Major chromosomal anomalies among very low birth weight infants in the Vermont Oxford Network.

OBJECTIVE: To 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 DESIGN: Infants 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.

RESULTS: Of 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.

CONCLUSION: In this cohort of VLBW infants, survival among infants with T18, T13, or triploidy was very poor. This information can be used to counsel families.