Sleep duration, vital exhaustion, and odds of spontaneous preterm birth: a case–control study

Table 2 Odds Ratio (OR) and 95% confidence interval (CI) of spontaneous preterm birth according to maternal sleep duration and vital exhaustion during the first six months of pregnancy, Lima, Peru, 2009-2010

	Term Controls (N = 480)		Cases (N = 479)		Unadjusted		Adjusted*		Adjusted**
Exposure parameters	n	%	n	%	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)
Hours of sleep per night
≤ 6 hours	79	16.5	107	22.3	1.55	(1.11-2.16)	1.56	(1.11-2.19)	1.53	(1.08-2.17)
7-8 hours	325	67.7	284	59.3	1.00	referent	1.00	referent	1.00	referent
≥ 9 hours	76	15.8	88	18.4	1.33	(0.94-1.87)	1.34	(0.94-1.91)	1.50	(1.04-2.16)
Complaint of vital exhaustion
Never	185	38.5	99	20.7	1.00	referent	1.00	referent	1.00	referent
Ever	295	61.5	380	79.3	2.41	(1.81-3.21)	2.41	(1.79-3.23)	2.46	(1.83-3.32)
1-3 times/Month	204	42.5	201	41.9	*1.84*	*(1.35-2.52)*	*1.89*	*(1.38-2.60)*	*1.97*	*(1.43-2.72)*
4 times/Month - Weekly	73	15.2	156	32.6	*3.99*	*(2.76-5.78)*	*3.85*	*(2.64-5.62)*	*3.91*	*(2.67-5.73)*
Daily	18	3.8	23	4.8	*2.39*	*(1.23-4.64)*	*2.42*	*(1.23-4.76)*	*2.23*	*(1.12-4.45)*
P-value for trend						<0.001		<0.001		<0.001

*Adjusted for maternal age, pre-pregnancy weight, unplanned pregnancy, and no vitamin use during pregnancy.
**Same as above but now also include sleep duration and vital exhaustion in the model.
Bolded estimates are statistically significant at the α = 0.05 level.

ISSN: 1471-2393