Background: Diabetes mellitus (DM) is a major risk factor for complications of pregnancy. Based on information for all inpatient births in Germany, we assessed the risks for selected pregnancy complications in women with pregestational diabetes mellitus (preDM) or gestational diabetes mellitus (GDM).
Methods: The underlying data comprised all singleton births contained in the inpatient perinatal medicine quality assurance statistics for the years 2013-2019. The frequencies of premature birth, elevated birth weight (large for gestational age, LGA), cesarean section, transfer of the newborn to the perinatal unit, and stillbirth were stratified by maternal age and diabetes status (preDM, GDM, no DM). Poisson regression was used to calculate the relative risks (RR) with 95% confidence intervals (95% CI) for the whole period and for each individual year in women with preDM or GDM relative to women without DM.
Results: Among the 4 991 275 singleton births included, GDM was documented in 283 210 (5.7%) and preDM in 46 605 (0.93%) cases. GDM was associated with higher RR for premature birth (1.13 [1.12; 1.15]), LGA (1.57 [1.55; 1.58]), cesarean section (1.26 [1.25; 1.27]), and transfer of the newborn (1.54 [1.52; 1.55]). These associations were even stronger in women with preDM: premature birth (2.13 [2.08; 2.18]), LGA (2.72 [2.67; 2.77]), cesarean section (1.62 [1.60; 1.64]), transfer of the newborn (2.61 [2.56; 2.66]). PreDM increased the risk of stillbirth (RR: 2.34 [2.11; 2.59]); GDM was associated with a lower risk (RR: 0.67 [0.62; 0.72]). For women with preDM, the risk of pregnancy complications increased over the study period.
Conclusion: GDM and preDM are still associated with elevated risks of pregnancy complications. In the case of preDM, the risks may be attributable to the fact that the hyperglycemia is more severe and is already present before conception. Continuous monitoring should include risk factors in pregnant women and care-relevant aspects.