Department of Health and Caring Sciences, Linnaeus University, Kalmar, Sweden.
Department of Obstetrics and Gynaecology, Lund University, Lund, Sweden.
PLoS One. 2023 Jan 30;18(1):e0281183. doi: 10.1371/journal.pone.0281183. eCollection 2023.
To investigate the mode of delivery and birth outcomes in relation to the duration of the passive second stage of labour in nulliparous women.
A retrospective cohort study of all nulliparous women (n = 1131) at two delivery units in Sweden. Maternal and obstetric data were obtained from electronic medical records during 2019. The passive second stage was defined as the complete dilation of the cervix until the start of the active second stage. The duration of the passive second stage was categorized into three groups: 0 to 119 min (0 to <2 h), 120-239 min (2- <4h) and ≥240 min (≥4h). Differences between the groups were examined using t-test and Chi2-tests and regression analyses were used to analyse adjusted odds ratio with 95% confidence intervals. The primary outcome was mode of delivery in relation to the duration of the passive second stage and the secondary outcomes covered a series of adverse maternal and neonatal birth outcomes. The rates of instrumental and caesarean deliveries increased as the duration of the passive second stage increased. A ≥4-hour duration of the passive second stage was associated with a nine-times increased risk of caesarean section, and a four-times risk of instrumental delivery compared to a duration of <2 hours in the adjusted analyses. No differences were found in the maternal birth outcomes. The risk of a 5-minute Apgar score <7 was increased in the 2-<4h group. A longer passive second stage was not associated with an increased risk of negative birth experience.
Our study demonstrates an increased risk of operative delivery for a longer duration (>2h) of the passive second stage in nulliparous women, although most of the women gave birth by spontaneous vaginal delivery even after ≥4 hours. There was no evidence of an increased risk of adverse maternal outcomes in a longer duration of the passive second stage but there were indications of increased adverse neonatal outcomes. Assessment of fetal well-being is important when the duration of the passive phase is prolonged.
研究初产妇第二产程中宫颈扩张停滞时间与分娩方式和分娩结局的关系。
这是一项在瑞典两家分娩中心进行的回顾性队列研究，共纳入 1131 名初产妇。研究数据来源于 2019 年的电子病历。第二产程分为活跃期和宫颈扩张停滞期，宫颈扩张停滞期是指宫口完全扩张至活跃期开始前的这段时间。将宫颈扩张停滞时间分为三组：0-119min（0-2h）、120-239min（2-4h）和≥240min（≥4h）。使用 t 检验和卡方检验比较组间差异，采用回归分析计算调整后的比值比及其 95%置信区间。主要结局为分娩方式与宫颈扩张停滞时间的关系，次要结局为一系列母婴不良分娩结局。随着宫颈扩张停滞时间的延长，器械助产和剖宫产的比例逐渐升高。与<2h 相比，≥4h 组剖宫产的风险增加 9 倍，器械助产的风险增加 4 倍。调整后分析中，宫颈扩张停滞时间与产妇分娩结局无显著相关性。2-<4h 组新生儿 5 分钟 Apgar 评分<7 的风险增加。第二产程时间延长与不良分娩体验风险增加无关。
本研究表明，初产妇第二产程宫颈扩张停滞时间延长（>2h）与剖宫产风险增加相关，但大多数产妇仍能经阴道自然分娩，即使宫颈扩张停滞时间≥4h。第二产程时间延长与产妇不良结局无显著相关性，但可能增加新生儿不良结局的风险。当第二产程时间延长时，应注意评估胎儿情况。
