Placental changes and obstetric outcomes among women with diabetes mellitus in pregnancy in Kano, Nigeria: a case control study

BACKGROUND: Diabetes mellitus may induce recognizable changes in the placenta and may lead to adverse obstetric outcomes. Placental examination may identify these changes. AIM: To compare ultrasonographic and histo-morphological changes in the placentae of diabetic with normo-glycaemic women, as well as determine and compare the obstetric outcomes of the women. METHODS: This was a case-control study of 65 pregnant diabetic women matched with 65 non-diabetic pregnant women from 34 weeks to 40 weeks' gestation. All the participants had ultrasound scanning (USS) for placenta changes done within the last seven days of delivery and histo-morphological placental examination postpartum. Obstetric outcomes and relationship between ultrasonographic and histo-morpholgical changes were also determined. RESULTS: The diabetics compared to non-diabetic had significantly higher mean ultrasonographic placental weight (610.0 ± 81.54 versus 513.2 ± 74.25, p < 0.001), volume (1001.5 ± 359.80 versus 721.7 ± 186.16, p < 0.001), diameter (14.6 ± 2.20 versus 13.7 ± 2.08, p = 0.015), central thickness (4.8 ± 1.18 versus 4.2 ± 1.34, p = 0.015), umbilical cord coiling index (0.6 ± 0.23 versus 0.3 ± 0.13, p < 0.001), vascularisation index (0.6 ± 0.09 versus 0.5 ± 0.08, p < 0.001), flow index (1.0 ± 0.30 versus 0.8 ± 0.20, p < 0.001) and vascularisation-flow (2.6 ± 0.61 versus 2.1 ± 0.38, p < 0.001) index. Histomorphology showed diabetics had significantly higher placental weight (764.9 ± 159.26 versus 570.0 ± 92.73, p < 0.001), volume (737.7 ± 179.85 versus 536.9 ± 83.00, p < 0.001), diameter (19.6 ± 1.75 versus 18.3 ± 2.05, p < 0.001), central thickness (2.9 ± 0.65 versus 2.4 ± 0.58, p < 0.001), villous immaturity, villous edema, chorangiosis, fibrinoid necrosis and stromal fibrosis. The diabetics were also significantly more associated with caesarean deliveries, fetal macrosomia, still births, poor first minute Apgar score, hypoglycaemia at birth, respiratory distress syndrome and SCBU admissions compared to non-diabetics. In both diabetics and non-diabetics, there was a significant relationship between the placental weight (P = 0.002), volume (P = < 0.001), diameter (P = 0.02) and calcifications (P = < 0.001) compared with the actual histomorphological assessment. CONCLUSION: Placental changes and adverse obstetric outcomes occurred more significantly in the diabetic group. Some of the histo-morphological and ultrasonographic changes were relatable. Sonographic placental examination can, therefore, be useful in the management of diabetes in pregnancy.