Shapiro-Mendoza Carrie K, Tomashek Kay M, Kotelchuck Milton, Barfield Wanda, Nannini Angela, Weiss Judith, Declercq Eugene
Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3717, USA.
Pediatrics. 2008 Feb;121(2):e223-32. doi: 10.1542/peds.2006-3629.
Late-preterm infants (34-36 weeks' gestation) account for nearly three quarters of all preterm births in the United States, yet little is known about their morbidity risk. We compared late-preterm and term (37-41 weeks' gestation) infants with and without selected maternal medical conditions and assessed the independent and joint effects of these exposures on newborn morbidity risk.
We used 1998-2003, population-based, Massachusetts birth and death certificates data linked to infant and maternal hospital discharge records from the Massachusetts Pregnancy to Early Life Longitudinal data system. Newborn morbidity risks that were associated with gestational age and selected maternal medical conditions, both independently and as joint exposures, were estimated by calculating adjusted risk ratios. A new measure of newborn morbidity that was based on hospital discharge diagnostic codes, hospitalization duration, and transfer status was created to define newborns with and without life-threatening conditions. Eight selected maternal medical conditions were assessed (hypertensive disorders of pregnancy, diabetes, antepartum hemorrhage, lung disease, infection, cardiac disease, renal disease, and genital herpes) in relation to newborn morbidity.
Our final study population included 26,170 infants born late preterm and 377,638 born at term. Late-preterm infants were 7 times more likely to have newborn morbidity than term infants (22% vs 3%). The newborn morbidity rate doubled in infants for each gestational week earlier than 38 weeks. Late-preterm infants who were born to mothers with any of the maternal conditions assessed were at higher risk for newborn morbidity compared with similarly exposed term infants. Late-preterm infants who were exposed to antepartum hemorrhage and hypertensive disorders of pregnancy were especially vulnerable.
Late-preterm birth and, to a lesser extent, maternal medical conditions are each independent risk factors for newborn morbidity. Combined, these 2 factors greatly increased the risk for newborn morbidity compared with term infants who were born without exposure to these risks.
晚期早产儿（妊娠34 - 36周）占美国所有早产的近四分之三，但对其发病风险知之甚少。我们比较了有和没有特定母亲疾病的晚期早产儿和足月儿（妊娠37 - 41周），并评估了这些暴露因素对新生儿发病风险的独立和联合影响。
我们使用了1998 - 2003年基于马萨诸塞州人口的出生和死亡证明数据，这些数据与来自马萨诸塞州从怀孕到早期生命纵向数据系统的婴儿和母亲医院出院记录相关联。通过计算调整后的风险比，估计与胎龄和选定的母亲疾病独立以及联合暴露相关的新生儿发病风险。基于医院出院诊断代码、住院时间和转诊状态创建了一种新的新生儿发病衡量标准，以定义有无危及生命情况的新生儿。评估了八种选定的母亲疾病（妊娠高血压疾病、糖尿病、产前出血、肺部疾病、感染、心脏病、肾病和生殖器疱疹）与新生儿发病的关系。
我们的最终研究人群包括26170名晚期早产儿和377638名足月儿。晚期早产儿发生新生儿发病的可能性是足月儿的7倍（22%对3%）。在38周之前，每提前一个孕周出生的婴儿，其新生儿发病率就会翻倍。与暴露情况相似的足月儿相比，母亲患有任何一种所评估母亲疾病的晚期早产儿发生新生儿发病的风险更高。暴露于产前出血和妊娠高血压疾病的晚期早产儿尤其脆弱。
晚期早产以及在较小程度上母亲的疾病都是新生儿发病的独立危险因素。与未暴露于这些风险的足月儿相比，这两个因素共同作用大大增加了新生儿发病的风险。
