Cotyledonary-like placenta associated with severe intrauterine growth restriction.

There have been no previous reports of human placentas mimicking the cotyledonary placenta of ruminants. We report a case of cotyledonary-like placenta associated with severe intrauterine growth restriction. A woman pregnant for the first time was referred to our hospital at 27 weeks' gestation because of severe intrauterine growth restriction. Characteristics of the placenta in the patient were examined by ultrasonographical and histopathological techniques. Ultrasonography revealed that a hypo-echoic area intermingled with small segmented tissues in the placenta. The hypo-echoic area changed in size and shape according to uterine contractions. At 31 weeks' gestation, a caesarean section was performed because of non-reassuring fetal status. A female baby weighing 814 g was delivered. The placenta, which weighed 260 g, contained several long stem villi running over a distance of 6 to 7 cm without branching into intermediate or terminal villi. Small villous tissues had developed only at the tips of these stem villi. The present case shows an extraordinarily abnormal development of the villous trees in the placenta, which may have caused fetal IUGR and non-reassuring fetal status.