Longitudinal changes in serum paraoxonase-1 activity throughout normal pregnancy.

The aim of this study was to investigate the longitudinal changes in serum paraoxonase-1 (PON1) activity from preconception throughout normal pregnancy and their relationships with maternal dietary vitamin C and E intake. The study was performed in 35 women (studied at preconception, at 8, 20 and 32 weeks of pregnancy, and at labour). PON1 activity decreased significantly from 145.8 (109.8-198.8) U/L at preconception to 111.1 (85.3-179.9) U/L (p<0.01) at 32 weeks and 100.4 (54.7-171.4) U/L (p<0.001) at labour. There was a direct association between vitamin C intake and PON1 at week 32 (p=0.018). We conclude that adequate vitamin C intake in pregnant women may merit consideration, since vitamin C supplementation has proved beneficial in the prevention of preeclampsia in women at increased risk of this condition.