Originally Posted by
atomic sagebrush
It is just a nice thing that people say mostly, though.
What you have to understand is that there is more than one way to look at fertility. One is by making more and/or better eggs, and that ~may~ be what miscarriage helps with. The pregnancy hormones in your system may possibly (totally unproven speculation!) make for a better egg and hyperovulation (which doubles your chances that one egg or the other is a good one)
But there is another way to think about fertility and THIS I believe is the key to swaying. The chances that sperm meet egg ALSO matter to your odds of conceiving. So I think miscarriage may alter your hormones in a way that may make it harder for sperm to meet egg (swaying pink) but ALSO may make a healthier egg and/or more eggs released.
So, weirdly, it can be a case of both things being true.