Is it obligatory for the couple to pay the cost of an ultrasound examination that was not officially registered, based on the nurse's statement that payment is not necessary if there is no money available, knowing that non-payment might protect the nurse from accountability?

The husband must return the cost of the ultrasound to the hospital, even if indirectly, such as sending it via a postal money order without mentioning his name, and stating that this amount is rightfully due to the hospital to clear his conscience, for the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions regarding what is permissible."