to become pregnant
彼女は第一子を身籠もった。
She became pregnant with her first child.
彼女は第二子を身籠もって、産休に入った。
Having become pregnant with her second child, she began her maternity leave.
小説のヒロインは最終章で身籠もることを知る。
The heroine of the novel learns that she is with child only in the final chapter.