Table 3.

Use of fertility treatment to conceive a first birth among women who work night shift compared to all other women and day workers.

	Use of fertility treatment				Night shift workers vs all other women		Night shift workers vs day workers
		Night shift workers	All other women	Day workers	Unadjusted OR [95%CI]	Adjusteda OR [95%CI]	Unadjusted OR [95%CI]	Adjusteda OR [95%CI]
Women aged ≤ 35 years	n	177	1,311	1,065	1.49 [1.28–1.75]	1.40 [1.19–1.64]	1.31 [1.12–1.54]	1.27 [1.08–1.50]
	Total	10,909	111,018	79,242
	%	1.6	1.2	1.3
Women aged > 35 years	n	66	504	449	0.98 [0.75-1.28]	0.96 [0.74-1.25]	0.92 [0.71–1.21]	0.92 [0.71−1.21]
	Total	910	6,834	5,749
	%	7.3	7.4	7.8

CI, confidence interval; OR, odds ratio.

^aAnalyses adjusted for ethnicity and socio-economic indexes for areas.