Muwatta Malik:Purity:Hadith 132
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ سَأَلَ ابْنَ شِهَابٍ عَنِ الْمَرْأَةِ الْحَامِلِ، تَرَى الدَّمَ قَالَ تَكُفُّ عَنِ الصَّلاَةِ، ‏.‏ قَالَ يَحْيَى قَالَ مَالِكٌ وَذَلِكَ الأَمْرُ عِنْدَنَا ‏.‏

Yahya related to me from Malik that he asked Ibn Shihab about a pregnant woman who noticed bleeding. Ibn Shihab replied, “She refrains from prayer.”

Yahya said that Malik said, “That is what is done in our community.”