Perineal tears (ie, tearing of the area between the vagina and anus) are birth injuries that happen during the second stage of labour as the baby is being delivered. However, they are not diagnosed until the third stage of labour, ie after the baby is born.
Perineal tears are graded from 1st degree to 4th degree according to their severity and are usually caused when the baby is delivered before the perineum has had a chance to slowly stretch widely enough to allow the baby to be born, or because the perineum is already scarred due to a previous injury causing it to be less stretchy than would be expected. This over-stretching of the perineum can result in birth injury to the perineum.
Continue reading about perineal tears.