Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University Hospital, Philadelphia, PA.
Department of Maternal and Child Health and Urological Sciences, Sapienza University of Rome, Italy.
Am J Obstet Gynecol. 2022 Apr;226(4):499-509. doi: 10.1016/j.ajog.2021.08.057. Epub 2021 Sep 4.
This study aimed to assess the efficacy of sonographic assessment of fetal occiput position before operative vaginal delivery to decrease the number of failed operative vaginal deliveries.
The search was conducted in MEDLINE, Embase, Web of Science, Scopus, ClinicalTrial.gov, Ovid, and Cochrane Library as electronic databases from the inception of each database to April 2021. No restrictions for language or geographic location were applied.
Selection criteria included randomized controlled trails of pregnant women randomized to either sonographic or clinical digital diagnosis of fetal occiput position during the second stage of labor before operative vaginal delivery.
The primary outcome was failed operative vaginal delivery, defined as a failed fetal operative vaginal delivery (vacuum or forceps) extraction requiring a cesarean delivery or forceps after failed vacuum. The summary measures were reported as relative risks or as mean differences with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I (Higgins I) >0% was used to identify heterogeneity.
A total of 4 randomized controlled trials including 1007 women with singleton, term, cephalic fetuses randomized to either the sonographic (n=484) or clinical digital (n=523) diagnosis of occiput position during the second stage of labor before operative vaginal delivery were included. Before operative vaginal delivery, fetal occiput position was diagnosed as anterior in 63.5% of the sonographic diagnosis group vs 69.5% in the clinical digital diagnosis group (P=.04). There was no significant difference in the rate of failed operative vaginal deliveries between the sonographic and clinical diagnosis of occiput position groups (9.9% vs 8.2%; relative risk, 1.14; 95% confidence interval, 0.77-1.68). Women randomized to sonographic diagnosis of occiput position had a significantly lower rate of occiput position discordance between the evaluation before operative vaginal delivery and the at birth evaluation when compared with those randomized to the clinical diagnosis group (2.3% vs 17.7%; relative risk, 0.16; 95% confidence interval, 0.04-0.74; P=.02). There were no significant differences in any of the other secondary obstetrical and perinatal outcomes assessed.
Sonographic knowledge of occiput position before operative vaginal delivery does not seem to have an effect on the incidence of failed operative vaginal deliveries despite better sonographic accuracy in the occiput position diagnosis when compared with clinical assessment. Future studies should evaluate how a more accurate sonographic diagnosis of occiput position or other parameters can lead to a safer and more effective operative vaginal delivery technique.
本研究旨在评估在经阴道分娩前对胎儿枕骨位置进行超声评估以降低经阴道分娩失败率的效果。
本研究检索了 MEDLINE、Embase、Web of Science、Scopus、ClinicalTrials.gov、Ovid 和 Cochrane Library 等电子数据库，检索时间从各数据库建立之初至 2021 年 4 月。未对语言或地理位置进行任何限制。
选择标准包括将孕妇随机分配到经阴道分娩前第二产程进行超声或临床数字诊断胎儿枕骨位置的随机对照试验。
主要结局为经阴道分娩失败，定义为胎儿经阴道分娩（真空或产钳）提取失败，需要剖宫产或真空提取失败后产钳。使用随机效应模型（DerSimonian 和 Laird）报告相对风险或均值差异，并报告 95%置信区间。使用 Higgins I 统计量（I（Higgins I）>0%）来确定异质性。
共有 4 项随机对照试验，包括 1007 名单胎、足月、头位胎儿，随机分为经阴道分娩前第二产程的超声（n=484）或临床数字（n=523）诊断枕骨位置，均纳入研究。在经阴道分娩前，超声诊断组枕骨位置为前位的比例为 63.5%，而临床数字诊断组为 69.5%（P=.04）。超声和临床诊断枕骨位置组的经阴道分娩失败率无显著差异（9.9% vs 8.2%；相对风险，1.14；95%置信区间，0.77-1.68）。与临床诊断组相比，随机分配到超声诊断枕骨位置的女性在经阴道分娩前和出生时评估的枕骨位置不一致的发生率显著降低（2.3% vs 17.7%；相对风险，0.16；95%置信区间，0.04-0.74；P=.02）。评估的其他次要产科和围产儿结局均无显著差异。
尽管与临床评估相比，超声在枕骨位置诊断方面具有更高的准确性，但在经阴道分娩前对枕骨位置进行超声知识评估似乎不会对经阴道分娩失败的发生率产生影响。未来的研究应评估更准确的超声诊断枕骨位置或其他参数如何能带来更安全、更有效的经阴道分娩技术。
