Trisomy 18: experience of a reference hospital from the south of Brazil.

Trisomy 18 is a chromosomal syndrome characterized by a broad clinical picture, as well as a very reserved prognosis. The aim of our study was to verify the clinical characteristics and survival of patients diagnosed in a referral hospital in southern Brazil. Our sample consisted of 31 patients, 22 were female (71%), ages ranging from 1 to 1,395 days (median 14 days). The majority had a single cell lineage with full trisomy of chromosome 18 (94%). Concerning pregnancy complications, pre-eclampsia was the main abnormality described (17%). Fetal ultrasound was performed in 23 cases, and the most frequent abnormalities were polyhydramnios (41%) and intrauterine growth retardation (27%). There were no reports of prenatal identification of the syndrome. Most patients were born by cesarean due to pregnancy and fetal complications and about half of the cases were premature. Congenital heart defects represented the main major malformation observed (94%). Thirty patients (97%) progressed to death (survival ranged from 2 to 780 days, and 87% died within the first 6 months of life). Trisomy 18 is a serious chromosomal disorder with limited survival. Abnormalities of pregnancy appear to be frequent, which can lead to complications for both fetus and mother. The prenatal identification of these patients in our country is still inadequate, resulting in important implications for genetic counseling and management of these patients and their families. And this makes the possibility of interruption of pregnancy, regardless of ethical factors involved, an unlikely option.