What are the risk factors for postpartum haemorrhage?

After the placenta is delivered, the uterus normally tightens to compress blood vessels. Uterine atony, meaning poor contraction, is a very common contributor to heavy bleeding. A placenta that remains partly attached, or an unusually positioned placenta, can also interfere with normal bleeding control.

A large baby, twins or more, a stretched uterus, prolonged labour, an assisted birth, or a caesarean birth may increase concern. Tears of the cervix, vagina or perineum can cause bleeding even when the uterus is firm. Medicines or health conditions that affect clotting may add another risk. Some people have no identifiable risk factor, so maternity teams remain watchful after every birth.

Tell your maternity team about previous postpartum haemorrhage, bleeding disorders, anaemia, medicines that affect clotting, and any concerns about the placenta. Keep planned antenatal appointments so the team can review your blood count and pregnancy findings.

During labour and after birth, staff monitor bleeding, pulse, blood pressure and how firmly the uterus contracts. If risk is higher, they may prepare blood tests, intravenous access and medicines that help the uterus contract. These preparations allow treatment to begin promptly if bleeding develops.

Heavy or rapidly increasing bleeding after birth needs urgent assessment. Seek immediate help for soaking pads quickly, passing large clots, faintness, severe weakness, shortness of breath, a racing heartbeat, confusion or severe abdominal pain. Do not travel alone if you feel faint; alert the maternity unit or emergency service immediately.

Ask whether anything in your pregnancy, medical history or birth plan raises bleeding risk, whether your blood count needs checking, and how the maternity unit would respond if bleeding occurred. You can also ask which warning signs should prompt you to call after discharge.