Objectives: To evaluate the effect of vaginal progesterone in the prolongation of duration of pregnancy in women at high risk of developing preterm labour. Material and Method: This is a prospective case control study carried out in the department of Obstetrics & Gynaecology S.N. Medical College Agra on 100 patients chosen from in patients and outpatient department (50 cases and 50 control). Women with singleton pregnancy having history of preterm labour, uterine malformation, prophylactic cerclage, currently suffering from premature pains were given daily vaginal progesterone 200mg from 24 weeks and discontinued at 34 weeks of gestation. In both groups rate of preterm labour and neonatal outcome was determined. Results: The incidence of preterm labour in progesterone group was 17.8% and in control group 36%, p value is <0.05.  Conclusion: Administration of progesterone in women at high risk developing preterm labour reduces the incidence of preterm labour, neonatal mortality and morbidity and increases baby weight.

 Keywords: Preterm labour; Progesterone.