Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Fatwa No.5168
Fataawa Ramadhaan – Volume 2, Page 589, Fatwa No.574
Question: A woman did not fast for five days in Ramadhaan and did not make up these fasts until such time she realised she was pregnant. [And] when she wanted to make up these fasts, she was unable to do so. She then estimated that she will be giving birth in Ramadhaan and [as such] will not be able to fast [the month of Ramadhaan] either. What should she do? Should she make up the fasts of Ramadhaan and the five days [remaining] from the previous year or should she feed a poor and needy person for the five days [remaining] and make up the fasts of Ramadhaan?
Response: If the situation is as mentioned, then she should make up the fast for the five days [remaining] and also make up the fasts of the month of Ramadhaan and there is no kaffaarah upon her.
And with Allaah lies all success, and may Allaah send prayers and salutations upon our Prophet Muhammad ﷺ and his family and his companions.