Yes he is. My bad for not typing more to explain. My omega example was meant more about other omegaverse, which mostly consisted of alpha x omega. And seeing that omega have higher chances of pregnancy to begins with, even more than beta, so if an omega have fertility issues then a beta with fertility issues would be even worst off. A few of the series I read, alpha x omega, the authors just leave the omega fertility problem as is and doesn't explore further. Of course every author have their own vision to the working of the people in their world in term of fertility rates, but I'm just happy that sachimo allowed miyauchi and kudo to have a child and did not just leave of at an uncertainty.
I'm so happy that unlike other omegaverse, if the omega have fertility problem with low chances, the chances of us seeing a baby is almost nay even if that's clearly a heartbreaking issues for the omega. I'm so happy sensei allowed miyauchi to get pregnant and even explored their relationships after marriage and with the child as well. ┗( T﹏T )┛ Their story is seriously the best.