The outcome of 72 pregnancies in 55 women with cystic fibrosis in the United Kingdom 1977-1996.

OBJECTIVE

To identify pregnancies in women with cystic fibrosis and describe obstetric, infant and maternal medical outcomes in relation to the severity of maternal disease.

DESIGN

Retrospective study, based on casenotes.

SETTING

Eleven cystic fibrosis centres in the United Kingdom.

POPULATION

Pregnant women with cystic fibrosis.

METHODS

Single observer medical and obstetric casenote review categorising maternal cystic fibrosis (e.g. genotype, pancreatic, hepatic and diabetic status) and pre-pregnant severity (e.g. weight and lung function) and noting fetal outcome and maternal morbidity.

MAIN OUTCOME MEASURES

Completed pregnancies and pregnancy losses, fetal outcome and complications, maternal morbidity, such as changes in weight, lung function, pulmonary infections during and after pregnancy. Relation of outcomes to severity of maternal cystic fibrosis.

RESULTS

From 72 pregnancies identified, the outcomes were known for 69; there were 48 live births (70%) of which 22 were premature (46%); 14 therapeutic abortions (20%); and 7 miscarriages (10%). There were no stillbirths, neonatal or early maternal deaths. Three major fetal anomalies were seen, but no infant had cystic fibrosis. At the conclusion of our study three pregnancies were still continuing. Prematurity with increased fetal complications and maternal morbidity with infection, declining lung function and poor weight gain were associated with poor pre-partum lung function.

CONCLUSION

Pregnancy occurs in women with cystic fibrosis of all degrees of severity. Outcomes for the infant are generally good but are variable for the mother. Predicting outcome on the basis of maternal severity is difficult but lung function appears to be the most significant determining factor. Pregnancy may be normal in women with normal lung function (forced expiratory volume > 80%). However, it may adversely affect mild and moderate lung disease due to cystic fibrosis and should be avoided in pulmonary hypertension, cor pulmonale and when forced expiratory volume < 50% predicted. Ideally, all pregnancies should be planned with prior counselling and monitored by dedicated cystic fibrosis teams, including obstetricians who are experienced in managing high risk pregnancies.