Prenatal and Postnatal Follow-up in Trisomies 13 and 18: A 20-Year Experience in a Tertiary Center

Perinatal Outcomes of Fetuses and Infants Diagnosed with Trisomy 13 or Trisomy 18

OBJECTIVES

To identify factors associated with prenatal, perinatal, and postnatal outcomes, and determine medical care use for fetuses and infants with trisomy 13 (T13) and trisomy 18 (T18).

STUDY DESIGN

This population-based retrospective cohort study included all prenatal and postnatal diagnoses of T13 or T18 in the greater Cincinnati area from January 1, 2012, to December 31, 2018. Overall survival, survival to hospital discharge, medical management, and maternal, fetal, and neonatal characteristics are analyzed.

RESULTS

There were 124 pregnancies (125 fetuses) that were identified, which resulted in 72 liveborn infants. Male fetal sex and hydrops were associated with a higher rate of spontaneous loss. The median length of survival was 7 and 29 days, for infants with T13 and T18, respectively. Of the 27 infants alive at 1 month of age, 13 (48%) were alive at 1 year of age. Only trisomy type (T13), goals of care (comfort care), and extremely low birthweight were associated with a shorter length of survival. A high degree of variability existed in the use of medical services, with 28% of infants undergoing at least 1 surgical procedure and some children requiring repeated (≤29) or prolonged (>1 year) hospitalizations.

CONCLUSIONS

Although many infants with T13 or T18 did not survive past the first week of life, nearly 20% lived for more than 1 year with varying degrees of medical support. The length of survival for an infant cannot be easily predicted, and surviving infants have high health care use throughout their lifespans.

A visual tool inclusive of fetal ultrasound and autopsy findings to reach a balanced approach to counseling on trisomy 18 in early second trimester

Identified by the eponym "Edwards' Syndrome," trisomy 18 (T18) represents the second most common autosomal trisomy after T21. The pathophysiology underlying the extra chromosome 18 is a nondisjunction error, mainly linked with the advanced maternal age. More frequent in female fetuses, the syndrome portends high mortality, reaching a rate of 80% of miscarriages or stillbirths. The three-step evaluation includes first trimester screening for fetal aneuploidy using a combination of maternal age, fetal nuchal translucency thickness, fetal heart rate and maternal serum free ß-hCG and PAPP-A; followed by the research for fragments of fetal DNA in maternal blood; and, finally, invasive techniques leave to the established diagnosis. Starting with the first trimester scan, selected ultrasound findings should be investigated to define not only the impact of the genetic problem on the fetus, but also to address the prenatal counseling. Previous series underline that T18 is not uniformly lethal. An active dialogue on the choices in the management of infants with T18 has emerged, sustained by the transition from the comfort care to the intervention attitude. Survival rates for individuals with supposedly fatal conditions have increased. In this novel scenario, an ad hoc counseling is pivotal. To support it, a comparative analysis by pictorial assays between ultrasound and autopsy findings could be beneficial. We provide an illustrative tool from a clinical case managed in early second trimester, with the purpose to strive a balanced approach in the hard choice faced by couples of fetuses with T18.

A rare case of postnatal mosaic trisomy 12 with severe congenital heart disease and literature review

Trisomy 12 is a rare autosomal aneuploidy. All postnatally diagnosed individuals with trisomy 12 have been mosaic for this chromosome abnormality. We herein report an infant girl presented at 2 weeks of age with severe congenital heart defect, tracheobronchomalacia, and dysmorphic features. All of the dysmorphic features of this patient fit into the known phenotype spectrum of mosaic trisomy 12, although this patient uniquely presented with macrocephaly. Tracheo-bronchomalacia has been described once previously but had a significant impact on this patient's clinical course. The patient passed away at 2-month-old due to cardiac and respiratory complications. Chromosomal single nucleotide polymorphism (SNP) microarray analysis on a peripheral blood sample from the patient revealed trisomy 12 in approximately 50% of cells. Concurrent fluorescence in situ hybridization analysis of uncultured blood cells detected a comparable level of trisomy 12 mosaicism. Compared to conventional cytogenetics, SNP microarray examines all nucleated cells without sampling bias, has an increased power to estimate mosaicism level, and can provide a quick assessment of the underlying mechanism. Here we demonstrate the utilization of SNP microarray in the clinical diagnosis of those once considered rare disorders but might have been missed by conventional cytogenetic techniques.