بُلُوغُ الْمَرَامِ
Bulugh al-Maram 226
The Book of Prayer
وَعَنْ أَبِي قَتَادَةَ - رضى الله عنه - قَالَ : { كَانَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -يُصَلِّي وَهُوَ حَامِلٌ أُمَامَةَ بِنْتِ زَيْنَبَ , فَإِذَا سَجَدَ وَضَعَهَا , وَإِذَا قَامَ حَمَلَهَا } مُتَّفَقٌ عَلَيْهِ . [1]
Narrated Abu Qatada (RA): Allah's Messenger (ﷺ) was (one time) offering prayer while he was carrying Umama, daughter of Zainab, when he prostrated he put her down and when he stood up he lifted her up. [Agreed upon].
Sunnah.com reference: Book 2, Hadith 91