Background: Events that occur at the maternal-fetal interface define the success of pregnancy. Information on the maternal-fetal interface in the first trimester can be gained from clinical, morphological studies. An important issue, also for Moldova is risk assessment of maternal-fetal pathologies development. Material and methods: A retrospective cohort study carried out in 2712 selected cases with deregulated pregnancy in the first trimester. Results: The incidence of normal uterine site of pregnancies (79,8%) prevailed on ectopic (20,2%). In 54% of selected cases a stopped progressing pregnancy were diagnosed. The spontaneous abortion during 6-12 of gestational weeks constitute 21,3%. In 67,9% the reason were fetus abnormalities, in 20,9% were described endometrial pathologies and in 11,25% both reasons, fetus-uterine problems were diagnosed. By analyzing macro- and microscopic features of germinative components, human (or fetal) conceptus (CU/ CF) were subdivided in 6 groups: I) CF with normoform development – where embryonic and chorionic structures resemble normal morphology (CFDN); II) CF – with embryo-placental retardation (CFREP); III) CF with abnormalities (CFA) subdivided in: single (isolated) (CFAI) and combined abnormalities (CFAC); IV) CF – with anembryonic gestational sac (CFSCA); V) CF – hydatidiform mole (CFHM); VI) CF – growth-disorganized embryos (CFD). Conclusions: This study represents a first interdisciplinary research, which evaluated a complex of clinical, biochemical and pathological features of pregnancies disrupted in the first trimester. The preliminary results emphasize the existence of several groups of risk, whose structure and incidence should be evaluated by future studies.