How serious a placental abruption is, will be determined by the size of the blood clot and if the bleeding continues. Sometimes small clots can be observed on ultrasound, but they do not significantly affect the health of the woman, or the baby. The pregnancy can still progress normally, and there are no complications.
If the clot is very large and/or the bleeding continues, the woman and baby are at risk and an emergency Caesarean is often the only alternative. The main health concerns of a placental abruption include:
Labour starting. If the baby is not due yet, then the labour may start prematurely. With a placental abruption, the labour can sometimes be excessively fast and intense (called hypercontractility). The uterus contracts too often (every minute or so), not giving the baby enough rest in between. Hypercontractility causes the labour to be extremely fast, but can also stress the baby, who may be having difficulty getting enough oxygen. Depending on the circumstances, an emergency Caesarean may need to be done.
The uterus not contracting. Sometimes the blood clot forming behind the placenta and in contact with the uterus, makes the muscles of the uterus 'soggy' and less able to contract. This can increase the chances of a haemorrhage after the birth, known as a
postpartum haemorrhage (PPH).
Excessive blood loss. If the bleeding is heavy, it can be life threatening for the baby (and in some cases, also for the woman). The main risk to the baby is the placenta not fully functioning and the baby's oxygen supplies being dramatically reduced, within a short period of time.
In very rare circumstances, the blood loss from the woman can result in physical shock and occasionally longer term health problems, including damage to other body organs, such as the kidneys (leading to renal damage or renal failure) or the woman's pituitary gland in her brain. The pituitary gland may not be able to produce some of the body's hormones, such as oxytocin.