Implications for practice and research

• Caesarean section was identified as a risk factor for preterm birth in a subsequent pregnancy, however it is not known if the relationship between caesarean section and preterm birth is causal.

• Large observational studies might provide additional information regarding the relationship between caesarean section and the increased risk on preterm birth.

Context

The aetiology of spontaneous preterm birth remains, despite many publications on the subject, largely indefinite.1 Studies focus on identification of risk factors for preterm birth in order to develop tailor-made care. Risk factor identification might however also provide clues in unravelling the pathophysiological processes leading …