RESUMO
BACKGROUND: Oxidative stress has been related to several conditions during pregnancy (preeclampsia, abortions and premature rupture of membranes); it causes higher sensitivity of the endothelial blood vessel constriction and aggravates the endothelium dependent vasodilatación. OBJECTIVE: To determine the oxidative stress level and histological changes in preeclamptic women's placenta. PATIENTS AND METHOD: Longitudinal and comparative study. There were included 25 patients referred from second level health units (IMSS, ISSSTE and Hospital General de Zacatecas). To evaluate oxidative stress level, a sample of blood and placenta were obtained during delivery and a second sample was taken during mediate puerperium (10 days). RESULTS: In control group, total lipidic peroxide levels in serum were 135.6 +/- 7.3 nmol of MDA/mL of serum, compared with the group of moderate hypertension, which registered 222.0 +/- 35.15 nmol MDA/mL. Total lipidic peroxides in serum during puerperium for control group were 150.4 +/- 30.8 and 183.3 +/- 18.51 nmol MDA/mL for the group of moderate hypertension. Placental lipoperoxidation for control group was 0.40 +/- 0.03 microg MDNg, and of 0.32 +/- 0.03 microg MDN/g for the group of mild hypertension. Patients of moderate hypertension group showed an increase at 34% on placental lipoperoxidation over control group. Placental histological alterations where characterized by vascular remodeling loss, deposits of proteinaceous material and macrophagic process. CONCLUSION: Total lipidic peroxide levels in serum increases during preeclampsia. Histological changes refer uterus-placental ischemia that, probably, induces the oxidative stress.