Plain language summary
Hepatitis B immunoglobulin (HBIG) during pregnancy for the prevention of mother-to-child transmission of hepatitis B virus (HBV)
Review question
We aimed to review the evidence for benefits and harms of HBIG injection to pregnant women during their last three months of pregnancy versus no treatment for the prevention of mother-to-child transmission of HBV infection.
Background
Hepatitis is a virus that infects the liver. When an infection goes on for a long time, it is said to be 'chronic'. It can cause damage to the liver and may cause liver failure and cancer.
Hepatitis B is mainly passed between people through contact with infected blood, but frequently from mother to baby in the womb. Hepatitis B is widespread in Africa and Asia, and when acquired during pregnancy, the infection poses serious risks to the unborn baby. Usually there are no symptoms in the early stages of infection. However, up to 85% of infants infected by their mothers at birth develop chronic HBV infection.
HBIG is a substance made from human blood that is used to prevent the child from getting HBV infection from the mother. When HBIG is given to pregnant women who have HBV, the high levels of antibodies (proteins produced by the immune system) to the virus pass easily across the placenta to the child to protect against HBV infection. This works best during the last third of pregnancy.
Search date
We searched for evidence on 22 December 2016.
Study funding sources
Four clinical trials were sponsored by a pharmaceutical company, or a group with a financial (or other) interest in the study results.
Study characteristics
After searching the medical literature for relevant trials, we identified 36 clinical trials that recruited 6044 pregnant women with signs of HBV infection. All trials originated from China. All trials and trial results were at high risks of bias, which makes potential overestimation of benefits and underestimation of harms more likely.
Key results
The studies assessed only hepatitis B surface antigen (HBsAg) (proteins on the surface of the HBV that cause immune system of the body to make antibodies when exposed to HBV), hepatitis B virus DNA (HBV-DNA) (self-dividing material of the HBV which carries its genetic information), and hepatitis B envelope antigen (HBeAg) (blood proteins that shows that the virus is still active in the liver) status in newborns. There was no information about the effects of HBIG on death from all causes (newborn or mother), antibodies to hepatitis B core antigen (proteins made by the immune system which bind to HBV and cause them to be destroyed), cost-effectiveness of HBIG, and side effects.
Antenatal (before birth) HBIG might have an effect on preventing mother-to-child transmission of HBV as more treated babies than non-treated babies had no HBsAg or HBV-DNA; however, both results could have been affected by the way the trials were conducted and were at high risk of bias. The authors could draw no conclusions about the side effects of HBIG for pregnant women with HBV infection. Well-designed clinical trials with low risks of bias are needed to establish the benefits and harms of HBIG compared with no treatment in pregnant women with HBV.
Quality of the evidence
Due to the very low to low quality evidence in this review, we do not know if antenatal HBIG administration has an effect on the proportion of newborns with HBsAg and HBV-DNA compared with no treatment. We could draw no conclusions about death of newborns or mothers as we found no data.