Various tests and procedures are used in
certain cased of pregnancy complications. Like all medical
procedures, they offer advantages, but also carry risks. Therefore,
they should be utilized only when medically indicated, to on a
routine basis for your your doctors convenience or to satisfy your curiosity.
When deciding whether to undergo a test , ask
your caregiver if the results will in any way alter his care of you.
If his answer is yes, ask him how . If his answer is no, ask him if
the test is therefore necessary. Make sure you understand all
the risks ad benefits involved before agreeing to, or reflecting,
a procedure. Continue to ask questions and to request explanations
until you feel comfortable. Understanding to benefits can help to
relax you and may free you from concern about the procedure. Or, it
can help you decide to ask for an alternative.
Among the more common tests used in pregnancy
are amniocentesis, chronic villus sampling, alpha-fetoprotein
screening, ultrasound, X-ray pelvimentry, the estriol excretion
study, fetal movement evaluation, the monstress test, and the
oxytocin challenge test.
Amniocentesis is a test to detect
abnormalities in the baby. It may also be done to assess fetal lung
maturity if induction of labor or cesarean delivery is indicated.
The test is performed by administering a local anesthetic, then withdrawing
a sample of amniotic fluid using a log needle inserted through the
abdominal ad uterine walls. It should be done in conjunction with
ultrasound, which will show the location of the fetus, the
placenta, ad the umbilical cord.
Chorionic villus sampling (CVS) is a test
that can detect genetic abnormalities earlier than amniocentesis
can. It usually done between the ninth and eleventh weeks of
pregnancy. However it is not available in all locations.
Alpha- Fetoprotein Screening
Alpha-fetoprotein (AFP) screening is a blood
test done on the women between the fifteenth and eighteenth weeks of
pregnancy to screen for fetal abnormalities. AFP is a protein
produced by the baby. A high level of AFP in the women's blood
indicates a possible open neural tube defect such as spina bifid or
anencephaly. A high level may also be caused by a multiple pregnancy
or a miscalculation of gestational age . A low level may indicate
Down syndrome. Also measuring two other substances human chorionic
gonadotropin and unconjugated estriol-increases the accuracy of detecting
Down syndrome. identifying about 70 percent of Down syndrome
Ultrasound was developed during World War I
when high frequency sound waves were used to detect enemy submarines
. A form of ultrasound used in pregnancy testing is the
sonogram, which uses intermittent sound waves. The sound waves are
directed intros the woman's abdomen with an outline of the
baby, or to confirm a multiple pregnancy. In addition, the location
of the placenta can be pinpointed when placenta previa (low
implanted placenta ) is suspected. Ultrasound is also used to
visualize the baby and placenta when amniocentesis or CVS is being
performed. since X-rays are now considered dangerous to developing
babies, ultrasound is used
X-ray pelvimetry measures the
size of the woman's pelvis to determine if the passageway is
adequate. It is seldom used except at the end of pregnancy when a
breech presentation is suspected and the doctor needs to determine
whether a vaginal delivery is possible. X-rays are avoided because
they carry the risk of being carcinogenic(cancer producing).
Estriol Excretion Study
Estriol is an estrogen-type hormone made be
the placenta and excreted in the woman's blood and urine. The
estriol excretion study measure the estrol level and helps to
determine the functioning of the placenta, as well as the
baby's well-being . The test can be conducted using urine
collected over a 24 hour r=period or a single sample of blood.
Fetal Movement Evaluation
Around the eighth month of your pregnancy,
your caregiver may suggest that you keep track of your baby's
movements. You can do this best by setting aside a certain
time each day ad recording how long it takes your baby to move ten
different times . A healthy baby moves about the some amount each
day. Report any decrease in movement to your caregiver immediately.
Fetal movement evaluation is a momimvasive test that cam provide
valuable information about your baby's health and will-being.
A nonstress test can be a very reliable
noninvasive test for fetal well-being . It is done by measuring the
fetal heart rate in response to fetal activity as observed on a
Oxytocin Challenge Test
The oxytocin challenge test ( OCT) is done in
the hospital to help determine how well the baby will undergo the
stress of labor. The OCT is also known as stress test.