Statistics from Altmetric.com
G193 TWENTY YEAR TRENDS IN LIVE BIRTH PREVALENCE OF DOWN’S SYNDROME: AN ANALYSIS OF INFLUENCES IN 1985–2004
C. Irving, A. Basu, C. Wren.Freeman Hospital, Newcastle upon Tyne, UK
Aims: To determine trends in live birth prevalence of Down’s syndrome (DS) in one health region over the last 20 years. To analyse trends in total live births, maternal age profile, antenatal screening, termination of pregnancy, and survival to one year with and without congenital heart disease (CHD).
Methods: The Northern Congenital Abnormality Survey (NorCAS) provided data on all live births and live births with DS between 1985 and 2004. Data on antenatal screening, amniocentesis, chorionic villus biopsy, termination of pregnancy, and presence of CHD were also obtained. The Office for National Statistics provided maternal age data.
Results: In 1985–2004 there were 690 215 live births in the population, with a 20% decrease in birth rate over 20 years. The proportion of mothers >35 years of age increased from 6% in 1985 to 14% in 2001. The uptake of maternal serum screening increased from zero in 1987 to 35% in 1993 but has remained at this level since. Between 1986 and 2004 there was a 39% increase in amniocenteses and a 94% increase in the number of chorionic villus biopsies. There were 377 terminations for DS (a fivefold increase in 1985–95 but constant since) and 58 stillbirths in DS pregnancies. In 20 years 738 babies were live born with DS (prevalence 1.07 per 1000 live births). Over the period of the study the prevalence of live birth of DS has remained constant at around 1 per 1000 live births. Overall 1 year survival with DS was 90% (87% in the years 1985–94 and 94% in the years 1995–2004). In DS babies with CHD, survival increased from 78% in 1985–94 to 90% in 1995–2004. Survival in DS babies without CHD was 93% in 1985–94 and 97% in 1995–2004.