Is a girl entitled to demand the Mahr (dowry) and everything else after concealing a physical defect (a clear burn in a sensitive area that may prevent natural conception) from the suitor and his family, and then refusing to complete the marriage?

Scholars differ regarding the defects that necessitate the annulment of marriage. What must be disclosed among defects is that which necessitates the right to annulment. According to the majority of scholars, there is no obligation to mention a defect that does not grant the option (to annul). However, according to the other view, if the defect impairs enjoyment or causes aversion, it is not permissible to conceal it, and it allows the husband to annul the marriage.

If the marriage is annulled before consummation due to a defect in the wife, the Mahr (dowry) is forfeited; because she is the deceptive party. But if the defect does not impair enjoyment and does not cause aversion, it does not permit the annulment of marriage. In this case, the husband may divorce her, and he owes half of the Mahr if the divorce occurs before consummation, in accordance with His, the Almighty's, saying: "And if you divorce them before you have touched them and you have already specified for them an obligation, then for you is half of what you specified – unless they forego it" (Al-Baqarah: 237). In case of disagreement, the matter should be referred to the Sharia court.