Battarbee Ashley N, Glover Angelica V, Stamilio David M
Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of North Carolina School of Medicine and University of North Carolina Health Care, Chapel Hill, North Carolina, USA.
Aust N Z J Obstet Gynaecol. 2020 Feb;60(1):108-114. doi: 10.1111/ajo.13031. Epub 2019 Jul 10.
Amniotomy is a commonly used, inexpensive method of labour induction; however, the optimal timing of amniotomy during labour induction is debated.
To investigate whether artificial rupture of membranes <4 cm dilation is associated with caesarean, severe maternal and neonatal morbidity, and labour induction duration.
Retrospective cohort study of 228 438 deliveries at 19 US hospitals. Women with a viable, singleton gestation undergoing induction ≥37 weeks with cervical dilation <4 cm were included. Women were excluded if membranes spontaneously ruptured <4 cm. Women were compared by early amniotomy (<4 cm dilation) versus not early. The primary outcome was caesarean. Secondary outcomes included severe maternal and neonatal morbidity, and labour duration. Logistic and Cox proportional hazard regression estimated the association between early amniotomy and study outcomes.
Of 15 525 eligible women, 10 421 (67%) had early amniotomy. Early amniotomy was associated with higher adjusted odds of caesarean and severe maternal morbidity, but not neonatal morbidity. After accounting for interaction, early amniotomy was associated with increasingly higher odds of caesarean as body mass index increased. Early amniotomy was associated with lower odds of severe maternal morbidity among multiparas with mechanical ripening. Median labour induction was 2.5 h shorter with early amniotomy, significant in hazard regression.
Early amniotomy was associated with increased odds of caesarean among obese women. The association between early amniotomy and severe maternal morbidity varied by maternal characteristics, but early amniotomy was not associated with neonatal morbidity. Early amniotomy in labour induction may be advantageous in certain populations, particularly non-obese women requiring mechanical ripening.
人工破膜是一种常用的、成本低廉的引产方法；然而，引产过程中人工破膜的最佳时机仍存在争议。
探讨宫颈扩张<4cm时人工破膜是否与剖宫产、严重母婴并发症及引产时间相关。
对美国19家医院的228438例分娩进行回顾性队列研究。纳入妊娠≥37周、单胎、宫颈扩张<4cm且进行引产的孕妇。若胎膜在宫颈扩张<4cm时自然破裂，则排除该孕妇。将孕妇分为早期人工破膜组（宫颈扩张<4cm）和非早期人工破膜组进行比较。主要结局为剖宫产。次要结局包括严重母婴并发症及产程。采用逻辑回归和Cox比例风险回归评估早期人工破膜与研究结局之间的关联。
在15525例符合条件的孕妇中，10421例（67%）进行了早期人工破膜。早期人工破膜与剖宫产及严重母体并发症的校正比值增加相关，但与新生儿并发症无关。在考虑交互作用后，随着体重指数的增加，早期人工破膜与剖宫产的比值增加幅度越来越大。早期人工破膜与机械性宫颈成熟的经产妇严重母体并发症的比值降低相关。早期人工破膜组引产中位时间短2.5小时，在风险回归中具有显著性。
早期人工破膜与肥胖女性剖宫产几率增加相关。早期人工破膜与严重母体并发症之间的关联因母体特征而异，但与新生儿并发症无关。引产时早期人工破膜在某些人群中可能具有优势，特别是需要机械性宫颈成熟的非肥胖女性。
