Accumulation of infected erythrocytes in placental intervillous
spaces characterizes malaria during pregnancy (3).
Additional features that were noted on histology in the HIV-positive group included evidence of meconium exposure (n=10), focal infarct (n=1), focal decidual vasculopathy (n=1), dysmaturity (n=3), fetal thrombotic vasculopathy (n=1), chorangiosis (n=1), intervillous
thrombus (n=2) and intervillous
haemorrhage (n=3); and in the HIV-negative group, infarcts (n=2), decidual vasculopathy (n=1) and dysmaturity (n=2).
It has been hypothesised that thrombophilic disorders cause thrombosis of the utero-placental vasculature (spiral arteries and intervillous
space) due to an increased haemostatic response.
Maternal blood bathes the chorionic villi within the intervillous
space, delivering nutrients and oxygen, and removes nutrient-depleted blood via maternal veins.
The extracellular matrix of chorionic villi can be decreased, and the villous cores, thus, as pale as the intervillous
space (Figure 1, F).
Watson, "Maternal Arterial Connections to the Placental Intervillous
Space during the First Trimester of Human Pregnancy," American journal of Obstetrics and Gynecology 181 (1999) 718-24.
It has been suggested that the therapeutic antioxidant window might be between 8 and 10 weeks' gestation at the initiation of intervillous
The maternal side was perfused by introducing three blunt metal cannulas into the intervillous
space by penetration of the decidual plate.
Maternal blood in the intervillous
space allows gaseous and nutrient exchange.
3 (or17) [beta]-HSD activity: In normal placenta the syncytial cytoplasm of chorionic villi showed intense HSD activity whereas the cytotrophoblasts, villous mesenchyme and cells in the intervillous
spaces were devoid of the oxidoreductase activity (Fig.
Normal placental development depends on proper trophoblast invasion, vascular remodeling, and maintenance of intervillous
blood flow (2).
No histologic evidence of intervillous
inflammation, infarcted areas, or chorioamnionitis was observed in the placenta of women with loiasis, and no microfilariae were observed in any examined cord blood samples.