The small West African nation ofBenin has a higher concentration of twins than any other country in the developing world.
That’s according to a study published in PLOS ONE, which surveyed twinning rates in 75 low and middle income countries from 1987 to 2010.
The researchers found that Benin had a rate of 27.9 twins per 1,000 births. The global average among the countries surveyed was 13.1 twins per 1,000 births.
Factors that can contribute to twinning, according to the study, include the mother’s age, height, previous pregnancies, oral contraceptive use, and heredity — which is why twins are said to run in families.