The purpose of the study is to assess the efficacy of vaginal micronized progesterone in the treatment of threatened miscarriage. All eligible pregnant women will be randomized to either receive vaginal progesterone or no treatment.Evaluation will be two weeks after intervention, then every 4 weeks up to 28 weeks gestation or termination of pregnancy.

Inclusion Criteria:

1. Pregnant with gestational age less than 24 weeks
2. Presented by bleeding with or without pain
3. Single viable fetus (confirmed by Ultrasound examination)
4. Accepting to have vaginal medication

Exclusion Criteria:

1. Currently under medication for any chronic diseases (DM, thyroid, liver, renal, cardiac and autoimmune disease).
2. Hypersensitivity to progesterone
3. Any documented congenital fetal anomaly in the current pregnancy
4. Women received hormonal treatment in the current pregnancy
5. Patients conceived via ART