Nitric oxide production is not altered in preeclampsia

Preeclampsia remains a disease of theories as the real aetiology has remained elusive. Altered nitric oxide production has been associated with preeclampsia although conflicting results showing elevation, decrease or no change in nitric oxide levels have emerged from previous studies.

The aim of the study was to measure the serum levels of nitrate and nitrite in normal pregnancies and pregnancies complicated by pre-eclampsia.

Venous blood was extracted from 39 normal pregnant women (control) and 34 women with preeclampsia (study group). Serum concentrations of nitrate and nitrite were determined using the HPLC method. Other special investigations including renal function tests were performed. The patients were managed according to protocol and the outcome of the pregnancies evaluated.

There was no significant difference in the mean maternal age and gestational age at delivery between the groups. However the mean systolic and diastolic blood pressure of the study group (150.5 mmHg and 98.8 mmHg) were significantly higher than the levels in the control group, (110.86 and 85.5), p<0.0001. There was no significant difference in the mean serum nitrate levels (19.157+/-13.407 vs. 19.189+/-16.805) p=0.993. The fetal and maternal outcomes were comparable.

Our study has demonstrated that there was no alteration in nitric oxide production in preeclampsia, thus contributing to the existing unresolved role of nitric oxide in the pathogenesis of preeclampsia. Further research is called for.