Aims: To ascertain the incidence and to review the obstetric and neonatal correlates of placental haemosiderosis. Secondly, to determine if placental haemosiderosis is due to blood contamination during placental handling.
Methods: One hundred consecutive singleton placentas with and 113 consecutive singleton placentas from uncomplicated pregnancies without an indication for pathological examination were stained for iron to detect haemosiderosis in the membranes, chorionic plate and/or basal plate. The obstetric and neonatal data were analysed. In the second part, maternal retroplacental blood was placed on the chorionic plates of 15 placentas for 1, 3, 4 and 5 days prior to sampling and examination for iron deposition.
Results: Haemosiderosis was observed in 110 of 213 (51.6%) placentas. Early decelerations during fetal heart rate monitoring (p = 0.0498) and, negatively, maternal thrombophilia (p = 0.0496) were related to haemosiderosis in the placenta. Preterm delivery, chronic separation of the placenta or procedures performed during pregnancy or delivery were not significantly related to haemosiderosis. Different patterns of iron staining were observed but these were not correlated with any maternal or neonatal factors. In the experimental study, haemosiderin was not found in sections taken at various time intervals from both blood contaminated and blood contamination-free parts of the placentas.
Conclusions: Haemosiderosis in the placenta is not an artefact of placental handling. Haemosiderosis is seen considerably more frequently than previously reported and may be physiological. Haemosiderosis is not a useful indicator for chronic placental abruption and adverse neonatal outcome is not significantly correlated with placental haemosiderosis.