What is the expiation for delaying the making up of Ramadan days for two consecutive years due to pregnancy and breastfeeding, with the onset of another pregnancy that prevents fasting?

A woman who breaks her fast for six days out of fear for her fetus must make up those days and feed a poor person for each day. As for the remaining days she broke her fast due to postpartum bleeding (nifas), she is only required to make them up. If she delays making up the fasts without a valid excuse until the next Ramadan begins, she must pay a fidyah (expiation) by feeding a poor person for each day (approximately 750 grams of rice, though 1.5 kilograms is preferable). If she is unable to make up the fasts due to excuses such as pregnancy or breastfeeding, then nothing is required of her, and she should make them up whenever she is able. The fidyah is not repeated if multiple Ramadans pass.