeding can confuse
gestational age estimates. To improve the accuracy of gestational age
estimates, many doctors use an ultrasound examination before about 20
weeks gestation. Ultrasound findings help your doctor confirm or correct
the gestational age estimate.
Hernia
An abnormal bulging or protrusion of tissue or an organ thru an
abnormal opening. The most common type of hernia is an inguinal hernia. It
is seen more often in boys, but it can be present occasionally in girls.
The testes develop inside the abdomen and migrate thru the inguinal
canal and into the scrotum. The inguinal canal is the passageway from the
abdomen into the scrotum and is bounded by membranes and muscle. When the
inguinal canal does not completely close or re-opens, intestine can travel
down the passageway and a hernia develops.
In most full-term babies the inguinal canal seals over before birth. In
prematurely born infants, the canal is opened by the pressure of the baby
crying and the increased abdominal pressure associated with feedings and
life outside the uterus. The incidence of hernias is about 15 percent
among prematurely born infants. It may be higher in those who are
extremely premature.
The only way to correct a hernia is to surgically repair it. The
anesthesia risks of the procedure are lessened if repair is delayed until
about five months of age; however, hernia repairs are often performed in
infants at much younger ages, if necessary, without complications. For
some infants a combination of a local and spinal anesthetic can be used
instead of general anesthesia. This combination of anesthetics reduces
the risk of apnea following anesthesia and surgery.
Humid-crib
Incubator (plastic box that is heated and sometimes humidified). It
provides a warm, protected environment for premature babies who are often
not able to maintain their own temperature because of their small size and
body mass.
Incompetent cervix
Painless cervical dilatation in the 2nd trimester often followed by
premature delivery of the fetus. This can sometimes be diagnosed early on
with the use of an ultrasound. The only real
treatment is a surgical procedure called cerclage, which reinforces the
cervix with sutures. An alternative to surgery is bed rest, but this is not
always effective. Possible complications to cerclage are bleeding,
contractions, and ruptured membranes, but if done by the 18th week these
risks are decreased. The success rate is about 85-90%. If an incompetent
cervix is not properly treated it will cause problems with each subsequent
pregnancy.
Induction
If labor has not started at an appropriate time or if there are maternal
indications for delivery before labor starts naturally, medications may
be used to initiate labor. Prostaglandin gel and oxytocin (Pitocin®)
are the most common medications. Rupture of the amniotic membranes may
also hasten the onset of active labor.
IUPC (intrauterine
pressure catheter)
A catheter inserted into the uterus during labor to
measure the actual pressure within the uterus. These measurements are
important in measuring the frequency and intensity of uterine contractions.
The fetal heart rate is usually measured simultaneously. The combination
of these measurements facilitates the evaluation of labor and fetal
well-being.
Lamaze
The oldest, most common technique for reducing the stress and pain of
labor and delivery. Lamaze trains women to replace unproductive behavior
during labor and delivery, such as anger and screaming, with more
productive actions, such as relaxation and deep breathing. Emphasis on
relaxation and breathing make pushing more effective and less painful.
Meconium
Dark green, sticky mucus normally found in infants' intestines. It is the
first stool passed by the newborn. Meconium is a mixture of amniotic
fluid, bile and secretions from the intestinal glands. Passage of
meconium within the uterus before birth can be a sign of
fetal
distress. Meconium is very irritating to the lungs. If there is a
possibility that an infant may have thick meconium in the lungs, the
doctor inserts a tube into the trachea and suctions out the loose
meconium. This tube, called an endotracheal tube, can also be used to help
an infant breathe after the meconium has been removed.
Miscarriage
Spontaneous abortion or loss of the fetus
before 21 weeks of gestation. Habitual abortion is defined as the
spontaneous loss of 3 or more consecutive pregnancies. Habitual or
recurrent abortion is a form of infertility. Couples who have had 2 or
more miscarriages (spontaneous abortions) have about a 5% chance that one
member of the couple is carrying a chromosome
problem that is contributing to the miscarriages. A considerable
proportion of pregnancies end in miscarriage.
Molding
The creation of shape, or fashioning of an object. Usually refers to the
newborn's head that is molded by passage thru the birth
canal during vaginal delivery. The head takes on a pointed shape that
quickly returns to normal after a few days. The brain is very plastic and
tolerates this molding well.
Mucus plug
A plug of mucus that fills the cervical canal during pregnancy. Discharge
of the plug is usually followed by rupture of the membranes and
progressive labor.
Natural childbirth
The process of giving birth without anesthesia or medication to relieve
pain. Natural childbirth is not possible for everyone, if you would like
to experience a natural childbirth discuss this with your doctor.
Neonate
The name given to a newborn infant for the first four weeks after birth.
Neonatologist
Doctor who specializes in the care of sick newborn babies. Physicians must
first become pediatricians thru three years of specialty training.
They then spend more years sub-specializing in the care of sick newborns.
Nubain
Nubain is a potent analgesic. Its analgesic potency is essentially
equivalent to that of morphine on a milligram basis. Its onset of action
occurs within 2 to 3 minutes Its onset of action occurs within 2 to 3
minutes after intravenous administration, and in less than 15 minutes
following subcutaneous or intramuscular injection. The plasma half-life of
nalbuphine is 5 hours and in clinical studies the duration of analgesic
activity has been reported to range from 3 to 6 hours.
The narcotic antagonist activity of Nubain is one-fourth as potent as
nalorphine and 10 times that of pentazocine.
Pediatrician
Specialists in pediatrics spend at least three years after medical school
studying children's health problems. Many devote additional years to
sub-specialize in a particular area of pediatrics such as heart, lung, or
endocrine problems. Pediatricians often employ nurse practitioners or
physician's assistants. These individuals work under the supervision of
the pediatrician and are often an important part of a pediatric clinic.
Prenatal
Refers to the time period after the 28th week of gestation and ending the
first week after birth. Some sources extend the prenatal period until the
fourth week after birth.
Perinatologist
An obstetrician who has sub-specialized in the care of pregnant women and
unborn babies. If you have a complicated pregnancy or one at high risk of
having complications, you may be referred to one of these physicians. They
are often the specialists who perform the level 2 or detailed ultrasound
examination.
Persistent fetal
circulation
The circulation of blood in the fetus is somewhat different from that of
the baby after birth. This transition from fetal to neonatal circulation
is one of the major physiologic changes after delivery. Before birth, the
lungs are collapsed and the blood pressure in the lungs is quite high.
This results in a very low blood flow thru the lungs. After delivery,
the lungs expand and the blood pressure in the lungs decreases.
In some babies, although the lungs expand the blood vessels in the
lungs remain constricted resulting in persistently high blood pressure in
the lungs. This reduces the amount of blood that the infant can pump
thru the lungs. This decreased blood flow thru the lungs after birth
is called persistent fetal circulation because it is a persistence of the
pattern of blood flow normally seen prior to birth during the fetal
period.
Infections, malformations of the lung or diaphragm, and lung immaturity
can all cause persistent fetal circulation. This is a very serious,
although infrequent, newborn problem. Several new treatments for
persistent fetal circulation have been developed in the past few years
and have increased survival of infants with this problem. The more
medically correct name for persistent fetal circulation is persistent
pulmonary hypertension.
Pitocin®
Synthetic formulation of a hormone, oxytocin, that stimulates uterine contractions
and is used to induce labor or delivery. Pitocin® is a commonly used
drug during labor.
Placenta
Organ within the uterus that provides communication between mother and
fetus thru the umbilical cord. The
placenta enables oxygen and nutrients to pass from the maternal blood
to the fetus. It also eliminates carbon dioxide and waste products from
the baby by passing them to the mother, who excretes them with her liver,
kidneys or lungs. It is a disk shaped organ and at term weighs around 500
grams.
Placenta accreta
Abnormally deep growth of the placenta into the uterus.
Placenta accreta prevents the normal placental separation from the uterus
and often causes severe uterine bleeding after delivery.
Post partum
Occurring after childbirth, or delivery.
Postnatal care
Care given to a mother after she has given birth. Usually this refers to
the care given before she is released from the hospital, but can extend
past discharge.
Premature infant
Baby born three or more weeks before the due date. The length of a
pregnancy is measured by gestational age.
Gestational age equals the amount of time that has elapsed since the first
day of the last menstrual period. A normal gestation lasts 40 weeks or 280
days. If delivery occurs before 37 weeks gestation, the baby is considered
prematurely born. About 11% of all babies born in 1997 (in the USA) were
born prematurely by this definition. Irregular menstrual periods or first
trimester vaginal bleeding can confuse gestational age estimates. To
improve the accuracy of gestational age estimates, some doctors use an ultrasound
examination before about 20 weeks gestation. Ultrasound findings help your
doctor to confirm or correct the gestational age estimate.
Premature labor
Onset of labor before 37 completed weeks of pregnancy. Tocolytic agents
(medications used to inhibit labor) are widely used today to treat
premature labor and permit pregnancy to proceed so that the fetus can
gain in size and maturity before delivery.
Birth weight is lower when a baby is born prematurely. Babies born with
a weight of less than 2500 grams are considered low birth weight babies.
Generally, infants with a birth weight less than 2500 grams are premature;
however, babies can be premature and still weigh more than 2500 grams at
birth. They can also be born at term and weigh less than 2500 grams. There
is no perfect system for categorizing infants; both measurements, birth
weight and gestational age, are used.
Many premature deliveries occur close to term and these infants
generally do well. For example, only 1.9 percent of all infants born in
1997 were born at less than 32 weeks gestation. These infants routinely
require lengthy stays in a special care nursery. These infants are also at
risk for long-term problems. The risk of complications accelerates as
gestational age decreases.
Prolapsed cord
Positioning of the umbilical cord ahead of
the baby's presenting part during labor and delivery. When this occurs,
the baby's body puts pressure on the umbilical cord which is caught
between the baby and the mother's birth canal. This pressure can seriously
reduce or altogether stop the blood flow thru the umbilical cord.
Unless the pressure is removed thru either delivery of the infant or
repositioning of the infant, serious problems occur. Prolapsed umbilical
cord occurs more commonly with breech
than with vertex presentation.
Prolonged labor
Labor which takes an abnormally long length of time. The usual length of
time in labor is longer in primiparous women and varies considerably
among individuals.
Prostaglandins
A class of chemicals produced by the prostate and other parts of the body
that can have various and powerful effects on the body. They were first
discovered in the prostate gland, hence
their name. Prostaglandins are sometimes used to induce
labor or soften the cervix in anticipation of
inducing labor.
Prostate gland
A male reproductive gland that produces part of the fluid in ejaculate. It
surrounds the urethra and often enlarges in older men to produce urinary
symptoms. Prostatic cancer commonly occurs in older men and is one
of the most important cancers in males.
Rh incompatibility
An incompatibility of blood types. Blood types are commonly characterized
by the ABO typing system and the Rh system. An incompatibility between the
mother and fetus in either of these systems can result in maternal
antibodies crossing the placenta and destroying fetal red blood cells.
The Rh system more often causes serious problems than the ABO system.
Individuals are either Rh-positive (red blood cells carry the Rh
antigen) or Rh-negative. When a Rh-negative woman is pregnant with a
Rh-positive fetus (Rh-positive inherited from the father), the mother can
produce antibodies against the Rh portion of the fetal red blood cells.
These antibodies attack the fetal red blood cells and destroy them. Loss
of the fetal red blood cells causes elevated bilirubin,
decreased red blood cell count and sometimes even heart failure in the
fetus. The combination of these problems can be fatal.
There are ways to treat this problem before the baby is born. More
effective than treatment is prevention of the problems. Women are exposed
to Rh-positive red blood cells thru a previous pregnancy, miscarriage
or a mismatched blood transfusion. If a Rh-negative mother has been
exposed to Rh-positive red blood cells, she should receive Rho-GAM, a
special immunoglobulin that destroys the Rh-positive red blood cells
before they can stimulate the woman to produce antibodies against
Rh-positive cells.
Rooming-in
An alternative rooming arrangement in postpartum units. With rooming-in
the infant does not stay in the newborn nursery, but in the mother's room
during her hospital stay.
Small for gestational age
(SGA)
Children whose birth weights are below the 10th percentile (smaller in
weight than 90 percent of other infants born at the same gestational age)
are considered small for gestational age (SGA). Being small for
gestational age has several other names. Some of these follow:
- Intrauterine growth retardation
- Small for dates
- Dysmature
- Light for dates.
SGA has many causes. If your baby is SGA, your baby's doctor should
search for an explanation. This is important because some problems cause
reduced growth in childhood as well. The following is a partial list of
factors that can contribute to an infant being SGA:
- Maternal high blood pressure [mother’s?]
- Cigarette smoking
- Maternal street drug use
- Maternal malnutrition
- Low maternal weight gain (less than 9 Kilograms)
- Mother was also SGA at birth
- Maternal chronic disease (advanced diabetes, anemia, etc.)
- Frequent, heavy, physical work during pregnancy
- Mother younger than 20 years of age
- Racial and ethnic background
- Multiple fetuses (twins, triplets)
- Rubella, cytomegalovirus, and other infections during pregnancy
- Placental abruption (separation of the placenta from the uterine
wall)
Fetal chromosome problems (Children with abnormal chromosomes seem
genetically programmed to remain small and not gain weight appropriately.)
SGA babies have more problems in the newborn period than infants who
are appropriately grown. Examples of these problems are low blood sugar
and too many red blood cells in the blood. These problems are all
treatable, but may require NICU care. SGA babies are also more likely than
AGA (appropriate for gestational age) infants to be small throughout life
and have delayed development. Babies whose growth slowed down later in
pregnancy are more likely to catch up with their peers than those whose
growth was slow throughout pregnancy.
Stadol
Stadol NS is the trade name for butorphanol tartrate nasal spray. Stadol
NS is a special type of prescription pain reliever used to treat moderate
to severe acute pain, including the pain of a migraine attack in progress.
Although it is a potent analgesic, it does not incorporate the addictive
properties of many narcotic drugs. Stadol NS was designed to activate
certain receptors in the brain to eliminate pain while blocking the
receptors that cause euphoria. In other words, it is designed to stop the
pain without causing a 'high'.
Ultrasound
Imaging of body parts using sound waves. Ultrasound uses sound waves that
are above the range of human hearing to create an image of organs within
the body. Sound waves are reflected off internal body structures and back
to the ultrasound machine. The reflected sound waves are analyzed by
computer and turned into pictures. This method of imaging results in
less clear pictures than X-rays, CAT scans or MRI. However, there is no
radiation risk with ultrasound and no confirmed adverse effects on the
fetus or mother from diagnostic ultrasound examinations in
pregnancy.
There are different types of ultrasound exams. They are differentiated
by the purpose for which they are done and the level of detail obtained.
- Limited exams are focused studies used to answer specific questions
about the fetus, mother, or both. This exam is often used when you go
to your doctor or the hospital with an urgent problem related to your
pregnancy.
- Basic exams are performed to survey for obvious malformations of the
fetus and to estimate fetal age, the amount of amniotic
fluid present, location of the placenta,
and for other concerns. These are the kind of exams that you would
likely receive in your doctor's office or in the hospital as a routine
evaluation. They are typically performed at 18-20 weeks of
pregnancy.
- Comprehensive exams are a more in-depth look at the fetus when
there is reason to suspect something is wrong with the fetus or
mother. They include a detailed examination that is often done as a
response to an abnormal screening test such as the alpha-fetoprotein
screen. In some areas of the country this is called a Level II or
Level III ultrasound. Technical difficulties and the need to image
many different areas of the fetus may extend the length of this exam
to 30 or more minutes.
Ultrasound can measure fetal size, the amount of amniotic
fluid, estimate fetal gestational age,
identify multiple fetuses, some fetal abnormalities such as microcephaly
or Down Syndrome, and locate the location of
the placenta. Although an ultrasound can usually
determine gender of your baby, many families do not want to know this
information before delivery and some ultrasound centers have a policy of
not revealing the gender.
Umbilical cord
The baby's lifeline from the mother during pregnancy. The umbilical cord
is formed during the fifth week of gestation and connects the fetus'
circulation with the mother's placenta. Thru
this vascular structure, the fetus receives nutrients such as oxygen,
glucose, and protein. When the baby is born the cord is about 600 mm long
and 12 mm thick.
The umbilical cord is clamped and cut shortly after birth. It will turn
black within the first few days and should protrude about 25 mm or less.
It will fall off within about 2-3 weeks. It is important to care for the
umbilical stump to ensure proper healing. Fold diapers below the stump to
expose it to air and keep it dry. Cleaning should be with a cotton swab
and alcohol. The ideal time to do this is just after changing a diaper. If
you notice that the skin around the stump has turned red or if the cord is
oozing, call your doctor.
Umbilical hernia
Hernia at the belly button. (see hernia.) The
abdominal wall is formed by two sheets of muscle that run along both sides
of the abdomen. In normal development, these sheets of muscle fuse
together. When the fusion is incomplete or abnormal, part of the bowel can
bulge thru the space between the muscles at the belly button. As the
infant grows, the muscle layers increase and gradually fuse, eliminating
the hernia. This is one of the few hernias that often resolves on its own.
Occasionally, surgical correction is required.
Uterus
Also called the womb. The uterus is the organ that houses and protects the
fetus during pregnancy. The uterus grows and expands with your baby's
growth. Your doctor will measure this growth during prenatal visits. The
uterus also helps the fetus leave the womb thru contractions. It will
take several weeks to months after delivery for your uterus to regain a
normal shape and size following delivery.
Vacuum extraction
The application of a suction cup to the head for helping deliver the
infant. This technique performs a similar function as forceps
and helps the baby to descend thru the birth canal. The vacuum
extractor has a soft plastic cup attached to a tube and suction pump. The
cup is inserted into the birth canal and attached to the baby's head by
suction. Increasing the suction causes a vacuum and the handle of the cup
can be used to pull the baby out of the birth canal. The vacuum extractor
is more gentle and less damaging to the mother's soft tissue than forceps.
However, there are risks with the vacuum extraction. Excessive suction or
traction can cause injury to the mother or baby. There is also a limit on
the number of pulls that should be made with the suction device attached.
Vaginal birth
Delivery of the infant thru the birth canal, of which the vagina is a
major component. The alternative method would be an operative delivery (caesarean
section).
Vaginal birth after
caesarean (VBAC)
A vaginal delivery after a previous caesarean
delivery. One of the most common reasons for caesarean sections is the
presence of a uterine scar from a previous caesarean section. A previous
uterine scar can tear or open up during a hard labor with a subsequent
pregnancy. For many years it was thought that once a caesarean, always a
caesarean. This is not so. If the incision from the previous caesarean
section has been performed low on the uterus, the scar is often
sufficiently strong to withstand labor.
The advantages of a VBAC are decreased risk of surgical complications
and a shorter recovery period. However, a VBAC is not possible for
everyone. The type of incision previously made is one important
determinant. For example, if you had a classical incision thru the
uterus, which is high up on the uterus, an attempted vaginal birth would
not be a good idea because there is a risk of uterine rupture during
labor. Multiple fetuses, medical complications such as high blood
pressure or abnormal fetal position may all require a caesarean section
and prevent a VBAC trial. If a VBAC is attempted you will need fetal
monitoring and IV in case a section becomes necessary. The risk of uterine
rupture is low, but if it occurs, the consequences can be severe for both
the mother and the baby.
Ventilator
A machine that assists adults or children to breathe. This most often
refers to newborn infants who sometimes have breathing problems so severe
that they need help from a breathing machine. If your baby was born with
lung problems or didn't breathe on his own he may be connected to a
ventilator. Lung immaturity in prematurely born infants is the most common
reason for a newborn to require a ventilator.
Vernix
Also called vernix caseosa. A cheesy, white substance that covers a baby's
skin at birth. The vernix is secreted by the sebaceous glands around the
20th week to protect the baby's skin from the amniotic
fluid. Without the vernix, the baby would have very wrinkled skin from
constant exposure to the watery amniotic fluid. The amount of vernix
present decreases toward the end of gestation. Remaining vernix is washed
off after birth. The loss of vernix may cause the skin to peel during the
first postnatal week.
Vertex
A vertex presentation is the most common and desirable. In this position
the baby's head enters the birth canal first.
Very low birth weight (VLBW)
A birth weight of less than 1500 grams. Babies with such a low birth
weight are almost always very prematurely born.
About 1.3% of all births result in babies with a birth weight of less than
1500 grams.
Viable
Able to survive. Refers to the condition of a newborn. |