ANALYSIS OF THE STRUCTURE OF CONGENITAL MALFORMATIONS OF THE FETUS IN THE FIRST AND SECOND TRIMESTER OF PREGNANCY

Congenital malformations (CM) represent a significant medical and social challenge both in Ukraine and globally. World Health Organization data indicate an average prevalence of 1 congenital anomaly per 33 live births, translating to approximately 8 million affected neonates worldwide annually. . The epidemiological situation in Ukraine mirrors this concerning global trend. The purpose of this study was to examine cases of pregnancy termination for medical reasons due to embryonic and fetal congenital malformations (up to 22 weeks' gestation) recorded in Poltava and Poltava region during 2022-2024. Materials and methods. The retrospective analysis included 142 cases of medically indicated abortions due to CM. Comprehensive evaluation encompassed parental demographic characteristics including age and social status, medical history with emphasis on extragenital and hereditary pathologies, obstetric-gynecological background,, diseases during pregnancy, data from ultrasound, biochemical, non-invasive screenings and pathological findings. All study participants underwent ultrasonographic examination. First-trimester biochemical screening (11-16 gestational weeks) was performed in 45.7% of cases, assessing α-fetoprotein (AFP), β-human chorionic gonadotropin (β-hCG), and pregnancy-associated plasma protein A (PAPP-A) levels, with results standardized as multiples of the median for gestational age adjustment. Advanced prenatal testing included noninvasive prenatal testing (14.1% of cases) and chorionic villus sampling (2.8% of cases). The women included in the study signed an informed consent form after an interview about the purpose and relevance of the examinations. All studies were conducted in accordance with the principles of the Helsinki Declaration and approved by the local bioethics protocol of Poltava State Medical University №236 dated 20 March 2025. The data were calculated using the STATISTICA programme, and the results were calculated using descriptive statistical methods. Quantitative data were presented as mean values and standard deviations (M±SD). Qualitative data are presented as frequencies and percentages. Pearson's criterion was used to assess correlation relationships. Differences between indicators were considered statistically significant at p<0.05. The work is part of the initiative research project of the Department of Obstetrics and Gynaecology №1 of Poltava State Medical University ‘The pathogenetic role of endothelial dysfunction and genetic features in pathology during pregnancy and gynaecological diseases’ (state registration No. 0117U005253, term of implementation 2017-2023). Research results. The study population had a mean maternal age of 28.5 ± 4.6 years. Gynecological history revealed an average of 0.97 ± 0.02 gynecological conditions per patient. Statistical analysis demonstrated significant correlations between specific maternal infections and fetal malformations: acute respiratory infections showed strong correlation with cardiac defects (r = 0.8, p < .05), while genital infections exhibited moderate correlation with musculoskeletal abnormalities (r = 0.6, p < .05). Ultrasonographic findings indicated isolated malformations in only 25.4% of cases (n = 36), with the majority (74.6%) presenting combined malformations. Male embryos predominated (70.4%, n = 100). Musculoskeletal system defects were most prevalent (56.3%, n = 80), followed by nervous system (45.1%, n = 64), cardiovascular (38.7%, n = 55), urinary (15.4%, n = 22), digestive (10.5%, n = 15), respiratory (5.63%, n = 8), and reproductive system anomalies (2.11%, n = 3). Chorionic abnormalities occurred in 6.33% of cases, including two-vessel umbilical cord (3.52%, n = 5) and anhydramnios (2.8%, n = 4). Biochemical analysis revealed distinct patterns: neural tube defects and renal malformations showed elevated maternal AFP levels (3.3 multiples of the median [MoM]), while gastrointestinal anomalies and trisomy 13 demonstrated intermediate elevation (2.1 MoM). Trisomies 21 and 18 presented with reduced AFP (0.4 MoM) accompanied by elevated hCG (0.48 MoM). PAPP-A was decreased in chromosomal abnormalities (0.34 MoM), musculoskeletal defects (0.6 MoM), and nervous system malformations (0.49 MoM). Free estriol was uniformly reduced across all cases (0.2 MoM). Conclusions. The study population characteristics included mean maternal age of 28.5 ± 4.6 years and paternal age of 33.1 ± 5.9 years. Historical gynecological pathology was dominated by adnexal inflammatory processes (48.9% of cases), with 75.35% of women presenting complicated comorbid extragenital conditions. Musculoskeletal defects represented the most prevalent fetal anomaly (56.3%), frequently co-occurring with nervous system abnormalities (43.75%). Male fetuses accounted for 80% of these cases.