Prenatal testing

Physicians for Women offers a series of blood tests and genetic tests during the first and second trimesters of pregnancy to determine whether your baby might have a congenital disorder. Speak with your obstetrician about whether this testing is right for you.

First trimester

TestStage of pregnancyIndication
Cell-free fetal DNA, a noninvasive test for women at higher risk of having a child with a chromosome disorder10 weeks or afterCertain conditions caused by an abnormal number of chromosomes, such as trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) and trisomy 13 (Patau syndrome).
For more information on cell-free fetal DNA testing, please click here
Genetic carrier screenFirst visitIncludes tests for cystic fibrosis, spinal muscular atrophy, Fragile X syndrome, and sometimes other conditions depending on ethnicity (for example, patients of Ashkenazi Jewish descent may also consider being screened for Tay-Sachs).
These conditions can also be tested for before pregnancy, which is sometimes preferred.
Nuchal translucency with PAPP-A11-13.5 weeksAn ultrasound that measures the thickness of the fluid build-up at the back of the fetus’ neck. If it is thicker than normal, it can be an early sign of Down syndrome, trisomy 18 or heart problems.
Tay Sachs disease (TSD) testing based on prenatal bloodFirst visitTSD is a fatal, progressive genetic disorder caused by the absence of an enzyme that helps to break down fatty substances. Though extremely rare, the disease is most common within the Ashkenazi Jewish community.

Physicians for Women offers a DNA screening test that can be done at nine weeks to test for chromosomal abnormalities, sex chromosomal abnormalities and microdeletion syndrome, disorders caused by a chromosomal deletion across several genes.

Second trimester

TestStage of pregnancyIndication
Blood-based alpha-fetoprotein (APF), Quad test (also known as maternal serum screen)15-20 weeksHelps detect chromosomal abnormalities, including trisomy 18 and 21. Also screens for abdominal wall defects and defects affecting a baby’s brain and spine (known as neural tube defects).
Amniocentesis15-18 weeks (if needed)Genetic birth defects such as Down syndrome or certain types of muscular dystrophy. We only perform this test if there is a high risk of genetic disorders or other problems.
Glucose challenge screening and complete blood count (CBC)24-28 weeksTo determine your risk of gestational diabetes.

Third trimester

TestStage of pregnancyIndication
Beta Strep Culture (GBS)36 weeksA test for group B Streptococcus bacteria, which can cause pneumonia or other serious infections in your baby.
4660 Kenmore Avenue, Suite 1100
Alexandria, Virginia 22304
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Appointment Hours
Monday - Friday
8:00AM - 3:45PM
Please arrive 15 minutes prior to your appointment time.
Phone Hours
(703) 370-0400
Monday - Friday
8:00AM - 12:00PM
1:00PM - 4:30PM