Table 2.

Two-step cluster analysis in SPSS to identify mother reported pet-ownership types (from 14,663 fetuses).

Variable	Included data (%)	Cluster name	Distribution (%)
Any pet—up to (and including) 7yrs	46	Never owned a pet	25
		Sometime owned a pet	38
		Always owned a pet	37
Dog—up to (and including) 7yrs	46	Never owned a dog	68
		Sometime owned a dog	17
		Always owned a dog	15
Any pet—all years (up to and including 10yrs)	37	Sometimes owned a pet	53
		Always owned a pet	47
Dog—all years (up to and including 10yrs)	37	Never owned a dog	64
		Sometime owned a dog	36