Placental dysfunction in congenital heart disease: Insights from anatomical pathology

Abstract

Women with congenital heart disease are at increased risk of obstetric and fetal complications during pregnancy. Placental dysfunction seems to emerge among the different etiological hypotheses. However, studies supporting this pathway are scarce, especially histopathological studies. The objectives of this study were to describe the placental lesions observed in pregnant women with CHD and to compare these findings with placentas from a control group of healthy women. In this single-center prospective study, we reported the results of 69 histopathological analyses (43 placentas from CHD and 26 from healthy women). Pathological findings were classified according to the Amsterdam Placental Workshop Group Consensus. In the control group, patients with comorbidities or risk factors for pre-eclampsia or fetal growth restriction were excluded. Patients were matched for age and BMI. Median gestational age at delivery was 38 [36–38.5] weeks for CHD group vs. 39.4 [38.5–40] weeks for control group ( P < 0.001). Pathologies were identified in 84% of CHD placentas vs. 42% of healthy placentas ( P < 0.001). Among the CHD group, there was 49% of anatomic pathologies, the main one being low placental weight for gestational age (95%). There was also 46% of vascular, 16% of infectious and 9% of inflammatory pathologies. The rate of small placentas for gestational age was significantly higher in the CHD group (46% vs. 15%, P = 0.009). As vascular pathologies, maternal vascular malperfusion (MVM) was significantly more frequent in CHD placentas (28% vs. 8%, P = 0.043). There was no significant difference between groups for infectious, inflammatory and other lesions: choriomanionitis, chorangiosis and villitis ( Fig. 1 ). Pregnant women with CHD had significantly more placental histopathologic abnormalities than healthy women. The most common placental pathologies were anatomic and vascular abnormalities. Small placenta for gestational age and MVM were significantly more present in CHD placentas. These results support the hypothesis of placental dysfunction in CHD women.