Concomitant and repeated happenings of complications of the third stage of labour.

Complications of the third stage of vaginal delivery have been studied among 36 312 women in Aberdeen between 1967 and 1981. There was no change in the incidence of retained placenta (RP), but there was a secular increase in postpartum haemorrhage (PPH). Postpartum haemorrhage was three times more common when there was a retained placenta. PPH was commoner in primiparae and after induced labour. The main focus of this paper is on the analysis of the risks of repetition among 6615 women with two or three live births between 1967 and 1980. A history of PPH and/or RP increased the relative risks of PPH and/or RP in a subsequent birth by between two and four times compared with women without such a history. The risk of repetition was increased if the subsequent birth was induced, or if there was an intervening abortion. Nevertheless, only a minority of the multiparae who experienced a third stage complication had a previous history of such a complication.