<prompt> All are risk factors for preterm delivery except:Absence of fetal fibronectin at 37 weeksPrevious history of preterm babyAsymptomatic cervical dilatationChlamydial infection of genital tract  <response>: Ans. is a, i.e. Absence of fetal fibronection at 37 weeksRef. Fernando Arias 4eRisk factors for preterm labor: have been discussed in Ans. 1Fetal fibronectinIt is a fetal glycoprotein found in the cervicovaginal discharge before 22 weeks and again after rupture of membranes.Levels of fibronectin 50mgml indicates preterm delivery not absence of fibronectin. 