Presence of HBV-DNA in cord blood is associated with spontaneous preterm birth in pregnant women with HBeAg-negative chronic hepatitis B virus infection.

Spontaneous preterm birth is the leading cause of perinatal morbidity and mortality. In this study the spontaneous preterm birth rates in a group of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV)-infected pregnant women without known risk factors for preterm delivery as well as the role of maternal laboratory data and hepatitis B surface antigen/HBV deoxyribonucleic acid (HBV-DNA) in cord blood in respect to preterm labour were evaluated. 138 consecutive HBeAg-negative chronic HBV-infected pregnant women were evaluated during the perinatal period. Serum HBV-DNA was determined by using the Cobas Amplicor HBV Test in both maternal and cord blood samples. 102 women were finally evaluated (36 were excluded) and 15 of them (14.7%) had spontaneous preterm birth. A significant association between spontaneous preterm birth and HBV-DNA in cord blood was observed (p = 0.007). HBV-DNA positivity in cord blood was significantly associated with maternal HBV-DNA levels (p = 0.002). The relative risk of HBV-DNA in cord blood was 6.43 times higher among women with serum HBV-DNA ≥10,000 copies/ml and lymphocyte count <1,500 compared to those with all the other combinations of both parameters (p = 0.001). In conclusion, the presence of HBV-DNA in cord blood is significantly associated with spontaneous preterm birth in chronic HBV-infected pregnant women. Women with HBV-DNA ≥10,000 copies/ml and lymphocyte count <1,500 during the perinatal period have a higher probability of HBV-DNA in their cord blood.