What is the value of the expiation of feeding ten needy persons for each day a pregnant woman missed fasting in Ramadan, and is it permissible to pay it in installments due to financial circumstances?

A pregnant woman may break her fast if she fears for herself and her child, and she is only required to make up the missed days (qada'). If she fears for her child only, then according to the majority of scholars, she must make up the missed days (qada') and pay a fidyah. The fidyah is to feed one poor person for each day she breaks her fast, and its amount is approximately one mudd of food (about 750 grams of rice). It is permissible to give it according to one's ability and capacity. It is not permissible to delay making up the missed days until another Ramadan unless there is an excuse; otherwise, she would be required to both make up the missed days and pay the fidyah.