Acute Maternal Infection and Risk of Pre-Eclampsia: A Population-Based Case-Control Study

BackgroundInfection in pregnancy may be involved in the aetiology of pre-eclampsia. However, a clear association between acute maternal infection and pre-eclampsia has not been established. We assessed whether acute urinary tract infection, respiratory tract infection, and antibiotic drug prescriptions in pregnancy (a likely proxy for maternal infection) are associated with an increased risk of pre-eclampsia.Methods and FindingsWe used a matched nested case-control design and data from the UK General Practice Research Database to examine the association between maternal infection and pre-eclampsia. Primiparous women aged at least 13 years and registered with a participating practice between January 1987 and October 2007 were eligible for inclusion. We selected all cases of pre-eclampsia and a random sample of primiparous women without pre-eclampsia (controls). Cases (n = 1533) were individually matched with up to ten controls (n = 14236) on practice and year of delivery. We calculated odds ratios and 95% confidence intervals for pre-eclampsia comparing women exposed and unexposed to infection using multivariable conditional logistic regression. After adjusting for maternal age, pre-gestational hypertension, diabetes, renal disease and multifetal gestation, the odds of pre-eclampsia were increased in women prescribed antibiotic drugs (adjusted odds ratio 1.28;1.14–1.44) and in women with urinary tract infection (adjusted odds ratio 1.22;1.03–1.45). We found no association with maternal respiratory tract infection (adjusted odds ratio 0.91;0.72–1.16). Further adjustment for maternal smoking and pre-pregnancy body mass index made no difference to our findings.ConclusionsWomen who acquire a urinary infection during pregnancy, but not those who have a respiratory infection, are at an increased risk of pre-eclampsia. Maternal antibiotic prescriptions are also associated with an increased risk. Further research is required to elucidate the underlying mechanism of this association and to determine whether, among women who acquire infections in pregnancy, prompt treatment or prophylaxis against infection might reduce the risk of pre-eclampsia.

妊娠期感染可能与子痫前期病因学有关。然而，急性母体感染与子痫前期之间的明确关联尚未确立。本研究旨在评估急性泌尿系感染、呼吸道感染以及孕期抗生素药物处方（可能为母体感染的替代指标）是否与子痫前期风险增加相关。研究方法与发现：本研究采用匹配嵌套病例对照设计，并利用英国普通实践研究数据库的数据来探究母体感染与子痫前期之间的关联。纳入标准为年龄至少为13岁且在1987年1月至2007年10月间注册于参与实践的初产妇。我们选取了所有子痫前期病例以及随机抽取的无子痫前期初产妇作为对照（n=1533; n=14236）。将病例与最多十个对照在分娩地点和年份上进行个体匹配。通过多变量条件逻辑回归计算暴露于感染和未暴露于感染的女性在子痫前期上的比值比及其95%置信区间。在调整母体年龄、孕前高血压、糖尿病、肾脏疾病和多胎妊娠后，使用抗生素药物的女性（调整比值比1.28；1.14–1.44）以及患有泌尿系感染的女性（调整比值比1.22；1.03–1.45）的子痫前期风险增加。我们没有发现母体呼吸道感染与子痫前期之间存在关联（调整比值比0.91；0.72–1.16）。进一步调整母体吸烟状况和孕前体重指数对研究结果无显著影响。结论：孕期发生泌尿系感染的女性（而非呼吸道感染的女性）子痫前期风险增加。母体抗生素处方也与子痫前期风险增加相关。为进一步阐明这种关联的潜在机制，并确定对于孕期感染的女性，及时治疗或感染预防是否能降低子痫前期风险，尚需进一步研究。