Department of Obstetrics and Gynecology, My Duc Hospital, Ho Chi Minh City, Viet Nam
HOPE Research Center, Ho Chi Minh City, Viet Nam.
BMJ Open. 2020 Jun 16;10(6):e036587. doi: 10.1136/bmjopen-2019-036587.
Women with twin pregnancies and a short cervix are at increased risk for preterm birth (PTB). Given the burden of prematurity and its attendant risks, the quest for effective interventions in twins has been an area of considerable research. Studies investigating the effectiveness of cervical cerclage, cervical pessary and vaginal progesterone in preventing PTB have yielded conflicting results. The aim of this study is to compare the effectiveness of cervical pessary and cervical cerclage with or without vaginal progesterone to prevent PTB in women with twin pregnancies and a cervical length (CL) ≤ 28 mm.
This multicentre, randomised clinical trial will be conducted at My Duc Hospital and My Duc Phu Nhuan Hospital, Vietnam. Asymptomatic women with twin pregnancies and a CL ≤28 mm, measured at 16-22 weeks' gestation, will be randomised in a 1:1:1:1 ratio to receive a cerclage, pessary, cerclage plus progesterone or pessary plus progesterone. Primary outcome will be PTB <34 weeks. Secondary outcomes will be maternal and neonatal complications. We preplanned a subgroup analysis according to CL from all women after randomisation and divided into four quartiles. Analysis will be conducted on an intention-to-treat basis. The rate of PTB <34 weeks' gestation in women with twin pregnancies and a cervix ≤28 mm and treated with pessary in our previous study at My Duc Hospital was 24.2%. A sample size of 340 women will be required to show or refute that cervical cerclage decreases the rate of PTB <34 weeks by 50% compared with pessary (from 24.2% to 12.1%, α level 0.05, power 80%, 5% lost to follow-up and protocol deviation). This study is not to be powered to assess interactions between interventions.
Ethical approval was obtained from the Institutional Ethics Committee of My Duc Hospital and informed patient consent was obtained before study enrolment. Results of the study will be submitted for publication in a peer-reviewed journal.
NCT03863613 (date of registration: 4 March 2019).
怀双胞胎且宫颈较短的女性早产（PTB）的风险增加。鉴于早产的负担及其伴随的风险，在双胞胎中寻找有效的干预措施一直是一个相当大的研究领域。研究调查了宫颈环扎术、宫颈托和阴道孕酮在预防 PTB 中的有效性，结果相互矛盾。本研究的目的是比较宫颈托和宫颈环扎术联合或不联合阴道孕酮预防宫颈长度（CL）≤28mm 的双胎妊娠妇女 PTB 的效果。
这项多中心、随机临床试验将在越南的美都医院和美都福缘医院进行。在 16-22 周妊娠时，对无症状的双胎妊娠且 CL≤28mm 的孕妇进行随机分组，1：1：1：1 比例分别接受环扎术、宫颈托、环扎术加孕酮或宫颈托加孕酮治疗。主要结局是 34 周前早产（PTB）。次要结局为母婴并发症。我们根据所有随机分组后的女性的 CL 预先计划了亚组分析，并将其分为四等分。分析将基于意向治疗进行。在我们之前在美都医院进行的研究中，接受宫颈托治疗的宫颈长度≤28mm 的双胎妊娠妇女的 34 周前早产率为 24.2%。为了显示或反驳与宫颈托相比，宫颈环扎术将 34 周前早产率降低 50%（从 24.2%降至 12.1%），需要 340 名妇女的样本量，α 水平为 0.05，效能为 80%，5%失访和方案偏离。本研究没有能力评估干预措施之间的相互作用。
美都医院机构伦理委员会已批准该研究，并且在研究入组前获得了患者的知情同意。研究结果将提交给同行评议的期刊发表。
NCT03863613（注册日期：2019 年 3 月 4 日）。
