The placental vascular component in early and late intrauterine fetal death

To compare the placental histopathological findings between pregnancies complicated by early (<34 weeks' gestation) and late (≥ 34 weeks' gestation) intrauterine fetal death (IUFD) and pregnancies with live births.

Placentas of patients with unexplained IUFD between 22-42 weeks of gestation were analyzed for maternal vascular supply lesions that include those related to maternal underperfusion (villous changes and vascular lesions), fetal vascular supply lesions that include findings consistent with fetal thrombo-occlusive disease (villous changes and vascular lesions) and maternal and fetal inflammatory response lesions. The clinical characteristics and placental findings were compared with those from live birth controls adjusted for gestational age.

In the early IUFD group (n=28), compared to controls with early delivery, a higher rate of vascular lesions consistent with fetal thrombo-occlusive disease (28.6% vs. 0, p=0.002), villous changes consistent with fetal thrombo-occlusive disease (21.4 vs. 3.6%, p=0.043), and cord related lesions (46.4% vs. 0, p<0.001), respectively, were observed. A similar high rate of maternal vascular supply lesions was detected in both groups. In the late IUFD group (n=30), compared to controls, a higher rate of cord related lesions, 40% vs. 0, respectively, p<0.001, were found. In contrast, maternal and fetal inflammatory response lesions were more common in controls than in placentas from early and late IUFD.

The involvement of placental fetal vascular supply lesions is more extensive in early IUFD than in late IUFD, when compared with matched controls.