MATERNAL AND FETAL NITRIC-OXIDE SYNTHESIS IS DECREASED IN PREGNANCIESWITH SMALL-FOR-GESTATIONAL-AGE INFANTS

Our purpose was to evaluate whether maternal and fetal nitric oxide sy nthesis in pregnancies with small for gestational age (SGA) infants ar e different from those in pregnancies with appropriate for gestational age (AGA) infants. Maternal and fetal circulating nitrate and nitrite concentrations were compared between 30 pregnancies with AGA and 10 p regnancies with SGA at birth. End-products of nitric oxide synthesis w ere measured in maternal and cord venous blood samples using a fluorom etric assay. Umbilical artery blood pH and PO2 were also measured. Mat ernal circulating nitrite and nitrate concentrations (6.91 +/- 1.27 mu M)in pregnancies with SGA were significantly lower than those (11.69 +/- 1.33 mu M) in pregnancies with AGA (P = 0.015). Fetal circulating nitrite and nitrate concentrations (7.54 +/- 1.09 mu M) in pregnancies with SGA were also significantly lower than those (11.24 +/- 1.08 mu M) in pregnancies with AGA (P = 0.024). There were no significant diff erences in umbilical artery blood pH and PO2 between the two groups. T hese results suggest that maternal and fetal nitric oxide synthesis ar e decreased in pregnancies with SGA infants.