Salihu Hamisu M, Lynch O'Neil, Alio Amina P, Liu Jihong
Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL 33613, USA.
Am J Epidemiol. 2008 Jul 1;168(1):13-20. doi: 10.1093/aje/kwn092. Epub 2008 May 1.
Using data from the Missouri maternally linked files (1989-1997), the authors examined the association among maternal obesity, obesity subtypes, and spontaneous and medically indicated preterm (<37 weeks) and very preterm (<33 weeks) births in singletons and twins. Adjusted odds ratios were obtained with correction for intracluster correlation. The prevalence of obesity increased by 77% over the study period (p(trend) < 0.001). Obese mothers had a lower risk for spontaneous preterm birth, and this was more pronounced among twins (odds ratio = 0.68, 95% confidence interval: 0.62, 0.75) than singletons (odds ratio = 0.84, 95% confidence interval: 0.82, 0.87). However, this association was present only among obese women who gained less than 0.69 kg/week for singletons and between 0.23 and 0.69 kg/week for twins. By contrast, obese mothers with singleton gestation had about 50% greater odds of medically indicated preterm (odds ratio = 1.46, 95% confidence interval: 1.39, 1.54) and very preterm (odds ratio = 1.49, 95% confidence interval: 1.34, 1.65) births, and the risk increases with ascending severity of obesity (p(trend) < 0.01). For extreme obesity, the risk of medically indicated preterm and very preterm births was almost double that for nonobese women. Similar findings were observed in twins. These data suggest that obesity increases the risk for medically indicated but not spontaneous preterm birth in both singletons and twins.
作者利用密苏里州母婴关联档案（1989 - 1997年）的数据，研究了孕妇肥胖、肥胖亚型与单胎和双胎自发性早产及医源性早产（<37周）和极早产（<33周）之间的关联。通过校正群内相关性获得调整后的优势比。在研究期间，肥胖患病率增加了77%（趋势p<0.001）。肥胖母亲自发性早产的风险较低，且在双胎中更为明显（优势比=0.68，95%置信区间：0.62，0.75），高于单胎（优势比=0.84，95%置信区间：0.82，0.87）。然而，这种关联仅存在于单胎体重增加每周少于0.69千克以及双胎体重增加每周在0.23至0.69千克之间的肥胖女性中。相比之下，单胎妊娠的肥胖母亲医源性早产（优势比=1.46，95%置信区间：1.39，1.54）和极早产（优势比=1.49，95%置信区间：1.34，1.65）的几率高出约50%，且风险随着肥胖严重程度的增加而升高（趋势p<0.01）。对于极度肥胖，医源性早产和极早产的风险几乎是非肥胖女性的两倍。在双胎中也观察到了类似的结果。这些数据表明，肥胖增加了单胎和双胎医源性早产而非自发性早产的风险。
