The Messenger of Allah ﷺ was leading the people in prayer with Umamah daughter of Zainab daughter of the Messenger of Allah ﷺ (in his lap). When he prostrated, he put her down and when he got up(after prostration) he lifted her up.
أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يُصَلِّي وَهُوَ حَامِلٌ أُمَامَةَ بِنْتَ زَيْنَبَ بِنْتِ رَسُولِ اللَّهِ ﷺ فَإِذَا سَجَدَ وَضَعَهَا وَإِذَا قَامَ حَمَلَهَا