It wasnarrated that Anas bin Malik said:
"The Messenger of Allah(ﷺ)granted a concession to pregnant women who fear for themselves,allowing them not to fast, and to nursing mothers who fear for theirinfants." (AR)
English reference (AR): Vol. 1, Book 7, Hadith 1668 (AR)
Arabic reference (AR): Book 7, Hadith 1737 (AR)