Hughes Kelly Margaret, Aberoumand Mason, Seidler Anna Lene, Swan Phoebe, Aboulghar Mona, de Lourdes Brizot Maria, Brock Clifton, Benito Vielba Marta, Fox Nathan, Gyamfi-Bannerman Cynthia, Kindinger Lindsay, Pagani Giorgio, Perales Marin Alfredo, Seravalli Viola, Di Tommaso Mariarosaria, Weitzner Omer, Worda Katharina, Staub Lukas, Brennecke Shaun, Thangaratinam Shakila, Mol Ben W, Wang Rui
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.
NHMRC Clinical Trial Centre, University of Sydney, Sydney, New South Wales, Australia.
BMJ Med. 2025 Apr 16;4(1):e000877. doi: 10.1136/bmjmed-2024-000877. eCollection 2025 Jan.
To quantify the prognostic value of mid-trimester cervical length for spontaneous preterm birth in asymptomatic women with twin pregnancy and to assess whether other factors may modify any association.
A two stage meta-analysis of individual participant data in a Cox proportional hazard model was performed using cervical length as a continuous variable.
Medline, Embase, Cochrane, and LILACS, among others, were searched to identify eligible studies; the search was from 1 January 2000 to 30 September 2020. Risk of bias was assessed with the QUIPS tool. Studies were from eight countries between 2001 and 2018.
Individual participant data were sought for eligible studies that reported mid-trimester (defined between 16 and 26 weeks) transvaginal sonographic cervical length and also gestational age at birth in asymptomatic women with twin pregnancy. The primary outcome was spontaneous preterm birth before 37 weeks.
Among 29 eligible studies, authors of 17 studies provided individual participant data for 6437 women with a twin pregnancy (69.1% of individual participant data). Mean cervical length measurement was 39 mm (SD=9, range 1-74 mm). 2889 women (44.9%) delivered before 37 weeks' gestation, and 934 (14.9%) delivered before 34 weeks. Each 1 mm increase in cervical length was associated with a 4.0% reduction in the rate of spontaneous preterm birth before 37 weeks (hazard ratio 0.96 (95% confidence interval 0.95 to 0.97)), and a 6.8% reduction in the rate of spontaneous preterm birth before 34 weeks' gestation (0.93 (0.92 to 0.95)). The prognostic value remained stable in models adjusting for different sets of variables.
The prognostic value of cervical length for spontaneous preterm birth in twin pregnancy is on a continuous scale. No specific cervical length has been identified that can reliably predict or exclude all spontaneous preterm births.
CRD42020146987.
量化孕中期宫颈长度对无症状双胎妊娠妇女自然早产的预后价值，并评估其他因素是否会改变这种关联。
在Cox比例风险模型中对个体参与者数据进行两阶段荟萃分析，将宫颈长度作为连续变量。
检索了Medline、Embase、Cochrane和LILACS等数据库以识别符合条件的研究；检索时间为2000年1月1日至2020年9月30日。使用QUIPS工具评估偏倚风险。研究来自2001年至2018年间的8个国家。
寻求符合条件的研究的个体参与者数据，这些研究报告了无症状双胎妊娠妇女孕中期（定义为16至26周）经阴道超声测量的宫颈长度以及出生时的孕周。主要结局是37周前的自然早产。
在29项符合条件的研究中，17项研究的作者提供了6437例双胎妊娠妇女的个体参与者数据（占个体参与者数据的69.1%）。宫颈长度的平均测量值为39毫米（标准差=9，范围1-74毫米）。2889名妇女（44.9%）在妊娠37周前分娩，934名（14.9%）在34周前分娩。宫颈长度每增加1毫米，37周前自然早产率降低4.0%（风险比0.96（95%置信区间0.95至0.97）），34周妊娠前自然早产率降低6.8%（0.93（0.92至0.95））。在调整不同变量集的模型中，预后价值保持稳定。
宫颈长度对双胎妊娠自然早产的预后价值呈连续变化。尚未确定能可靠预测或排除所有自然早产的特定宫颈长度。
CRD42020146987。
