861: Preventing Preterm Birth with Progesterone in Women with Short Cervical Length, Outcomes in Children at 24 Months of Age

To evaluate the effects of antenatal progesterone on long-term neurodevelopmental and physical outcomes in offspring from women with a short cervix but otherwise from low-risk population. We approached children born from 80 women randomised to progesterone (n=41) or placebo (n=39) at 2 years corrected age for a Bayley- Scales of Infant and Toddler Development-third edition (Bayley-III) assessment and a neurological and physical examination. Mothers with singleton pregnancies had been identified from a screening program through a cervix ≤30mm but were otherwise without risk factors. Outcomes were assessed double-blinded. Mean cognitive and motor-developmental scores were compared after adjustment for potential confounders in linear regression analysis. Our sample size was dictated by the original sample of the Triple P trial and gave us 95% power to detect a mean difference of 15 points, 1SD from the mean, in the Bayley scales. Of the 77 surviving children in the Triple P trial, 59 children (77%) were reached for follow-up and 57 (74%, n=28 progesterone, vs n=29 placebo) Bayley-III outcomes were collected. Adjusted mean differences in cognitive and motor scores were -3.2 [95%CI -9.2 to 2.8] and -4.9 [95%CI -11.3 to 1.4]. Minor congenital malformations were seen in 8 (30%) and 2 (11%) children in the progesterone and placebo group respectively, RR 4.0 [95% CI 0.9 to 17.1]. No differences in physical, genital and neurological examination were seen between both groups. In this sample of low risk women with a short cervix no differences in neurodevelopmental outcome were found in the offspring at 2 years corrected age between those exposed to progesterone in second and third trimester and those exposed to placebo. The difference in (minor) congenital abnormalities should be further explored.