Yahya related to me from Malik that he had heard that A'isha, thewife of the Prophet, may Allah bless him and grant him peace, saidthat a pregnant woman who noticed bleeding left off from prayer. (RU)
USC-MSA web (English) reference: Book 2, Hadith 102 (RU)
Arabic reference (RU): Book 2, Hadith 131 (RU)