Dude Annie M, Lane-Cordova Abbi D, Grobman William A
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL.
Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
Am J Obstet Gynecol. 2017 Sep;217(3):373.e1-373.e6. doi: 10.1016/j.ajog.2017.05.024. Epub 2017 May 17.
Approximately one third of all deliveries in the United States are via cesarean. Previous research indicates weight gain during pregnancy is associated with an increased risk of cesarean delivery. It remains unclear, however, whether and to what degree weight gain between deliveries (ie, interdelivery weight gain) is associated with cesarean delivery in a subsequent pregnancy following a vaginal delivery.
The objective of the study was to determine whether interdelivery weight gain is associated with an increased risk of intrapartum cesarean delivery following a vaginal delivery.
This was a case-control study of women who had 2 consecutive singleton births of at least 36 weeks' gestation between 2005 and 2016, with a vaginal delivery in the index pregnancy. Women were excluded if they had a contraindication to a trial of labor (eg, fetal malpresentation or placenta previa) in the subsequent pregnancy. Maternal characteristics and delivery outcomes for both pregnancies were abstracted from the medical record. Maternal weight gain between deliveries was measured as the change in body mass index at delivery. Women who underwent a subsequent cesarean delivery were compared with those who had a repeat vaginal delivery using χ statistics for categorical variables and Student t tests or analysis of variance for continuous variables. Multivariable logistic regression was used to determine whether interdelivery weight gain remained independently associated with intrapartum cesarean delivery after adjusting for potential confounders.
Of 10,396 women who met eligibility criteria and had complete data, 218 (2.1%) had a cesarean delivery in the subsequent pregnancy. Interdelivery weight gain was significantly associated with cesarean delivery and remained significant in multivariable analysis for women with a body mass index increase of at least 2 kg/m (adjusted odds ratio, 1.53, 95% confidence interval, 1.03-2.27 for a body mass index increase of 2 kg/m to <4 kg/m; adjusted odds ratio, 1.99, 95% confidence interval, 1.19-3.34 for body mass index increase of 4 kg/m or more). Furthermore, women who gained 2 kg/m or more were significantly more likely to undergo cesarean delivery specifically for the indications of arrest of dilation or arrest of descent (adjusted odds ratio, 2.01, 95% confidence interval, 1.21-3.33 for body mass index increase of 2 to <4 kg/m; adjusted odds ratio, 2.34, 95% confidence interval, 1.15-4.76 for body mass index increase of ≥4 kg/m). Contrarily, women who lost ≥2 kg/m were less likely to undergo any cesarean delivery (adjusted odds ratio, 0.41, 95% confidence interval, 0.21-0.78) as well as less likely to undergo cesarean delivery for an arrest disorder (adjusted odds ratio, 0.29, 95% confidence interval, 0.10-0.82). Weight gain or loss was not significantly associated with a cesarean delivery for fetal indications.
Among women with a prior vaginal delivery, interdelivery weight gain was independently associated with an increased risk of intrapartum cesarean delivery in a subsequent pregnancy.
在美国，约三分之一的分娩是剖宫产。先前的研究表明，孕期体重增加与剖宫产风险增加有关。然而，分娩间隔期间的体重增加（即两次分娩间的体重增加）是否以及在何种程度上与经阴道分娩后的后续妊娠中的剖宫产有关，仍不清楚。
本研究的目的是确定两次分娩间的体重增加是否与经阴道分娩后产时剖宫产风险增加有关。
这是一项病例对照研究，研究对象为2005年至2016年间连续两次单胎妊娠且孕周至少36周、首次妊娠为经阴道分娩的女性。如果她们在后续妊娠中有阴道试产禁忌证（如胎位异常或前置胎盘），则被排除。从病历中提取两次妊娠的产妇特征和分娩结局。两次分娩间的产妇体重增加以分娩时体重指数的变化来衡量。将后续接受剖宫产的女性与再次经阴道分娩的女性进行比较，分类变量采用χ²检验，连续变量采用Student t检验或方差分析。多变量逻辑回归用于确定在调整潜在混杂因素后，两次分娩间的体重增加是否仍与产时剖宫产独立相关。
在10396名符合入选标准且数据完整的女性中，218名（2.1%）在后续妊娠中接受了剖宫产。两次分娩间的体重增加与剖宫产显著相关，在多变量分析中，体重指数增加至少2 kg/m²的女性中这种相关性仍然显著（体重指数增加2 kg/m²至<4 kg/m²时，调整后的比值比为1.53，95%置信区间为1.03 - 2.27；体重指数增加4 kg/m²或更高时，调整后的比值比为1.99，95%置信区间为1.19 - 3.34）。此外，体重增加2 kg/m²或更多的女性因宫颈扩张停滞或胎头下降停滞而行剖宫产的可能性显著更高（体重指数增加2至<4 kg/m²时，调整后的比值比为2.01，95%置信区间为1.21 - 3.33；体重指数增加≥4 kg/m²时，调整后的比值比为2.34，95%置信区间为1.15 - 4.76）。相反，体重减轻≥2 kg/m²的女性接受任何剖宫产的可能性较小（调整后的比值比为0.41，95%置信区间为0.21 - 0.78），因产程停滞而行剖宫产的可能性也较小（调整后的比值比为0.29，95%置信区间为0.10 - 0.82）。体重增加或减轻与因胎儿指征而行剖宫产无显著关联。
在有过经阴道分娩史的女性中，两次分娩间的体重增加与后续妊娠中产时剖宫产风险增加独立相关。
