Reference for Yevamot 109:22

העראה דחייבי לאוין מנלן

it might have been assumed to refer to children born before the offence<span class="x" onmousemove="('comment',' The expression shall be childless would have been taken to imply that the children born prior to the offence would die as a result of the offence. The parents, however, would not die childless because the children born after the offence would live. ');">⁴⁹</span> but not to those born subsequent to the offence,<span class="x" onmousemove="('comment',' Who would live. V. supra note 5. ');">⁵⁰</span> hence the All Merciful wrote, <i>They shall die childless</i>.<span class="x" onmousemove="('comment',' Ibid. 20. ');">⁴⁷</span>

Jastrow