Multinucleated foreign body giant cells in placental membrane.

We report the pathologic finding of a multinucleated foreign body giant cell reaction to squames and fetal hair in the placental membranes in a 37-week 1-day intrauterine gestation. This reaction appeared to have developed in association with repeated intrauterine procedures performed in the third trimester, including cordocentesis for fetal blood sampling, intrauterine blood transfusion, and amnioreduction for polyhydramnios. This type of reaction most likely was directed to prolonged amniotic fluid leakage that occurred spontaneously or after intrauterine procedures in the second half of the second trimester and the third trimester. Careful examination of the placental membranes and recognition of the foreign body giant cell reaction may provide etiologic insight in cases of unexplained oligohydramnios.