Chorionic villus sampling (CVS) has been used as a successful and safe first-trimester prenatal diagnostic technique for over 12 years. Developed to avoid the medical and psychological complications of later prenatal diagnosis by amniocentesis, CVS rapidly became a primary tool for the diagnosis of fetal cytogenetic, molecular, and biochemical disorders. In addition, its development has led to an improved understanding of several biologic processes, including confined placental mosaicism and uniparental disomy. It has also opened up an active debate on the potential of early prenatal diagnostic procedures to cause congenital abnormalities.

The ability to sample and analyze villus tissue from the developing placenta was demonstrated over 25 years ago by the Chinese.<sup>31 Department of Obstetrics and Gynecology, Tietung Hospital of Anshan Iron and Steel Co Anshan, China: Fetal sex prediction by sex chromatin of chorionic villi cells during early pregnancy Chinese Med J 1975 ;  1 : 117

Haga clic aquí para ir a la sección de Referencias</sup> In an attempt to develop a safe first-trimester technique for accurately determining fetal sex, these investigators passed a thin catheter through the cervix until resistance from the gestational sac was felt, applied suction and aspirated small pieces of villus material. These were analyzed by sex chromatin evaluation; full karyotyping was not performed. Despite the fact that this technique seems relatively crude by today's standards of ultrasonically guided invasive procedures, the diagnostic accuracy and low miscarriage rate in their experience demonstrated that invasion of the early first-trimester uterus is both safe and feasible.

Subsequent investigators attempted to improve villus retrieval by using optically directed biopsies of the chorion frondosum using transcervically inserted modified cystoscopes.<sup>54 Hahneman N. Early prenatal diagnosis: A study of biopsy techniques and cell culturing from extraembryonic membranes Clin Genet 1974 ;  6 : 294

Haga clic aquí para ir a la sección de Referencias, 55 Hahnemann N., Mohr J. Genetic diagnosis in the embryo by means of biopsy from extraembryonic membranes Bull Eur Soc Hum Genet 1968 ;  2 : 23

Haga clic aquí para ir a la sección de Referencias, 56 Hahnemann N., Mohr J. Antenatal foetal diagnosis in genetic disease Bull Eur Soc Hum Genet 1969 ;  3 : 47

Haga clic aquí para ir a la sección de Referencias, 77 Kullander S., Sandahl B. Fetal chromosome analysis after transcervical placental biopsies during early pregnancy Obstet Gynecol Scand 1979 ;  52 : 355

Haga clic aquí para ir a la sección de Referencias, 90 Mohr J. Foetal genetic diagnosis: Development of techniques for early sampling of foetal cells Acta Pathol Microbiol Scand 1968 ;  73 : 7377

Haga clic aquí para ir a la sección de Referencias</sup> These attempts did not improve tissue retrieval, were technically difficult (frequently complicated by inadvertent tearing of the amnion), and had an unacceptable miscarriage rate. With the development of real-time ultrasound guidance came the ability to direct small sampling instruments into the developing chorion frondosum accurately and atraumatically.<sup>75 Kazy Z., Rozovsky I.S., Bakharev V.A. Chorion biopsy in early pregnancy: A method of early prenatal diagnosis for inherited disorders Prenat Diagn 1982 ;  2 : 39

Haga clic aquí para ir a la sección de Referencias, 130 Ward R.H.T., Modell B., Petrou M. , y al. Method of sampling chorionic villi in first trimester of pregnancy under guidance of real-time ultrasound Br Med J 1983 ;  286 : 1542

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