Hep B Infection and Assisted Reproductive Technology: Are the Outcomes the Same?

Studies have linked hepatitis B to a higher risk for miscarriage and preterm birth in natural pregnancies. Those studies, however, were unclear about whether that same risk applies to pregnancies through assisted reproductive technology.

But now a recent retrospective study has confirmed that maternal hepatitis B status is not associated with pregnancies outcomes in women undergoing freeze-thaw embryo transfer.

The study, conducted by physicians in China along researchers in the Department of Biomedical Sciences at State University of New York at Albany, used data between January 1, 2018, and April 30, 2021, from thousands of Chinese women impregnated using freeze-thaw embryo transfer. It was published last month as a brief research letter in the JAMA Network Open.

“Previous research has not explored the association between HBV infection and pregnancy outcomes in FET,” wrote corresponding authors Yu-Bin Ding, Ph.D., of Chongqing Medical University, and Qi Wan, M.D., of Sichuan University, and colleagues. “To fill this knowledge gap, we conducted a retrospective cohort study to examine the association of maternal HBV serostatus with pregnancy outcomes in women undergoing FET.”

The study focused on three cohorts of women: hepatitis B surface (HBsAg) positive and hepatitis Be antigen (HBeAg) negative; HBsAg positive and HBeAg positive; and HBsAg negative and HBeAg negative.

The presence of HBsAg indicates that the person is infectious, except when it might be transiently positive within 30 days after a dose of hepatitis B vaccine. HBeAg is a viral protein and a positive test indicates a person is infectious. made by the hepatitis B virus and is released from the infected liver cells into the blood.

The primary outcome was live birth, the secondary ones The secondary outcomes included biochemical pregnancy, clinical pregnancy, ectopic pregnancy, miscarriage (early and late), and preterm delivery. The researchers found no statistically significant differences in live births among the women grouped by HBsAg and HBeAg status. They also didn’t find differences when they looked at the secondary outcomes.

“Our study confirms that maternal HBV serostatus is not associated with pregnancy outcomes in infertile women undergoing FET,” wrote Ding and Wan. “In conclusion, maternal HBV serostatus was not associated with FET pregnancy outcomes. These findings may reduce the psychological burden of infertile couples with HBV.”

They note, though, that HBV infection was significantly associated with miscarriage and preterm birth during natura pregnancy. “This correlation may be due to the accumulation of HBV DNA in the placenta and trophoblast cells that lead to placental inflammation,” they note.

HBV infects an estimated 300 million people worldwide, including 6 million children under the age of five, according to the CDC. Roughly 1 million people a year die from HBV-related liver disease, according to the WHO.

Mother-to-child transmission is the most common route of HBV transmission globally, according to the Hepatitis B Foundation. China, according to the NIH, has the world’s largest HBV “disease burden.” An estimated 90.87 million pregnant women living in mainland China tested HBV positive between 2015 and 2020.

In 2022, the NIH examined 42 studies conducted between 2016 and 2021 of more than 4 million HBV cases from across China. It found that 6.64% of pregnant Chinese women were infected with HBV.

HBV can cause chronic infection in infants, according to the Hepatitis B Foundation. The CDC and WHO recommend that all pregnant women be tested for HBV and that the mother’s attending physician be informed about an HBV infection to monitor the health of the mother’s liver.

The CDC recommends that babies born to infected mothers receive three doses of the HBV vaccine starting shortly after birth, followed by another dose one to two months later and again at 6 to 18 months.

Research findings published in 2017 in the Morbidity and Mortality Weekly Report showed that about 70% of newborns in the U.S. receive their first doses of the HBV vaccine by three days of age.