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During the second
trimester, you and your spouse should continue to see your doctor
for prenatal care. Most pregnant women have monthly office visits
with their doctor or midwife until the end of this trimester.
During the second
trimester your doctor can use an ultrasound to see if the baby is
developing in a healthy way and to find out your baby's sex. You
will also be offered screening tests to look for genetic birth defects.
According to
the U.S. Department of Health & Human Services, birth defects
result from problems with a baby's genes, inherited factors that
are passed down from the mother and the father at conception. Genetic
birth defects sometimes occur in people with no family history of
that disorder. Women over the age of 35 have the greatest chances
of having a baby with birth defects. Some of the diagnostic and
screening tests the doctor might suggest in the second trimester
include:
Amniocentesis
According to
the U.S. Department of Health & Human Services, this test is
performed in pregnancies of at least 16 weeks. It involves your
doctor inserting a thin needle through your spouse’s abdomen,
into her uterus, and into the amniotic sac to take out a small amount
of amniotic fluid for testing. The cells from the fluid are grown
in a lab to look for problems with chromosomes. The fluid also can
be tested for AFP. About 1 in 200 women have a miscarriage as a
result of this test.
Chorionic
villus sampling (CVS)
This test is
performed between 10 and 12 weeks of pregnancy. The doctor inserts
a needle through your partner’s abdomen or inserts a catheter
through her cervix in order to reach the placenta. He then takes
a sample of cells from the placenta. These cells are used in a lab
to look for problems with chromosomes. This test cannot find out
whether your baby has open neural tube defects. About 1 in 200 women
have a miscarriage as a result of this test.
Maternal
serum screening test
This blood test
can be called by many different names including multiple marker
screening test, triple test, quad screen, and others. This test
is usually given between 15 and 20 weeks of pregnancy. It checks
for birth defects such as Down syndrome, trisomy 18, or open neural
tube defects. Doctors take a sample of your blood. They check the
blood for 3 chemicals: alpha-fetoprotein (AFP) (made by the liver
of the fetus), and two pregnancy hormones: estriol and human chorionic
gonadotropin (hCG). Sometimes, doctors test for a fourth substance
in the blood called inhibin-A. Testing for inhibin-A may improve
the ability to detect fetuses with a high risk of Down syndrome.
According to
the U.S. Department of Health & Human Services, higher levels
of AFP are linked with open neural tube defects. In women age 35
and over, this test finds about 80% of fetuses with Down syndrome,
trisomy 18, or an open neural tube defect. In this age group, there
is a false positive rate (having a positive result without actually
having a fetus with one of these health problems) of 22%. In women
under age 35, this test finds about 65% of fetuses with Down syndrome,
and there is a false positive rate of about 5%.
Targeted
ultrasound
The best time
to get a targeted ultrasound is between 18 and 20 weeks of pregnancy.
Most major problems with the way the baby is formed can be seen
at this time. Some physical defects such as clubbed feet and heart
defects may not be seen.
According to
the U.S. Department of Health & Human Services, your doctor
can also use ultrasound on your pregnant wife to see if your baby
has any neural tube defects, such as spina bifida. In most cases,
if you want to find out the sex of your baby, you can ask your doctor
during this test. This is not the most accurate test for Down syndrome.
Only 1 in 3 babies with Down syndrome have an abnormal second trimester
ultrasound.
About the Author:
Paul Banas is a founder of GreatDad.com.
He writes articles on pregnancy care, ovulation calculator, stages
of pregnancy and many more topics related to expectant dads.
Article Source:
http://www.articlealley.com/article_633455_61.html
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