Hepatitis B is the most common form of viral hepatitis. Much has been done for the prevention of Hepatitis B transmission from mother to child. However, there is still very limited evidence looking at maternal obstetrics and perinatal outcomes, such as gestational diabetes, antepartum haemorrhage and preterm labour, hypertensive disorders in pregnancy and small for gestational age, with Hepatitis B infected women. These adverse pregnancy outcomes, if significant, may affect future antenatal care and have a negative impact on public health. This study aims to determine the association between these adverse pregnancy and neonatal outcomes with maternal Hepatitis B carrier state.
This is a retrospective cohort study comparing adverse pregnancy and neonatal outcomes in primigravid women who delivered singleton babies after 24 completed weeks of gestation and are carrier for Hepatitis B virus with those who are non-carrier for Hepatitis B virus, between 1992 and 2013 in Aberdeen Maternity Hospital. The adverse pregnancy and neonatal outcomes studied include hypertensive disorders in pregnancy, antepartum haemorrhage, preterm birth <37 weeks, induction of labour, caesarean delivery, low birth weight and admission to neonatal unit. Data was extracted from the Aberdeen Maternity and Neonatal Databank (AMND), which was established in 1950 to record all pregnancy-related events occurring in Aberdeen city and district in the northeast of Scotland. Statistical analysis was done with SPSS version 21 using independent samples t-test for normally distributed continuous variables and chi-squared test for categorical variables. Multivariate logistic regression analysis using a multilevel random effects regression model was also conducted to adjust for confounding factors.
The data set contained a sample size of 35116 primigravid women with singleton pregnancies, with 59 being carrier for Hepatitis B virus (represented by positive HBsAg status). HBsAg-positive women had significantly lower mean Body Mass Index and were more likely to be from the manual social class (registrar general’s occupation-based social class). On unadjusted analysis, there were no significant differences in the prevalence of all maternal and perinatal outcomes in both groups. However, after adjusting for confounding factors, HBsAg-positive women were more likely to have smaller babies (aOR 4.28; 95% CI 1.57-11.66).
Our study suggested higher frequencies of low birth weight babies in women with hepatitis B infection. We found no statistically significant differences in other adverse pregnancy and perinatal outcomes. As current evidence still shows inconsistent results, further research evaluating the possible effects of Hepatitis B viraemia on pregnancy outcomes is justified.