Antioxidant defence in recurrent abortion.

Increased free radical activity has been implicated in the pathogenesis of recurrent abortion. This investigation was conducted to determine if changes in some parameters of the antioxidant system contribute to this condition. Plasma ascorbic acid, alpha-tocopherol, total thiols, ceruloplasmin, uric acid, albumin, and erythrocyte glutathione (GSH) were assayed in 25 nonpregnant (NP) healthy women, 25 normotensive pregnants (NTP), and 120 women with recurrent abortion. Recurrent aborters were divided into four subgroups according to the etiology: autoimmune (AUTO, n=25), luteal phase defect (LPD, n=25), anatomical defect (AD, n=20) and unexplained (UNEx, n=50). Plasma levels of ascorbic acid, alpha-tocopherol, and erythrocyte GSH were significantly decreased in AUTO, UNEx and LPD subgroups than those in two control groups and the AD group (ANOVA). Plasma thiols of UNEx and AUTO aborters were diminished according to controls and other abortion subgroups (ANOVA). Ceruloplasmin levels showed a decline in AUTO and UNEx subgroups when compared to controls, AD and LPD aborters (ANOVA). When UNEx, AUTO and LPD recurrent abortion subgroups were compared with each other (Student's t-test) total thiols and erythrocyte GSH of UNEx and AUTO subgroups were diminished in comparison with LPD. We suggest that decreased concentrations of plasma ascorbic acid, alpha-tocopherol, total thiols and erythrocyte GSH in UNEx, AUTO and LPD reflect the increased oxidative stress, expressing a progress of the condition. Also, the imbalance between antioxidant defence and free radical activity is more evident in the AUTO subgroup. As a conclusion, although impaired antioxidant defence may be responsible for recurrent abortions, the recurrent abortions may also result in oxidative stress and depletion and weakness of antioxidant defence.