Premature rupture of the fetal membrane is a major cause of preterm birth and it is associated with infant morbidity. To examine the relationship between maternal oxidative stress (OS) and antioxidant statue and premature rupture of membranes (PROM). 30 pregnant women with PROM and 30 normal pregnant women were compared for maternal malonaldihyde concentration, erythrocyte glutathione (GSH) concentration, glutathione peroxidase (G-PX) and catalase (CAT) activities, using a cross sectional study and spectrophotometer method. Unpaired t test and Chi-square test were used for comparison of variables between controls and patient groups. A significant reduction was found in fthe GSH concentration of the PROM subjects when compared to the controls (6.40±0.43 µmol/g of Hb versus 7.28±0.40 µmol/g of Hb, P <0.001). The G-PX and CAT activities of the PROM population were significantly lower than controls (35±9.41 versus 44.17±11.92 U/g Hb, P=0.01 and 149.83±31.86 U/g of Hb versus 172.07±47.14U/g of Hb, P<0.01, respectively). The maximal rate of oxidation (Vmax) was shorter in the PROM group when compared to the control group (0.0068±0.00003 versus 0.008±0.00003, OD245 nm/min, P=0.01), whereas the maximal accumulation of absorbing products (ODmax) of the PROM subjects was higher than in the controls (0.73±0.013 versus 0.68±0.017 OD245 nm, P=0.01). The lag phase, reflecting resistance of serum lipids to oxidation, was different in the PROM group when compared to the control group (47.90±2.13 versus 53.53±2.54 min, P=0.01). The maternal malondialdehyde (MAD) percentage of the PROM group was higher than controls (75.62±3.73% versus 63.80±9.32%, P=0.001). Present study revealed that PROM is associated with decreased maternal erythrocyte antioxidant activities. As opposed to term labor, PROM is associated with increased maternal systemic OSwhen compared to normal pregnant women. The role for OSin preterm PROM warrants further studies.
Key words: Oxidative stress, antioxidant, premature, rubture, membrane.