Trial Design:~Single center, longitudinal, randomized, interventional, controlled, pharmacological study, enrolling women attending clinical Centers of medically assisted reproduction (ART).~The study protocol consists in the record of all the diagnostic and clinical outcome parameters, according to clinical practice, for the following patient cohorts:~The patients who are undergoing frozen embryo transfers with blastocyst or cleavage stage embryos and have progesterone levels below 10 ng/mL on the day of embryo transfer~Study groups~Group supplemented with progesterone intramuscular 50 mg per day until the day of beta-hcg testing (Intervention group);~Group with no supplementation (Control group).~Endometrial cycle is started with estradiol valerate dose of 4 mg to 8 mg per day, the patients then are appointed to have ultrasound scan of their endometrium every 3 to 7 days and the dose of estradiol may be increased to 16 mg per day maximum depends on the thickness of endometrium; when their endometrium reach 8 mm or higher and duration of endometrial preparation is ≥ 12 days, the embryo transfer will be planned and transvaginal progesterone are prescribed according to the day of transfer.~If this is the first cycle of embryo transfer and she is < 35 years of age, 1 grade 1 embryo is transferred, otherwise 2 embryos are transferred.~In the morning of embryo-transferred day, all patients will have their blood tested for progesterone levels, if their levels below 10 ng/mL, they will be recruited into the study and randomized into two groups.~In the study group, the patients will be prescribed with intramuscular progesterone supplemetation 50 mg + 800mg vaginal micronized progesterone per day for 14 days, until the day of beta-hcg testing.~In the control group, the patients will continue their regular medications (800mg vaginal micronized progesterone per day) until the day of beta-hcg testing without any progesterone supplementation.~If the beta-hcg test is positive, the patients will be continued their prescriptions depending on study or control group as mentioned above till 7 weeks of pregnancy when the fetal heart can be confirmed, then the patients will be followed up till 11 - 12 weeks of pregnancy
The main objective of this study is to compare clinical pregnancy rates between two groups of women who have progesterone levels below 10 ng/mL on the day of frozen embryo transfer: group 1 (vaginal micronized progesterone supplemented with progesterone intramuscular 50 mg per day) and group 2 (vaginal micronized progesterone with no supplementation)