Objective: To compare two dosages of recombinant human follicle-stimulating hormone for controlled ovarian stimulation.
Design: Prospective, randomised double-blind study.
Setting: Tertiary assisted reproduction unit, Hong Kong.
Participants: Forty subfertile Chinese women aged 24 to 38 years undergoing in vitro fertilisation. Entry criteria included good physical and mental health, and a body mass index between 18 and 29 kg/m2. Exclusion criteria were subfertility caused by an endocrine abnormality, polycystic ovarian syndrome, or absent ovarian function; previous assisted reproduction treatment in which fewer than three oocytes were retrieved; prior hospitalisation due to severe ovarian hyperstimulation syndrome; chronic cardiovascular, hepatic, renal, or pulmonary disease; alcohol or drug abuse; and the administration of investigational drugs within the previous 3 months.
Intervention: Injection of recombinant follicle-stimulating hormone, 100 IU/d or 200 IU/d.
Main outcome measures: The number of oocytes, total dose of drug used, and pregnancy rates.
Results: Compared with the 20 women receiving 200 IU/d, the 20 who received 100 IU/d had a significantly lower median number of oocytes retrieved and median total dose of drug used (7.5 versus 15.0 [P<0.001] and 1200 IU versus 2000 IU [P<0.001], respectively). The pregnancy rates in the fresh cycles were similar (20%) in both groups, but the cumulative pregnancy rates in the 100 IU/d and 200 IU/d groups were 20.0% and 45.0% per stimulated cycle, respectively. The incidence of ovarian hyperstimulation syndrome in the 100 IU/d and 200 IU/d groups was 5.0% and 20.0%, respectively.
Conclusions: Use of 100 IU/d of recombinant follicle-stimulating hormone requires a lower total dose but results in the harvest of half the number of oocytes compared with when a dosage of 200 IU/d is used.