We are all aware of the increased risk of various congenital heart defects in babies born with Down syndrome, but we never stop to think if the nature of the defects might change over time. Fortunately, Bergstrom et al. (peds.2016-0123) did wonder about these trends and this week we publish their analysis of a Swedish cohort of more than 2500 infants with Down syndrome from 1992-2012.
The authors looked at risk ratios for various congenital heart lesions in patients with Down syndrome adjusting for a variety of possible confounders including such things as maternal age, parity, BMI, smoking and illnesses like diabetes and hypertension. The findings of their analysis are quite interesting in that while they found that the risk of any defect did not differ by year of birth, the risk of being born with a complex congenital heart disease in the setting of Down syndrome did decrease over time with a drop in severe risk of almost 40%. Since the overall risk did not change, that means that less serious lesions such as atrial and ventricular septal defects increased over the same period of time.
So why have the most serious lesions become less common over time? Cardiologists Dr. Tiffany Riehle-Colarusso and Matthew Oster (peds.2016-1223)offer their opinion in a commentary (REF) that accompanies this study and gets to the heart of the matter, trying to make sense of the changing trends. Read both the study and commentary and learn more.