Placental maternal and fetal vascular circulation in healthy non-obese and metabolically healthy obese pregnant women.

Background And Aims: We investigated placental histopathology for lesions that are associated with maternal and fetal circulation abnormalities in obese pregnant women with and without metabolic alterations.

Methods: 332 pregnant women were divided into three groups: Group 1 included 163 non-obese metabolically healthy (NOMH), Group 2 106 obese metabolically healthy (OMH), and Group 3 63 obese metabolically abnormal (OMA) subjects, respectively.

Results: Fetal vascular supply (FVS) abnormalities and Willous maturation defect (WMD) rate were higher in obese subjects without metabolic abnormalities, compared to NOMH subjects (p < 0.021 and p < 0.018, respectively). In the logistic regression analysis, obesity emerged as a significant independent predictor of FVS abnormalities (OR 1.54, 95% CI 1.193-1.992, p = 0.001) and WMD (OR 2.004, 95% CI 1.173-3.422, p = 0.011). Although maternal vascular supply (MVS) abnormalities differed significantly across groups (31%, 38% and 54% respectively, p < 0.005), in the logistic regression analysis, obesity was not significantly associated with MVS abnormalities.

Conclusions: We demonstrated that obesity, per se, is associated with an increased rate of placental vascular supply abnormalities and has a more adverse effect on fetal vascular circulation than on maternal vascular supply.