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Updated: Oct 17, 2026

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Published on: August 2, 2017
[The changes of maternal and umbilical serum nitric oxide in patients with pregnancy induced hypertension]
Objective:
To determine whether levels of maternal and umbilical serum nitric oxide (NO) were changed in patients with pregnancy induced hypertension (PIH).
Methods:
40 women with PIH, 40 normal late trimester pregnant women and 20 nonpregnant women were studied. Maternal venous blood were collected from all the cases and umbilical venous blood were collected from 28 of the first two groups respectively. Serum NO2-/NO3-, the endproducts of NO, were measured with the Griess reaction after reduction with nitrate reductase.
Results:
The mean NO2-/NO3- in maternal venous serum were 23.30 +/- 5.60 mumol/L in nonpregnant group, 26.42 +/- 4.54 mumol/L in normal pregnant group and 32.58 +/- 5.06 mumol/L in PIH group. Umbilical serum NO2-/NO3- were 12.26 +/- 4.91 mumol/L in normotensive groups and 14.64 +/- 3.90 mumol/L in PIH group. Maternal serum NO2-/NO3- in nonpregnant group were lower than that both in normal pregnant group (P < 0.05) and in PIH group (P < 0.01). Compared with the normotensive group, maternal serum NO2-/NO3- in PIH group was significantly higher (P < 0.01), while significantly higher serum NO2-/NO3- were also found in umbilical venous blood in PIH group (P < 0.05). There were no correlations between serum NO2-/NO3- level and blood pressure or birth weight. The total nitrite levels in fetal circulation was lower than that in maternal circulation in both pregnant groups (P < 0.01).
Conclusion:
Total nitrites are increased both in maternal and fetal circulation in PIH. The result indicates that the increase of NO may be secondary compensative reaction in PIH.
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