This is caused by pressure from the child's head, which can block the circulation in that area, giving rise to necrosis of the tissue at a particularly vulnerable point. Often the perianal nerve is also damaged, as a result of which some of these women are left limping for the rest of their lives. An operation to patch the damaged wall of the urethra can be performed, using a muscle from the inside of the thigh which is normally removed subcutaneously. This technique was first developed by a medical couple, Reginald and Catherine Hamlin, who devoted their lives to these women, and it has since been successfully adopted in Nigeria. The women regain full control over their bodily functions and are accepted back into society, usually going on to remarry.
Specialists suggest a figure of two million.
It is also present in Haiti, India, Pakistan and Bangladesh. Wherever, as a result of war, peoples are displaced and there is disruption to an already fragile public health infrastructure, there is a return or an increase in the number of cases of childbirth-related fistulae. In Afghanistan, the regressive policy of the Taliban's new Islamist regime is likely to increase the number of cases by restricting women's access to surgical care. That is 400 times more than in the West. A number of cultural factors also come into play, but these are less straightforward to address.