Maternal and neonatal factors and mortality in children with Down syndrome born in 1973-1980 and 1995-1998

Aims: To investigate maternal and neonatal factors in Down syndrome (DS) at birth, the impact of a congenital heart defect (CHD) on these factors and changes over time. Methods: Medical data of children with DS born in northern Sweden in the periods 1973-1980 (n=219) and 1995-1998 (n=88) obtained from the Swedish Medical Birth Register were compared. A comparison with the general population on a group level was also made. Results: The main finding was a reduction in infant mortality in DS, from 14.2% to 2.3% in 1995-1998 (p<0.001), but this was still significantly higher than in the general population. The rate of Caesarean sections increased over time (from 14.5% to 27.3%, p<0.05) even after adjustment for increased maternal age. No change over time was detected in the following rates: premature birth (gestational age less than or equal to36) (25%); asphyxia (5-min Apgar score less than or equal to6) (8%); low birthweight (<2500 g) (14%); or small for gestational age (SGA) (14%); all rates were significantly higher than those of the general population. A CHD did not seem to influence the rates of these factors in a logistic regression model. Conclusion: Infant mortality decreased substantially over time in the DS group, whereas there was no reduction in the rate of asphyxia, SGA, low birthweight or prematurity. The presence of a CHD did not influence any of the neonatal factors studied.