Premium
Performance of first‐trimester combined test for Down syndrome in different maternal age groups: reason for adjustments in screening policy?
Author(s) -
Engels Melanie A. J.,
Heijboer A. C.,
Blankenstein Marinus A.,
Vugt John M. G.
Publication year - 2011
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.2873
Subject(s) - advanced maternal age , medicine , pregnancy , false positive rate , down syndrome , obstetrics , fetus , odds ratio , retrospective cohort study , first trimester , odds , gynecology , logistic regression , biology , statistics , genetics , mathematics , psychiatry
Objective To evaluate the performance of the first‐trimester combined test (FCT) in different maternal age groups and to discuss whether adjustments in screening policies should be made. Methods In this retrospective study data ( n = 26 274) from a fetal medicine center on FCT (maternal age, fetal NT, free β‐human chorionic gonadotrophin, pregnancy‐associated plasma protein‐A) were studied. Results 70.6% of cases was <36 years and 43% of the Down syndrome (DS) cases were detected in this age group. For women <36 years and advanced maternal age (AMA) women (≥36 years) detection rate (DR) and false positive rate (FPR) were 94.5% and 4.1%, and 95.8% and 13.0%, respectively (cut‐off 1:200). Lowering the cut‐off showed an improved balance in DR and FPR. With increasing maternal age FPR and DR increased and odds of being affected given a positive result (OAPR) decreased. Conclusion FCT is effective in women <36 and ≥36 years. The balance between FPR and DR is more favourable in women <36 years with comparable OAPR. Although FPR increases with increasing maternal age, performance of FCT in AMA women is more effective than screening based on maternal age alone. Lowering the cut‐off to 1:100 in AMA women is suggested to improve screening performance. Routinely offering diagnostic testing to AMA women as a screening policy for the detection of DS seems not reasonable. Copyright © 2011 John Wiley & Sons, Ltd.