Seroprevalence of hepatitis B in pregnant women in Mexico.

OBJECTIVE To determine the seroprevalence of hepatitis B in pregnant women from several regions of Mexico, as well as the risk factors associated with its occurrence. MATERIAL AND METHODS A cross-sectional study was conducted between May and August 2000. It included 9,992 pregnant women attending the health services of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social-IMSS) in five cities: Tijuana, Ciudad Juarez, Acapulco, Cancun, and Mexico City (northeast and southeast regions). RESULTS The overall prevalence for confirmed cases was 1.65% (165/9,992). The prevalences for individual cities were as follows: Tijuana, 1.27%; Ciudad Juarez, 1.46%; Acapulco, 2.47%; Cancun, 0.93%; northeastern Mexico City, 1.20%, and southeastern Mexico City, 2.52%. The risk factors found to be associated with HBsAg were: age, age at first sexual intercourse, city (Acapulco and southeastern Mexico City), and marital status (single or divorced). CONCLUSIONS The prevalence of HBsAg in pregnant women (1.65%) was greater than that reported in previous studies and showed geographical differences. This high prevalence suggests that a considerable amount of cases of hepatitis B occurs perinatally and through contact with carriers in the general population. Vaccination of newborns of high-risk pregnant women should be considered.