Female BMI and Body Weight Is Not Associated with Oocyte Yield and Maturation in hCG, Agonist or Dual Trigger Cycles: A Large Observational Study including 5000 Cycles.

Background: Triggering final oocyte maturation is a key step of ovarian stimulation. Although previous studies demonstrated a negative association between female BMI and serum hCG levels, little evidence is available regarding the association between oocyte yield and patients' BMI. The scope of the current study was to examine whether the efficiency of the r-hCG and triptorelin to trigger final oocyte maturation may be associated with patients' BMI or weight.

Methods: This is a retrospective observational study including 5190 ovarian stimulation cycles performed between January 2019 and September 2022 in the Reproductive Medicine Department of Dexeus University Hospital. Cycles were analyzed according to the type of trigger (triptorelin vs. r-hCG vs. dual). The primary outcome measures were oocyte maturation rate (MII/oocytes) and FOI (oocytes/AFC); secondary outcomes were oocyte and MII yield.

Results: Multivariable regression analysis, adjusting for confounding factors, demonstrated that BMI was not associated with oocyte maturation rate (OR: 1.00 [95%CI: 0.99; 1.01]), FOI (Beta 0.52 [95%CI: -0.49; 1.54]), number of oocytes (Beta 0.02 [95%CI: -0.08; 0.13]) or MIIs (Beta 0.01 [95%CI: -0.08; 0.10]) retrieved. Similarly, all analyses conducted considering patients' weight failed to reveal any association.

Conclusion: Our study demonstrates that, independent of the type of trigger, patients' BMI and weight are not associated with oocyte yield, maturation, or FOI.