Prenatal testing is part of prenatal care and it usually checks the health of the fetus as well as the mother. Knowing about your baby before birth can be helpful in making decisions before and after birth.
Doctors use various methods to determine gestational age of a pregnancy.
The most common test is the ultrasound, which measures the size of the
gestational sac and the length between crown and rump to determine the
age of the fetus in weeks.
There are several tests done at the first visit in pregnancy with your doctor.
The multiple marker test (sometimes referred to as the triple screen) can tell you if your baby is at an increased risk of having certain birth defects and genetic abnormalities.
The quad marker screen is a blood test done between 15 and 20 weeks (usually closer to 15 weeks), that will help to recognize the risk of the fetus having certain birth defects.
Amniocentesis and CVS are both invasive tests done in pregnancy to diagnoses certain problems.
What prenatal tests should I have done?
Which routine blood tests are done at the first prenatal visit?
What to do and what not to do when getting Amniocentesis.
You can screen for Down syndrome by ultrasound as early as 11-12 weeks.
Screening is done with an ultrasound (sonogram) examination and two
blood tests, and it can detect up to 90% of Down syndrome fetuses.
What are some of the signs?
What can happen?
What are the reasons for doing a genetic amniocentesis?
Around 35-37 weeks of the pregnancy women are often screened for the presence of GBS or Group B Streptococcus bacillus in the vagina.
A nonstress test (NST) is a test done during the last three to four months of pregnancy in certain high-risk situations, usually to evaluate the fetus' health.