The effect of pregnancy and delivery on anal function in black Africans and Indians

Occult anal sphincter disruption, following childbirth may contribute to the development of anal incontinence (AI). The type and mechanism of injury may differ between first and subsequent deliveries.

To describe the effect of pregnancy and delivery on the endosonographic morphology of the anal sphincter and on anal sphincter pressures, and to highlight any differences in these between nulliparous and multiparous Black African and Indian women.

One hundred Black African and Indian women delivering at two hospitals in the Pietermaritzburg area underwent anal endosonography and manometry in the third trimester of pregnancy and 24 hours post-delivery. Those with occult injury were followed up at 6 weeks and six months. Participants were asked about bowel symptoms at each visit. Ante-natal and intra-partum obstetric data was also recorded.

The majority were Black African (82%), and 76% were multiparous. Symptoms of urgency increased from 9% antenatally to 14.6% post-delivery, decreasing to 8.3% at six months. Symptoms of AI increased from 10% antenatally to 12.5% post-delivery, falling to 3.1% at six months. Internal sphincter defects were more common among primiparous and multiparous women delivering vaginally. There was a significant drop in functional anal length post-delivery, irrespective of the mode of delivery. Anal pressures also fell post-delivery and at six weeks post-partum. However, by six months there appeared to be a return to pregnancy values.

Occult anal sphincter injuries and reduced anal pressures occur after delivery, in the absence of clinically detected anal sphincter trauma, irrespective of the mode of delivery.