Comparison of ovarian response to follitropin delta in Japanese and White IVF/ICSI patients.

ABSTRACT

RESEARCH QUESTION Is ovarian response associated with individualized follitropin delta dosing regimen comparable across different ethnic populations? DESIGN: Post-hoc analysis of ovarian response in 800 IVF/intracytoplasmic sperm injection (ICSI) patients (170 Japanese women and 630 White women) undergoing stimulation with individualized follitropin delta dosing based on serum anti-Müllerian hormone concentration and body weight in two randomized controlled trials conducted in Japan (NCT03228680) and in Europe, North America and South America (NCT01956110). RESULTS: On average, Japanese women weighed 10 kg less, which affected the total follitropin delta dose, compared with White women (83.5 ± 28.9 versus 90.2 ± 25.2 µg). At the end of stimulation, serum FSH concentrations were not significantly different between Japanese and White women (median 14.3 versus 14.0 IU/l), whereas serum oestradiol concentrations were significantly higher in Japanese women (median 6517 versus 5298 pmol/l, P < 0.0001). Japanese and White women had a similar number of oocytes retrieved with no significant differences among all women who started stimulation (9.3 ± 5.4 versus 9.5 ± 5.7), potential low responders (7.2 ± 3.7 versus 7.6 ± 4.6) or potential high responders (10.8 ± 5.9 versus 11.0 ± 6.0). At each level of ovarian response, serum oestradiol concentrations were significantly higher in Japanese women (P = 0.024). The incidence of early ovarian hyperstimulation syndrome was significantly higher in Japanese women compared with White women; overall (10.0% versus 2.2%, P = 0.0124) and at similar serum oestradiol concentrations (P = 0.0137). CONCLUSIONS: The individualized follitropin delta dosing provides similar serum FSH concentrations and similar oocyte yield in Japanese and White IVF/ICSI patients, but the oestradiol response is higher in Japanese women.