Pessary for preterm birth prevention in twin pregnancy with short cervix: 3-year follow-up study

OBJECTIVE: We recently found in a randomized clinical trial (ProTWIN) that cervical pessary prevented preterm birth and improved neonatal outcome in women with a multiple pregnancy and a cervical length (CL) <38mm. In this follow-up study we evaluated long-term developmental outcomes in the offspring of these women at three years corrected age. METHODS: We conducted a follow-up study of the ProTWIN trial, a trial in which between 2009 and 2012 asymptomatic women with a multiple pregnancy had been randomized to pessary or no pessary. Our current follow-up and analysis was limited to mothers with a midtrimester CL< 38mm (78 and 55 mothers, 157 and 111 children in the pessary and control group, respectively). At 3 years of corrected age, surviving children were invited for a Bayley Scales of Infant and Toddler Development-third edition (Bayley-III) assessment. We compared death after randomization or neurodevelopmental disability (Bayley score of ≤ 85, 1SD below mean) rates between pessary and controls according to intention-to-treat principle and using multiple imputation for missing data. We compared mean Bayley-III scores in surviving children. A linear mixed effects model was used to adjust for correlation between children of one mother. RESULTS: In total 27 children had died (6 pessary vs 21 control group, 5% versus 26%, adjusted odds ratio (aOR) 0.14; [95% CI 0.04 to 0.50]). Bayley-III outcomes were collected for 173 out of 241 (72%) surviving children (114 (75%) pessary vs 59 (66%) control group). The cumulative incidence of death or survival with a neurodevelopmental disability was 12 (10%) vs 23 (29%) in pessary and control group respectively; aOR 0.26 [95% CI 0.09 to 0.75]. We found neither statistical nor clinically relevant differences in cognitive, language and motor development among surviving children between both groups. Comparable results were found after multiple imputation. CONCLUSION: In women with a twin pregnancy and a CL < 38 mm, the use of cervical pessary strongly improved survival of the children without affecting neurodevelopmental disability at three years corrected age.