Evaluation of adrenomedullin and endothelin-1: Are they factors in the adaptation of maternal vascular system in normotensive pregnancy

INTRODUCTION: The aim of our study was to analyse the role of adrenomedullin (AM) and endothelin-1 (ET-1) in the adaptation of the maternal vascular system in normotensive pregnancy. METHODS: Twenty-eight pregnant women, who were normotensive throughout the duration of their pregnancy, were recruited into the study. Plasma levels of AM and ET-1 at each trimester were measured and the AM/ET-1 ratio was calculated. RESULTS: Our experiment showed a significant decrease in plasma concentrations of AM in the first trimester for the study group (n=28) compared with the non-pregnant control group (n=16). There was also a significant decrease in plasma concentrations of ET-1 in all three trimesters (P<0.05) and a significant increase in the AM/ET-1 ratio in all three trimesters (P<0.05) for the study group compared with the control group. CONCLUSION: An alteration in vascular equilibrium between AM and ET-1, favouring AM, may be a reason why the physiological adaptation of the maternal vascular system to pregnancy occurs during normotensive pregnancy.