Plasma uric acid remains a marker of poor outcome in hypertensive pregnancy: a retrospective cohort study

Objective To examine the relationship between hyperuricaemia, haemoconcentration and maternal and fetal outcomes in hypertensive pregnancies. Design Retrospective analysis of a database of hypertensive pregnancies. Setting St George Hospital, a major obstetric unit in Australia. Population A cohort of 1880 pregnant women without underlying hypertension or renal disease, referred for management of preeclampsia or gestational hypertension. Methods Demographic, clinical and biochemical data at time of referral and delivery were collected for each pregnancy. Women were grouped according to diagnosis ( pre- eclampsia or gestational hypertension) and logistic regression analysis was used to determine the relationship between uric acid, haemoglobin, haematocrit and adverse outcomes; an a level of P < 0.01 was used for statistical significance. Main outcome measures Composites of adverse maternal and fetal outcomes. Results In women with ` benign' GH (without proteinuria or any other maternal clinical feature of pre-eclampsia) gestation-corrected hyperuricaemia was associated with increased risk of a small-forgestational- age infant (OR 2.5; 95% CI 1.3-4.8) and prematurity (OR 3.2; 95% CI 1.4-7.2), but not with adverse maternal outcome. In the whole cohort of hypertensive pregnant women (those with pre-eclampsia or gestational hypertension) the risk of adverse maternal outcome (OR 2.0; 95% CI 1.6-2.4) and adverse fetal outcome (OR 1.8; 95% CI 1.5-2.1) increased with increasing concentration of uric acid. Hyperuricaemia corrected for gestation provided additional strength to these associations. Haemoglobin and haematocrit were not associated with adverse pregnancy outcome. Conclusions Hyperuricaemia in hypertensive pregnancy remains an important finding because it identifies women at increased risk of adverse maternal and particularly fetal outcome; the latter, even in women with gestational hypertension without any other feature of pre-eclampsia.