Our Gemara on the end of 65b and the beginning of 65a concludes a discussion about women not being obligated in the commandment to have children.  We even learned on the previous amud about Rav Chiyya’s wife, who had such difficulty with childbirth that she obtained a heter to drink a potion that would render her infertile.

The Yam Shel Shelomo on Yevamos quotes this Gemara as a support that a woman may render herself infertile via a medical concoction.  He maintains that such a step is only justified if she experiences extreme duress from childbirth, but it is not a blank check heter for every woman.  The Yam Shel Shelomo adds an interesting comment, which I will print in Hebrew and English so you can decide for yourself what it might mean.

אלא למי שיש לה צער כעין דביתהו דרב חייא, וכל שכן אם אין בניה הולכין בדרך ישרה ומתייראה שלא תרבה בגידולין כאלו, הרשות בידה

This heter (of drinking the potion) is only for a person who suffers from childbirth pain such as Rav Chiyyah’s wife. And, surely in the case where she has children and sees that they are not following a proper path and she fears lest she have more children such as these, she has permission to render herself infertile through this medication.

Did the Yam Shel Shelomo really just say that?  So a woman may preemptively not have more children if she already had children who were not following the proper path?  This would seem to be incredibly fatalistic as well as contradicting the sentiment of the Gemara (Berachos 10a) about Chizkiyahu. Chizkiyahu was almost punished with a heavenly death decree because he did not want to have children.  He had a prophecy that his child would turn out to be evil (indeed he became the notorious King Menashe).  The prophet Yeshayahu rebuked him saying, “Of what business of yours are the secrets of God?”  The implication is clear.  A mitzvah is a mitzvah and we do not let prophecies of doom interfere with our resolve.  In that light, how is this woman’s preemptive birth control justifiable?

I can offer two possible answers that are technically correct, though I still find this Yam Shel Shelomo difficult to understand.  Chizkiyahu was commanded in Periya Ureviya so he had no option to decline that mitzvah, despite the prophecy.  The Torah is not in heaven.  However, the woman in this situation was not obligated in this mitzvah.  Additionally, while Chizkiyahu had a prophecy, in a certain sense, she had a reality. She already knew that she had an unfortunate  propensity to produce poorly adjusted children. 

These technical explanations are difficult to accept, as ultimately the theme of the Aggadah about Chizkiyahu is not to give up nor predict doom, and instead do one’s best effort to fulfill God’s wishes. 

Another interesting point emerges from this ruling along the lines of what we discussed on Daf 64, that sometimes no one person in the relationship is principally at fault, but the combination doesn’t work. Perhaps she has the right to her conviction that sadly they either weren’t good parents or their genetic / spiritual combination just did not produce good children.