Recent research demonstrates that erythrocyte sedimentation rate (ESR) increases during pregnancy. Also, both gestational age and haemoglobin concentration significantly influence ESR.
The erythrocyte sedimentation rate is one of the measurements of the acute phase response. It is helpful in detecting the presence of inflammation and its response to treatment. It is influenced by anaemia, which may be present in inflammatory diseases, and by the proteins of the acute phase response.
The research, published in the November issue of British Journal of Obstetrics and Gynaecology, was conducted to determine the range of ESR values obtained in healthy pregnant women, and to examine the effect of gestational age and haemoglobin concentration on ESR.
More than a thousand healthy pregnant women attending for routine outpatient antenatal visits at Queen Charlotte's Hospital in London were examined for the study.
It was found that gestational age and haemoglobin concentration both significantly influenced erythrocyte sedimentation rate. For non-anaemic women the 95% reference range of ESR 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.
The authors conclude that for the correct interpretation of erythrocyte sedimentation rate values obtained during pregnancy gestational age and haemoglobin concentration must be taken into account.
These results support the commonly held belief that erythrocyte sedimentation rate increases during pregnancy. The authors suggest that these values will help define the limits of the range of the erythrocyte sedimentation rate in healthy pregnant women.