[Utility of systematically determining serum HBsAg in the 3d trimester of pregnancy].

A group of pregnant women living in the south of the province of Pontevedra (Spain) have been studied in order to determine the prevalence of hepatitis B virus biological markers. For that respect we have prospectively studied HBsAg and other markers in 535 pregnant women from June 1987 to March 1988. The prevalence of HBsAg was 0.75%, and in 6.12% certain biological markers were detected. Only one carrier fulfilled the current criteria recommended by the Advisory Committee on Immunization Practices (ACIP) for selective screening of pregnant women. Although the prevalence and costs of the detection are similar to those for voluntary blood donors of the same region (1%), the frequency with which infected neonates develop chronic antigenemia along with the low sensitivity of the selective screening justifies the systematized serological study of the pregnant women.