I'd like to return to the weight I was at before I had my baby.
I'd like to get back to my pre-pregnancy weight.
ーI'd like to return to the weight I was at before I had my baby.
「産前の体重に戻りたい」
before I had my baby で「産前」を表現できます。
to return で「戻る」
ーI'd like to get back to my pre-pregnancy weight.
「産前の体重に戻りたい」
pre-pregnancy で「妊娠前の」
to get back で「戻る」
ご参考まで!