Antenatal screening for chromosomal and genetic abnormalities:Cost effectiveness and outcome

Introduction: As an essential part of antenatal care, pregnant women of all ages should be offered screening for chromosomal abnormalities before 20 weeks of gestation. This study was aimed to evaluate the type and frequency of chromosomal abnormalities following pregnancy screening tests, so that we can compare the actual pregnancy outcomes with test results, helping us in practical decision making. Methods: A cross-sectional study was conducted on 557 pregnant patients, presenting for prenatal diagnostic amniocentesis for chromosomal abnormalities, to Al-Zahra hospital, Tabriz, Iran, since 2012 to 2015. Amniocentesis was conducted by an expert obstetrician at second trimester between 16 and 22 weeks of gestation. An interview was set for pregnancy outcomes to assess the test results. Results: Of 557 cases, the mean maternal age in amniocentesis was 31.84 ± 6.92 years (range: 15-47 years). Amniocentesis revealed the presence of chromosomal abnormalities in 32 cases (5.7%). The most common diagnosed chromosomal abnormality was Down syndrome (50.0%) followed by other chromosomal abnormalities. Following up the patients, 92.4% of newborns did not have any congenital abnormality, but the remaining (7.6%) had both chromosomal and non-chromosomal abnormalities. No fetal loss was reported in this study. Assessment of total costs revealed that $US100 had been spent for hospitalization, and about $US500 for genetic tests. Conclusion: There is still no consensus on the most cost-effective strategy that should be implemented to diagnose chromosomal anomalies. Therefore, we did not have an actual gold standard to compare with amniocentesis. More studies analyzing natural outcome after prenatal diagnosis of these chromosomal abnormalities are needed