A big study looked at whether a woman's body‑mass index (BMI) or weight changes how many eggs are retrieved and how well they mature when using the hormone triggers triptorelin, hCG, or a mix of both. They found no link – heavier or lighter women got the same number and quality of eggs as others, regardless of the trigger used.

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