The outcome of pregnancy in women with cystic fibrosis: a UK population-based descriptive study

Objective To estimate the incidence of cystic fibrosis in pregnancy and to explore obstetric and neonatal outcomes. Design A population-based descriptive study using the methodology of the UK Obstetric Surveillance System (UKOSS). Setting All consultant-led maternity units in the UK. Population All pregnant women with a diagnosis of cystic fibrosis who booked for antenatal care in a UK obstetric unit between March 2015 and February 2017. Methods Prospective case collection identified using UKOSS monthly notification. Main outcome measures Incidence, maternal morbidity, maternal mortality, gestation at delivery, neonatal mortality, neonatal morbidity. Results We report 71 pregnancies over a 2-year period. There was one early miscarriage, four terminations and three sets of twins, resulting in the live birth of 69 infants. There were no maternal deaths. One infant died following spontaneous preterm birth at 29 weeks' gestation. The mean gestation at delivery was 36.2 completed weeks. The mean birthweight centile for gestational age was the 61st centile. We report a positive correlation between both maternal lung function (FEV1) and mean gestation at delivery, and between FEV(1)and mean birthweight centile for gestational age. Conclusions Pregnancy outcomes are generally good in women with cystic fibrosis. Successful pregnancy is possible even in those women with FEV1<60% predicted, although such women have higher chance of preterm delivery and a smaller baby. Tweetable abstract Pregnant women with cystic fibrosis who have poorer lung function at the beginning of pregnancy have a higher risk of having a premature or smaller baby.