Can Pregnancy be Contagious? Female High School Friends More Likely to be Pregnant in Early Adulthood

Could pregnancy be contagious? In the case of female high school students, it just might be. Scientists have found that having children could be "catching" among female high school friends during early adulthood.

In order to examine the prevalence and possibility that friendships influence pregnancy, the researchers focused on more than 1,700 American women. They tracked these women from when they were at least 15-years-old through approximately the age of 30.

"The study shows the contagion is particularly strong within a short window of time: it increases immediately after a high school friend gives birth, reaches a peak about two years later, and then decreases, becoming negligible in the long-run," said Nicolette Balbo, one of the researchers, in a news release. "Overall, this research demonstrates that fertility decisions are not only influenced by individual characteristics and preferences, but also by the social network in which individuals are embedded. In addition, it shows that high school friends impact our lives well after graduation."

In fact, the researchers found that while the median age at first birth for women in the study was just over 27-years-old. Yet having a high school friend who had a baby increased the likelihood that the woman would have a baby of her own.

"We believe there are three possible explanations," said Balbo in a news release. "First, people compare themselves to their friends. Being surrounded by friends who are new parents makes people feel pressure to have kids as well. Second, friends are an important learning source. Becoming a parent is a radical change. By observing their friends, people learn how to fulfill this new role. Lastly, having children at the same time as friends may bring about many advantages-friends can share the childbearing experience and thus reduce the stresses associated with pregnancy and childrearing. It's also easier for people to remain friends when they are experiencing parenthood at the same time."

The findings reveal how friends can influence behaviors. The scientists also note that the effect of a friend giving birth isn't immediate; instead, it develops over time.

The findings are published in the journal American Sociological Review.