Adjusted covariates for chlamydia.

BackgroundInfection is thought to play a part in some infant deaths. Maternal infection in pregnancy has focused on chlamydia with some reports suggesting an association with sudden unexpected infant death (SUID).ObjectivesWe hypothesized that maternal infections in pregnancy are associated with subsequent SUID in their offspring.SettingAll births in the United States, 2011–2015Data sourceCenters for Disease Control and Prevention (CDC) Birth Cohort Linked Birth-Infant Death Data Files.Study designCohort study, although the data were analysed as a case control study. Cases were infants that died from SUID. Controls were randomly sampled infants that survived their first year of life; approximately 10 controls per SUID case.ExposuresChlamydia, gonorrhea and hepatitis C.ResultsThere were 19,849,690 live births in the U.S. for the period 2011–2015. There were 37,143 infant deaths of which 17,398 were classified as SUID cases (a rate of 0.86/1000 live births). The proportion of the control mothers with chlamydia was 1.7%, gonorrhea 0.2% and hepatitis C was 0.3%. Chlamydia was present in 3.8% of mothers whose infants subsequently died of SUID compared with 1.7% of controls (unadjusted OR = 2.35, 95% CI = 2.15, 2.56; adjusted OR = 1.08, 95% CI = 0.98, 1.19). Gonorrhea was present in 0.7% of mothers of SUID cases compared with 0.2% of mothers of controls (OR = 3.09, (2.50, 3.79); aOR = 1.20(0.95, 1.49)) and hepatitis C was present in 1.3% of mothers of SUID cases compared with 0.3% of mothers of controls (OR = 4.69 (3.97, 5.52): aOR = 1.80 (1.50, 2.15)).ConclusionsThe marked attenuation of SUID risk after adjustment for a wide variety of socioeconomic and demographic factors suggests the small increase in the risk of SUID of the offspring of mothers with infection with hepatitis C in pregnancy is due to residual confounding.

研究背景：感染被认为与部分婴儿死亡存在关联。孕期母体感染的研究多聚焦于衣原体感染，已有多项报道提示其与婴儿猝死综合征（Sudden Unexpected Infant Death，SUID）存在相关性。
研究目的：本研究假设孕期母体感染与子代随后发生的婴儿猝死综合征（SUID）存在关联。
研究场景：2011-2015年美国境内所有活产分娩案例。
数据来源：美国疾病控制与预防中心（Centers for Disease Control and Prevention，CDC）出生队列关联出生-婴儿死亡数据集文件。
研究设计：本研究虽为队列研究，但数据分析采用病例对照研究范式。病例组为最终死于SUID的婴儿，对照组为随机抽取的存活满1周岁的婴儿，每1例SUID病例对应约10例对照个体。
暴露因素：衣原体感染、淋病及丙型肝炎病毒感染。
研究结果：2011-2015年美国共计活产19,849,690例，婴儿死亡37,143例，其中17,398例被归类为SUID病例，发生率为0.86/1000活产。对照组母亲的衣原体感染率为1.7%，淋病感染率为0.2%，丙型肝炎感染率为0.3%。在子代随后死于SUID的母亲中，衣原体感染率为3.8%，显著高于对照组的1.7%（未校正比值比[OR]=2.35，95%置信区间[CI]=2.15~2.56；校正后比值比[aOR]=1.08，95%CI=0.98~1.19）。SUID病例组母亲的淋病感染率为0.7%，对照组为0.2%（OR=3.09，95%CI=2.50~3.79；aOR=1.20，95%CI=0.95~1.49）；SUID病例组母亲的丙型肝炎感染率为1.3%，对照组为0.3%（OR=4.69，95%CI=3.97~5.52；aOR=1.80，95%CI=1.50~2.15）。
研究结论：在校正了涵盖社会经济与人口统计学特征在内的多种混杂因素后，SUID发生风险的关联强度显著减弱，提示孕期母体感染丙型肝炎病毒者其子代SUID风险的小幅升高，实则可能源于残余混杂偏倚。