RESUMO
Aim of the study - the assessment of the diagnostic value of Progesterone-Induced Blocking Factor (PIBF) in Early Pregnancy Loss (EPL), in naturally conceived women and in women who underwent In Vitro Fertilization (IVF). In the prospective and retrospective study 50 naturally conceived women were divided into three groups: Group I - patients with progressive pregnancy; Group II- patients with EPL; Group III - patients with biochemical pregnancy (BP). 36 pregnant women after IVF were divided into three groups: Group IV - patients with progressive pregnancy, Group V - patients with EPL, and Group VI - patients with BP. ß human Chorionic Gonadotropin (ßhCG), PIBF and Progesterone (PG) were assessed in the women conceived naturally and after IVF on the 12th to 14th day after ovulation and embryo transfer (ET), respectively. PG and PIBF levels were significantly higher in the progressive and significantly lower in the biochemical pregnancy groups as in the naturally conceived women, so after IVF. PIBF was not significantly different in EPL and BP groups of naturally conceived and IVF pregnant, opposite to the PG, which was significantly lower in the BP group. Thus, PIBF is more informative in the prognosis of EPL and PG - in the diagnosis of clinical pregnancy. PIBF emerges as a prognostic indicator for early pregnancy loss, encompassing even its preclinical stage.