عَن أبي سعيدٍ الخدريِّ رَفْعَهُ إِلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ فِي سَبَايَا أَوْطَاسٍ: «لَا تُوطَأُ حَامِلٌ حَتَّى تَضَعَ وَلَا غَيْرُ ذَاتِ حَمْلٍ حَتَّى تَحِيضَ حَيْضَةً» . رَوَاهُ أَحْمَدُ وَأَبُو دَاوُدَ وَالدَّارِمِيُّ
Translation

Abu Sa'id al-Khurdi traced to the Prophet the following statement regarding the captives taken at Autas, “There must be no intercourse with a pregnant woman till she gives birth to her child, or with one who is not pregnant till she has had one menstrual period.” Ahmad, Abu Dawud and Darimi transmitted it.