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

Abstract

Research questionIs ovarian response associated with individualized follitropin delta dosing regimen comparable across different ethnic populations? DesignPost-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). ResultsOn 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). ConclusionsThe 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.