Prenatal diagnosis of critical congenital heart defects in Kazakhstan: a single-center 8 years’ experience

Abstract

Purpose. To give a quantitative and qualitative assessment of the results of prenatal diagnosis of critical congenital heart defects in the Republic of Kazakhstan based on the treatment of newborns at the head cardiac surgery center.Methods. A retrospective analysis of the medical records of 511 newborns with critical congenital heart defects treated at the National Research Cardiac Surgery Center (NRCSC) in 2012–2019 was performed. The proportion of those operated on was 474/511 (92.8%). The studied parameters were the presence of prenatal diagnosis of critical congenital heart defects (yes/no); prenatal diagnosis formulation; postnatal diagnosis formulation; discrepancy between pre- and postnatal diagnoses (yes/no); for a prenatally diagnosed newborn — the gestational age at the time of the diagnosis and the region where the diagnosis was firstly made.Results. Prenatally, 297/511 (58.1%) newborns were diagnosed. The rate of discrepancies between pre- and postnatal diagnoses was 62/288 (21.5%). According to the timing of the prenatal diagnosis, newborns were distributed as follows: first trimester screening — 20/272 (7.4%), second trimester screening — 139/272 (51.1%), third trimester screening — 113/272 (41.5%). Up to 22 weeks of gestation, 71/272 (26.1%) patients were diagnosed. Among the newborns treated at the NRCSC, the proportion of those diagnosed prenatally in different regions of the Kazakhstan varies from 20% to 100%.Conclusions. 1) Prenatal diagnosis of critical congenital heart defects is carried out in all regions of Kazakhstan, providing an acceptable level of detection; 2) in half of the cases, critical congenital heart defects are diagnosed during the second screening, however, there is an experience of their accurate detection as early as during the first screening; 3) individually, doctors of ultrasound diagnostics in Kazakhstan apply an extended protocol for examining the fetal heart; 4) a significant proportion of fetuses diagnosed before the 22nd week of gestation shows the choice of families in favor of carrying of a pregnancy when a critical congenital heart defects is detected; 5) the greatest difficulty for prenatal diagnosis is presented by patients with total anomalous pulmonary veins return.