Progesterone for prevention of preterm birth in women with short cervical length: 2‐year infant outcomes

ABSTRACT Objective To evaluate the long‐term outcomes of children born to women with a short cervix and otherwise low risk for preterm birth, after antenatal exposure to vaginal progesterone vs placebo. Methods This was a follow‐up study of the Triple P trial, which randomized 80 low‐risk women with a short cervix (≤ 30 mm) at 18–22 weeks' gestation to progesterone (n = 41) or placebo (n = 39). At 2 years of corrected age, children were invited for a neurodevelopmental assessment, using the Bayley Scales of Infant and Toddler Development, third edition (BSID‐III), and a neurological and physical examination by an assessor blinded to the allocated treatment. Parents filled out the Ages and Stages Questionnaire, the Child Behavior Checklist (CBCL) and a general‐health questionnaire. The main outcome of interest was mean BSID‐III cognitive and motor scores. Additionally, a composite score of mortality and abnormal developmental outcome, including BSID‐III ≤–1 SD, CBCL score in the clinical range and/or parental reported physical problems (at least two operations or at least two hospital admissions in the previous 2 years), was evaluated. Our sample size, dictated by the original sample of the Triple P trial, provided 80% power to detect a mean difference (MD) of 15 points (1 SD) between groups for the BSID‐III tests. Results Of the 80 children born to the randomized women, one in the progesterone group and two in the placebo group died in the neonatal period. Follow‐up data were obtained for 59/77 (77%) children and BSID‐III outcomes in 57 children (n = 28 in the progesterone group and n = 29 in the placebo group) born at a median gestational age of 38 + 6 weeks (interquartile range (IQR), 37 + 3 to 40 + 1 weeks) with a median birth weight of 3240 g (IQR, 2785–3620 g). In the progesterone vs placebo groups, mean BSID‐III cognitive development scores were 101.6 vs 105.0 (MD, –3.4 (95% CI, –9.3 to 2.6); P = 0.29) while mean motor scores were 102.4 vs 107.3 (MD, –4.9 (95% CI, –11.2 to 1.4); P = 0.13). No differences were seen between the two groups in physical (including genital and neurological examination), behavioral and health‐related outcomes. Conclusion In this sample of children born to low‐risk women with a short cervix at screening, no relevant differences in neurodevelopmental, behavioral, health‐related and physical outcomes were found between offspring exposed to vaginal progesterone and those exposed to placebo. © 2020 The Authors. Ultrasound in Obs