But much of the animal kingdom’s unborn young don’t attach themselves all that strongly to the womb. For example, horse placentas are only superficially attached to the inner lining and the embryo receives its nutrients by osmosis through tissue walls. On the other side of the coin, you have primates and rodents, that have systems designed to really tap into the mother’s anatomy.
Humans and chimps are the worst of them all. The need for a large amount of resources to create a new intelligent life form causes the placenta to really dig in to the uterine wall and actually tap into the mother’s blood supply. Evolution has created an intensely invasive pregnancy for us.
The problem is that it’s killing us.
At least, that’s the hypothesis put forth by a new paper published by Julianne Rutherford of the University of Chicago. She argues that because of our need to tap into our mother’s blood supply, human placentas create a danger not found amongst any other animals. Once the woman goes into labor and the placenta detaches, there is a fair chance that the usual systems designed to staunch the blood flow won’t kick into action.
And voila. You have PPH, or postpartum hemmorage, a catastrophic loss of maternal blood and the leading cause of maternal mortality worldwide. In fact, it accounts for up to 35 percent of maternal deaths, which adds up to 125,000 women annually.
It’s a high price to pay for our highly developed selves, but its obviously worth it from an evolutionary perspective, or else we would have died out long ago.
Or perhaps not.
Perhaps its our ability to learn about our own anatomy and override evolution that has kept us going. As many as 34 percent of maternal deaths result from PPH in rural areas like sub-Saharan Africa and Asia, but in resource-rich areas like the U.S., it accounts for just 13 percent. It’s a good thing, then, that the percentage of women in developing countries who received skilled assistance during delivery rose ten percent between 1990 and 2008. But it rose only to 63 percent.
I say we can do better.