If one of your good friends is having a baby – you might be next.

It’s true, having babies can be contagious. 

Studies have found that close friends of a woman who has a baby are more likely to have one of their own within two years. Women who were friends in high school seem to have the biggest baby influence on each other. According to the researchers, a woman’s childbearing experience is a very strong one and can help to trigger maternal instincts among her peers. That influence increases after the birth, peaks at about two years, and then begins to decline. 

Experts say men may experience a similar phenomenon but is much harder to document. That’s because it’s difficult to determine that a specific man caused a particular pregnancy without a blood test.