Preterm or premature birth, at least three weeks before a baby's due date, can result in life-threatening health problems for the baby, and its increased risk in later life, such as heart disease and diabetes.
A study of more than 3,000 pregnant women has detailed the most common risk factors for preterm birth, the journal Public Library of Science ONE reports.
The research team, led by professor Gus Dekker from the University of Adelaide's Robinson Institute, found that the greatest risks for spontaneous preterm birth include strong family history of low birth weight babies, use of marijuana prior to pregnancy, history of pre-eclampsia, vaginal bleeds and diabetes type 1 or 2.
The team also found that the greatest risk factors involved in the preterm rupture of membranes leading to birth included mild hypertension, gestational diabetes, hormonal fertility treatment, body mass index of less than 20, according to an Adelaide statement.
"Our study has found that the risk factors for both forms of preterm birth vary greatly, with a wide variety of health conditions and histories impacting on preterm birth," says Dekker.