Your explanation might make sense in a perfect world... but we do not live in a perfect world. We live in a fallen one. Where disease and illness can strike anyone. And so when an infertile husband and wife turn to modern science to give them the child they desire, who are you to tell them that God says they shouldn’t have a child? I believe that God decides, not us.
They are nothing wrong with IFV if people cant have kids on their own. Like someone said you wouldn’t turn down someone else organ if you life or family members life depended on it. Alot of people are sounding awfully backward and stupid here. Zealotry with shades of Galileo redux. AKA blind ignorance.