Hardin DS et al. (2005) The metabolic effects of pregnancy in cystic fibrosis. Obstet Gynecol 106: 367–375

The number of pregnancies per year reported in women with cystic fibrosis (CF) is on the increase. Studies have shown that insulin secretion decreases in CF patients, but this has not been previously investigated in pregnant women with CF. Hardin et al. therefore set out to investigate the metabolic effects of pregnancy in CF patients.

The authors recruited eight pregnant women with CF and compared them with two matched control groups—one consisting of nine pregnant women and the other consisting of eight non-pregnant CF women. Metabolic tests, such as the oral glucose tolerance test, hyperinsulinemic euglycemic clamp and hepatic glucose production were carried out on all participants.

During the second trimester, seven of the eight pregnant women with CF developed gestational diabetes mellitus. Insulin secretion was lower, protein catabolism and hepatic glucose production were higher in the CF pregnant group compared with the pregnant control group. Total weight gain throughout pregnancy was lower in women with CF compared with the control group.

Pregnant women with CF are at an increased risk of gestational diabetes mellitus, probably because of insulin resistance and abnormal substrate metabolism. The authors, therefore, recommend that pregnant women with CF be screened using the oral glucose tolerance test throughout pregnancy and also obtain nutritional guidance, in particular, to increase their calorie and protein intake.