Sisters are likely to spend more time together and getting strong behavioral influence from each other as compared to their friends or class-mates. Further, having a sister who acquired pregnancy during her teenage doubles the probability of teenage pregnancy for her sister as well, suggested an analysis of census data from almost 43,000 women.

In addition, the study has also claimed that young people, who leave school later and attains higher qualifications, are less likely to have sex early. The UK has topped for the highest rate of teenage pregnancies in Western Europe.

To conclude the findings, experts have analyzed over 42,000 women and found that among young people, having an older sibling becoming pregnant in teenage had a major effect on their chances of also becoming pregnant in their teens.

While explaining the findings professor Carol Propper of the University of Bristol has also referenced previous research work suggesting that family background along with education plays a role to decrease the chances of teenage pregnancy.

"These findings provide strong evidence that the contagious effect of teen motherhood in siblings is larger than the general effect of being better educated. This suggests that more policies aimed directly at decreasing teenage pregnancy may be needed in order to reduce teen births", added Professor Carol Propper.