Hep B before pregnancy is linked to infant congenital heart disease

A retrospective study in China found that maternal hepatitis B virus infection (HBV), prior to pregnancy, was strongly associated with congenital cardiac diseases (CHDs), among offspring.

Compared to uninfected women, pregnant with HBV before pregnancy had a higher chance of CHDs in offspring with an adjusted relative ratio (aRR), of 1.23 (95% CI 1.02-1.49), according to Ying Yang, PhD of the National Research Institute for Family Planning, Beijing and her colleagues. JAMA Pediatrics.

After multivariable adjustment, it was found that couples with previously infected HBV-infected partners had a higher chance of having CHDs than those who were uninfected prior to conception.

There was no association between HBV infected mothers and CHDs in their offspring.

Yang and colleagues wrote that “our study provided new evidence regarding associations between maternal HBV preconception infection and risk for CHDs in offspring in Chinese childbearing-aged mothers,” Yang and her team. Even if they are not contagious, women with a history of HBV infection should be treated to reduce the chance of CHDs in their offspring.

Yang and her colleagues found that CHD is responsible for approximately one-third all birth defects. HBV is a serious disease that affects between 3% and 10% of Chinese women. Screening should be done for both the woman and her partner.

According to the authors, HBV infection is known to affect both sperm as well as oocytes. There may also be an interaction effect between spouses with preconception HBV infections.

They cited previous studies which showed HBV DNA sequences could be integrated into chromosomes during embryo development. This might lead to abnormal embryonic heart development.

“Maternal preconception HBV infections may alter the epigenome profile for newborns, which could affect embryonic heart growth,” they said.

Yang and her team also suggested that HBV status should be checked in this group.

They wrote that HBV vaccination was included in the Chinese immunization program from the early 1990s. However, because serum HBsAb titers can decrease with age, it is recommended that both men and women regularly monitor their HBV status. HBV-related education should also be reinforced, particularly for couples planning to conceive to reduce the chance of CHDs.

Every adult in the U.S. should have HBV testing and be vaccinated. The CDC updated its guidance last week to recommend that pregnant women are screened for HBV in their first trimester, regardless of whether they have had any previous testing or received vaccinations.

Yang and her colleagues studied 3,690,427 women aged 20-49. Of these, 738,945 were infected by HBV. This included 393,332 with a previous infection and 345.613 with a new infection.

They used 1 to 4 propensity score matching data from 2013 to 2019, from the National Free Preconception Checkup Project. This national free service is for women of childbearing age who intend to conceive anywhere in mainland China.

CHDs were found in approximately 0.3% of newly infected women, and 0.04% among pregnant women with HBV.

CHDs were atrial septal deficiency, ventricular septal deficiency, atrioventricular Septal defect. Patent ductus arteriosus. Tetralogy of Fallot. Pulmonary stenosis. Transposition of the great vessels.

Yang and his colleagues stated that it was possible to miss diagnoses of CHDs within 28-days of delivery. CHD subtypes weren’t recorded, which was a limitation of their research. It was also impossible to determine if HBV DNA load and risk of CHDs in offspring were related.

Additionally, the study didn’t take into consideration pregnancy complications like gestational diabetes. This could have resulted in a biased estimate of the association between maternal HBV infections and CHDs in offspring.