The association between parity and birthweight in a longitudinal consecutive pregnancy cohort.

ABSTRACT:

Background

Nulliparity is associated with lower birthweight, but few studies have examined how within-mother changes in risk factors impact this association.

Methods

We used longitudinal electronic medical record data from a hospital-based cohort of consecutive singleton live births from 2002-2010 in Utah. To reduce bias from unobserved pregnancies, primary analyses were limited to 9484 women who entered nulliparous from 2002-2004, with 23,380 pregnancies up to parity 3. Unrestricted secondary analyses used 101,225 pregnancies from 45,212 women with pregnancies up to parity 7. We calculated gestational age and sex-specific birthweight z-scores with nulliparas as the reference. Using linear mixed models, we estimated birthweight z-score by parity adjusting for pregnancy-speci

SUBMITTER: Hinkle SN 

PROVIDER: S-EPMC3922415 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature