Table 1.

Model input parameters.

Input parameter			Deterministic value	Probabilistic distribution	Source
IVFa costs (per cycle), €
	Hospital costs
		Hormone stimulation - medication	1580	Fixed	Fiddelers et al [9]
		Hormone stimulation - hospital care	331	Fixed	Fiddelers et al [9]
		Ovum pick-up	596	Fixed	Fiddelers et al [9]
		Lab	1339	Fixed	Fiddelers et al [9]
		Embryo transfer	316	Fixed	Fiddelers et al [9]
		Other	295	Gamma	Fiddelers et al [9]
	Other health care costs
		General practitioner	3	Gamma	Fiddelers et al [9]
		Other	13	Gamma	Fiddelers et al [9]
	Costs outside health careb
		Sick leave	569	Gamma	Fiddelers et al [9]
		Leave of absence	141		Fiddelers et al [9]
		Loss of leisure time	73	Gamma	Fiddelers et al [9]
		Out of pocket expenditures	77	Gamma	Fiddelers et al [9]
		Informal care	32	Gamma	Fiddelers et al [9]
		Other	22	Gamma	Fiddelers et al [9]
Intervention costs, €
		Smarter Pregnancy program costs	61c	Gamma	Luyendijk [12]
Lifestyle costsb, €
		Folic acid supplement use	64	Fixed	Luyendijk [12]
		Healthy nutrition	113	Fixed	Luyendijk [12]
		Smoking	1,223	Fixed	Based on data from [15] and [16]
		Alcohol consumption	913	Fixed	Based on data from [17] and [18]
Pregnancy rates usual care
		First IVF cycle	0.329	Beta	Based on Wade et al [11]
		Second IVF cycle	0.229	Beta	Based on Wade et al [11]
Pregnancy rate intervention
		First IVF cycle - 65% increase	0.543	Beta	Based on Twigt et al [8]
		Second IVF cycle - 65% increase	0.443	Beta	Based on Twigt et al [8]

^aIVF: in vitro fertilization.

^bOnly included in the analysis from a societal perspective. We assumed that the participants who smoke use 10 cigarettes per day (average daily use of smokers in the Netherlands) and that alcohol consumers drink one alcoholic beverage per day.

^cBased on the annual tariff. This is considered to be an indication for the actual costs, which mainly consist of maintenance, insurance, overhead, and text messages.