Methemoglobin levels in umbilical cord blood of women with intrauterine growth restriction and preeclampsia.

ABSTRACT

OBJECTIVE: To measure nitric oxide (NO) levels, as assessed by methemoglobin (MetHb), in the umbilical cord arterial blood of women with preeclampsia (PE), normotensive pregnancies with intrauterine growth restriction (IUGR, <10th percentile for birth weight) and normotensive pregnancies with appropriate for gestational age (AGA) infants. DESIGN/METHODS: Prospective analysis of MetHb levels in umbilical arterial blood of pregnancies with PE, normotensive IUGR and normotensive AGA infants using spectrophotometry. Exclusion criteria included cigarette smoke exposure, hemolytic disorders, chronic hypertension, any significant medical illness and medications affecting NO or MetHb levels. RESULTS: There were 42 women in the PE, 42 in the AGA and 37 in the IUGR group. Maternal age, mode of delivery, gravidity, parity and infant gender were similar in the three groups. MetHb levels were significantly lower in the IUGR group compared to the AGA group (p < 0.01). MetHb levels, while higher in the PE group compared to the AGA group, did not reach statistical significance. CONCLUSION: Our data suggests that NO may play a key role in the pathogenesis of IUGR. We also, for the first time, provide information on umbilical arterial MetHb levels in PE, normotensive IUGR and normotensive AGA pregnancies.