A:
If the reality is as you have mentioned, nothing is due on you concerning
the death of the fetus. Your refusal to have the surgery did not cause him to die. The surgery might not have achieved the target which the doctor mentioned. The general rule is that one is free from responsibility as long as there is no evidence to prove otherwise. All Praise is due to Allah.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.