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, meaning two eggs were released and fertilized at the same time.

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 ultrasound study revealed that twins have less fat tissue ...

Identifying issues early allows parents and doctors to prepare for medical care after birth. And in some cases, doctors can intervene before the baby is born. Thanks to advances in imaging, surgical tools and anesthesia, medical teams can now safely treat a growing number of complex conditions before birth.

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 (@taylortwinmom), has gathered 3.6 million views since ...

In 2021, Deonna Fletcher, who goes by “Dee,” gave birth to three girls. But during Fletcher's first ultrasound, there was just one baby. A couple of weeks later, a follow-up ultrasound revealed the addition of twins who were conceived six days after ...