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, ...

Rylie Parman screamed in shock when she learned her twin sister is pregnant. Twin sisters in Wisconsin are proving there is no one more supportive than a twin, especially when they learn you're having ...

Twins—smaller at birth, on average, than singletons—start out smaller in pregnancy than was previously known, according to a study by researchers at the National Institutes of Health (NIH). The ...