A group of researchers have suggested that premature birth risk may have genetic links.
In the University of Aberdeen study, which was published in Obstetrics and Gynecology journal, boffins found that early births tend to run in families.
The study, based on maternity records of 22,343 Scottish mothers and their daughters, found that women born prematurely or who have brothers or sisters who were born too early are 50-60 percent more likely to have a premature baby themselves, reports The BBC.
Lead author of the study Dr Sohinee Bhattacharya said: "Our research supports a genetic predisposition to preterm birth.
"Further research should focus on the identification of candidate genes for the condition."