CHICAGO, Ill. (WOWO) — Birth order may be associated with certain health conditions, according to a massive study examining medical records involving about 10 million American siblings over two decades.
Researchers from the University of Chicago and Columbia University analyzed 569 disease categories across families and between siblings, identifying 150 conditions that showed statistically significant associations with birth order.
The findings suggest first-born and second-born children can show different patterns of health risks, although researchers emphasize that the study does not establish that birth order directly causes any particular disease…