Secular trends of HBeAg prevalence among HBsAg-positive delivery mothers in a hepatitis B endemic area

A high prevalence of HBeAg among HBsAg-positive mothers at the time of deli very results in a high prevalence of hepatitis B vertical transmission. Fro m 1990 to 1995, 896 pregnant HBsAg-positive women, including 411 (46 per ce nt) HBeAg-positive subjects, were enrolled in our study to analyse the secu lar change in HBeAg prevalence, Their mean age, number of pregnancies and p arity were 29.5 +/- 4.1 years, 2.0 +/- 1.2, and 0.6 +/- 0.7, respectively. The prevalence rates of HBeAg were 48, 54, 49, 47, 40, and 40 per cent amon g the subjects enrolled in 1990, 1991, 1992, 1993, 1994, and 1995, respecti vely. In univariate analyses, prevalence of HBeAg decreased by the calendar year of pregnancy (p = 0.01), and also by age (p < 0.00001), number of pre gnancies (p < 0.0001) and parity (p < 0.0002). After adjusting for age in m ultiple logistic regression, the calendar year of pregnancy was still the i ndependent variable, while gravida and parity became insignificant. The odd ratios (95 per cent confidence interval) of HBeAg negative-seroconversion in the equations were 1.09 (1.00-1.19) per calendar year and 1.14 (1.10-1.1 8) per year of age. Our results have shown a secular decrease in HBeAg-prev alence among pregnant HBsAg-positive women in Taiwan.