Prenatal diagnosis of fetal chromosomal abnormalities: report of an 18-year experience in a Brazilian public hospital

The study of the fetal karyotype became an important tool for the fetal diagnosis of genetic diseases in the 1970s. Although application of this test has remained very restricted in Brazil, we had 905 referrals for prenatal fetal karyotyping between 1989 and 2007. In 879 cases, a fetal karyotype was obtained. We detected 74 abnormal karyotypes (8.4%), the majority being found when the prior indication was fetal malformation. When obtaining amniotic fluid or chorionic villus samples was difficult, alternative fetal materials (urine, cystic hygroma, cystic lung, intreperitoneal and cerebrospinal...