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." (TR)
English reference (TR): Vol. 1, Book 7, Hadith 1668 (TR)
Arabic reference (TR): Book 7, Hadith 1737 (TR)