Department of Obstetrics and Gynaecology, The Coombe Women and Infants' University Hospital, Dublin, Ireland.
Departments of Epidemiology and Public Health Medicine and Obstetrics and Gynaecology, Royal College of Surgeons, Ireland.
Eur J Obstet Gynecol Reprod Biol. 2022 Jul;274:142-147. doi: 10.1016/j.ejogrb.2022.05.010. Epub 2022 May 20.
The objective of this study was to: 1. Establish the median gestational age of spontaneous labour for low-risk nulliparas. 2. Examine the variation in mode of delivery and short-term neonatal outcomes with gestation at onset of spontaneous labour.
This is a retrospective observational cohort study conducted at a tertiary obstetric unit. The study population was 12, 323 low risk nulliparous women with singleton pregnancies who experienced spontaneous onset of labour. The study period was over seven years, from Jan 1st 2011 to 31st Dec 2017. Exclusion criteria were multiparity, multi-fetal pregnancy, booking after 14 weeks gestation, antepartum or intrapartum death, or any obstetric or fetal indication for delivery with the exception of post-maturity. Gestation of onset of spontaneous labour, demographic variables and maternal and neonatal outcomes were collected. The primary outcome was median gestational age at onset of spontaneous labour and its distribution at term. Secondary outcomes were mode of delivery and neonatal outcomes including low-apgar score and NICU admission.
12, 323 patients were eligible for inclusion. Median gestation for onset of labour was 40.1 weeks gestation, with 80.5% of spontaneous labour occurs by 41 + 0 weeks gestation. The risk of assisted delivery (RR 1.32, 95% CI 1.23 - 1.42), caesarean section (RR 2.17, 95% CI 1.88-2.51) and low-apgar scores (RR 3.13 95% CI 1.50-6.55) increased significantly with spontaneous labour after 41 weeks' gestation.
Nulliparous women with low-risk pregnancies are most likely to experience spontaneous labour between 40 + 0 and 40 + 6. 80.5% of spontaneous labour occurred by 41 + 0 weeks gestation. Assisted vaginal delivery, caesarean section and low-apgar scores were significantly more likely with spontaneous labour after 41 weeks' gestation.
本研究旨在：1. 确定低危初产妇自发性分娩的中位孕龄。2. 研究自发分娩起始时的分娩方式和短期新生儿结局随孕周的变化。
这是一项在三级产科单位进行的回顾性观察性队列研究。研究人群为 12323 名经历自发性分娩起始的低危初产妇，单胎妊娠。研究期间为 2011 年 1 月 1 日至 2017 年 12 月 31 日，共 7 年以上。排除标准为多胎妊娠、多胎妊娠、14 周后建档、产前或产时死亡、或除过期妊娠外任何产科或胎儿分娩指征。收集自发性分娩起始的孕周、人口统计学变量及母婴新生儿结局。主要结局为自发性分娩起始的中位孕龄及其在足月时的分布。次要结局为分娩方式和新生儿结局，包括低 Apgar 评分和新生儿重症监护病房（NICU）入住。
共有 12323 名患者符合纳入标准。分娩起始的中位孕周为 40.1 周，80.5%的自发性分娩发生在 41+0 周。辅助分娩（RR 1.32，95%CI 1.23-1.42）、剖宫产（RR 2.17，95%CI 1.88-2.51）和低 Apgar 评分（RR 3.13，95%CI 1.50-6.55）的风险随着 41 周后自发性分娩而显著增加。
低危妊娠的初产妇最有可能在 40+0 至 40+6 周之间经历自发性分娩。80.5%的自发性分娩发生在 41+0 周。41 周后自发性分娩时，辅助阴道分娩、剖宫产和低 Apgar 评分的可能性显著增加。
