Aims To assess the extent to which the increased risk of congenital abnormalities seen in women with pre-gestational insulin-treated diabetes mellitus is unspecific or related to the embryology of specific organs.
Methods Cases with congenital abnormalities were identified in the population-based Hungarian Congenital Abnormality Registry from 1980 to 1996 with two newborn children without congenital abnormality selected from the National Birth Registry as controls. We adjusted for parity, maternal age, and use of antipsychotic drugs.
Results Among cases we found 63/22 843 babies with maternal diabetes compared with 50/38 151 in the control group [adjusted prevalence odds ratio (POR) 2.1; 95% CI 1.5–3.1]. The association was strongest for the following congenital abnormalities: renal agenesis (POR: 14.8; 95% CI, 3.5–62.1), obstructive congenital abnormalities of the urinary tract (POR: 4.3; 95% CI, 1.3–13.9), cardiovascular congenital abnormalities (POR: 3.4; 95% CI, 2.0–5.7), and multiple congenital abnormalities (POR: 5.0; 95% CI, 2.4–10.2).
Conclusions These data indicate that pre-gestational maternal diabetes is associated with strong teratogenic effects on the kidney, urinary tract, and heart, and strongly associated with multiple congenital abnormalities. We found no material association between diabetes and spinal congenital abnormalities and limb deficiencies.