Maternal haemoglobin concentration, haematocrit and renal handling of urate in pregnancies ending in the births of small-for-dates infants.

In nine patients who gave birth to babies below the fifth centile in weight, serum urate concentration and fractional reabsorption of urate were significantly higher than in 25 control patients whose babies were of normal birth weight. Haemoglobin concentration and haematocrit were also significantly increased in the small-for-dates group. All of these changes may reflect depletion of extracellular fluid volume.