剖宫产不能减少乙型肝炎病毒母婴传播

Cesarean section does not reduce mother-to-infant transmission of hepatitis B virus

目的探讨剖宫产能否降低乙型肝炎病毒（hepatitis B virus，HBV）母婴传播的风险。方法回顾性分析2002年7月至2004年8月采集并保存的江苏省14个县市妊娠15～20周孕妇的外周血血清，采用固相酶联免疫法检测HBV血清学标志物，其中419例单胎妊娠孕妇HBsAg阳性，进一步采用实时荧光定量聚合酶链反应技术定量检测HBVDNA。2009年10月至2010年3月，对这419例孕妇所分娩的子女进行随访，随访到298例（71．1％），纳入资料完整、按“0、1、6月”方案正规接种乙肝疫苗的281例儿童为研究对象，采血检测HBV血清学标志物。比较剖宫产组和阴道分娩组儿童5～7岁时的HBV感染率。采用t检验、X^2检验或Fisher精确概率法进行统计分析。结果（1）剖宫产组136例和阴道分娩组145例，比较2组孕妇妊娠期HBeAg阳性率[25．7％（35／136）与34．5％（50／145）]和HBeAg阳性者的HBVDNA水平[（2．30×10^6）IU／ml与（2．09×10^6）IU／ml]，以及所分娩子女在新生儿期注射乙肝免疫球蛋白（hepatitis B immunoglobulin，HBIG）的比例[38．2％（52／136）与35．9oA（52／145）]、婴儿期母乳喂养比例[82．4％（112／136）与75．9％（110／145）]、儿童随访时年龄[（5．9±0．8）岁与（6．0±0．6）岁]等指标，差异均无统计学意义（P均〉0．05）。（2）281例儿童中，272例（96．8％）HBsAg阴性，9例（3．2％）HBsAg阳性，163例（58．0％）抗-HBs阳性。剖宫产组和阴道分娩组儿童的HBsAg阳性率[2．9％（4／136）与3．4％（5／145）]、自限性感染（HBsAg阴性且抗-HBc阳性）率[0．0％（0／136）与1．4％（2／145）]、抗-HBs阳性率[57．4％（78／136）与58．6％（85／145）]比较，差异均无统计学意义（P均〉0．05）。结论剖宫产不能减少HBV母婴传播，临床工作中，不建议为阻断HBV母婴传播而选择剖宫产。

Objective To investigate whether cesarean section on pregnant women with chronic hepatitis B virus （HBV） infection may reduce mother-to infant transmission risk of HBV. Methods Preserved serum samples of pregnant women at 15-20 weeks of gestation which were collected from July 2002 to August 2004 in 14 counties of Jiangsu Province were analyzed retrospectively. These samples were tested for HBV serologic markers with enzyme immunoassay, and 419 cases of positive hepatitis B surface antigen （HBsAg） were found. HBV DNA level of these HBsAg-positive women were further quantitatively measured with real-time polymerase chain reaction assay. Children of these 419 HBsAg-positive mothers were followed up during October 2009 to March 2010 and 298 of them were eontactable （71.1%）, among which 281 were enrolled in final analysis as they had complete information and had been vaccinated with three regular doses of HBV vaccine during infantile period. The 281 children were tested for serum HBV markers. The HBV infection rate in these children at age 5-7 was compared between those born by cesarean setion （CS group, n = 136） and by vaginal delivery （VD group, n： 145）. T-test, Z2 test or Fisher＇s exact test was used to analyze relevant parameters. Results（I） Maternal HBeAg-positive rates [-25.7% （35/136） vs 34. 5% （50/145）7, HBV DNA levels in HBeAg-positive women [（2.30 × 10^6 ） IU/ml vs （2.09 × 10^6 ） IU/ml], the percentages of HBIG injection after birth [38.2% （52/136） vs 35.9% （52/145）1, breastfeeding ratios [82.4%（112/136） vs 75.9% （110/145）], and children＇s ages at the follow-up [（5.9±0.8） vs （6.0±0.6）1 were comparable between CS group and VD group （all P〉0.05）. （2） Among these 281 children, 272 （96.8%） were HBsAg-negative, 9 （3.2%） were HBsAg-positive and 163 （58.0%） were anti-HBs-positive. The prevalence of HBsAg-positive [（2.9~ （4/136） vs 3.4% （5/145）], HBsAg negative and anti-HBc positive [0.0% （0/136） vs 1.4% （2/145）1 and anti-HBs positive [-57.4%（78/136） vs 58.6%（85/145）] in CS group were similar to those in VD group. Conclusions Cesarean section does not reduce the risk of mother-to-infant transmission of HBV. In clinical practice, elective cesarean section should not be suggested in order to prevent HBV vertical infection.