Ventriculomegaly in very-low-birthweight infants with Down syndrome

The prevalence of Down syndrome in infants with fetal ventriculomegaly is 5% to 10%; however, the converse, the prevalence of cerebral ventriculomegaly in live-born infants with Down syndrome, is not well established. Because cranial ultrasounds are performed on most very-low-birthweight (VLBW) infants (birthweight <1500g), our aim was to examine ultrasound abnormalities of VLBW infants to determine prevalence of ventriculomegaly and intraventricular hemorrhage (IVH) in VLBW infants with Down syndrome, and whether VLBW infants with Down syndrome are at higher risk for cranial ultrasound abnormalities, compared with the already elevated risk in other VLBW infants.

This study comprised retrospective analysis of data from Pediatrix BabySteps Clinical Data Warehouse. The study population consisted of 121 736 VLBW infants (61 869 males, 59 867 females), born between 1996 and 2013, of whom 441 had Down syndrome (233 males, 208 females; mean gestational age 30wks, standard deviation [SD] 2.8wks). Logistic regression was used to calculate odds of ventriculomegaly and IVH for Down syndrome.

Prevalence of ventriculomegaly in Down syndrome was 5.2% compared with 0.8% in other VLBW infants. Multivariate analysis indicated 5.8× odds (95% confidence interval [CI] 3.4-9.7) of ventriculomegaly in Down syndrome and 0.9× odds (95% CI 0.7-1.1) of IVH for Down syndrome.

Very preterm infants with Down syndrome are at increased risk for ventriculomegaly (but not for IVH) compared with other infants born very preterm.