Activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in fetal erythrocytes.

It is generally accepted that the balance between the formation and inactivation of reactive oxygen species may be abolished within the perinatal period, as a consequence of rapid changes in tissue oxygen concentration and the development of antioxidant defence enzyme activities. We studied the ontogeny of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in fetal blood samples. The activity of SOD in fetal erythrocytes taken in the 17th gestational week was the same as that in erythrocytes of healthy blood donors. On the other hand, GPx activity was significantly lower between the 17th and 25th gestational week and at the time of delivery, compared with the healthy adult control. Our results suggest that the supposed underdevelopment of the antioxidant system in the lungs or in the other organs of premature infants cannot be monitored by SOD and GPx activities in erythrocytes, because these reach adult levels before the 17th week for SOD and from the 26th to the 35th gestational week for GPx, with lower levels from the 17th to the 25th week and at term.

[Fetal fibronectin in cervico-vaginal secretions--an indicator of incipient premature labor using a membrane immunoassay]. / Fetální fibronektin v cerviko-vaginálním sekretu--indikátor pocínajícího predcasného porodu metodou membránové imunoeseje.

The objective of the investigation was to test the presence of foetal fibronectin in the cervicovaginal secretion in symptomatic pregnancies and assess the possible prediction of imminent premature delivery. Prospectively 84 pregnant women were examined who were admitted to hospital with symptoms of imminent premature delivery between the 24th and 34th week of pregnancy (more than 20 contractions per day or a cervical score higher than the critical value for the given week of gestation). The secretion was collected by means of a dacron brush from the posterior labium of the portio vaginalis uteri and examined by a single-use kit FFN (Fetal Fibronectin Membrane Immunoassay, Adeza Co.). From the total of 84 specimens of secretions examined for the presence of foetal fibronectin 32 were positive and 52 negative. Of 32 pregnant women with a positive test 19 women delivered within two weeks, 13 were discharged and the deliveries took place after the 36th week of pregnancy. In the group of 52 women with a negative result of the test 50 women were discharged and the deliveries occurred after the 36th week of gestation; only two women who remained in hospital had premature deliveries within two weeks after collection of the specimen. In no patient discharged from hospital delivery occurred before the end of the 36th week of gestation. The finding of positive foetal fibronectin can be interpreted only as an increased risk of premature delivery (positive predictive value 59.4%). A negative test has a better predictive value. If the test is negative, there is a 96.1% probability that premature delivery will not occur (negative predictive value).