Impact of different feeding patterns on mother-to-child transmission of hepatitis B virus

Abstract

Objective To explore the effect of different feeding patterns on mother-to-child transmission of hepatitis B virus (HBV). Methods Chronic HBV-infected puerperae, who gave birth to a single baby at term in Beijing DiTan Hospital from December 18, 2010 to June 26, 2012, were recruited and separated into breast-feeding group and formula-feeding group according to the mother's will. Each group was then divided into three subgroups based on maternal serum HBV-DNA load before delivery: HBV-DNA negative subgroup (<5×102 copies/ml), low viral load subgroup (≥5×102 -<1.0×106 copies/ml) and high viral load subgroup (≥1.0×106 copies/ml). A total of 199 patients in breast-feeding group were divided into three subgroups, separately including 73, 62 and 64 patients, while a total of 210 patients in formula-feeding group into three subgroups, including 74, 62 and 74 patients. Newborns were injected with Hepatitis B hyper-immune globulin (HBIG) within 2 h after birth and at 15 to 30 days, followed by the routine injection of recombinant yeast derived Hepatitis B vaccine in accordance with the scheme of0, 1, 6 months. HBV-DNA was determined by fluorescence quantitative polymerase chain reaction, while serological markers of HBV by microsome chemiluminescence method. Comparisons were made between the breast-feeding and formula-feeding group on maternal background information, immune responses of the infants at one-month and seven-month old, the infectious status when they were between seven-month to two-year old. Statistical analysis was made with independent sample t-test, rank-sum test, χ2 test and Fisher's exact test. Results The HBeAg positive rates of puerperae in the three subgroups (HBV-DNA negative, low viral load and high viral load) among women of the breast-feeding group were 12.3% (9/73), 37.1% (23/62) and 96.9%(62/64), respectively, while 5.4% (4/74), 51.6% (32/62) and 95.9% (71/74) among the formula-feeding group. There was no significant difference between breast-feeding group and formula-feeding group (all P>0.05). Seventy of the 409 infants missed the follow-up at seven-month old, but returned between one to two years old. The anti-HBs positive rates of the three subgroups in infants of the breast-feeding group at seven-month old were 98.4% (61/62), 98.2% (54/55) and 95.7% (44/46), while 100.0% (63/63), 98.2% (56/57) and 92.9% (52/56) in the formula-feeding group (all P>0.05). The infection rate of infants in the breast-feeding group and the formula-feeding group were 3.0% (6/199) and 2.4% (5/210) at seven-month to two-year old. Notably, infected infants was identified in HBV-DNA negative subgroup in neither the breast-feeding group nor the formula-feeding group, while 0.0% (0/62) and 9.4% (6/64) of infection rate were reported in low viral load and high viral load subgroups of the breast-feeding group and 1.6% (1/62) and 5.4% (4/74) of the formula-feeding group (both P>0.05). Conclusion With combined immunization, breast-feeding in chronic HBV infected mothers does not increase the risk of infantile infection. Key words: Hepatitis B, chronic; Infectious disease transmission, vertical; Breast feeding; Feeding methods