Preterm Birth: Mechanisms, Prediction and InterventionsAbout This Hardback Preterm birth is the delivery of a baby when it is less than 37 weeks of gestational age. It is accompanied by uterine contractions occurring more frequently than every ten minutes, or vaginal fluid discharge. The presence of fetal fibronectin in cervical or vaginal secretions is a primary indicator of preterm birth. Obstetric ultrasound allows the assessment of the cervix in women who are at risk for premature birth. Although the