Health Update: Not such a curse

WOMEN'S periods may have evolved as a way of ridding the body of bacteria introduced by sexual intercourse, according to Margie Profet, a biologist at the University of California at Berkeley. Ms Profet says in New Scientist that the way female mammals are fertilised allows entry of bacteria that cling to the sperm's neck and tail; menstruation wards off infections of the uterus that could spread to the fallopian tubes.