Seyb S T, Berka R J, Socol M L, Dooley S L
Department of Obstetrics and Gynecology, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois, USA.
Obstet Gynecol. 1999 Oct;94(4):600-7. doi: 10.1016/s0029-7844(99)00377-4.
To quantify the risk of cesarean delivery associated with elective induction of labor in nulliparous women at term.
We performed a cohort study on a major urban obstetric service that serves predominantly private obstetric practices. All term, nulliparous women with vertex, singleton gestations who labored during an 8-month period (n = 1561) were divided into three groups: spontaneous labor, elective induction, and medical induction. The risk of cesarean delivery in the induction groups was determined using stepwise logistic regression to control for potential confounding factors.
Women experiencing spontaneous labor had a 7.8% cesarean delivery rate, whereas women undergoing elective labor induction had a 17.5% cesarean delivery rate (adjusted odds ratio [OR] 1.89; 95% confidence interval [CI] 1.12, 3.18) and women undergoing medically indicated labor induction had a 17.7% cesarean delivery rate (OR 1.69; 95% CI 1.13, 2.54). Other variables that remained significant risk factors for cesarean delivery in the model included: epidural placement at less than 4 cm dilatation (OR 4.66; 95% CI 2.25, 9.66), epidural placement after 4 cm dilatation (OR 2.18; 95% CI 1.06, 4.48), chorioamnionitis (OR 4.61; 95% CI 2.89, 7.35), birth weight greater than 4000 g (OR 2.59; 95% CI 1.69, 3.97), maternal body mass index greater than 26 kg/m2 (OR 2.36; 95% CI 1.61, 3.47), Asian race (OR 2.35; 95% CI 1.04, 5.34), and magnesium sulfate use (OR 2.18; 95% CI 1.04, 4.55).
Elective induction of labor is associated with a significantly increased risk of cesarean delivery in nulliparous women. Avoiding labor induction in settings of unproved benefit may aid efforts to reduce the primary cesarean delivery rate.
量化足月初产妇择期引产与剖宫产的风险。
我们在主要服务于私立产科诊所的一家大型城市产科机构进行了一项队列研究。在8个月期间分娩的所有足月、初产、单胎头位妊娠妇女（n = 1561）被分为三组：自然分娩、择期引产和医学指征引产。使用逐步逻辑回归来控制潜在混杂因素，以确定引产组剖宫产的风险。
自然分娩的妇女剖宫产率为7.8%，而择期引产的妇女剖宫产率为17.5%（调整优势比[OR] 1.89；95%置信区间[CI] 1.12，3.18），医学指征引产的妇女剖宫产率为17.7%（OR 1.69；95% CI 1.13，2.54）。模型中仍为剖宫产显著危险因素的其他变量包括：宫口扩张小于4 cm时放置硬膜外导管（OR 4.66；95% CI 2.25，9.66）、宫口扩张4 cm后放置硬膜外导管（OR 2.18；95% CI 1.06，4.48）、绒毛膜羊膜炎（OR 4.61；95% CI 2.89，7.35）、出生体重超过4000 g（OR 2.59；95% CI
