<unk>  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.<unk>  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.
Fetal-maternal haemorrhage
Placental disease
Fetal distress
Neonatal sepsis
Maternal death
Artificial rupture of membranes
Prelabor rupture of membranes
Fetal warfarin syndrome