Table 7.

Odds ratio (OR) for preterm delivery and post-term delivery by maternal height¹ revertrestricted to pregnancies with spontaneous onset of delivery²

	Preterm delivery (< 37.0) weeks					Post term delivery (>42.0 weeks)
Maternal height (in quintiles)	Cases/non-cases	Crude estimate3	Adjusted estimate4	95% CI	p for trend	Cases/non-cases	Crude estimate3	Adjusted estimate4	95% CI	p for trend
Estimated date of delivery based on US
<163	25/662	1.0	1.0	Ref		22/665	1.0	1.0	Ref
163-165	18/575	0.8	0.8	0.4,1.5		15/578	0.8	0.8	0.4,1.6
166-168	17/637	0.7	0.7	0.3,1.3		36/618	1.8	1.8	1.0,3.1
169-172	18/685	0.7	0.7	0.4,1.3		29/674	1.3	1.4	0.8,2.5
173+	12/497	0.6	0.6	0.3,1.4	0.18	27/482	1.7	1.9	1.0,3.4	0.01
Estimated date of delivery based on LMP
<163	42/808	1.0	1.0	Ref		87/763	1.0	1.0	Ref
163-165	19/704	0.5	0.5	0.3,0.9		71/652	1.0	1.0	0.7,1.4
166-168	25/783	0.6	0.6	0.3,1.0		109/699	1.4	1.4	1.0,1.9
169-172	27/812	0.6	0.6	0.4,1.1		94/745	1.1	1.2	0.8,1.6
173+	25/586	0.8	0.8	0.5,1.4	0.52	76/535	1.3	1.3	0.9,1.9	0.06

¹Pregnancy length according to date of delivery estimated by ultrasound (3146 pregnancies) and by last menstrual period (3831 pregnancies). ²After exclusion of pregnancies with induced onset of delivery (medically or by Caesarean section). ³Adjusted for maternal age at HUNT participation. ⁴Additionally adjusted for maternal age at birth,duration between baseline (maternal participation in HUNT 2) and delivery, maternal education, parity, smoking, receiving social security benefits, pre-pregnancy maternal hypertension, diabetes mellitus, kidney and heart disease, BMI, systolic and diastolic blood pressure, blood concentration of glucose and lipids.

Pregnancies restricted to spontaneous onset of delivery².