Prospective cohort study of prevention of mother to child transmission of hepatitis B infection and 9 months follow-up of hepatitis B-exposed infants at Ile-Ife, Nigeria

Abstract

Objectives Eliminating mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is central to WHO’s target of reducing hepatitis B infection in children to <0.1% by 2030. While Nigeria accounts for 8.3% of the global burden, interventional studies on prevention of MTCT of HBV are hardly available. This study aimed to assess the impact of prevention of MTCT interventions on vertical transmission of HBV among pregnant women in Nigeria.Design A prospective cohort study.Setting A University Teaching Hospitals Complex in Nigeria between 2015 and 2021.Participants 10 866 pregnant women and their pre-existing children.Interventions Eligible pregnant women were screened for HBsAg using chromatographic immunoassay (Micropoint, USA). HbsAg-positive women had HBV serological assay done and their pre-existing children were screened. Women with HBV DNA ≥2 00 000 IU/mL and those positive for hepatitis B e-antigen (HBeAg) had 300 mg/day of Tenofovir Disoproxil Fumarate (TDF) in the third trimester. The newborns had hepatitis B vaccines and HB immunoglobulin (HBIG) administered, followed by testing for HBsAg at 9 months postnatally.Primary outcome measures Prevalence of chronic hepatitis B infection in pregnancy, and the incidence of MTCT of HBV.Results Overall, 395 women had chronic HBV infection, giving a prevalence of 3.64%. Their mean age was 31.51±5.71 years, with a median parity of 1.2. Thirteen women (5.2%) were positive for HBeAg, seven (3.1%) of the 225 pre-existing hepatitis B-exposed children were HbsAg positive and 17 women had prenatal TDF. Overall, 376 women completed the study, with mean birth weight of 3.21±1.86 kg and perinatal mortality rate of 29.2/1000 births. Hepatitis Bvaccine-HBIG combination was administered to 260 newborns, while the others had hepatitis B vaccine alone. All the children tested negative to the HbsAg at 9 months.Conclusion Eliminating MTCT of HBV infection through validated protocols in low and middle income countries with the highest burden of chronic HBV infections is feasible. National scale-up of such protocols is recommended.