From the Department of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois; the University of Texas Southwest Medical Center, Dallas, Texas; the University of Alabama at Birmingham, Birmingham, Alabama; the University of Utah, Salt Lake City, Utah; the University of Texas Health Science Center at Houston, Houston, Texas; Wayne State University, Detroit, Michigan; Drexel University, Philadelphia, Pennsylvania; Case Western Reserve University-MetroHealth Medical Center, Cleveland, Ohio; the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Columbia University, New York, New York; Wake Forest University Health Sciences, Winston-Salem, North Carolina; The Ohio State University, Columbus, Ohio; the George Washington University Biostatistics Center, Washington, DC; and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland.
Obstet Gynecol. 2011 Dec;118(6):1309-1313. doi: 10.1097/AOG.0b013e318236fbd1.
To evaluate the length of the second stage of labor in relation to increasing maternal prepregnancy body mass index (BMI) among nulliparous parturient women, and to determine whether route of delivery differs among obese, overweight, and normal-weight women reaching the second stage of labor.
We performed a secondary analysis of a multicenter trial of fetal pulse oximetry conducted among 5,341 nulliparous women who were induced or labored spontaneously at 36 weeks or more of gestation. Normal weight was defined as BMI of 18.5-24.9 kg/m, overweight was a BMI of 25.0-29.9 kg/m, and obese was a BMI of 30 or higher.
Of the 5,341 women, 97% had prepregnancy BMI recorded. Of these, 3,739 had BMIs of 18.5 or higher and reached the second stage of labor. Increasing maternal BMI was not associated with second stage duration: normal weight, 1.1 hour; overweight, 1.1 hour; and obese, 1.0 hours (P=.13). Among women who reached the second stage, as BMI increased, so did the likelihood that the woman had undergone induction of labor. Even so, the lack of association between second-stage duration and BMI did not vary by method of labor onset (P=.84). The rate of cesarean delivery in the second stage did not differ by increasing BMI (normal weight 7.1%, overweight 9.6%, obese 6.9%, P=.17).
Among nulliparous women who reach the second stage of labor, increasing maternal BMI is not associated with a longer second stage or an increased risk of cesarean delivery.
II.
评估初产妇的第二产程与母体孕前体重指数（BMI）增加的关系，并确定达到第二产程的肥胖、超重和正常体重妇女的分娩方式是否存在差异。
我们对一项胎儿脉搏血氧饱和度多中心试验进行了二次分析，该试验纳入了 5341 名初产妇，这些产妇在妊娠 36 周或以上时接受了引产或自然分娩。正常体重定义为 BMI 为 18.5-24.9kg/m2；超重为 BMI 为 25.0-29.9kg/m2；肥胖为 BMI 为 30 或更高。
在 5341 名女性中，97%有孕前 BMI 记录。其中，3739 名女性 BMI 为 18.5 或更高，并进入第二产程。母体 BMI 的增加与第二产程持续时间无关：正常体重为 1.1 小时；超重为 1.1 小时；肥胖为 1.0 小时（P=0.13）。在进入第二产程的女性中，随着 BMI 的增加，接受引产的可能性也随之增加。即便如此，第二产程持续时间与 BMI 之间的关联不因分娩方式的不同而变化（P=0.84）。第二产程中剖宫产率也不因 BMI 的增加而有所不同（正常体重组为 7.1%，超重组为 9.6%，肥胖组为 6.9%，P=0.17）。
在进入第二产程的初产妇中，母体 BMI 的增加与第二产程延长或剖宫产风险增加无关。
II 级。
