Table 2.

Binomial regression with logit link function to model the immaturity rate formulated as number of events (immature oocytes) per cohort (total collected oocytes) versus all variables that were significant from the univariate analyses. Non-linear associations were modelled with restricted cubic splines and model fits were compared using Akaike information criterion

Predictors	Risk ratio	95%CI	p-value
(Intercept)	0.23	0.20–0.27	< 0.001
Duration of ovarian stimulation [< 11 days]	0.45	0.38–0.54	< 0.001
Duration of ovarian stimulation [> 11 days]	0.89	0.71–1.11	0.306
Trigger type [GnRH agonist versus urinary hCG]	0.92	0.88–0.95	< 0.001
Ovulation trigger to oocytes’ denudation interval [< 39 h]	0.69	0.60–0.80	< 0.001
Ovulation trigger to oocytes’ denudation interval [> 39 h]	0.99	0.86–1.13	0.870
Ratio COC to fol1icle > 14 mm at ovulation trigger [< 1.13]	3.11	2.63–3.67	< 0.001
Ratio COC to fol1icle > 14 mm at ovulation trigger [> 1.13]	1.52	1.34–1.71	< 0.001