More invasive procedures are done to detect each case of Down's syndrome in younger women.

Department of Obstetrics and Gynecology, Oulu University Hospital, Oulu, Finland.

Acta obstetricia et gynecologica Scandinavica 2011 Jun

filter terms:

To evaluate the performance of first-trimester combined screening in 5-year periods according to maternal age in a low-risk population. A prospective study. Multicenter study in Finland. A total of 76949 voluntary women with singleton pregnancies participated in first-trimester combined screening in public healthcare between 1 May 2002 and 31 December 2008. The serum samples were analyzed using the PerkinElmer AutoDELFIA® time-resolved fluoroimmunoassay kit for the measurement of pregnancy-associated plasma protein-A and free beta-human chorionic gonadotropin. Nuchal translucency was measured by trained personnel (midwives or physicians) in a university or central hospital. Performance, detection rate, false positive rate and the number of invasive procedures needed to detect a single case of Down's syndrome were analyzed. There was a direct connection between maternal age and the prevalence of Down's syndrome with a low prevalence in young women being 1:1 193 in the 25-29 age group and 1:150 in the 35-39 age group. Consequently, for a fixed false positive rate of 5%, the number of invasive procedures needed to detect one case of Down's syndrome is higher in younger women to achieve the same detection rate. In combined first trimester screening the risk for Down's syndrome is individual, varying with maternal age. This should be taken into consideration when counseling women. © 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.

Citation

Jaana Marttala, Jenni K Ranta, Marja Kaijomaa, Pentti Nieminen, Paivi Laitinen, Hannaleena Kokkonen, Jarkko Romppanen, Esa Hamalainen, Johanna Kultti, Aydin Tekay, Veli-Matti Ulander, Timppa Honkasalo, Markku Ryynanen. More invasive procedures are done to detect each case of Down's syndrome in younger women. Acta obstetricia et gynecologica Scandinavica. 2011 Jun;90(6):642-7