IMPORTANCE OF THE PRENATAL SCREENING IN DIAGNOSTICS OF CONGENITAL ANOMALY OF A FETUS

SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 126 IMPORTANCE OF THE PRENATAL SCREENING IN DIAGNOSTICS OF CONGENITAL ANOMALY OF A FETUS G.A. Yusupaliyeva1, I.A. Shamansurova2 Tashkent State Medical University1,2 https://doi.org/10.5281/zenodo.17468189 Abstract. We have assessed the screening efficiency in the the first trimester of pregnancy by the prenatal ultrasound examination in the diagnostics of fetal congenital anomaly. For the assesment of individual risk of birth of children with chromosomal syndromes and define the indications for the invasive manipulations was done this investigation. Keywords: prenatal diagnostics, prenatal screening, chromosomal abnormalities, sonographic markers. Introduction Many researchers have shown the low effectiveness of prenatal screening focused on the second trimester of pregnancy, as well as the use of ultrasound examination in the absence of control over the quality of measurements of fetometric parameters and echo markers (2). In Uzbekistan, screening is carried out according to the national clinical protocol “Antenatal care, management of pregnant women at risk”, according to order No. 195, approved by the Ministry of Health of the Republic of Uzbekistan on June 14, 2024 (1). Congenital and hereditary diseases in the fetus are prevented through mass screening of women in the first three months of pregnancy and the gradual introduction of biochemical testing for genetic syndromes in pregnant women at risk. In order to increase the effectiveness of prenatal screening examinations and prevent the birth of children with congenital malformations and hereditary (chromosomal) diseases that do not allow preserving the health and life of the fetus, pregnant women undergo three-stage prenatal screening examinations. During the first stage of prenatal screening, all pregnant women undergo a mass ultrasound examination. As a result, pregnant women with congenital malformations are included in the "risk group." These examinations are conducted three times in the prenatal examination rooms of district (city) central multidisciplinary clinics. The first examination is conducted between 11 and 13.6 weeks of pregnancy, the second time to identify congenital defects in the child is between 16 and 20 weeks, and the third time is between 28 and 32 weeks to identify late-diagnosed congenital defects and assess the functional state of the fetus. The first examination is conducted between 11 and 13.6 weeks of pregnancy, the second time to identify congenital defects in the child is between 16 and 20 weeks, and the third time is between 28 and 32 weeks to identify late-diagnosed congenital defects and assess the functional state of the fetus. The screening center conducts ultrasound and biochemical screening tests, and based on the results, pregnant women who are found to have a high risk of giving birth to a fetus with chromosomal syndromes undergo invasive examination methods (chorionic villus sampling, placentacentesis, cordocentesis), followed by genetic analysis of fetal cells and other tests. Following the second stage of prenatal screening, the pregnant woman receives a medical genetic report. If congenital malformations or genetic (chromosomal) diseases are detected in the fetus, the pregnant woman is referred to the appropriate clinic with the medical genetic report. This SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 127 medical genetic report is submitted for review The medical advisory commission of the district (city) multidisciplinary central polyclinic. The commission provides full information to the pregnant woman and her close relatives, discussing the results of prenatal screening tests, the presence of congenital malformations in the fetus, Their impact on the health and life of the child after birth, treatment methods and the associated risks, possible medical procedures and their consequences, and the potential or potential benefits of such treatment. After this, the pregnant woman and her immediate family decide whether to continue the pregnancy. I would like to emphasize that the allocation of additional staff for midwives in all "medical teams" has facilitated the organization of the screening process. District and city prenatal screening offices are now providing hourly schedules, and home care and forward the examination results to the appropriate specialist at the local clinic. Study objective: To evaluate the effectiveness of early prenatal screening in identifying birth defects in primary healthcare. Material and methods. In the antenatal examination room of the central multidisciplinary polyclinic of the Mirabad district, 549 women were examined for congenital malformations (CM) based on the results of prenatal ultrasound screening (USS). Ultrasound examination was performed on a Voluson P6 (USA) device. Ultrasound scanning was performed on all women registered for pregnancy at 11–13+6 weeks (3, 4, 5). Clarifying ultrasound diagnostics were performed on high-risk patients was carried out in the prenatal diagnostics room on the Voluson P6 device using transducers with a frequency of 3.5 and 5.0 MHz according to the generally accepted transabdominal technique. The study included 549 pregnant women registered with a gynecologist. All patients underwent prenatal ultrasound screening (USS) according to a standard protocol, as well as an assessment of their medical history and clinical data. The patients were distributed according to gestational age as follows: • First trimester (11–13.6 weeks) — 147 women (26.8%), • Second trimester (16–20 weeks) — 294 women (53.6%), • Third trimester (28–32 weeks) — 108 women (19.6%). First Trimester During early prenatal screening, two pregnant women (1.36%) were found to have severe fetal congenital malformations (CM): • Anencephaly — 1 case, • Cervical hygroma — 1 case. Both patients were classified as high-risk and referred to the National Center for Prenatal Diagnosis for confirmation and medical consultation regarding pregnancy termination. In addition, 7 women (4.76%) were found to have hyperechogenic foci in the left ventricular cavity of the fetal heart, regarded as “soft sonographic markers” of potential chromosomal abnormalities (primarily trisomy 21). All women with these markers were referred for biochemical screening (PAPP-A and free β-hCG testing) to further assess their individual risk of chromosomal abnormalities. Five patients (3.4%) demonstrated sonographic signs of amniotic bands that were clinically insignificant but required follow-up observation to exclude fetal compression or limb restriction. Thus, the overall rate of ultrasound findings requiring additional evaluation or follow-up in the first trimester was 9.5% of all examined women during this period. Second Trimester. In the second trimester (16–20 weeks), the main focus was on confirming structural anomalies and assessing fetal functional status. SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 128 • 3 women (1.0%) were found to have cardiovascular anomalies (ventricular septal defect, echogenic cardiac focus, or venous sinus dilation). • 2 women (0.68%) presented with mild renal pelvis dilation (pyelectasia), considered isolated and requiring observation. • In isolated cases, mild polyhydramnios and placental thickening were observed. Third Trimester In the third trimester (28–32 weeks), the primary aim was to assess the functional condition of the fetus and placenta. • 6 patients (5.5%) showed signs of fetal growth restriction (FGR), • 4 patients (3.7%) — polyhydramnios, • 3 patients (2.8%) — placental hypoplasia with grade I blood flow disturbance. All of these patients were placed under dynamic monitoring and received corrective treatment as indicated. Summary of Findings Among the 549 examined pregnant women: • 2 (0.36%) had severe congenital fetal malformations incompatible with life, • 7 (1.27%) had soft sonographic markers of chromosomal abnormalities, • 5 (0.91%) had minor ultrasound findings without clinical significance, • 14 (2.55%) in total presented with various pathological findings requiring observation. Considering the number of examinations, the rate of significant anomalies detected during early ultrasound screening was 1 in 275 pregnancies, which corresponds to international data on the sensitivity of early combined screening (80–90% with a false-positive rate of 3–5%). Conclusion: Thus, the conducted study demonstrated that early prenatal ultrasound screening, performed at the expert diagnostic level in the first trimester of pregnancy, is an effective method for the primary detection of fetal congenital and chromosomal abnormalities. Ultrasound examinations carried out between 11 and 13.6 weeks of gestation made it possible to reliably identify pregnant women belonging to the high-risk group for congenital and chromosomal pathologies, which is a key step in determining further pregnancy management tactics. Despite the relatively low frequency of severe congenital malformations (0.36%), their early detection ensured timely referral of patients to specialized centers for diagnostic clarification and clinical decision-making. The identification of soft sonographic markers (1.27%) and minor ultrasound findings (0.91%) allowed for the selection of a cohort of pregnant women requiring dynamic observation and additional biochemical testing, thereby increasing the overall informativeness and specificity of the screening process. Early detection of severe and lifeincompatible fetal malformations has significant medical and social importance, as it enables families to make an informed decision about the continuation of pregnancy based on an objective prenatal diagnosis. Timely and high-quality early ultrasound screening contributes to: • the prevention of births of children with uncorrectable congenital and chromosomal anomalies; • optimization of pregnancy management and rational selection of delivery tactics; • timely preparation for postnatal treatment in cases of correctable fetal malformations; • reduction of infant mortality, morbidity, and disability associated with congenital and hereditary diseases. Conclusion SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 129 Therefore, the results of this study confirm that the integration of early ultrasound screening into the primary healthcare system is an effective tool for improving the quality of prenatal diagnostics and preventing congenital pathologies in newborns. Detection rates of first-trimester fetal anomalies ranged from 32% in low-risk groups to more than 60% in high-risk groups, demonstrating that first-trimester ultrasound has the potential to identify a large proportion of fetuses affected with structural anomalies. The use of a standardized anatomical protocol improves the sensitivity of first-trimester ultrasound screening for all anomalies and major anomalies in populations of varying risk. The development and introduction of international protocols with standard anatomical views should be undertaken in order to optimize first-trimester anomaly detection. REFERENCES 1. «Антенатальный уход, ведение беременных групп риска», приказ МЗ РУз от 14 июня 2024 г. 2. Медведев М.В., Юдина Е.В. Дифференциальная пренатальная ультразвуковая диагностика. 4-е изд., перер. – М.: Реал Тайм, 2010. – 160 с. 3. Николаидес К. Ультразвуковое исследование в 11–13+6 недель беременности. Перевод с английского А. Михайлова, Е. Некрасовой. Санкт-Петербург, ИД «Петрополис», 2007 г. — 144 с. 4. Nicolaides K. N. A model for a new pyramid of prenatal care based on the 11 to 13 weeks’ assessment. Prenat. Diagn. 2011; 31(1): 3–6. 9. 5. Nicolaides K. N. Screening for fetal aneuploidies at 11 to 13 weeks. Prenat. Diagn. 2011; 31(1): 7–15.