Lone hyperuricemia during pregnancy: maternal and fetal outcomes

Uric acid and risk of pre-eclampsia: results from a large case-control study and meta-analysis of prospective studies

To quantify the association between maternal uric acid levels and pre-eclampsia risk in a large collection of primigravid women. A case-control study (1365 cases of pre-eclampsia and 1886 normotensive controls) was conducted. Pre-eclampsia was defined as blood pressure ≥ 140/90 mmHg and proteinuria ≥ 300 mg/24 h. Sub-outcome analysis included early, intermediate, and late pre-eclampsia. Multivariable analysis for pre-eclampsia and its sub-outcomes was conducted using binary and multinomial logistic regression, respectively. Additionally, a systematic review and meta-analysis of cohort studies measuring uric acid levels < 20 weeks of gestation was performed to rule out reverse causation. There was a positive linear association between increasing uric acid levels and presence of pre-eclampsia. Adjusted odds ratio of pre-eclampsia was 1.21 (95%CI 1.11-1.33) for every one standard deviation increase in uric acid levels. No differences in the magnitude of association were observed between early and late pre-eclampsia. Three studies with uric acid measured < 20 weeks' gestation were identified, with a pooled OR for pre-eclampsia of 1.46 (95%CI 1.22-1.75) for a top vs. bottom quartile comparison. Maternal uric acid levels are associated with risk of pre-eclampsia. Mendelian randomisation studies would be helpful to further explore the causal role of uric acid in pre-eclampsia.

Birth Weight < 3rd Percentile Prediction Using Additional Biochemical Markers-The Uric Acid Level and Angiogenesis Markers (sFlt-1, PlGF)-An Exploratory Study

(1) Aim: Ultrasound is the gold standard for assessing fetal growth disorders. The relationship between high sFlt-1/PlGF scores and LBW (low birth weight) was described. In this study, we attempted to assess whether uric acid could be used as a secondary marker in estimating the pregnancy risk associated with LBW. (2) Material and methods: 665 pregnant women with a suspected or confirmed form of placental insufficiency were enrolled. In each of the patients, sFlt-1 and PlGF and uric acid levels were determined. Patients were divided into two groups according to birth weight below and above the third percentile for the given gestational age with the criteria of the neonatal definition of FGR (fetal growth restriction). (3) Results: A significant negative correlation between neonatal birth weight and the uric acid level across the entire study group was observed. We found a significant negative correlation between neonatal birth weight and the uric acid level with birth weights < 3rd percentile. (4) Conclusions: There is a significant link between the uric acid concentration and LBW in the group with placental insufficiency. Uric acid can improve the prediction of LBW. An algorithm for LBW prognosis that makes use of biophysical (ultrasound) and biochemical (uric acid level, angiogenesis markers) parameters yields better results than using these parameters separately from each other.

Increase in maternal adiposity and poor lipid profile is associated with oxidative stress markers during pregnancy

OBJECTIVE

This study aimed to evaluate changes in maternal adiposity and lipid profile and to correlate these parameters with Deoxyribonucleic acid (DNA) damage and total antioxidant capacity (TAC) levels among pregnant women.

METHOD

This was a longitudinal study which took place in Kelantan state, Malaysia. Fasting blood samples of 159 healthy pregnant women were collected in second and third trimesters from April 2010 until October 2011. Maternal total body fat was assessed using bioimpedance analysis method.

RESULTS

When compared to data in second trimester, pregnant women in third trimester showed significantly higher levels of total body fat (p<0.001), total cholesterol (p<0.001), triglyceride (p<0.001), LDL-C (p=0.001), DNA damage (p<0.001) and TAC (p<0.001) but a lower level of HDL-C (p<0.001). Maternal adiposity and lipid profile were positively and consistently correlated with DNA damage in second and third trimesters. Significant and positive correlations of triglyceride with TAC levels were noted in both periods indicating compensatory action against increased oxidative stress.

CONCLUSION

Normal pregnancy is associated with marked changes in lipid metabolism, prooxidant and antioxidant status. Dyslipidemia-associated oxidative stress was demonstrated with advancing gestational age. Appropriate preventive and compensatory measures should be practiced to minimize the effect of oxidative stress throughout pregnancy.

Uric acid: is it time to give up routine testing in management of pre-eclampsia?

Ever since it was first linked with the pathophysiology of pre-eclampsia, uric acid has been a routine test requested by many care-givers managing pregnant women with hypertensive disease of pregnancy for almost 100 years. Existing evidence however suggests that it has no definitive role in prediction, diagnosis or management of pre-eclampsia. We argue against routine uric acid testing in pregnancies complicated by hypertension not only because it has become a fruitless academic exercise but also because ceasing its routine use will ensure cost-savings for the health services.

Does uric acid provide information about maternal condition and fetal outcome in pregnant women with hypertension?

OBJECTIVE

To evaluate associations between maternal serum uric acid (UA) levels, maternal status, and fetal outcome.

METHODS

Maternal UA, urinary protein-creatinine ratio (P/C), blood pressure (BP), gestational age at delivery, and birth weight were evaluated in hypertensive pregnant women (n = 58). These were divided into two groups: high UA (> or =357 micromol/L) or normal UA (<357 micromol/L).

RESULTS

Maternal diastolic BP and P/C ratio were higher in pregnant women with elevated UA levels. Systolic BP, gestational age and birth weight were not significantly different.

CONCLUSION

UA equal or above 357 micromol/L in pregnant hypertensive women was associated with proteinuria and diastolic BP, but not with fetal outcome.

Uric acid and preeclampsia

Increased uric acid level is a key clinical feature of preeclampsia; higher levels correlate with significant maternal and fetal morbidity and mortality. The cause of hyperuricemia and its specific role in the pathogenesis of preeclampsia, however, remain unclear. Although uric acid has been shown to roughly parallel the severity of the maternal syndrome, it has not been useful in predicting the development of preeclampsia. Nevertheless, there have been recent data supporting a pathogenic role potentially in the hypertension and endothelial cell dysfunction of preeclampsia. This article reviews our current understanding of hyperuricemia in the setting of preeclampsia, and highlights the hypothesis that hyperuricemia may contribute to vascular damage in preeclampsia.

[Important elevation of uric acid associated with vomiting at the third trimester of pregnancy: report of five cases with favorable outcome]

We report five cases of vomiting associated with a very important increase of maternal plasma uric acid (> 595 mmol/l, 100 mg/l) at the third trimester of pregnancy. In all cases, elevation was transitory and regressive with rehydratation. Pregnancies proceeded normally to term and delivered healthy babies. An important rise of plasmatic uric acid during pregnancy can be found in severe hypertensive disorders (preeclampsia, HELLP syndrome, acute fatty liver). Nevertheless, it can be related to transient renal insufficiency without any severe pathology. In our five observations, digestive disorders seem to be the reason for this phenomenon and spontaneous prognosis was excellent in all cases.

Oxidative stress and normal pregnancy

OBJECTIVE

To determine whether, in normal pregnancies, there is evidence of oxidative stress that is related to the lipid changes observed in pregnancy.

DESIGN

Longitudinal study of healthy women having a normal pregnancy. Samples were obtained towards the end of each trimester and after 8 weeks postpartum.

PATIENTS

Seventeen healthy women during a normal singleton pregnancy were compared with 12 healthy, non-pregnant women.

MEASUREMENTS

Oxidative stress was determined by measuring total antioxidant capacity (TAC), uric acid and lipid hydroperoxides (LHP). Lipid status was evaluated by measuring total and high-density lipoprotein cholesterol, triglycerides and low-density lipoprotein (LDL) subfractions.

RESULTS

Pregnancy was associated with decreased TAC and uric acid in the first trimester, which gradually increased during pregnancy, reaching normal values during the postpartum period. LHP significantly increased towards the end of pregnancy. The changes observed in LHP were significantly correlated with increases in LDL subfraction profile.

CONCLUSIONS

Late pregnancy was associated with the formation of susceptible, oxidisable particles (high LDL score) and an increase in oxidative damage. These biochemical changes may be relevant for the long-term cardiovascular health of women, especially those of high parity or those who are at high risk for cardiovascular disease (e.g. women with diabetes).

Maternal endothelial soluble cell adhesion molecules with isolated small for gestational age fetuses: comparison with pre-eclampsia

OBJECTIVE

1. To evaluate the activation profile of the endothelium in pregnancies complicated by small for gestational age fetuses compared with pre-eclampsia and normal pregnancy, by measuring the plasma levels of soluble adhesion molecules soluble E-selectin, intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1. 2. To determine whether soluble adhesion molecules were related to the severity of small for gestational age fetuses and pre-eclampsia.

DESIGN

Observational study.

PARTICIPANTS

Sixteen women with small for gestational age fetuses; 15 women with pre-eclampsia and 15 healthy primigravidae were recruited as controls.

METHODS

Plasma levels of soluble E-selectin, intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 were measured by ELISA.

RESULTS

Compared with the healthy controls, soluble E-selectin was significantly increased in both small for gestational age fetuses and pre-eclampsia, whereas intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 were increased only in pre-eclampsia. In the small for gestational age fetuses group, soluble E-selectin correlated inversely with the ratio between birthweight and the expected normal birthweight (r = -0.4, P = 0.007). In the pre-eclampsia group, a significant correlation was observed between vascular cell adhesion molecule-1 and blood pressure (r = 0.54, P = 0.039).

CONCLUSIONS

Endothelial activation, reflected by raised levels of soluble E-selectin, is a feature of small for gestational age fetuses and is correlated with the severity of the disease. Differences in the profile of soluble cell adhesion molecules suggest variations in the degrees of endothelial activation between pre-eclampsia and small for gestational age fetuses.