Fetal-maternal haemorrhage is the loss of fetal blood cells into the maternal circulation. It takes place in normal pregnancies as well as when there are obstetric or trauma related complications to pregnancy.
Normally the maternal circulation and the fetal circulation are kept from direct contact with each other, with gas and nutrient exchange taking place across a membrane in the placenta made of two layers, the syncytiotrophoblast and the cytotrophoblast. Foetal-maternal haemorrhage occurs when this membrane ceases to function as a barrier and fetal cells may come in contact with and enter the maternal vessels in the decidua/endometrium.
Other articles related to "haemorrhage":
... If ongoing and rapid haemorrhage is occurring then immediate delivery of the foetus may be indicated if the foetus is sufficiently developed ... If the haemorrhage has already occurred and now stopped, an inutero transfusion of red cells to the foetus may be recommended ...