PMC

Associations of gestational age at birth, birth weight, and infant weight gain with preschool wheezing and school-age asthma. Values are ORs (95% CIs) from multilevel models for the associations of gestational age at birth (A and B), gestational age–adjusted birth weight (C and D), and gestational age–and birth weight–adjusted infant weight gain (E and F) with asthma outcomes. Models are adjusted for confounders (see the section). Reference groups are represented by open circles.

Meta-analysis for associations of preterm birth and low birth weight with preschool wheezing and school-age asthma. A, Preterm birth and preschool wheezing. B, Preterm birth and school-age asthma. C, Low birth weight and preschool wheezing. D, Low birth weight and school-age asthma. Values from random-effects models reflect ORs (95% CIs) of preschool wheezing and school-age asthma in preterm children (<37 weeks) compared with those in children born at term (≥37 weeks) adjusted for birth weight (A and B) and of preschool wheezing and school-age asthma in low-birth-weight children (<2500 g) compared with children born with a normal birth weight (≥2500 g) adjusted for gestational age at birth (C and D). Arrows represent 95% CIs that exceed the outer limits (0.1-10). Models are adjusted for confounders (see the section).

Combined associations of gestational age at birth, birth weight, and infant weight gain with preschool wheezing and school-age asthma. Values are ORs (95% CIs) from multilevel models for the associations of gestational age at birth and birth weight SDSs (A and B), gestational age at birth and infant weight gain (C and D), and birth weight SDSs and infant weight gain (E and F) with asthma outcomes. Models are adjusted for confounders (see the section). Reference groups are represented by a white bar. P values for gestational age*SD birth weight interactions are as follows: wheezing, .97; asthma, .04. P values for gestational age*weight gain interaction are as follows: wheezing, .05; asthma, .23. P values for birth weight SDS*weight gain interactions are as follows: wheezing, .15; asthma, .57. *P < .05, **P < .01, and ***P < .001.