Infant returned to newborn, mother returned to 3rd trimester after entering CAS

Very odd. Base game only, no mods. Went to CAS immediately after aging up a newborn. Baby had a newborn outline in CAS. Edited mother's surname to agree with husband's, wanted to edit the baby's surname as well but can't select or edit newborns in CAS. Exited CAS, and the baby was back in the bassinet and mother was back to third trimester, and other things about the mother seem to have reverted to previous save (except the mother had not gotten pregnant, let alone advanced to third trimester after the baby was born, so this was a previous save state with the addition of the newborn.)