
The quest to untangle why pregnancy can turn deadly - chapulin
http://www.wsj.com/articles/the-quest-to-untangle-why-pregnancy-can-turn-deadly-1481298026
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bediger4000
Compared to egg-laying (first amniotes, approx 340 million years ago),
pregnancy hasn't been around that long. Combined with vertebrates adaptive
immune system, a placental-mammal-style pregnancy is bound to be problematic.
Interesting that they're trying to untangle specifics, but the overarching
"why" isn't that mysterious.

