Clinical Epidemiology Division, Department of Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Health Sciences, Faculty of Medicine, Lund University, Lund, Sweden.
School of Nursing and Midwifery, Western Sydney University, Sydney, NSW, Australia.
Lancet. 2022 Mar 26;399(10331):1242-1253. doi: 10.1016/S0140-6736(22)00188-X. Epub 2022 Mar 15.
Severe perineal trauma (SPT) affecting the anal sphincter muscle complex is a serious complication following childbirth, associated with short-term and long-term maternal morbidity. Effective preventive strategies are still scarce. The aim of the Oneplus trial was to test the hypothesis that the presence of a second midwife during the second stage of labour, with the purpose of preventing SPT, would result in fewer injuries affecting the anal sphincter than if attended by one midwife.
In this multicentre, randomised, controlled parallel group, unmasked trial done at five obstetric units in Sweden, women were randomly assigned to be assisted by either one or two midwives in late second stage. Nulliparous women and women planning the first vaginal birth after caesarean section who were age 18-47 years were randomly assigned to an intervention when reaching the second stage of labour. Further inclusion criteria were gestational week 37+0, carrying a singleton live fetus in vertex presentation, and proficiency in either Swedish, English, Arabic, or Farsi. Exclusion criteria were a multiple pregnancy, intrauterine fetal demise, a planned caesarean section, or women who were less than 37 weeks pregnant. Randomisation to the intervention group of two midwives or standard care group of one midwife (1:1) was done using a computer-based program and treatment groups were allocated by use of sealed opaque envelopes. All women and midwives were aware of the group assignment, but the statistician from Clinical Studies Forum South, who did the analyses, was masked to group assignment. Midwives were instructed to implement existing prevention models and the second midwife was to assist on instruction of the primary midwife, when asked. Midwives were also instructed to complete case report forms detailing assistance techniques and perineal trauma prevention techniques. The primary outcome was the proportion of women who had SPT, for which odds ratios (ORs) and 95% CIs were calculated, and logistic regression was done to adjust for study site. All analyses were done according to intention to treat. The trial is registered with ClinicalTrials.gov, NCT0377096.
Between Dec 10, 2018, and March 21, 2020, 8866 women were assessed for eligibility, and 4264 met the inclusion criteria and agreed to participate. 3776 (88·5%) of 4264 women were randomly assigned to an intervention after reaching the second stage of labour. 1892 women were assigned to collegial assistance (two midwives) during the second stage of labour and 1884 women were assigned to standard care (one midwife). 13 women in each group did not meet the inclusion criteria and were excluded. After further exclusions, 1546 women spontaneously gave birth in the intervention group and 1513 in the standard care group. 1546 women in the intervention group and 1513 in the standard care group were included in the intention-to-treat analysis of the primary outcome. There was a significant reduction in SPT in the intervention group (3·9% [61 of 1546] vs 5·7% [86 of 1513]; adjusted OR 0·69 (0·49-0·97).
The presence of two midwives during the active second stage can reduce SPT in women giving birth for the first time.
The Swedish Research Council for Health, Working Life and Welfare; Jan Hains Research Foundation; and Skane County Council's Research and Development Foundation.
严重的会阴创伤（SPT）影响肛门括约肌复合体，是分娩后严重的并发症，与短期和长期产妇发病率有关。有效的预防策略仍然很少。Oneplus 试验的目的是检验这样一个假设，即在第二产程中增加一名助产士，目的是预防 SPT，与由一名助产士接生相比，会导致更少的肛门括约肌损伤。
在瑞典五家产科单位进行的这项多中心、随机、对照平行组、非盲试验中，妇女在第二产程中随机分配由一名或两名助产士协助。初产妇和计划经剖宫产分娩后的第一次阴道分娩的妇女，年龄在 18-47 岁之间，当达到第二产程时随机分配到干预组。进一步的纳入标准是妊娠周 37+0，携带头位单胎活胎，以及熟练掌握瑞典语、英语、阿拉伯语或波斯语。排除标准是多胎妊娠、宫内胎儿死亡、计划剖宫产或妊娠不足 37 周的妇女。干预组（两名助产士）和标准护理组（一名助产士）（1:1）的随机分组使用基于计算机的程序进行，通过使用密封的不透明信封分配治疗组。所有妇女和助产士都知道分组情况，但负责进行分析的临床研究论坛南部的统计学家对分组情况不知情。助产士被指示实施现有的预防模式，当被初级助产士要求时，第二名助产士应根据指令协助。助产士还被指示填写详细说明协助技术和会阴创伤预防技术的病例报告表。主要结局是发生 SPT 的妇女比例，计算了比值比（OR）和 95%置信区间，并进行了 logistic 回归以调整研究地点。所有分析均根据意向治疗进行。该试验在 ClinicalTrials.gov 注册，编号为 NCT0377096。
在 2018 年 12 月 10 日至 2020 年 3 月 21 日期间，对 8866 名妇女进行了资格评估，4264 名符合纳入标准并同意参加。4264 名妇女中，3776 名（88.5%）在达到第二产程后随机分配到干预组。1892 名妇女在第二产程中接受协同协助（两名助产士），1884 名妇女接受标准护理（一名助产士）。每组各有 13 名妇女不符合纳入标准并被排除在外。进一步排除后，1546 名妇女在干预组自然分娩，1513 名妇女在标准护理组自然分娩。1546 名干预组和 1513 名标准护理组妇女被纳入主要结局的意向治疗分析。干预组 SPT 发生率显著降低（3.9%[61/1546]vs 5.7%[86/1513]；调整后的 OR 0.69[0.49-0.97]）。
在初产妇的活跃第二产程中增加两名助产士可以减少 SPT。
瑞典研究委员会、健康、工作生活和福利；Jan Hains 研究基金会；以及斯科讷省议会的研究与发展基金会。
