Is the husband required to complete the sixty days of fasting that he vowed in gratitude to Allah for the pregnancy, even though the pregnancy was not completed and the fetus was miscarried before he finished the fasting?

A vow that brings no benefit and prevents no harm is disliked, yet it must be fulfilled, for the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him." If the husband intended by his vow merely the occurrence of pregnancy, he must complete his fasting. However, if he intended a child, he is not obligated to complete the fasting.