Abstract
BACKGROUND: A low progesterone level on the embryo transfer (ET) day significantly reduces the pregnancy rate. Therefore, the present study aims to investigate the effect of adding daily 50 mg intramuscular progesterone to a total of 800 mg progesterone suppository on the in vitro fertilization (IVF) success rate in women with low progesterone levels. MATERIALS AND METHODS: This parallel open-label clinical trial was performed on 218 IVF candidate infertile women who had <9.2 ng/ml progesterone levels on the ET day. These women were randomised to the intervention or control group using the randomisation allocation rule. In the intervention group, 50 mg progesterone was prescribed intramuscularly once daily in addition to 400 mg of progesterone suppository every 12 hours from the day of ET. The control group received only 400 mg of progesterone suppositories every 12 hours. In the case of pregnancy, the drugs above were continued until 12 weeks after the ET. RESULTS: Clinical pregnancy occurred in 54 (50.0%) women in the intervention group and in 39 (36.8%) women in the control group, which was significantly different (P=0.035). Ongoing pregnancy occurred in 47 (43.5%) women in the intervention group, and 33 (31.1%) women in the control group, which was significantly different (P=0.042). There were no significant differences in terms of abortion and multiple pregnancy rates between the two groups. CONCLUSION: Intramuscular injection of 50 mg progesterone significantly increases the clinical and ongoing pregnancy rates (registration number: IRCT20150105020558N6).