Extended Injection Intervals of Gonadotropins by Intradermal Administration in IVF Treatment

Context: Gonadotropins can be administered every 5 days under intradermal injection in in vitro fertilization (IVF) treatment. Objective: To explore the effectiveness of intradermal injection of recombinant human FSH (rhFSH) for women undergoing IVF. Methods: Women who received their first IVF treatment enrolled in this prospective intervention in 2018. All women received a bolus of 900 IU rhFSH intradermally at day 2 of the treatment cycle followed by additional dosage of rhFSH at day 7 and/or day 10. The main outcome measures included the total dose of rhFSH and number of injections required, sequential serum FSH level detected, and number of mature oocytes retrieved. Results: Seventy women completed the study. On average, 2.31?±?0.73 injections and 1662?±?397 IU of rhFSH were administered. While the baseline FSH level was 5.6?±?2.2 IU/L, the serum concentrations of FSH after rhFSH administration were 35.3?±?7.0 on the first day (24 hours) and 10.7?±?3.7 IU/L on the fifth day (120 hours). A total of 10.5?±?6.6 mature oocytes were retrieved, resulting in 7.3?±?5.1 pronuclear embryos; 1.8?±?0.6 embryos were transferred to the uterus. Our findings resulted in 72% fertilization, 91% cleavage, 31% implantation, and 36% live birth rates. Although fewer larger follicles were found, noninferiority results were noted in the mature oocytes retrieved, good embryos available, and clinical pregnancy rate compared with those received conventional daily subcutaneous rhFSH administration. Conclusion: Intradermal administration of rhFSH, with a smaller dose of rhFSH and fewer injections, may achieve the goal of a cost-effective and more patient-friendly regimen.