There have even been cases of simultaneous uterine AND abdominal pregnancies, which makes the kids more like neighbors than womb-mates.

甚至还有同时是同母异父而且在腹部的妊娠，让孩子们看起来像邻居而不是处在同子宫的伙伴。

Turns out, male fetuses are much worse at surviving an uncomfortable gestation environment, although for both sexes, abdominal pregnancies very rarely produce a live birth.

原来，男胎儿非常不能存活在一个不舒服的孕育环境，虽然对两个性别来说，腹部怀孕很难产下活胎。