Fine Structure of the Human Placenta in Prolonged Pregnancy Preliminary Report

Abstract

Placentas from 15 prolonged ( > 42 weeks), but otherwise normal pregnancies, and 8 normal-term placentas were studied. Placental villi from term placentas revealed intact syncytial and cytotrophoblast elements. All term placentas presented a minimal to mild degree of villous necrosis and deposition of fibrinoid material. Placental villi from cases of prolonged pregnancy presented a moderate to severe degree of necrosis in 11 of 15 placentas and a minimal to mild degree in 4 of 15 placentas. A moderate to severe degree of fibrinoid deposition was noted in 7 of 15 placentas whilst 8 of 15 revealed a minimal to mild degree of deposition. The presence or absence of meconium was noted in the prolonged-pregnancy group and correlated with the above morphological features. Statistically, a correlation was found between prolonged pregnancy and necrosis (p < 0.001), prolonged pregnancy and fibrinoid deposition (p < 0.03) and between necrosis and deposition of fibrinoid (p < 0.05). There was no correlation between the incidence of meconium staining and the above parameters.

A morphometric and histological study of placental malaria shows significant changes to villous architecture in both Plasmodium falciparum and Plasmodium vivax infection

“…The images were scanned at a resolution of 1,600 × 1,200 pixels using Olympus DP-20 BSW software (Version 2.2) and stored. Only the intermediate zone of the placenta was used and areas where villi could not be distinguished, with placental infarction, intervillous fibrin deposition, or arterial vessels forming the primary stem and intermediate villi were avoided, as these can distort the observed villous size [ 7 , 13 ]. Only terminal villi showing outlines completely within the microscopic field were counted.…”

“…Both the age and parity of the mother have been shown to affect villous numbers and vascularity. For instance, the volume density of capillaries in terminal villi was shown to be significantly lower in older women in comparison to the placenta in younger mothers [ 7 ]. In idiopathic IUGR, the number of capillaries in the terminal villi and the villous area was significantly decreased compared with controls appropriate for gestational age group [ 10 , 11 ].…”

Fetal deaths in the United States, 1997 vs 1991

“…In the absence of severe maternal/fetal disorders or complications such as heart disease, diabetes, hypertension, congenital anomalies, placenta previa, and premature rupture of membrane, postterm perinatal deaths (fetai death + neonatal deaths) remain two-to threefold as high as perinatal deaths at term (Lucas et al, 1965). In fact, pathologic studies have revealed an increased incidence of placental histologic abnormalities such as placental infarcts, calcification, intervillous thrombosis, perivillous fibrin deposits, arterial thrombosis, and arterial endarteritis in postterm pregnancies (Vorherr H, 1975;Thliveris and Baskett, 1978). This has usually been attributed to 'placental insufficiency.'…”

Postdate pregnancy Part I. A literature review

“…Thliveris and Baskett 77 examined placentas from 25 prolonged (>42 weeks) well‐dated pregnancies, and eight normal term pregnancies. They concluded that there was an increase in the incidence of syncytial degenerations and fibrinoid deposition in the prolonged pregnancy.…”