Unexplained recurrent miscarriages: predictive value of immune biomarkers and immunomodulatory therapies for live birth.

Introduction Recurrent miscarriages are defined as three or more early miscarriages before 12 weeks of gestation. The aim of this study was to describe a cohort of women with unexplained recurrent miscarriages, evaluate several potential biomarkers of immune origin and describe the outcome of pregnancies under immunomodulatory therapies METHODS: Women having a history of at least 3 early miscarriages without any etiology were recruited from 3 university hospitals. Results Among 101 women with recurrent miscarriages, overall, 652 pregnancies have been included in the analysis. Women which experienced miscarriages were older (33.3 ± 5.4 versus 31.9 ± 6.7; p = 0.03), with history of more pregnancies (4 (2-6) versus 3.5 (1-5.75); p 0.0008), and less frequently the same partner (406 (74%) versus 79 (86%); p=0.01). There was no difference in the level and frequencies of biomarkers of immune origin (NK, lymphocyte, gammaglobulins and blood cytokine levels and endometrial uNK activation status), except the higher rates of positive antinuclear antibodies in women with live birth (12 (13%) versus 36 (7%); p=0.03). Among the 652 pregnancies, 215 (33%) have been treated and received either aspirin/low weighted molecular heparin (LMWH) and/or combined to different lines of immunomodulatory treatment. Patients with pregnancy under treatment had a significantly higher rate of cumulative live birth rate that those with untreated ones (43.0% vs 34.8%; p = 0.04). When compared to patients with untreated pregnancies, patients with steroids during the pregnancy had twice more chances to obtain live birth (OR 2.0, CI95% 1.1 - 3.7, p = 0.02). Conclusions Unexplained recurrent miscarriages could have improved obstetrical outcome under immunomodulatory therapies and in particular steroids.