Objective  To verify if neurokinin B plasma level is increased in pre-eclampsia and IUGR. Also, to ascertain if there is a correlation between neurokinin B plasma level and nitric oxide production.

Design  A total of 90 pregnant women were studied. Thirty had a gestation complicated by pre-eclampsia and 30 by isolated IUGR; the other 30 were controls. In all patients, neurokinin B plasma level and nitric oxide metabolites (nitrites/nitrates) level were measured.

Setting  University, General Hospital, Messina, Italy.

Methods  Neurokinin B blood samples were taken at 33.5 weeks of gestation and at term. Samples for nitric oxide breakdown products were taken at delivery from the antecubital vein and then from the umbilical vein.

Results  Neurokinin B plasma levels in the pre-eclamptic and IUGR groups were significantly higher than controls. Nitric oxide metabolites levels in pre-eclamptic and IUGR patients were also higher than controls. Regression analysis showed a significant correlation among neurokinin B plasma values and nitric oxide metabolite levels either in pre-eclampsia, in IUGR or in the control group.

Conclusion  Neurokinin B could be involved in pregnancy haemodynamic adaptation via nitric oxide production. In pregnancies complicated with pre-eclampsia and IUGR, increased neurokinin B plasma level, correlated well with increased nitric oxide metabolite level, which may be a compensatory mechanism to improve blood flow to the uteroplacental unit.