Muwatta Malik 131

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

Reference

Muwatta Malik 131

In-book

Book 2, Hadith 100