Decreased selenium concentration in maternal and cord blood in preterm compared with term delivery†

Abstract

The Se concentration in maternal and cord whole blood and plasma was determined spectrofluorimetrically in: (1) 42 women at term and (2) 46 at preterm parturients, and in the placenta. The glutathione peroxidase (GSH-Px) activity was measured in red cells and plasma in maternal and cord blood of both groups. The Se concentrations and GSH-Px activities of the above-mentioned groups were compared with those of non-pregnant women. Whole blood and plasma Se concentration of parturients at term did not differ significantly from those of non-pregnant women (72.3 versus 80.3 ng ml-1 whole blood and 48.7 versus 56.2 ng ml-1 plasma). In preterm parturients, however, Se concentrations were significantly lower (61.1 ng ml-1 whole blood and 39.2 ng ml-1 plasma) when compared with term parturients. The Se levels in cord blood and plasma were similar to their mothers' Se concentrations. No difference was observed in placenta Se levels (130 ng g-1 wet weight in both groups). The same was true for glutathione (GSH): the concentration in maternal and cord blood of term and preterm parturients did not differ and varied from 2.43 to 2.50 mmol l-1 red cells. Red cell GSH-Px activities were similar in maternal and cord blood of both term and preterm groups and ranged from 14.3 to 15.7 U g-1 Hb. The plasma enzyme activity in the maternal blood of preterm parturients was significantly (p < 0.05) lower than that of mothers at term delivery. The GSH-Px activity in the plasma of cord blood was significantly (p < 0.001) lower in the preterm than in the term group. It is suggested that low Se levels in the blood of women at preterm delivery, as shown here, may be one of the causes of retinopathy and respiratory distress syndrome in preterm infants.

Maternal selenium status during early gestation and risk for preterm birth

“…Although lower values have often been found in mothers who had their babies preterm than in mothers who had their babies at term, the findings were inconsistent. [13][14][15] We did a prospective study to assess selenium status in a large cohort of pregnant women who were followed from early gestation to delivery.…”

“…However, several studies have shown that, in healthy pregnant women, plasma concentrations of selenium decrease linearly as pregnancy progresses, so measurement at 12 weeks' gestation is likely to be a good representation of subsequent values. 13 We chose to measure selenium during early gestation to increase our chances of seeing any early involvement of selenium in the cause of preterm birth or another adverse outcome. Measurements at a later stage of pregnancy could be confounded by the adverse outcome itself (e.g., a lack of expansion of plasma volume could show up as a higher selenium concentration).…”

Selenium and breast-feeding

“…Events related to length of gestation and reproductive experience were investigated and results comparing term and preterm total milk Se are summarized in Table 4. Total Se and GPX activity in sera of parturients delivering preterm was reported to be low (Dobrzynski et al 1998). However, the GPX activity was higher in preterm human milk (Ellis et al 1990;L'Abbe & Friel, 2000) and even increased as milk protein content declined (L' Abbe & Friel, 2000).…”

Cadmium, Lead, and Selenium in Cord Blood and Thyroid Hormone Status of Newborns

“…When Y was used as an internal standard, mean of measured Se concentration (n=3) was 125, 122, 134, 176 ng/g at m/z= 77, 78, 80, and 82, respectively, whereas reference range of the RM was 68-84 ng/g. Measured Cd and Pb concentration of the RM was 0.78±0.07 ng/g (reference 0.66-0.80) and 28±5 ng/g [27][28][29][30][31][32][33][34][35][36] when Y was used as internal standard. When standard addition technique was employed, mean of Se concentrations was 73, 71, 78, and 105 ng/g at the aforementioned m/z, respectively, and was consistent with the reference value except for that at m/z=82.…”