Researchers at Columbia University Medical Center analyzed the medical records of more than one million patients, finding 55 diseases that were connected to either the individual's birth month or season. Mary Regina Boland, PhD student at Columbia University Medical Center and a study co-author, spoke with Yahoo Parenting and summarized some of the findings, citing May and July as low-risk months. By contrast, those born in October and November have the highest risk of developing diseases or other conditions.
More specific examples include an increased likelihood of chest pain and heart issues for people born in April, and respiratory infections and complicated pregnancies and childbirths for those born in September.
Despite the findings, the study's authors maintain that health risks tied to birth months are "relatively minor when compared to more influential variables like diet and exercise."