Changes of plasma C-type natriuretic peptide levels in normal pregnant women and in the patients with pregnancy induced hypertension

Objective: To investigate the changes and clinical significance of plasma C type natriuretic peptide （CNP） levels in pregnant women of different gestational periods and in patients with pregnancy induced hypertension （PIH）. Methods: Plasma CNP levels were detected by radioimmunoassay in 193 subjects with different gestation age, 89 patients with PIH and 46 normal non pregnant women. Results: The plasma CNP concentration in 60 women of the first trimester （2 07±5 59） is greatly higher than that of other trimesters and healthy non pregnant women （ F =10 84, P ＜0.01）. The plasma CNP levels in patients with PIH （30 51±33 61） is significantly higher than that of normal pregnancies （19.43±5.13, F =13.61, P ＜0.01）. The plasma CNP levels of patients with mild PIH is lower, moderate nearby and severe greatly higher than that of normal pregnancies （ F =66.17, P =0.0001）。Conclusion: CNP plays a role in the regulation normal pregnancy as an autocrine/paracrine model under physiological conditions. During the whole pregnancy duration, plasma CNP levels is increased in the first trimester. CNP is also closely related to path physiological changes of PIH as a circulating peptide model under pathological conditions. The changing of plasma CNP levels from low to high is believed to be the reflection of patients PIH progress and can be used as a biochemical index for judging the progress and guiding the therapy and prevention of PIH.