Maternal serum uric acid levels in twin gestations

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Clinical Chemistry

Background:

• Serum uric acid is a marker for hypertensive disorders in pregnancy.
• Normative values for serum uric acid in twin gestations are not well-established.

Purpose of the Study:

• Establish normative serum uric acid values for twin gestations.
• Compare maternal serum uric acid levels in twin versus singleton pregnancies.
• Stratify comparisons by the presence or absence of preeclampsia.

Main Methods:

• Serum uric acid levels were measured in 67 normotensive and 16 preeclamptic women with twin gestations.
• Levels were compared to 83 normotensive and 10 preeclamptic singleton pregnancies.
• Receiver operating characteristic (ROC) curve analysis identified optimal cutoff values.

Main Results:

• Non-preeclamptic twin pregnancies showed higher mean serum uric acid than non-preeclamptic singleton pregnancies (5.4 vs. 4.7 mg/dL).
• Preeclamptic twin pregnancies had higher serum uric acid than preeclamptic singleton pregnancies (7.7 vs. 5.9 mg/dL).
• A serum uric acid cutoff of 6.5 mg/dL demonstrated 94% sensitivity and 78% specificity for preeclampsia in twin gestations.

Conclusions:

• Women with twin gestations exhibit elevated serum uric acid levels compared to singleton gestations, irrespective of preeclampsia.
• Separate normative values for serum uric acid are needed for twin pregnancies.
• A serum uric acid level of ≥6.5 mg/dL is proposed as a risk indicator for preeclampsia in women with twin gestations.