A review on prenatal screening and diagnosis

With significant improve in health-care and treatment of infectious diseases, genetic disorders have created a new era of notification. Changes in social attitude towards family life and tendency of parents for limited number of children, sense of responsibility of parents for mental and physical healthiness of children along with their education, needed a new strategy. Since most genetic disorders did not have definitive treatments, physicians tried to prevent these disorders and their disabilities. Early diagnosis of these diseases started in 1934, and first prenatal diagnosis (amniocentesis) was reported in 1967. Rapid progress in cytogenetic and molecular genetic, necessitates each major medical center to have a "prenatal diagnosis department". The first amniocentesis in Iran was done in 1988 with a delay of 20 years. Different problems including no permission for abortion, lack of public knowledge especially authorities and physicians about provided services, and financial limitations of families to afford the expenses of laboratory tests, all were major obstacles to use this technology. Gradually, most of these problems have been solved, and nowadays many centers throughout the country provide these services. In this article, a short list of 15,600 prenatal diagnoses (amniocentesis, chorionic villus sampling, etc) including 13,225 chromosomal abnormalities, 1786 hemoglobinopathies, 283 myopathies, 197 metabolic disorders, 171 triple nucleotide repeats, 32 rare diseases, and eight dermatologic diseases are presented. From 6,473 performed amniocenteses (from 21 February 2007 to 11 April 2009) for evaluation of chromosomal abnormalities, 230 (3.6%) chromosomal abnormalities and 12 (0.2%) unsuccessful responses were documented. In other cases, except for a very few ones who ended in spontaneous abortion, pregnant women continued their pregnancy. Samplings of the amniotic fluid and the placenta were derived by experienced specialties with a very few complications (0.2%), and misdiagnosis was nearly zero.