Departments of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama, Northwestern University, Chicago, Illinois, University of Utah Health Sciences Center, Salt Lake City, Utah, Stanford University, Stanford, California, Columbia University, New York, New York, Brown University, Providence, Rhode Island, University of Texas Medical Branch, Galveston, Texas, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, University of Texas Health Science Center at Houston-Children's Memorial Hermann Hospital, Houston, Texas, The Ohio State University, Columbus, Ohio, Metro Health Medical Center-Case Western Reserve University, Cleveland, Ohio, University of Texas Southwestern Medical Center, Dallas, Texas; University of Pennsylvania, Philadelphia, Pennsylvania, Duke University, Durham, North Carolina, University of Pittsburgh, Pittsburgh, Pennsylvania, Washington University in St. Louis, St. Louis, Missouri; 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. 2021 Feb 1;137(2):250-257. doi: 10.1097/AOG.0000000000004230.
To compare risks of maternal and perinatal outcomes by completed week of gestation from 39 weeks in low-risk nulliparous patients undergoing expectant management.
We conducted a secondary analysis of a multicenter randomized trial of elective induction of labor at 39 weeks of gestation compared with expectant management in low-risk nulliparous patients. Participants with nonanomalous neonates, who were randomized to and underwent expectant management and attained 39 0/7 weeks of gestation, were included. Delivery gestation was categorized by completed week: 39 0/7-39 6/7 (39 weeks), 40 0/7-40 6/7 (40 weeks), and 41 0/7-42 2/7 (41-42 weeks) (none delivered after 42 2/7). The coprimary outcomes were cesarean delivery and a perinatal composite (death, respiratory support, 5-minute Apgar score 3 or less, hypoxic ischemic encephalopathy, seizure, sepsis, meconium aspiration syndrome, birth trauma, intracranial or subgaleal hemorrhage, or hypotension requiring vasopressor support). Other outcomes included a maternal composite (blood transfusion, surgical intervention for postpartum hemorrhage, or intensive care unit admission), hypertensive disorders of pregnancy, peripartum infection, and neonatal intermediate or intensive care unit admission. For multivariable analysis, P<.0125 was considered to indicate statistical significance for the coprimary outcomes.
Of 2,502 participants who underwent expectant management, 964 (38.5%) delivered at 39 weeks of gestation, 1,111 (44.4%) at 40 weeks, and 427 (17.1%) at 41-42 weeks. The prevalence of medically indicated delivery was 37.9% overall and increased from 23.8% at 39 weeks of gestation to 80.3% at 41-42 weeks. The frequency of cesarean delivery (17.3%, 22.0%, 37.5%; P<.001) and the perinatal composite (5.1%, 5.9%, 8.2%; P=.03) increased with 39, 40, and 41-42 weeks of gestation, respectively, and hypertensive disorders of pregnancy decreased (16.4%, 12.1%, 10.8%, P=.001). The adjusted relative risk, 95% CI (39 weeks as referent) was significant for cesarean delivery at 41-42 weeks of gestation (1.93, 1.61-2.32) and for hypertensive disorders of pregnancy at 40 weeks (0.71, 0.58-0.88) and 41-42 weeks (0.61, 0.45-0.82). None of the other outcomes were significant.
In expectantly managed low-risk nulliparous participants, the frequency of medically indicated induction of labor, and the risks of cesarean delivery but not the perinatal composite outcome, increased significantly from 39 to 42 weeks of gestation.
比较低危初产妇期待管理时妊娠 39 周完成周数的母婴围产结局风险。
我们对一项多中心随机试验进行了二次分析，该试验比较了 39 孕周时选择性引产与低危初产妇的期待管理。纳入了随机分配并接受期待管理且达到 39 0/7 孕周的具有正常新生儿的参与者。分娩孕周按完成周分类：39 0/7-39 6/7（39 周）、40 0/7-40 6/7（40 周）和 41 0/7-42 2/7（41-42 周）（无 42 2/7 周后分娩）。主要复合结局为剖宫产分娩和围产儿复合结局（死亡、呼吸支持、5 分钟 Apgar 评分 3 分或更低、缺氧缺血性脑病、癫痫发作、脓毒症、胎粪吸入综合征、分娩创伤、颅内或骨膜下出血或需要血管加压支持的低血压）。其他结局包括产妇复合结局（输血、产后出血的手术干预或入住重症监护病房）、妊娠高血压疾病、围产期感染和新生儿中或重症监护病房入住。对于多变量分析，P<.0125 被认为是主要复合结局的统计学显著水平。
在接受期待管理的 2502 名参与者中，964 名（38.5%）在 39 孕周分娩，1111 名（44.4%）在 40 孕周，427 名（17.1%）在 41-42 孕周。总体上有医学指征分娩的发生率为 37.9%，从 39 孕周的 23.8%增加到 41-42 孕周的 80.3%。剖宫产分娩的频率（17.3%、22.0%、37.5%；P<.001）和围产儿复合结局（5.1%、5.9%、8.2%；P=.03）分别随 39、40 和 41-42 孕周而增加，妊娠高血压疾病减少（16.4%、12.1%、10.8%；P=.001）。调整后的相对风险（39 孕周为参照），95%CI（41-42 孕周）在剖宫产分娩方面具有统计学意义（1.93，1.61-2.32），在 40 孕周和 41-42 孕周时妊娠高血压疾病方面具有统计学意义（0.71，0.58-0.88 和 0.61，0.45-0.82）。其他结局均无统计学意义。
在期待管理的低危初产妇中，有医学指征引产的频率以及剖宫产分娩的风险，但不是围产儿复合结局的风险，从 39 孕周显著增加到 42 孕周。
