Enhanced urinary albumin excretion after 35 weeks of gestation and during labour in normal pregnancy

Scand J Clin Lab Invest. 1992 Sep;52(5):409-13. doi: 10.3109/00365519209088376.

Abstract

This study reports on the urinary albumin to creatinine ratio during normal pregnancy, with special emphasis on the pre-delivery and labour periods. Albumin was determined in single voided urine specimens obtained from healthy non-pregnant women (n = 16) and healthy pregnant women (n = 203; Groups A and B, 133 females examined during clinic visits and presentation at obstetric department; Group C, 70 females examined during labour) by radioimmunoassay (RIA). The mean ratio (+/- SD) for albumin/creatinine (A/Cr) in non-pregnant women was 1.46 +/- 0.32 mg mmol-1 Cr. Thus, 2.10 mg mmol-1 Cr (mean+2 SD) was considered to be the upper limit of normo-albuminuria. During pregnancy, 73% of the women (97 out of 133, Groups A and B) excreted less than or equal to 2.10 mg mmol-1 Cr. During the first 35 weeks of gestation, 30 of 34 pregnant women (88%) excreted less than or equal to 2.10 mg mmol-1 Cr, the mean being 0.93 +/- 0.64 mg mmol-1 Cr (median 1.0 mg mmol-1). During 36-42 weeks of gestation, the median A/Cr was 1.93 mg mmol-1 Cr (range 0.43-12.16) and 32 of 99 (32%) had values greater than 2.10 mg mmol-1 Cr, an increase of more than two-fold (p less than 0.031) compared with the first 35 weeks. During labour, 61% of non-haematuric urines (33 of 54, Group C) were greater than 2.10 mg mmol-1 Cr, being 125% greater (p less than 0.006) than that observed during pregnancy. Thus in normal pregnancy, A/Cr is increased during the late period of pregnancy and during labour.

MeSH terms

  • Adolescent
  • Adult
  • Albuminuria / urine*
  • Creatinine / urine
  • Female
  • Humans
  • Labor, Obstetric / urine*
  • Pregnancy / urine*
  • Pregnancy Trimester, Third

Substances

  • Creatinine