Intervention
BLOOD, GROUP B
Outpatients who met the inclusion and exclusion criteria for this research were selected as potential candidates for this study. Prior to their participation, the researcher provided a description of the study’s purpose, methodology, potential benefits, and risks. Participants were, only after they signed the informed consent form, recruited for the study. A computer-generated random number table was used to allocate eligible participants into two groups (Group A and Group B) in a 1:1 ratio. Group A participants (letrozole 2.5 mg/FSH group) received a daily dosage of 2.5 mg letrozole (Furui, Jiangsu Hengrui Medicine Co., Ltd., Lianyungang, China) from cycle days 3 to 7, followed by a sequential therapy of 75 IU FSH (urofollitropin, Lizhu Pharmaceutical Factory, Zhuhai, China) daily from cycle days 8 to 10. Participants in Group B (letrozole 5 mg/FSH group) were given 5 mg of letrozole daily from cycle days 3 to 7, followed by sequential therapy with 75 IU of FSH daily on cycle days 8 to 10. The duration of FSH administration varies according to follicular development. Vaginal B-ultrasound was utilized to monitor follicular development beginning on day 11 of the cycle. During scanning, the number/size of follicles and endometrial thickness were measured. Blood was drawn to detect the sex hormone concentration when at least one dominant follicle reached ≥ 18 mm, and then 10,000 IU human chorionic gonadotrophin (HCG) was injected intramuscularly to trigger ovulation. Participants were advised to engage in intercourse 24 to 36 hours later. In order to monitor ovulation, a vaginal B-ultrasound was conducted 48 hours after HCG injection. Two weeks of Dydrogesterone were consumed orally. Quantitative HCG testing was carried out two weeks later to diagnose conception, and B-ultrasound was conducted four weeks later to diagnose clinical pregnancy. Each participant underwent one to three cycles of treatment until pregnancy was achieved.