Screening for Down syndrome using first-trimester combined screening followed by second-trimester ultrasound examination in an unselected population

• Published in: American journal of obstetrics and gynecology Vol. 195; no. 5; pp. 1379 - 1387
• Main Authors: Rozenberg, Patrick, Bussières, Laurence, Chevret, Sylvie, Bernard, Jean Pierre, Malagrida, Lydia, Cuckle, Howard, Chabry, Chantal, Durand-Zaleski, Isabelle, Bidat, Laurent, Lacroix, Isabelle, Moulis, Max, Roger, Marc, Jacquemot, Marie Christine, Bault, Jean Philippe, Boukobza, Philippe, Boccara, Patrick, Vialard, Francois, Giudicelli, Yves, Ville, Yves
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Mosby, Inc 01.11.2006; Elsevier
• Subjects: Adult; Biological and medical sciences; Chromosome aberrations; Cost; Down syndrome; Down Syndrome - diagnosis; Down Syndrome - epidemiology; Female; Fetal nuchal translucency; Free human chorionic gonadotropin; Gynecology. Andrology. Obstetrics; Health Care Costs; Humans; Medical genetics; Medical sciences; Pregnancy; Pregnancy Trimester, First; Pregnancy Trimester, Second; Pregnancy-associated plasma protein A; Prenatal Diagnosis - economics; Prenatal Diagnosis - standards; Prevalence; Screening; Ultrasonography, Prenatal - economics; Ultrasonography, Prenatal - standards; Ultrasound; Screening; Fetal nuchal translucency; Free human chorionic gonadotropin; Pregnancy-associated plasma protein A; Down syndrome; Ultrasound; Cost; Chromosomal aberration; Second trimester; Costs; Trisomy; Aneuploidy; Pregnancy associated plasma protein A; Protein hormone; Fetus; Chorionic gonadotrophin; Down syndrome;Screening;Free human chorionic gonadotropin;Pregnancy-associated plasma protein A;Fetal nuchal translucency;Ultrasound;Cost; Public health; Sonography; Human; Prenatal Diagnosis; Gynecology; Chromosome G21; First trimester; Medical screening; Obstetrics; Pregnancy; Health economy; Echography; Nuchal translucency; Economic aspect
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2006.02.046

Recent studies have reported the efficacy of first-trimester combined screening for Down syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20-22 weeks’ anomaly scan. We carried out a multicenter, interventional study in the unselected population of a single health authority in order to assess the performance of first-trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free β-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein, and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for nonverified issues. A cost analysis was also performed. During the study period, 14,934 women were included. Fifty-one cases of Down syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first (n = 41) or second (n = 5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first-trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7%, and 4.2%, respectively, when combined with second-trimester ultrasound screening. The average cost of the full screening procedure was 108 € ($120) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 € ($7909). Our findings suggest that 1 pragmatic interventional 2-step approach using first-trimester combined screening followed by second-trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.