>>11640539while pregnant the women is cared for, given special attention and privileges both in the relationship and in society. She is given an excuse to overeat, get chubby and be a whiny bitch demanding things all of the time.
After pregnancy, all of that goes away. Instead she is expected to give that level of attention and caring to the new baby. Now the baby is the whiny bitch and she has to obey it. Not only that but her body is likely fatter with baggy stomach skin and a stretched vagina. All of this happens rather rapidly and the juxtaposition of it makes them sad.