Research On The High-Risk Factors Of Mother-Infant Transmission Of Hepatitis B Virus

Purposes: Hepatitis B virus (HBV) infection is a worldwide public health problem, which mostly occurs in infants and young children. Chronic HBV infection may develop chronic liver inflammation, cirrhosis, and closely relate to liver neoplasms. The mother-infant transmission is a major cause of chronic infection. At present it is still incompletely clear about the mechanisms of HBV transmission, and people think it may be related to multiple factors such as the placenta, peripheral blood mononuclear cells (PBMCs), paternal transmission, breast milk, body fluid, and time period around childbirth. Most of scholars think that immunization with hepatitis b-type vaccine is an effective method to prevent chronic HBV infection and related diseases, and it significantly decreases the mother-infant transmission of HBV in economical developed area by carrying out passive immunity to hepatitis B surface antigen (HBsAg)-positive pregnant women before delivery and a combination of passive and active immunization to newborns. At present it is still controversial about the preventive effects of passive immunity before delivery. The failure rate of immunization is about 10-20% in infants with active immunity or the combination of active and passive immunity. The studies have shown that ovarian infection is the major cause of the failure of immunization.In view of above situation, we studied the effects of multiple factors on HBV transmission and evaluated the active/passive immunization to further strengthen understanding of mother-infant transmission of HBV and reduce the infection rate.Methods: This study included 164 cases of HBV- carrying pregnant women without symptoms and their newborns, and 13 cases of HBsAg-negative mothers, HBsAg-positive fathers and their newborns. There were two groups: prenatal preventive group (110 cases) and prenatal non-preventive group (54 cases) according to whether mothers received the passive immunization during pregnancy. Each group contained single-positive and double positive groups according to HBsAg and hepatitis B e antigen (HBeAg) in maternal serum (Prenatal preventive group had 68 single positive cases and 42 double positive cases; prenatal non-preventive group had 39 single positive cases and 15 double positive cases.) In prenatal preventive group HBsAg-positive pregnant women received intramuscular injection of hepatitis B immune globulin (HBIG) in the dose of 200IU every 3-4 weeks since 24th week of pregnancy; and all of newborns got intramuscular injection of HBIG in right flank in front of thigh within one hour and at 14th day as well as the preventive vaccinates of yeast gene recombination hepatitis B-type vaccine in the order of 0~l~6 months (lOug per time). The vein blood samples got respectively 1-3 days before delivery from pregnant women, who are HBsAg-positive or whose spouse are HBsAg-positive, and their newborns were tested in the fifteen minutes after birth for hepatitis B virus mark (HBVM), hepatitis B virus Pre-SI antigen (PreSI), alanine transaminase (ALT), aspartate aminotransferase (AST), and hepatitis B virus-deoxyribonucleic acid (HBV-DNA). The first milk from HBsAG-positive mothers 1-5 days after delivery was tested for HBVM. There were 99 following7cases (in the prenatal preventive group: 35 single positive cases, 20 double positive cases; in the prenatal non-preventive group: 34 single positive cases, and 10 double positive cases). The newborns in the following cases were taken vein blood samples to test HBVM, PreSI, ALT, AST, and HBV-DNA. All data was analyzed with SPSS 12.0 statistical software after investigation, checkup and recording all correlation factors.Results: The statistical analyses results from each group shows: 1. The ovarian infection rate of newborns whose mothers are HBeAg-positive and/or HBV-DNA-positive is significant higher than those whose mothers are HBeAg-negative and/or HBV-DNA-negative (p<0.05). 2. There is no significant difference between ovarian infection newborns and non-ovarian infection newborns on birth weight, baby sex, embryo age, the childbirth way, HBVM positive in the first milk, prenatal maternal passive immunization, many factors around childbirth (the umbilical cord, the amniotic fluid, placenta illnesses and unequal trough, omens of premature delivery, poverty-stricken embryos, newborn suffocates, pre-eclampsia and so on) (p>0.05). 3. Mothers in the double positive group have significantly higher rates of the HBV-DNA positive and the HBVM positive than those in the single positive group (p<0.05). 4. The failure rate of immunization is significantly different between ovarian infection newborns and non-ovarian infection newborns.Conclusion: 1. The HBeAg positive status and content of HBV-DNA are the high-risk factors for the mother-infant HBV transmission and obviously relate to HBV ovarian infection. 2. There is no obvious relationship between ovarian infection and birth weight, baby sex, embryo age, the childbirth way, HBVM positive in the first milk, prenatal maternal passive immunization, many factors around childbirth (the umbilical cord, the amniotic fluid, placenta illnesses and...