An AMH-based FSH dosing algorithm for OHSS risk reduction in first cycle antagonist protocol for IVF/ICSI.

The study assessed the impact of an AMH algorithm for FSH dosing in 589 patients to maintain pregnancy rates while minimizing OHSS rates in 1st antagonist cycles for IVF. Patients with low AMH < 12 pmol/L (n = 203) had maximal stimulation with corifollitropin, patients with AMH 12-32 pmol/L (n = 256) had standard stimulation with 150 IU/day of rFSH and patients with AMH > 32 pmol/L (n = 130) had minimal stimulation with 112 IU/day of HP-hMG. The proportion of patients with targeted (5-14) number of oocytes at retrieval was: Low AMH 42%, intermediate AMH 76% and high AMH 67% (p < 0.001). Low responses (≤ 4 oocytes) was found in 55%, 16% and 26% (p < 0.001) in the low, intermediate and high AMH group, respectively. Excessive responses (≥15 oocytes) was found in 2.5%, 6.2% and 6.1% in the low, intermediate and high AMH groups, respectively. Despite the high proportion of low responses, the ongoing pregnancy rates in the high AMH group was 41% per started cycle. A total of 14 patients had OHSS preventive actions like agonist triggering (n = 12) and/or cryopreservation of all embryos (n = 4) and all avoided OHSS. Three (0.5%) patients were admitted to hospital with severe OHSS, and all occurred after hCG triggering and all cases were late OHSS in relation to pregnancy. All were in the high AMH group after aspiration of 10-15 follicles. The conclusion is that among high AMH patients, low dose HP-hMG will limit the mean number of oocytes, without compromising pregnancy rates. The OHSS risk will be low, but as long as transfer after hCG triggering is used OHSS will occur unless a cut-off for OHSS preventive actions as low as 10-15 follicles is used.