Maternal HBsAg status and infant size - a Faustian bargain?

Information on the impact of maternal hepatitis B virus (HBV) infection on pregnancy outcome is conflicting. Some studies reported an association with increased infant birthweight, which could be interpreted as advantageous to pregnancy. A retrospective study was performed to compare birthweight outcome between 6261 and 55,817 singleton pregnancies in mothers screened positive and negative for hepatitis B surface antigen (HBsAg), respectively. The HBsAg positive women were younger, had higher body mass index (BMI) and incidence of overweight, but less gestational weight gain, and were associated with increased macrosomia (birthweight ≥4000 g) in mothers 90th percentile) infants in nulliparas (OR 1.13), age