Understanding preterm labour: the use of Path Analysis.

A retrospective study was performed on 465 spontaneous preterm and 13,949 term births, in order to analyze the sequence of events that culminate in preterm labour. Twenty-one variables were investigated by the mathematical technique of Path Analysis. Nine direct and independent precursors of preterm labour were identified. These were antepartum haemorrhage, poor antenatal attendance, previous delivery of a small baby, multiple pregnancy, proteinuria, grand multiparity, cervical suture, low maternal weight, and a history of bleeding before 20 weeks.