There is evidence that twins begin to interact with one another well before birth. Researchers associated with two Italian universities, the University of Turin and the University of Parma, found that twin fetuses begin to reach for one another as early as 14 weeks after conception. The research efforts involved the use of ultrasonography, a process that makes it possible to capture internal body images.
More facts about twins:
Approximately 90,000 sets of twins are born in the United States every year. Women who delay having children until after the age of 30 are slightly more likely to have twins.
The perinatal mortality rate for twins is significantly higher than that for single babies. During this period that encompasses the time shortly before and after birth, twins are five times more likely to die than individual babies.
The chances of giving birth to twins is roughly 1 in 90.