Normal pregnancy It is estimated that less than 1 mL of fetal blood is lost to the<unk>  circulation during normal labour in around 96% of normal deliveries. The loss of this small amount of blood may however be a sensitising event and stimulate antibody production to the foetal red blood cells, an example of which is Rhesus disease of the newborn. Abnormal pregnancy Causes of increased<unk>  are seen as a result of trauma, placental abruption or may be spontaneous with no cause found. Up to 30 mL of foetal-maternal transfusion may take place with no significant signs or symptoms seen in either mother or foetus. Loss in excess of this may result in significant morbidity and mortality to the fetus.<unk>  is one cause of intrauterine death (IUD).
Fetal-maternal haemorrhage
Placental disease
Fetal distress
Neonatal sepsis
Maternal death
Artificial rupture of membranes
Prelabor rupture of membranes
Fetal warfarin syndrome