Placental fetal vascular malperfusion in maternal diabetes mellitus.

Objectives: To study the clinical and placental correlations in diabetic pregnancies in which placental histopathology included routine double E cadherin/CD34 immunostaining.

Methods: Retrospective study of 229 cases of diabetic pregnancies, mostly with gestational diabetes mellitus. The cases were individually matched for gestational age at delivery with non-diabetic pregnancies to yield a comparative group of 229 cases. 23 independent clinical and 50 placental phenotypes (variables) were statistically compared by analysis of variance or Chi-square with application of the Bonferroni correction for multiple comparisons.

Results: The study group showed statistically significantly more common gestational hypertension, chronic hypertension, polyhydramnios, umbilical cord compromise, cesarean sections, macerated stillbirths, neonatal deaths, and fetal malformations. About a third of cases in each group showed lesions of maternal and fetal vascular malperfusion (FVM), the latter more common than reported in literature. The CD34 component of the double immunostaining increased the sensitivity of placental examination by highlighting clustered endothelial fragmentation of recent fetal vascular malperfusion or increasing the grade of fetal vascular malperfusion (on-going distal villous fetal vascular malperfusion with temporal heterogeneity).

Conclusions: With the double immunostaining, FVM is as common as maternal vascular malperfusion pattern of placental injury in diabetic pregnancies with high prevalence of fetal congenital malformations. This is likely due to umbilical cord compression evoked by mass-forming fetal anomalies. Recognizing placental FVM may sensitize to the increased risk of neonatal systemic thrombotic pathology. However, several hypoxic lesions and patterns as well as those of shallow placental implantation were also seen with increased frequencies in diabetic pregnancies.