Rachel was shocked when she learned she would be welcoming quadruplets. Speaking to ABC News, the mom of six recalled being ...

Twins have proportionally less fat tissue accumulation in utero compared with singletons as early as 15 weeks of gestation, ...

For a group that makes up just 0.4 percent of the world’s population, identical twins have enthralled moviegoers.

The trans-Neptunian object Altjira, 44 times farther from the Sun than Earth is, could be the second known trinary, ...