Features of nephropathy in various types of thrombotic microagniopathies in obstetric practice

Abstract

Introduction. We assessed the features of kidney injury in patients with different types of TMA during pregnancy, taking into consideration the fact that the acute kidney injury (AKI) that occurs during pregnancy or in the early postpartum period is main- ly caused by various types of thrombotic microangiopathies (TMA), and AKI itself is a serious obstetric complication with the risk of serious complications and mortality for both mother and fetus.Objective of the study. To study the features of nephropathy in different types of pregnancy-associated TMA.Materials and methods. The study included 313 pregnant women, women in childbirth and puerperas, of which 71 women had atypical hemolytic uremic syndrome (aHUS), 124 – HELLP syndrome, 70 – varying degrees of severity of PE, a group of patients with more rare causes of TMA was also identified: TTP, CAPS and sepsis (13 patients) and 45 patients for the control group. We assessed and compared the main clinical, laboratory and instrumental data, and assessed the outcome of labour. Also, histological examination of the kidneys was performed in five patients with aHUS.Results and discussion. The results of the study have shown that the most severe manifestations of TMA in the form of target organ injury and nephropathy are usually occur in patients with aHUS, where all women developed AKI, in some cases with the formation of chronic kidney disease. In the HELLP syndrome group, AKI was recorded in 39%, but renal function quickly restored. It was found that the very fact of the presence of AKI points to a more unfavourable prognosis not only for the patients themselves, but also for the child, being the main risk factor for perinatal death. The findings of urinary sediment tests and morphological evaluation indicate that the resulting ischemia of the renal tissue in cases of aHUS, HELLP syndrome and other types of TMA can lead to tubular necrosis as compared with PE. Our results suggest that it is AKI in HELLP syndrome that is the main risk factor for perinatal death. Alas, this relationship is difficult to trace in patients with aHUS, as all of them had AKI.Conclusions. Timely recognition of the AKI phenomenon in all cases of obstetric TMA can reduce the risks for both mother and fetus. Both the prognosis for mother and the prognosis for child depend on AKI, and timely therapy can lead to a regression of AKI phenomena and the complete restoration of renal function.

Keywords

• hellp syndrome
• hemolytic uremic syndrome
• acute kidney injury
• thrombotic microangiopathies
• pregnancy