Health Issue: Allow Pregnancy only After Compatibility

Woman's body is picky about sperm Allow Pregnancy Only After Compatibility Of Male Has Been Established Sydney: A woman's body may be unconsciously selective about sperm, allowing some men's to progress to pregnancy but killing off the chances of less suitable mathces, an Australian researcher said on Wednesday.        University of Adelaide Professor Sarah Robertson said her research suggested that sperm contains "signalling molecules" that activate immunity changes in a woman so her body accepts it.          But some apparently healthy sperm failed to activate these changes, leading to the suggestion that the female system can be "choosy" about its biological mate, she said. "It's rather like a two way dance," Robertson said.         "The male provides information that increases the chances of conception and progression to pregnancy, but the female body has a quality control system which needs convincing that his sperm is compatible.         "That's where the dance can go wrong with some couples - if the male signals are not strong enough, or if the female system is too 'choosy'." Robertson said sperm was more likely to fail if the woman had not previously been exposed to that man's semen for at least three months.         "We used to think that if a couple couldn't get pregnant, and the man's semen test was normal, the problem lay with woman. But it appears this is not always the case," Robertsion said.         The researchers plan to continue their work, which they hope will lead to improved treatments for infertility and miscarriages. The research trial has primarily been on mice and pigs, but Robertson said there was some indication that it will have the same or similar effect on human females.         "At the moment we've done lots of work on mice and pigs and we've done a little bit of work with human cells and we've found if we put seminal flued on cells in vitro that we get the same kind of changes in human cells.         We also have a little bit of preliminary work from people showing or suggesting that the same things are going to occur in real in vitro situations. " she said.         She further commented that this discovery could be extremely important from an evolutionary perspective, because it means the female body has the ability to decide when the time is right for pregnany.