8 reasons everyone should know their blood type
5 of 9
Fertility: Type O reduces it
Women with this blood type were twice as likely to have blood levels of the hormone FSH high enough to indicate low ovarian reserve, a measure of fertility, according to a study published in Human Reproduction. Researchers couldn’t say for sure why, though. Given that type O blood is the most prevalent, it doesn’t pay to worry too much about it. Age is a far more important risk factor for fertility problems.