Do parental heights influence pregnancy length?: a population-based prospective study, HUNT 2

Table 9 Crude and adjusted associations of maternal and paternal height with offspring birth weight ¹

	N	Age-adjusted²	P for trend	Add. adjusted³	95% CI	P for trend	Add. adjusted⁴	95% CI	P for trend
Differences in z-score for birth weight
Maternal height(cm), by quintiles)
≤163	701	0		0	Ref		0	Ref
163-165	511	0.2		0.1	0.0,0.3		0.1	0.0,0.3
166-168	592	0.2		0.2	0.0,0.3		0.2	0.1,0.3
169-172	589	0.3		0.2	0.1,0.3		0.2	0.1,0.4
≥173	424	0.5	<0.0001	0.4	0.3,0.6	<0.0001	0.4	0.4,0.7	<0.0001
Paternal height (cm), by quintiles
≤ 175	668	0		0	Ref		0	Ref
176-178	518	0.2		0.1	0.0,0.3		0.1	0.0,0.3
179-181	525	0.2		0.1	0.0,0.3		0.2	0.0,0.3
182-185	582	0.3		0.2	0.1,0.3		0.2	0.1,0.4
≥186	524	0.4	<0.0001	0.3	0.1,0.4	<0.0001	0.3	0.2,0.4	<0.0001

¹Birth weight assessed as differences in sex- and gestational age-adjusted z-scores for birth weight and estimated in 2798 offspring of parents participating in HUNT 2 1995-1997. ²Adjusted for parental age at HUNT. ³Additionally adjusted for maternal age at birth, duration between Hunt2 and delivery, education, parity, smoking, receiving social security benefits and partner`s height ⁴Additionally adjusted for maternal cardiovascular risk factors: prepregnancy and gestational hypertensive disease and, diabetes of the mother⁵ z-score for birth weight indicate the standard deviations of offspring’s birth weight above or below the expected mean birth weight for gestational age and sex. A mean difference of z score = 0.1corresponds to a difference of 46 grams if the infant is male and delivered at a gestational age of 40.0 weeks. Thus, at a gestational age of 40.0 weeks, the offspring birth weight of a male newborn differ by 184 grams between the tallest and shortest maternal height groups and by 138 grams between the tallest and shortest paternal height groups.
Birth weight assessed as differences in sex-and gestational age –adjusted z-scores for birth weight and estimated in 2798 offspring of parents participating in the HUNT Study 1995-1997.

ISSN: 1471-2393