To assess the effect of gestational age (GA) and cervical length (CL) measurements at transvaginal ultrasound (TVUS) in the prediction of preterm birth in twin pregnancy.Individual patient data (IPD) meta-analysis.International multicentre study.Asymptomatic twin pregnancy.MEDLINE and EMBASE searches were performed and IPD obtained from authors of relevant studies. Multinomial logistic regression analysis determined probabilities for birth at ?28(+0) , 28(+1) to 32(+0) , 32(+1) to 36(+0) , and ?36(+1) weeks as a function of GA at screening and CL measurements.Predicted probabilities for preterm birth at ?28(+0) , 28(+1) to 32(+0) , and 32(+1) to 36(+0) .A total of 6188 CL measurements were performed on 4409 twin pregnancies in 12 studies. Both GA at screening and CL had a significant and non-linear effect on GA at birth. The best prediction of birth at ?28(+0) weeks was provided by screening at ?18(+0) weeks (P <0.001), whereas the best prediction of birth between 28(+1) and 36(+0) weeks was provided by screening at ?24(+0) weeks (P <0.001). Negative prediction value of 100% for birth at ?28(+0) weeks is achieved at CL 65 mm and 43 mm at ultrasound GA at ?18(+0) weeks and at 22(+1) to 24(+0) weeks, respectively.In twin pregnancies, prediction of preterm birth depends on both CL and the GA at screening. When CL is 22(+0) weeks is most predictive of delivery at 28(+1) to 36(+0) weeks. In twins, we recommend CL screening in twins to commence from ?18(+0) weeks.An individual patient meta-analysis assessing gestation and CL in the prediction of preterm birth in twins.? 2015 Royal College of Obstetricians and Gynaecologists.
- Cervical length
- individual patient meta-analysis
- preterm birth
- twin pregnancy