Female circumcision can complicate childbirth, leading to higher mortality among infants, officials from the World Health Organization said Friday.
It's estimated more than 100 million women and girls have had the procedure, also called female genital mutilation.
In cultures where it is accepted, female genital mutilation is practised by followers of all religious beliefs.
It is usually performed on girls before the age of 10 by a traditional practitioner with crude instruments and without anesthetic, the agency said.
It usually involves removal of the clitoris or other external genitalia for cultural or other non-therapeutic reasons.
Having health professionals perform the procedure to ensure it's done in a clean or safe setting endorses an unacceptable practice, said Joy Phumaphi, WHO assistant director general for family and community health.
"That is the worst possible thing we can do,"Phumaphi told Reuters. "It is worse than turning a blind eye."
Researchers from the UN health agency studied data from some 28,000 women giving birthbetween November 2001and March 2003 in Burkina Faso, Ghana, Kenya, Nigeria, Senegal and Sudan.
Three-quarters of the women studied had some degree of genital mutilation.
Up to 20 out of every 1,000 babies born in Africa die as a direct result of their mothers' circumcision, the agency said.
Scars forming around the wound could cause an obstruction, prolonging labour, "which increases the risk of caesarean section, heavy bleeding, distress in the infant and stillbirth."
In Saturday's issue of the medical journal The Lancet, the researchers report women who had the procedure were:
- 31 per cent more likely to have a caesarean delivery.
- 66 per cent more likely to have a baby that needed resuscitation.
- 55 per cent more likely to have a child who died before or after birth.
Female genital mutilation "is estimated to lead to an extra one or two perinatal deaths per 100 deliveries," the study said.
The more extensive the mutilation, the higher the risks, the study's authors found.
The excess risks remained after taking into account factors such as maternal age, education, socio-economic status and care after birth.