Obesity or diabetes: what is worse for the mother and for the baby?

OBJECTIVES: The aim of the present study is to evaluate pregnancy outcomes in a cohort of Caucasian pregnant women in relation to their body mass index and glucose tolerance status; the role of central fat distribution, as indicated by waist-to-hip circumference ratio, was also considered.
METHODS: Seven hundred women were studied; they had gestational diabetes or impaired glucose tolerance (250) or normoglycaemia (450). Among them 117 had pre-pregnancy overweight/obesity (44 were obese), 133 hyperglycaemia, but normal weight, and 117 hyperglycaemia and overweight/obesity (42 were obese).
RESULTS: Hypertension, cesarean delivery and prevalence of large-for-gestational age babies were higher in obese (both with normoglycaemia and hyperglycaemia), mainly in those with greater gestational weight gain and central fat distribution (waist-to-hip ratio > 0.90). Normal weight hyperglycaemic women showed better outcomes than obese normoglycaemic women did. In a multiple logistic regression model, obesity (OR=10.6; 95% CI 5.00-22.54) was directly related to hypertension, and independent predictors of cesarean section were: gestational hyperglycaemia (OR=1.78; 95% CI 1.21-2.62), gestational weight gain (OR=1.06; 95% CI 1.02-1.10), and central obesity (OR=1.51; 95% CI 1.02-2.24), while obesity (OR=4.48; 95% CI 2.30-8.71) gestational weight gain (OR=1.08; 95% CI 1.03-1.12) and central fat distribution (OR=1.81: 95% CI 1.12-2.93) were directly related to delivering larger babies, after multiple adjustments.
CONCLUSION: These results suggest that pre-pregnancy obesity and gestational hyperglycaemia were independent risk factors for different adverse pregnancy and neonatal outcomes, while central distribution of fat, and gestational weight gain play an additive adverse role on these outcomes.