Pregnant women with cystic fibrosis (CF) are more likely to develop diabetes and deliver prematurely by cesarean than other women, a retrospective study reports. They are also more likely to have babies with birth anomalies, although not necessarily life-altering ones.
The study, “Maternal co-morbidities and neonatal outcomes associated with cystic fibrosis,” was published in the Journal of Maternal-Fetal & Neonatal Medicine and based on an analysis of single births among more than two million pregnant women in California between 2005–08. As such, it is one of the few large-scale studies of pregnancy and CF, and it may be of aid in counseling patients who decide to have children.
Current therapy for CF has improved longevity and gives women the opportunity to conceive and have successful pregnancies. But due to their chronic lung disease, these women are also at higher risk of serious complications during pregnancy and delivery. Specific genetic mutations associated with CF also appear to increase the risk for diabetes in pregnancy.
Of the 2,178,954 women identified at 20 weeks or more of gestation and followed, 77 also had CF. The low prevalence of CF in pregnancy, researchers said, likely reflects that women with CF are only recently surviving to childbearing age and remaining healthy enough to conceive.
Compared to pregnant women without CF, those with the disease were found to have a higher risk of hypertension (4.6% versus 3.2%), gestational diabetes (4.6% versus 0.7%), and to deliver before 37 weeks of gestation (18.2% versus 8.9%). Importantly, researchers found that their babies’ survival rate was normal, and these infants “were not at increased risk for significant neonatal morbidity or mortality when adjusted for gestational age.” Still, premature babies of CF mothers had significantly increased rates of jaundice (24.2% of babies to mothers with CF versus 15.3% to mothers without CF).
The premature delivery may be explained by the mother’s poorer pulmonary function or malnutrition. The health status of the mother may also contribute to a tendency toward reduced fetal growth, a condition known as intrauterine growth restriction (IUGR). “[F]urther exploration of the potential etiology of fetal anomalies in women with CF might examine the impact of malnutrition or diabetes that many individuals with CF experience,” the researchers wrote.
Because of the relatively few pregnancies in women with CF (more are case studies), this study is one of the few analyzing a large number of pregnant women. As such, researchers suggest that its findings could help to counsel women with CF who are considering having children. Specifically, they recommended that these women would profit from early diabetic screening and genetic counseling, and that they should undergo fetal ultrasonography because of the higher rate of anomalies seen in babies born to these mothers.