Abstract
Background: Identifying effective factors in the success rate of assisted reproductive technologies can be a promising step. This study examined the effects of changes in endometrial thickness and vascularity following administration of progesterone on pregnancy rates in women who underwent frozen-thawed euploid blastocyst transfer cycles.
Methods: Overall, 200 infertile women underwent in vitro fertilization (IVF) to treat infertility. All patients received estrogen, and 10 days after the start of estrogen, if the thickness of the endometrium was more than 7 mm, progesterone was started for the patient. A transvaginal ultrasound was performed on the day of starting progesterone, and the thickness of the endometrium and endometrial view, presence of blood flow in zone III of the endometrium, and uterine artery pulsed Doppler indices were evaluated. The second time of ultrasound was performed 3 days after the initiation of progesterone, and the same parameters were checked on the day of transfer of the cleavage embryo. Eight weeks after the transfer of the embryo, a beta-human chorionic gonadotropin test and ultrasound were conducted to check the pregnancy and the presence of a fetal heartbeat.
Results: Endometrial thickness significantly decreased after progesterone administration, but it was considerably thicker in the pregnant group than in the non-pregnant. After receiving progesterone therapy, noticeable differences were observed in the appearance of the endometrium and the distribution of vascularity in zone III across the groups.
Conclusion: Endometrial thickness, view, and zone III vascularity were associated with IVF success rate, but there were no significant changes regarding Doppler indices. Whatever change in Doppler indices that occurs after progesterone administration has no significant effect on embryo transfer success rate.