Who’s got twins? Look up

Taller women are more likely to have twins, researchers have found.

Gary Steinman, an obstetrician at New York’s Long Island Jewish Medical Center, compared the heights of 129 women who gave birth to twins or triplets with the average height of women in the United States and found that women with multiple-birth pregnancies averaged more than an inch taller.

Steinman, whose study was published in the September issue of the Journal of Reproductive Medicine, said the reason seemed to be an insulin-like growth factor, which has been positively linked to height and twinning.

Insulin-like growth factor is a protein that is released from the liver in response to growth hormone. It increases the sensitivity of the ovaries to follicle stimulating hormone, thereby increasing ovulation, the study said.