Maternal urine albumin excretion and pregnancy outcome

Am J Kidney Dis. 2005 Jun;45(6):1010-8. doi: 10.1053/j.ajkd.2005.02.030.

Abstract

Background: Vascular dysfunction has been hypothesized as a causal pathway for preeclampsia, impaired fetal growth, and early parturition. The relationship between increased urine albumin excretion (albuminuria), a marker of endothelial dysfunction, and preterm birth has not been fully evaluated.

Methods: We conducted a nested case-control study of 404 pregnancies from 1998 to 2000 within the Pregnancy, Infection and Nutrition cohort. Cases consisting of live births delivered before 37 weeks of gestation (preterm birth, n = 111) were compared with term births from the same cohort (n = 293). Albumin-creatinine ratio (in milligrams per gram) was measured in urine collected around 27 weeks of gestation. We compared risks for preterm birth in mothers with albuminuria with albumin levels of 3 to 20 mg/g and greater than 20 mg/g relative to those with albumin levels less than 3 mg/g by using logistic regression.

Results: Median albuminuria was albumin level of 2.7 and 4.3 mg/g for term and preterm births, respectively. Albuminuria was strongly associated with preterm birth in a dose-response fashion, with adjusted odds ratios of 1.9 (95% confidence interval, 1.1 to 3.1) and 4.7 (95% confidence interval, 1.7 to 12.6) for albuminuria with albumin of 3 to 20 mg/g and greater than 20 mg/g, respectively. The association was present for both spontaneous and medically induced preterm births, but the effect was decreased and the dose-response relationship was eliminated by excluding high-risk groups and those with pregnancy complications.

Conclusion: Low levels of albuminuria are associated with preterm birth. The mechanism underlying this association warrants additional exploration.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • African Americans / statistics & numerical data
  • Albuminuria / epidemiology*
  • Case-Control Studies
  • Cohort Studies
  • Endothelium, Vascular / physiopathology
  • European Continental Ancestry Group / statistics & numerical data
  • Female
  • Humans
  • Hypertension / epidemiology
  • Hypertension, Pregnancy-Induced / epidemiology
  • Infant, Newborn
  • Infant, Premature
  • Labor, Induced / statistics & numerical data
  • North Carolina / epidemiology
  • Obesity / epidemiology
  • Obstetric Labor, Premature / epidemiology
  • Pre-Eclampsia / epidemiology
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Complications / epidemiology*
  • Pregnancy Outcome*
  • Pregnancy Trimester, Third
  • Smoking / epidemiology