The impact of maternal HBsAg carrier status on pregnancy outcomes: A case–control study

Background/Aims To examine the impact of maternal HBsAg carrier status on pregnancy outcomes. Methods Two hundred and fifty-three carriers of hepatitis B surface antigen (HBsAg) with singleton pregnancy, were retrospectively compared with 253 controls matched for age and parity and year of delivery. Results On univariable analysis, HBsAg carriers had higher incidences of threatened preterm labour at <37 weeks (11.9% vs. 6.3%, P=0.030), preterm birth at <34 weeks (4.7% vs. 1.2%, P=0.033), gestational diabetes mellitus (19.0% vs. 11.1%, P=0.012) and antepartum haemorrhage (11.5% vs. 5.5%, P=0.026). Their infants had lower Apgar scores at the 1st (8.47±1.67 vs. 8.87±1.07, P=0.001) and 5th minute (9.56±1.29 vs. 9.80±0.54, P=0.007), and increased incidence of intraventricular haemorrhage (4.7% vs. 0.8%, P=0.007). On multivariable analysis, the association between HBsAg carrier state with antepartum haemorrhage, gestational diabetes mellitus and threatened preterm labour were confirmed. Conclusions HBsAg carriers have increased risk of gestational diabetes mellitus, antepartum haemorrhage, and threatened preterm labour. This may be related to the chronic inflammatory state in these subjects. The role of chronic HBV infection in pregnancy complications has to be further elucidated.