Background Preterm birth (PTB) is the end result of a heterogenous group of complications of pregnancy. Women with a previous mid-trimester spontaneous abortion or PTB are at higher risk of PTB in a subsequent pregnancy.1 No studies have compared the risk conferred to a subsequent pregnancy if the spontaneous abortion or PTB was immediately preceded by a vaginal bleeding, to those without a bleed.

Aim To investigate whether women with a history of late spontaneous abortion or PTB with preceding vaginal bleeding deliver at greater gestations than those without bleeding.

Method Retrospective analysis of the pregnancy outcome of 119 women who presented to a preterm clinic between March 2008 and September 2009 with a history of at least one spontaneous abortion >16 weeks or PTB <37 weeks.

Results Women were significantly less likely to deliver preterm if their prior pregnancy loss had been precipitated by a bleed: 9/44 (20%) of women with history of bleed and PTB delivered before 37 weeks, compared with 30/75 (40%) without history of a bleed (p=0.04).

A similar trend existed for delivery before 34 weeks: 4/44 (9%) of women with history of bleed and PTB delivered before 34 weeks, compared with 17/75 (23%) and of those who did not have a bleed (p=0.08).

Discussion Bleeding may represent a different aetiology for PTB, likely placental, in which risk of recurrence is less in a subsequent pregnancy. Further research is needed to fully inform risk-counselling of these high-risk women.