Objectives: To determine the range of erythrocyte sedimentation rate values obtained in healthy pregnant women. To examine the effect of gestational age and haemoglobin concentration on erythrocyte sedimentation rate.
Setting: Queen Charlotte's Hospital, London, UK.
Design: Cross sectional descriptive study. Population Healthy pregnant women attending for routine outpatient antenatal visits at Queen Charlotte's Hospital in London.
Methods: Erythrocyte sedimentation rate was determined by the Westergren method, haemoglobin concentration by automated cell counter and gestational age by ultrasonography. The median and 95% reference range was determined for erythrocyte sedimentation rate values obtained. Linear regression analysis was used to determine the influence of haemoglobin concentration and gestational age on erythrocyte sedimentation rate.
Results: For 1,019 women examined, the range of erythrocyte sedimentation rate values obtained was 4-112 mm/ h. Gestational age and haemoglobin concentration both significantly influenced erythrocyte sedimentation rate. (P < 0.0001). For non-anaemic women the 95% reference range rose from 18-48 mm/h in the first half of pregnancy to 30-70 mm/h in the second half of pregnancy. For anaemic women the corresponding reference ranges were 21-62 mm/h and 40-95 mm/h, respectively.
Conclusion: For the correct interpretation of erythrocyte sedimentation rate values obtained during pregnancy gestational age and haemoglobin concentration must be taken into account.