Ante-partum haemorrhage is defined as bleeding from the vaginal canal from about the 20th week of pregnancy (some define it as 24-28 weeks of pregnancy) until birth. It is associated with placental abnormality such as placenta praevia or placental abruption (both described below), both of which can be life-threatening to mother and infant. Less seriously it is due to disorders of the cervix such as cervical ectropion or cervical polyps (described in the section on the female genital tract) or cervical or vaginal infection. Any bleeding during pregnancy requires investigation.