Major Chromosomal Anomalies among Very Low Birth Weight Infants in the Vermont Oxford Network

ObjectiveTo examine prevalence, characteristics, interventions, and mortality of very low birth weight (VLBW) infants with trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), or triploidy.Study designInfants with birth weight 401-1500 g admitted to centers of the Vermont Oxford Network during 1994-2009 were studied. A majority of the analyses are presented as descriptive data. Median survival times and their 95% CIs were estimated using the Kaplan-Meier approach.ResultsOf 539 509 VLBW infants, 1681 (0.31%) were diagnosed with T21, 1416 (0.26%) with T18, 435 (0.08%) with T13, and 116 (0.02%) with triploidy. Infants with T18 were the most likely to be growth restricted (79.7%). Major surgery was reported for 30.4% of infants with T21, 9.2% with T18, 6.4% with T13, and 4.8% with triploidy. Hospital mortality occurred among 33.1% of infants with T21, 89.0% with T18, 92.4% with T13, and 90.5% with triploidy. Median survival time was 4 days (95% CI, 3-4) among infants with T18 and 3 days (95% CI, 2-4) among both infants with T13 and infants with triploidy.ConclusionIn this cohort of VLBW infants, survival among infants with T18, T13, or triploidy was very poor. This information can be used to counsel families.