My son and his wife had difficulty conceiving, but eventually his wife became pregnant. Arguably she was saved from barrenness at that point, and could have claimed that they were saved from the problem of not having an heir, but the baby miscarried.
I would suggest that beginning to believe the gospel is not becoming a spiritual child or son, but a spiritual foetus. There is a process of growing understanding of the cost of following Christ as a disciple that precedes a decision to be baptised and become born of water into the kingdom, rather than only conceived by the Spirit into faith in Christ. Paul warned that believers can be still-born
1Co 15:1 Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand;
1Co 15:2 By which also ye are being saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.
Gal 4:19 My little children, of whom I travail in birth again until Christ be formed in you,
But the end of the path from conception to adoption as sons, which happens biblically when one is old enough to become a joint partner with one's father in his business, is not completed by all who were conceived or became foetuses or even became birthed babies.