IRCT20181207041879N1 IRCT 2019-02-24 Mashhad University of Medical Sciences comparison of oral Dydrogesterone and 17α Hydroxyprogesterone Caproate in prevention of preterm birth in patients with preterm labor comparison of oral Dydrogesterone and 17α Hydroxyprogesterone Caproate in prevention of preterm birth in patients with preterm labor 2018-10-23 anticipated 150 Complete https://irct.ir/trial/35819 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Simple randomization is done by means of table of random numbers using ''www.randomization.com'' website. Numbers will be placed in sealed envelopes and once a patient enters the study, an envelope will be assigned to her based on which she will be placed in one of the 3 groups. 3 preterm labor. Intervention 1: Intervention group: Patients with gestational age up to 36 weeks and 6 or with any delivery time less than it will receive three tablets of 10 mg Dihydrogesterone made by Abouryhan Pharmaceutical Company daily after each meal. Intervention 2: Intervention group: Patients will receive a 250 mg intramuscular 17α Hydroxyprogesterone Caproate (femolife), made by the Abouryhan Pharmaceuticals Company weekly. Intervention 3: Control group: No medication is prescribed. Yes - There is a plan to make this available What will be shared: All data can be shared after patients are made unidentifiable. When: Data can be accessible 6 months after results are published. To whom: Data will be available for researchers in universities and other scientific institutes. Conditions: Carrying out analysis on data is permitted. Where to obtain: Data can be accessible through sending an email to the corresponding author. How to obtain: After sending a request email to the corresponding author, data will be sent in 1 month. Comments: