Answered by Ustadh Salman Younas
Question: My son has donated one of his kidneys to his mother for her transplantation surgery. Now he is planning to get married. Doctors have told me that one kidney is sufficient for a healthy life and living with one kidney is not a physical deficiency. Should he tell this to the girl or her family?
Answer: assalamu `alaykum
This is not something that you would have to reveal from a strictly religious perspective, since, as you mention, it is not a defect nor something required to make an informed decision on marriage.
With this said, your family would be the best judge as to how withholding such information would be perceived of in the future following the marriage. If it will cause problems, it may be best to inform the other side as spouses value openness. When it comes to these issues, one has to look at what is most conducive to a smooth and happy marriage as opposed to the minimal dictates of religious law.
Checked & Approved by Shaykh Faraz Rabbani