Antepartum bleeding, also known as antepartum haemorrhage (APH) or prepartum hemorrhage, is genital bleeding during pregnancy after the 28th week of pregnancy up to delivery.It can be associated with reduced fetal birth weight. Use of aspirin before 16 weeks of pregnancy to prevent pre-eclampsia also appears effective at preventing antepartum bleeding.In regard to treatment, it should be considered a medical emergency (regardless of whether there is pain), as if it is left untreated it can lead to death of the mother or baby. Classification
The total amount of blood loss and signs of circulatory shock due to blood determine the severity of the antepartum haemorrhaging. There are 4 degrees of antepartum haemorrhaging:

Causes
Placenta praevia
Placenta praevia refers to when the placenta of a growing foetus is attached abnormally low within the uterus. Intermittent antepartum haemorrhaging occurs in 72% of women living with placenta praevia. The severity of a patients placenta praevia depends on the location of placental attachment;

Types 1 and 2 are classified as minor placental praevia as these typically result in minor antepartum haemorrhaging. Types 3 and 4 are referred to as major placental praevia due to the risk of heavy haemorrhaging in the case of a rupture due to the location of placental attachment. During the third trimester of pregnancy, thinning of the lower uterine segment or contractions caused by cervical dilation can increase the amount of stress placed on the placental attachment to the uterine wall. In patients with placenta praevia, these stresses can cause detachment of the placenta from the uterine wall causing haemorrhaging.
If the foetus is developed enough caesarean sections are often recommended. Abnormal placental shape
Circumvallate placentaA circumvallate placenta refers to when the foetal membrane wraps twice around, over the foetal side around the edge of the placenta. This is to compensate for an undersized chorionic plate resulting in a decreased nutritional supply to the foetus. Thickening of the placental edge due to a circumvallate placenta can lead to placental abruption, causing antepartum haemorrhaging. Bilobed PlacentaA bilobed placenta has a cleavage in the middle dividing it into two lobes with membranous vessels branching in between. The exposed connecting membranous vessels present risk of rupturing due to limited protection from thrombosis and trauma. Bilobing of the placenta can be caused by placental implantation occurring over areas of uterine fibroid scarring, previous surgery, decreased blood supply or implantation occurring over the internal cervical orifice. Chances of vasa previa and placental abruption increase in the presence of a bilobed placenta due to decreased surface area for attachment to the uterine wall and the exposure of membranous vessels. Multilobed or Succenturiate PlacentaWhen a placenta has multiple lobes which are distal and not of equal size this is referred to as a succenturiate placenta. Distal lobes are connected by a placental artery and vein extending from the main placenta, which tends to be centrally located and is the largest in mass. At the time of contraction or delivery the connecting placental arteries and veins may rupture resulting in significant haemorrhaging.