Prenatal screenings - what should you expect?

• Blood type and antibody testing determines a woman’s blood group (A, B, AB, or O) and Rh type (positive or negative). Fetal problems may occur when an Rh negative woman carries a fetus that is Rh positive. Special care may be needed.
• Late in pregnancy, women are tested for group B streptococcus (GBS) bacteria, which can cause infections of the blood, lungs, brain, or spinal cord in infants. GBS can be transmitted from an infected mother to the baby during delivery. Women who test positive can be treated before vaginal delivery or can consider cesarean delivery.
• Hemacrit and hemoglobin tests check the blood for anemia (low iron). Anemia can be treated with supplements.
• Hepatitis B affects the liver and can cause severe complications in newborns if passed from mother to baby. If a woman’s results are positive, she and her baby can  be treated after delivery.
• All pregnant women should be screened for HIV infection—a disease that attacks the body’s immune system. Treatment of
HIV-positive mothers during pregnancy can drastically reduce the risk that the infants will become infected and help improve the mother’s health.
• Pap testing may be suggested to check for precancerous changes to cervical cells.
• A blood test is used to check for signs of past rubella (German measles) infection. Pregnant women who have not had or not been vaccinated against rubella should avoid any infected individuals and be vaccinated after delivery.
• Screening for sexually transmitted diseases (STDs), such as chlamydia, gonorrhea, and syphilis may be recom-mended. They can cause preterm birth, miscarriage, eye infections, birth defects, or other problems. STDs can be treated during pregnancy. 
• At each prenatal visit, urine analysis is performed to check blood sugar and protein levels and signs of bladder and kidney infections. Excess sugars could signal diabetes, while excess protein could be a sign of a urinary tract infection, kidney disease, or pregnancy-related high blood pressure.

Depending on a woman’s age, health history, or ethnic background, additional screenings may be offered for genetic disorders and birth defects, such as cystic fibrosis or spina bifida.

For more information, the ACOG Patient Education Pamphlet “Routine Tests in Pregnancy” is available in English and Spanish at www.acog.org/publications/ patient education.