Elevated circulating nitric oxide levels correlates with enhanced oxidative stress in patients with hyperemesis gravidarum.

Since the biochemical and molecular mechanisms responsible for ongoing oxidative stress in hyperemesis gravidarum (HEG) patients have not yet been fully elucidated, the aim of this study was to evaluate the possible role of nitric oxide (NO), malondialdehyde (MDA) and other oxidative stress markers in the disease pathophysiology. Moreover, the relation between oxidative stress markers and Helicobacter pylori (H. pylori) infection was also investigated. Women with pregnancies complicated by HEG (n = 33) were compared with pregnant women without HEG (n = 30) and with healthy non-pregnant women (n = 31). Serum NO, MDA, total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI) and H. pylori infection status were determined for each subject. Serum NO levels and OSI index were found to be increased (p = .001 and .013, respectively) and TAS levels were decreased (p < .001) in HEG patients compared with both controls regardless of H. pylori infection status. Serum MDA and TOS levels were not different between the study groups. Helicobacter pylori infection rates were similar in each group. The reduced antioxidant activities, as well as the increased OSI and NO levels in HEG patients indicate possible oxidative stress conditions in HEG patients. Moreover, serum NO levels may be used as an adjunctive marker to distinguish HEG patients from other causes of emesis during pregnancy. Impact statement What is already known on this subject? Current evidence suggests that oxidative stress is a significant factor responsible for a number of complications during pregnancy. What do the results of this study add? Hyperemesis gravidarum is an oxidative stress condition, as reflected by increased nitric oxide (NO) and decreased total antioxidant status activity, regardless of H. Pylori infection. What are the implications for clinical practice and/or further research? Full disclosure of the association between circulating NO and hyperemesis gravidarum would shed light on underlying biological mechanisms and could help clinical management of similar pregnancy-associated morbidity states.