The prevalence of congenital anomalies: nationwide study in 2020 in Estonia

Abstract

Objective: To assess the prevalence of congenital anomalies (CAs), chromosomal abnormalities and monogenic diseases among births and terminated pregnancies due to fetal anomalies (TOPFA) in 2020 in Estonia. Up to 2020 no data on prevalence of CAs in Estonia is reported. Methods: For retrospective observational study data of all births and terminations of pregnancies after 12th gestational week from (i) the Estonian Medical Birth Registry, (ii) Abortion Registy, (iii) Health Insurance Fund and (iv) hospital records were linked. To calculate the total, live birth, stillbirth and TOPFA prevalence of CAs with 95% confidence intervals (CI), guidelines issued by EUROCAT, European network for the epidemiological surveillance of CAs, https://eu-rd-platform.jrc.ec.europa.eu/eurocat_en were followed. Results: In 2020 the total prevalence of CAs, chromosomal abnormalities and monogenic diseases in Estonia was 378.6 per 10,000 births (95% CI 346.0, 413.5). The most prevalent CAs were heart defects, 163.7 cases per 10,000 births (95%CI 142.5, 187.2). The prevalence of chromosomal abnormalities and genetic diseases was 92.6 per 10,000 births (95%CI 76.8, 110.6), 80% of cases were among TOPFAs. No newborns with major aneuploidies (Trisomy 21, 18, 13, polyploidy) were reported in 2020. Live birth prevalence of CAs, including chromosomal abnormalities and genetic diseases was 258.4 per 10,000 live births (95%CI 231.5, 287.5) and stillbirth prevalence of CAs 0.8 per 10,000 births. Conclusions: The prevalence of CAs and genetic disorders in Estonia is one of the highest compared to prevalence reported by other European regions. It indicates to high population coverage with prenatal diagnostics in Estonia. Low number of major aneuploidies among live births may reflect good detection rate of major chromosomal abnormalities and cultural preferences.