Effect modification by developmental stage of embryos on the association between late follicular phase progesterone elevation and live birth in fresh transfers

Table 2 Effect modification of stage of embryos on influence of progesterone on probability of live birth

	Cleavage-Stage Embryo Transferred			Blastocyst-Stage Embryo Transferred			*P-value for interaction test
	Crude	Model I^a	Model II^b	Crude	Model I^a	Model II^b	Crude	Model I^a	Model II^b
	OR (95% CI) P-value	aOR (95% CI) P-value	aOR (95% CI) P-value	OR (95% CI) P-value	aOR (95% CI) P-value	aOR (95% CI) P-value	Crude	Model I^a	Model II^b
Progesterone as a continuous variable	0.87 (0.73, 1.03) 0.095	0.79 (0.65, 0.97) 0.021	0.80 (0.65, 0.98) 0.032	0.66 (0.56, 0.78) < 0.001	0.59 (0.49, 0.72) < 0.001	0.61 (0.50, 0.73) < 0.001	0.021	0.018	0.016

Generalized estimate equation were used
CI Confidence interval, OR Odd ratio
^aModel I model adjusted for: age, gonadotrophin consumption, basal FSH, AFC, E₂ levels on trigger day, oocytes retrieved
^bModel II adjusted for: age, gonadotrophin consumption, basal FSH, AFC, E₂ levels on trigger day, oocytes retrieved, BMI categories, number of embryos viable and transferred
^*P-value for interaction test: 2-way interaction of stage of embryo transfer (cleavage vs blastocyst) and serum progesterone concentrations on live birth

ISSN: 1471-2393