Effect of pregestational diabetes mellitus on first trimester placental characteristics: Three-dimensional placental volume and power Doppler indices

ObjectiveTo investigate whether pregestational diabetes mellitus (DM) induces changes in vascular placental development detectable at first trimester.MethodsThis was a prospective case–control study in 69 women with pregestational DM and 94 controls undergoing first-trimester combined screening for aneuploidies. Maternal characteristics, fetal nuchal translucency thickness, maternal serum pregnancy-associated plasma protein A (PAPP-A) and free β human chorionic gonadotrophin (β-hCG) were evaluated. Three-dimensional ultrasound was used to measure placental volume and three dimensional power Doppler (3D-PD) placental vascular indices including: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). Pregnancy-associated hypertensive complications (PAHC) and perinatal outcomes were analyzed. The total group of diabetic women and the group of diabetic women without PAHC were compared separately with the control group.Results3D-PD placental vascular indexes were significantly lower in women with DM than in controls (VI p = 0.007, FI p = 0.003 and VFI p = 0.04). These differences remained on excluding cases with PAHC in the DM group. No differences were found in placental volumes between the DM group and controls. Serum PAPP-A levels were also lower in diabetic women (p < 0.02) and negatively correlated with the degree of maternal metabolic control at first trimester.ConclusionsPregestational DM induces demonstrable alterations in first trimester placental development, with significantly reduced placental vascularization indices and PAPP-A values. This effect is independent of the later development of PAHC.