Elective Induction of Labor and Pregnancy Outcomes

描述(由调查人员提供)：背景和目标：在美国，每年有多达49万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。这是否会对女性或胎儿造成风险尚不清楚。最近只有一项临床试验研究了胎儿怀孕41周前的选择性引产，结果发现与继续妊娠(期待治疗)相比，结果没有差异。观察性研究发现，引产后更多的是剖腹产，但大多数人将引产与相同胎龄的自然分娩进行比较，这并不是真正的临床替代方案。相反，应该将选择性诱导与真正的替代方案、期待管理相提并论。大多数研究规模太小，无法研究不常见但重要的结果，也没有研究母亲的种族/民族或肥胖是否会导致风险不同。我们的目标是比较妊娠38周、39周或40周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：将在两个综合卫生保健系统中对2001年至2011年出生的婴儿进行多阶段回顾研究。在第一阶段，符合资格的人口(206,000名独生子女)将 根据电子健康计划和出生证明数据，根据其明显的诱因和结局状况进行识别和分类。在第二阶段，我们将进行8000次简短的病历审查，以确定真实的暴露状态(选择性诱导与预期管理)。在第三阶段，我们将深入审查3500条记录，以了解真实的结果状态和风险因素。第二和第三阶段将过度抽样有选择性引产或罕见结局的妇女，以提高我们针对这些特定目标的能力：目标1：比较选择性引产后38、39或40周妊娠与围产期处理下列结果的风险：剖腹产、产后出血、绒毛膜羊膜炎、新生儿重症监护病房住院时间、肩部难产、低阿普加评分、死产及新生儿死亡；目标2：研究母亲种族/族裔、产次及孕前肥胖等因素对风险的影响。二次分析将开发一种算法，从电子数据中更准确地识别选择性诱因。影响：这项研究将对妊娠38周、39周或40周的选择性引产与孕期管理进行比较，以提供关于其对母亲和胎儿的风险或好处的新信息。我们的结果可以帮助女性和提供者一起做出更明智的选择，从而立即影响临床实践。它们还将为实践指导方针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.