Question

Hello Rabbi, according to the halakhic decisors who say that the commandment of be fruitful and multiply is about the result (the main thing is that there be children), let’s say there is a couple who have only daughters and they are very old and there is one last chance to get pregnant andhave a son, in order to fulfill the commandment of be fruitful and multiply. Would they be commanded to do everything in their power to have a son including genetic engineering (I’m not sure exactly what it’s called but you understand me) or would we say to them that they are commanded to do everything within accepted norms, namely regular sexual relations and if no son results then they are coerced by circumstances?
While I was writing this the question became sharper for me: are they commanded to use the best technology available in order to fulfill be fruitful and multiply or do we act according to the norm and no more, even though there is a “new” way to fulfill the commandment?