Accounting for urinary dilution in peri-implantation samples: implications for creatinine adjustment and specimen pooling.

ABSTRACT: This study examines critical issues in accounting for urinary dilution in peri-implantation samples used to assess environmental exposures. Early pregnancy could impact creatinine excretion, which could bias biomarker measurement and interpretation when creatinine adjustment is used. We compared creatinine levels pre-implantation with levels soon after implantation at 3-6 weeks gestation. Using data and urine specimens from 145 women who conceived, we used linear mixed models to estimate the effect of pregnancy on creatinine concentrations. We also studied whether creatinine adjustment is biased when using pooled, within-person samples rather than averaging individually-adjusted results. For this, we grouped 2655 daily urinary estrogen metabolite and associated creatinine measures into 762

SUBMITTER: Rosen Vollmar AK 

PROVIDER: S-EPMC7671945 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature