Elective Induction of Labor and Pregnancy Outcomes

描述（由研究者提供）：背景和目标：在美国，每年有多达490，000名孕妇接受选择性引产，这是一种在没有医学原因的情况下进行分娩的干预措施。这是否会对妇女或胎儿造成风险尚不清楚。只有一项最近的临床试验研究了在胎儿妊娠41周之前选择性引产，结果与让妊娠继续（期待管理）相比没有差异。观察性研究发现，引产后剖宫产率更高，但大多数将引产与相同胎龄的自然分娩进行比较，这不是真正的临床选择。相反，选择性诱导应与真正的替代方案，期待管理。大多数研究规模太小，无法研究不常见但重要的结果，也没有研究风险是否因母亲的种族/民族或肥胖而不同。我们的目标是比较妊娠38、39或40周时选择性引产与期待治疗的结果，以帮助孕妇及其提供者做出更明智的决定。方法：2001年至2011年的出生多阶段回顾性研究将在两个综合卫生保健系统进行。在第一阶段，符合条件的人口（206，000名单胞胎）将 根据电子健康计划和出生证明数据，根据其明显的诱导和结局状态进行识别和分类。在第2阶段，我们将对8000份病历进行简要审查，以确定真实的暴露状态（选择性诱导与期待治疗）。在第3阶段，我们将深入审查3500份记录，以了解真实的结局状态和风险因素。第2阶段和第3阶段将对择期引产或罕见结局的妇女进行过采样，提高我们解决这些特定目标的能力：目标1：比较妊娠38、39或40周时择期引产与期待治疗后以下结局的风险：剖宫产、产后出血、绒毛膜炎、新生儿重症监护室停留、肩难产、低Apgar评分、死产，和新生儿死亡;目标2：检查风险如何因母亲的种族/民族、产次和孕前肥胖而变化。次要分析将开发一种算法，以更准确地从电子数据中识别择期诱导。影响：本研究将比较妊娠38、39或40周的选择性引产与期待治疗，以提供有关其对母亲和胎儿的风险或益处的新信息。我们的研究结果可以立即影响临床实践，帮助妇女和提供者一起做出更明智的选择。它们还将为实践准则和政策制定提供坚实的基础。

DESCRIPTION (provided by investigator): Background and goals: Each year in the US, up to 490,000 pregnant women undergo elective induction, an intervention to bring on labor without a medical reason. Whether this causes risks to the woman or fetus is unclear. Only one recent clinical trial studied elective induction before 41 weeks of fetal gestation, and it found no difference in outcomes compared to letting the pregnancy continue (expectant management). Observational studies have found more cesarean delivery after induction, but most compared induction to spontaneous labor at the same gestational age, which is not the genuine clinical alternative. Instead, elective induction should be compared to the true alternative, expectant management. Most studies were too small to study uncommon but important outcomes, and none looked at whether risks differ by the mother's race/ethnicity or obesity. Our goal is to compare outcomes for elective induction at 38, 39 or 40 weeks' gestation versus expectant management, to help pregnant women and their providers make more informed decisions. Methods: A multiphase retrospective study of births from 2001 to 2011 will be conducted in two integrated health care systems. In Phase 1, the eligible population (206,000 singleton births) will be identified and classified by their apparent induction and outcome status based on electronic health plan and birth certificate data. In Phase 2, we will conduct 8000 brief medical record reviews to determine true exposure status (elective induction vs. expectant management). In Phase 3, we will review 3500 records in depth for true outcome status and risk factors. Phases 2 and 3 will oversample women with elective induction or rare outcomes, improving our power to address these specific aims: Aim 1: Compare the risk of the following outcomes after elective induction at 38, 39 or 40 weeks' gestation versus expectant management: cesarean delivery, postpartum hemorrhage, chorioamnionitis, neonatal intensive care unit stay, shoulder dystocia, low Apgar score, stillbirth, and neonatal death; and Aim 2: Examine how risks vary by the mother's race/ethnicity, parity, and pre-pregnancy obesity. Secondary analyses will develop an algorithm to more accurately identify elective inductions from electronic data. Impact: This research will compare elective labor induction at 38, 39 or 40 weeks' gestation to expectant management to provide new information about its risks or benefits for the mother and fetus. Our results could immediately affect clinical practice by helping women and providers make more informed choices together. They will also provide a solid foundation for practice guidelines and policy making.