Can we predict gestational diabetes mellitus according to risk factors in the previous pregnancy?

Objective
Gestational diabetes mellitus (GDM) constitutes a greater impact on diabetes epidemic. We aimed to identify risk factors in the first pregnancy for developing GDM in the subsequent pregnancy.

Study Design
A nested case control study was conducted in a large tertiary hospital. Study population included all women with two singleton consecutive deliveries, who were not diagnosed with GDM in their first pregnancy. Cases were defined as women with GDM in the second pregnancy, and controls were defined as women with no GDM in both pregnancies. Characteristics and complications of the first pregnancy were compared between cases and controls, including: preeclampsia, perinatal death, placental abruption, post- partum hemorrhage, obesity and macrosomia. A multivariable logistic regression model was used to study the association between pregnancy complications in the first pregnancy and GDM in the subsequent pregnancy, while adjusting for maternal age and inter- pregnancy interval.

Results
A total of 38,750 women were included in the study. 1.9 % (n=728) of women had GDM in their second pregnancy (i.e., cases). The following first pregnancy complications were associated with GDM in the subsequent pregnancy (Table): preeclampsia, perinatal death, maternal obesity or fetal macrosomia. Results were similar in the multivariable model (Table). Women exposed to more than one complication (adjusted OR=5.38; 95%CI 2.85-10.17) were at an increased risk as compared to only one complication (adjusted OR=2.33; 95%CI 1.93-2.82) or no complications (reference; Figure).

Conclusion
First pregnancy complications, including preeclampsia, perinatal death, maternal obesity or fetal macrosomia, are associated with an increased risk for GDM in the subsequent pregnancy. Women with these complications may require an early screening for GDM in their subsequent pregnancy.