Trisomy 18: Experience of a reference hospital from the south of Brazil

Abstract

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.

Retrospective cohort of trisomy 18 (Edwards syndrome) in southern Brazil

“…The average maternal age observed (34.4 years) was similar to that described by Rosa et al 4 (33.9 years). The maternal age was similar to the paternal age (mean of 33.9 years).…”

“…These high rates of cesarean section have also been frequently described in the literature (50 to 90%). 4,5,13,17,19,20 It is noteworthy that there are some studies specifically drawing attention to this finding. 17 In our sample, we believe that this feature was related to prenatal detection of major malformations, which thus influenced the choice of cesarean section as the delivery route.…”

“…3 T18 is clinically characterized by a broad clinical picture, with more than 130 different findings already described, and a prognosis that is considered poor. 2,4 Most fetuses diagnosed during gestation are spontaneously aborted and, among those that are born alive, most die within the first six months. 1,2,4 In Brazil, prenatal identification of patients with T18 is important in determining issues relating to their evolution and prognosis, as well as their birth and clinical management.…”

“…2,4 Most fetuses diagnosed during gestation are spontaneously aborted and, among those that are born alive, most die within the first six months. 1,2,4 In Brazil, prenatal identification of patients with T18 is important in determining issues relating to their evolution and prognosis, as well as their birth and clinical management. Many countries have also adopted a more interventionist stance and have made more investment in cases that come to birth, thereby increasingly respecting family autonomy in decision-making.…”

“…4,5,[17][18][19] However, it is noteworthy that some authors have found equal frequencies of the sexes in evaluations performed during the prenatal period, 20 especially before the 18 th week of gestation. 21 These features may perhaps be related to the fact that female patients have been associated with a greater chance of being born alive and surviving for longer periods than boys.…”