A twin pregnancy is when there are two fetuses in the uterus at the same time. Twins can be identical, meaning they developed when a single fertilized egg split early in development, or fraternal, ...

A viral TikTok video showcases the surprising effects of a twin pressing against their sibling's jaw in the womb, and the child's mom told Newsweek of her concerns. The clip, shared by Taylor Deal, 29 ...