Abstract P350: Profiling Of The Renin Angiotensin Aldosterone System In High Risk Human Pregnancy

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and infant morbidities and mortalities. There is a lack of clinical tools identifying subtypes of this heterogenous group of disorders, which limits optimization of individual patient care. The RAAS, a hormonal system activated during pregnancy, is suppressed in pregnancies with hypertension, but key RAAS biomarkers in subgroups of HDP have not been defined. We quantified serum biomarkers of the RAAS using LC-MS/MS in the first and third trimesters of pregnancy in a cohort of n=92 women at high-risk for preeclampsia. Data are expressed as median [IQR] of the delta of the third - first trimester. There were n=15 women that developed gestational hypertension (GH) and n=12 women that developed pre-eclampsia (Pre-e). Serum aldosterone levels increased with pregnancy in high-risk women with no adverse outcomes, but not in women that developed GH (GH, n=15: 19.4 [-321.6 - 661.6] versus Control, n=22: 502.5 [161-1019]; Data are pmol/L; P<0.01). PRA-S, a marker for activity of the RAAS that normally increases in healthy pregnancy, did not increase with pregnancy in patients that developed GH, and was further reduced in patients that developed Pre-e (GH: -17.4 [-57.1 to 2.2] versus Pre-E: -56.3 [-160.9 to -3.5] pmol/L; P<0.05). In high-risk patients that developed pre-eclampsia, aldosterone levels varied widely, depending pre-existing risk factors, such as chronic hypertension. Serum levels of RAAS biomarkers differed by pregnancy outcome and were influenced by pre-existing risk. Declining aldosterone and PRA-S over gestation may be indicative of development of Pre-e in women with clinical risk factors for Pre-e.