Testing for a Healthy Pregnancy from Sugar Land OB/GYN Associates


Pregnancy is one of the most exciting times in people’s lives.  To assure a healthy pregnancy, several tests are offered.

First Trimester

During the first trimester, weeks 1 to 13, patients undergo a physical exam including height, weight, blood pressure and a pelvic exam.  Laboratory tests include a complete blood count checking for anemia, blood type and Rh factor testing, urinalysis, infection blood tests including hepatitis B, HIV, Rubell and also vaginal cultures to test for sexually transmitted diseases.  First trimester genetic testing for chromosomal abnormalities includes the noninvasive prenatal testing, which is a test after ten weeks detecting fetal DNA fragments in maternal blood, and Chorionic villi sampling, invasive testing of the chorionic tissue by a needle guided by abdominal or pelvic ultrasound.

Second Trimester

In the second trimester, weeks 14 to 27, other blood tests include the alpha-fetoprotein, which is a marker that could indicate issues with the fetal spinal cord performed at 15 to 18 weeks, and the one-hour glucose challenge test, which is a screen for gestational diabetes performed 24 to 28 weeks.

Second trimester genetic testing options include an amniocentesis.  This genetic test evaluates fetal fluid obtained via a needle through the maternal abdominal wall done at 15 to 18 weeks.  Between 18 and 20 weeks, an anatomy ultrasound is ordered to evaluate fetal anatomy, amniotic fluid, placenta and cervical length.

Third Trimester

In the third trimester, weeks 28 to 42, a vaginal/rectal swab is performed to test for group B strep at 35 to 37 weeks. If this test is positive, antibiotics will be given during labor to decrease transmission of the bacteria to the fetus.  Additionally, at 35 to 37 weeks, an ultrasound is again performed to assess fetal position, amniotic fluid and growth.

These are recommended routine tests; however, each pregnancy is different and may require more testing to assure a healthy pregnancy.  Consult the board-certified physicians Dr. Deanna D. McDonald, Dr. Niraj C. Patel and Dr. Duc B. Le at Sugar Land OB/GYN Associates at www.SugarLandOBGYN.com or 281.499.4999 with questions regarding these or any other maternal testing questions.