Table 4.

Associations Between Gestational Age and Incidence of Poor CRF Through Adolescence to Young Adulthood (N=791)^a

Main Determinant	Model 1			Model 2			Model 3
Gestational Age	RR	95% CI	P Value	RR	95% CI	P Value	RR	95% CI	P Value
Per wk	0.86	0.77–0.96	0.008	0.86	0.76–0.96	0.009	0.87	0.79–0.97	0.011
Per category
Early term	1.00	Ref.	···	1.00	Ref.	···	1.00	Ref.	···
Full term	0.66	0.48–0.91	0.010	0.65	0.47–0.89	0.008	0.71	0.52–0.97	0.032
Late term	0.60	0.40–0.90	0.014	0.59	0.40–0.90	0.013	0.64	0.44–0.93	0.021
P value, linear trendb			0.012			0.011			0.021

Model 1, adjusted for cohort, age, sex, age×sex, and birth weight Z scores; model 2, model 1 plus adjustments for socioeconomic status, maternal age at child's birth, delivery mode, breastfeeding, maternal body mass index, and maternal smoking history; model 3, model 2 plus adjustment for height, maturity level, and total body fatness (sum of 4 skinfolds). Ref. indicates reference; RR, incident risk ratio of poor cardiorespiratory fitness through adolescence to young adulthood per week increase in gestational age or between individuals who were born full (n=533) or late term (n=148) vs early term (n=110); CRF indicates cardiorespiratory fitness.

^aDefined on the basis of the following age‐ and sex‐specific cut points for maximal oxygen uptake (in mL/kg per minute): <41.8 (childhood and adolescence) and <33 (young adulthood) in males and <34.6 (childhood and adolescence) and <24 (young adulthood) in females.

^bMean gestational ages per gestational age category were 37.7 weeks (early term), 39.7 weeks (full term), and 41.1 weeks (late term).