Table 2.

Distribution of selected exposures in 0–24 hour and 48–72 hour windows in cases with spontaneous preterm delivery and control subjects.

	Cases (n=100)		Controls (n=158)
	0–24 h window	48–72 h window	0–24 h window	48–72 h window
Any stress	18 (18.0%)	21 (21.0%)	13 (8.2%)	11 (7.0%)
At least very stressful event	10 (10.0%)	13 (13.0%)	8 (5.1%)	8 (5.1%)
Any work	11 (11.0%)	39 (39.0%)	47 (29.8%)	72 (45.6%)
Any sexual activity	6 (6.0%)	1 (1.0%)	8 (5.1%)	12 (7.6%)
Any exercise	32 (32.0%)	28 (28.0%)	45 (28.5%)	52 (32.9%)
5+ METs	12 (12.0%)	15 (15.0%)	33 (20.9%)	32 (20.3%)
Ate spicy food	15 (15.0%)	3 (3.0%)	25 (15.8%)	20 (12.7%)
Skipped one or more meals	17 (17.0%)	7 (7.0%)	17 (10.8%)	11 (7.0%)
Disturbed sleep	26 (26.0%)	12 (12.0%)	28 (17.7%)	20 (12.7%)