Objective: To determine the concentrations of the low molecular weight anti
oxidants urate, bilirubin, albumin and sulphydryl groups and to measure lip
id peroxidation levels in pair-matched maternal and cord blood plasma.
Design: Venous blood plasma concentrations of urate, bilirubin, albumin and
sulphydryls were determined in healthy pregnant women and in pair matched
umbilical cords. The ability of maternal and cord plasma to withstand Cu2+-
induced lipid peroxidation was assessed by measuring the production of thio
barbituric acid reactive substances (TBARS) over time in plasma incubated w
ith Cu2+.
Subjects: Forty healthy women, between 10 and 20 weeks gestation, were recr
uited randomly from an antenatal clinic. Venous blood samples were obtained
from the mothers at the recruitment stage and from the umbilical cords of
their newborn after delivery.
Results: Urate, bilirubin and sulphydryls were present in significantly hig
her concentrations (P < 0.001) in cord plasma than in maternal plasma. Albu
min levels were similar in mothers and cords. Significantly lower levels (P
= 0.018) of TBARS were produced in cord plasma compared with maternal plas
ma following incubation with Cu2+. There were significant correlations betw
een albumin and sulphydryl concentrations in maternal plasma (r 0.43, P = 0
.007) and between urate concentrations in maternal and cord plasma (r 0.37,
P = 0.026).
Conclusion: Urate, bilirubin and sulphydryls are present in significantly h
igher concentrations in cord blood than in maternal blood. The increased le
vels of these antioxidants in cord plasma may contribute to the increased r
esistance of cord plasma to Cu2+-induced lipid peroxidation.
Sponsorship: University College Cork, Ireland.
Descriptors: pregnancy; neonates; blood plasma; antioxidants; lipid peroxid
ation.