All women should be screened for the hepatitis B surface antigen as early as possible in the course of each pregnancy. Twenty-two thousand infants are born each year in the U.S. to women with chronic hepatitis B disease. Of the 6,000 infants subsequently infected, most are free of symptoms. Nonetheless, up to 90 percent of infected infants become chronic carriers of the hepatitis B virus (HBV), and 25 percent of those will eventually succumb to chronic cirrhosis and liver cancer in the years that follow. Prenatal hepatitis B surface antigen (HBsAg) screening of all pregnant women ensures that every infant at risk is afforded the benefits of vaccination at birth.
Although it's not the standard of practice in all settings, some care providers recommend thyroid testing in the preconceptional period or in early pregnancy. When thyroid hormone levels are too low or too high, complications of pregnancy may develop. If a pregnant woman is in a hypothyroid state, she may develop anemia, preeclampsia, placental abruption, postpartum hemorrhage, cardiac dysfunction or miscarriage. Fetal or neonatal complications include prematurity, low birth weight, congenital anomalies, stillbirths and delayed mental development.
Rubella Immunity Testing
All pregnant women should be tested for rubella immunity early in their first pregnancy and in any subsequent pregnancy if their rubella status is not known with certainty to be immune. Because infection or immunization confers lifelong immunity in more than 95 percent of subjects, those patients known to be immune do not need retesting.