Tosefta for Yevamot 83:17

א"נ לשיתא ופלגא ילדה איכא למימר דבתרא הוא דאמר מר זוטרא אפילו למאן דאמר יולדת לט' אינה יולדת למקוטעין ילדה לז' יולדת למקוטעין

Let her wait, however, one month only and then marry, so that, should she give birth at seven months, the child would be a seven-months one of the last husband;<span class="x" onmousemove="('comment',' Had he been an eight-months child of the first husband he would not have been viable. ');">²⁸</span> and should she give birth at eight months the child would obviously be a nine-months one of the first!<span class="x" onmousemove="('comment',' Husband. ');">²⁷</span>

Tosefta Niddah