PURPOSE: To evaluate ovarian stimulation response in couples undergoing preimplantation genetic testing (PGT-M) for myotonic dystrophy type 1 (DM1) METHODS: Retrospective, observational, multicentric study. Parameters of ovarian response and PGT-M outcomes were compared according to the DM1-affected patient (female or male). A total of 229 couples underwent at least one controlled ovarian hyperstimulation cycle for the PGT-M procedure. Overall, 678 COS cycles were started, leading to 560 cycles with oocyte retrievals and subsequent PGT-M analysis. RESULTS: At the time of the first PGT-M attempt, affected DM1 females were 1 year older and their serum AMH level was significantly lower than that of the healthy partner of affected DM1 males. After higher starting and total doses of exogenous gonadotropins, the number of mature oocytes was not statistically different between both groups (9 [6-13] vs 9 [6-13] mature oocytes, p=0.73). The FORT index was similar in both groups (35.2% [19.2-52.8] vs 33.3% [19.6-50.0], p=0.09), suggesting that antral follicle responsiveness to FSH is not altered. The live birth rate per fresh embryo transfer was 23.8% in the affected females group and 27.6% for the affected males. CONCLUSION: After adapted controlled ovarian stimulation protocol and starting dose, a similar response (number of mature oocytes) and sensitivity (FORT index) was observed in DM1 females when compared to healthy partners of DM1 males undergoing PGT-M.