Contingent screening for Down syndrome is an efficient alternative to non‐disclosure sequential screening

To present a first and second trimester Down syndrome screening strategy, whereby second‐trimester marker determination is contingent on the first‐trimester results. Unlike non‐disclosure sequential screening (‘the Integrated test’), which requires all women to have markers in both trimesters, this allows a large proportion of the women to complete screening in the first trimester.

[1]  A. Herman,et al.  A model for disclosing the first trimester part of an integrated Down's syndrome screening test , 2004, Clinical genetics.

[2]  R. Snijders,et al.  First-trimester screening for trisomies 21 and 18. , 2004, The New England journal of medicine.

[3]  R. Snijders,et al.  First-trimester screening for trisomies 21 and 18 , 2003 .

[4]  K. Nicolaides,et al.  Screening for chromosomal abnormalities in the first trimester using ultrasound and maternal serum biochemistry in a one‐stop clinic: a review of three years prospective experience , 2003, BJOG : an international journal of obstetrics and gynaecology.

[5]  N J Wald,et al.  First and second trimester antenatal screening for Down's syndrome: the results of the Serum, Urine and Ultrasound Screening Study (SURUSS). , 2003, Health technology assessment.

[6]  K. Nicolaides,et al.  One‐stop clinic for assessment of risk for trisomy 21 at 11–14 weeks: a prospective study of 15 030 pregnancies , 2002, Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology.

[7]  M. Christiansen,et al.  An increase in cost‐effectiveness of first trimester maternal screening programmes for fetal chromosome anomalies is obtained by contingent testing , 2002, Prenatal diagnosis.

[8]  A. Herman,et al.  Comparison between disclosure and non-disclosure approaches for trisomy 21 screening tests. , 2002, Human reproduction.

[9]  H. Cuckle,et al.  Growing complexity in the choice of Down's syndrome screening policy , 2002, Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology.

[10]  E. Hafner,et al.  The first trimester ‘combined test’ for the detection of Down syndrome pregnancies in 4939 unselected pregnancies , 2002, Prenatal diagnosis.

[11]  F. Bahlmann,et al.  Screening for trisomy 21 by maternal age, fetal nuchal translucency and maternal serum biochemistry at 11–14 weeks: a German multicenter study , 2002, The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians.

[12]  D. Krantz,et al.  First‐Trimester Down Syndrome Screening Using Dried Blood Biochemistry and Nuchal Translucency , 2000, Obstetrics and gynecology.

[13]  N. Wald,et al.  Integrated Screening for Down’s Syndrome Based on Tests Performed During the First and Second Trimesters , 2000 .

[14]  F. Orlandi,et al.  First-trimester Down syndrome screening. , 2000, American Journal of Obstetrics and Gynecology.

[15]  I. Bray,et al.  Estimating birth prevalence of Down's syndrome. , 2000, Journal of epidemiology and biostatistics.

[16]  R. Bahado-Singh,et al.  Prenatal screening for Down's syndrome--a search for the family's values. , 1999, The New England journal of medicine.

[17]  N. Wald,et al.  Integrated screening for Down's syndrome based on tests performed during the first and second trimesters. , 1999, The New England journal of medicine.

[18]  P. Royston,et al.  Model-based screening by risk with application to Down's syndrome. , 1992, Statistics in medicine.

[19]  S J Pocock,et al.  Interim analyses for randomized clinical trials: the group sequential approach. , 1982, Biometrics.

[20]  J. Aitchison,et al.  Statistical Prediction Analysis , 1975 .