Interesting article on genes and pregnancy in the NYT

judyblueeyes · Mar 16, 2006

"Pregnancy can be the most wonderful experience life has to offer. But it can also be dangerous. Around the world, an estimated 529,000 women a year die during pregnancy or childbirth. Ten million suffer injuries, infection or disability.

THE THEORIST Dr. David Haig sees pregnancy as a tug of war between mother and fetus over nutrients. To David Haig, an evolutionary biologist at Harvard, these grim statistics raise a profound puzzle about pregnancy.

"Pregnancy is absolutely central to reproduction, and yet pregnancy doesn't seem to work very well," he said. "If you think about the heart or the kidney, they're wonderful bits of engineering that work day in and day out for years and years. But pregnancy is associated with all sorts of medical problems. What's the difference?"

The difference is that the heart and the kidney belong to a single individual, while pregnancy is a two-person operation. And this operation does not run in perfect harmony. Instead, Dr. Haig argues, a mother and her unborn child engage in an unconscious struggle over the nutrients she will provide it.

Dr. Haig's theory has been gaining support in recent years, as scientists examine the various ways pregnancy can go wrong.

His theory also explains a baffling feature of developing fetuses: the copies of some genes are shut down, depending on which parent they come from. Dr. Haig has also argued that the same evolutionary conflicts can linger on after birth and even influence the adult brain. New research has offered support to this idea as well. By understanding these hidden struggles, scientists may be able to better understand psychological disorders like depression and autism."

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The rest of the article is here: http://www.nytimes.com/2006/03/14/health/14preg.html?_r=1&oref=slogin

( He goes on to say that PIH may be the fetus attempting to force more nutrients for itself and lots of other interesting ideas:

"The fetuses somehow raised the blood pressure of their mothers so as to drive more blood into the relatively low-pressure placenta. Dr. Haig suggested that pre-eclampsia would be associated with some substance that fetuses injected into their mothers' bloodstreams. Pre-eclampsia happened when fetuses injected too much of the stuff, perhaps if they were having trouble getting enough nourishment.

In the past few years, Ananth Karumanchi of Harvard Medical School and his colleagues have gathered evidence that suggests Dr. Haig was right. They have found that women with pre-eclampsia had unusually high levels of a protein called soluble fms-like tyrosine kinase 1, or sFlt1 for short.

Other labs have replicated their results. Dr. Karumanchi's group has done additional work that indicates that this protein interferes with the mother's ability to repair minor damage to her blood vessels. As that damage builds up, so does her blood pressure. And as Dr. Haig predicted, the protein is produced by the fetus, not the mother. ")