First-trimester screening for trisomy 21 combining biochemistry and ultrasound at individually optimal gestational ages. An interventional study (original) (raw)
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Two-stage first-trimester screening for trisomy 21 by ultrasound assessment and biochemical testing
Ultrasound in Obstetrics and Gynecology, 2010
K E Y W O R D S: ductus venosus flow; nasal bone; nuchal translucency; screening for trisomy 21; tricuspid regurgitation ABSTRACT Objectives This study was carried out to examine the performance of a contingent policy in first-trimester screening for trisomy 21, in which the estimated risk was first derived by a combination of maternal age, fetal nuchal translucency (NT) thickness, presence/absence of the nasal bone, blood flow in the ductus venosus or flow across the tricuspid valve, and biochemical testing was carried out only in those who were found to have an intermediate risk. We also examined the performance of a policy in which the estimated risk was first derived by a combination of maternal age and biochemical testing, and ultrasound examination was carried out only in those with an intermediate risk.
Prospective validation of first-trimester combined screening for trisomy 21
Ultrasound in Obstetrics and Gynecology, 2009
Objective To examine the performance of the new algorithm in screening for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) and maternal serum free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A).
Fetal Diagnosis and Therapy, 2006
Objective: To examine the efficacy of first trimester screening for trisomy 21 using a combination of maternal age, fetal nuchal translucency (NT), maternal serum free β-human chorionic gonadotropin (free β-hCG) and pregnancy-associated plasma protein A (PAPP-A) in a regional setting [maternity unit of the Women’s University Hospital, Hannover Medical School (study center); two regional private centers for prenatal diagnosis and human genetics; laboratory for prenatal diagnosis and human genetics]. Methods: Fetal NT, crown-rump length, maternal serum free β-hCG and PAPP-A were measured at 11–14 weeks of gestation. Risk calculation was carried out using the FMF computer algorithm. The patients were informed and counseled about possible invasive test options if the risk was 1 in 300 or greater. Fetal outcome was obtained by questionnaires given to the patients or sent to their gynecologists. The detection and false-positive rates for the different screening strategies were calculated....
Screening for fetal trisomy 21 in gestational weeks 6 and 7
Acta Obstetricia et Gynecologica Scandinavica, 2010
The objective was to examine the applicability of the two biochemical markers PAPP-A and free b-hCG for fetal trisomy 21 (T21) in very early pregnancy: gestational weeks (GA) 6 and 7. Medians for the two markers were generated on 36,745 fetal T21 unaffected pregnancies from gestational weeks 6-14. Concentrations were converted to Multiples of the Medians (MoMs). Median MoM from T21 affected pregnancies were compared over three intervals of gestational age; the very early weeks 6 and 7, weeks 8-10 and weeks 11-14. Median MoM from 9 affected pregnancies with a very early blood sample had a PAPP-A median MoM of 0.269, compared to 0.392 in weeks 8-10 and 0.531 in weeks 11-14. On the contrary, free b-hCG diverged from the median with increasing gestational age. Our data suggest that PAPP-A is a useful marker for very early testing in first trimester screening for fetal T21.
First-Trimester Screening for Trisomies 21, 18 and 13 by Ultrasound and Biochemical Testing
Fetal Diagnosis and Therapy, 2014
cutoff of 1: 100, the estimated detection rate (DR) was 87.0% for trisomy 21 and 91.8% for trisomies 18 and 13, at a falsepositive rate (FPR) of 2.2%. Addition of PLGF, AFP and DV PIV increased the DR to 93.3% for trisomy 21 and 95.4% for trisomies 18 and 13 and reduced the FPR to 1.3%. Conclusions: Effective screening for trisomies can be achieved using specific algorithms based on NT, FHR, DV PIV, β-hCG, PAPP-A, PLGF and AFP.
Ultrasound in Obstetrics and Gynecology, 2002
Objective To evaluate the performance of a one-stop clinic for assessment of risk (OSCAR) for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free β -human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks of gestation. Method Screening for trisomy 21 was carried out by OSCAR in 15 030 singleton pregnancies with live fetuses at 11-14 weeks. The estimated risk for trisomy 21 was calculated, and the women were counseled regarding this risk and the option of invasive testing or expectant management. Follow-up of the outcome of all pregnancies was carried out. The detection and false-positive rates for different risk cut-offs were calculated. Results Fetal NT and maternal serum free β -hCG and PAPP-A were successfully measured in all cases. Pregnancy outcome, including karyotype results or the birth of a phenotypically normal baby, was obtained from 14 383 cases. The median maternal age of these cases was 34 (range 15-49) years and in 6768 (47.1%) the age was 35 years or greater. The median gestation at screening was 12 (range 11-14) weeks and the median fetal crown-rump length was 64 (range 45-84) mm. The estimated risk for trisomy 21 based on maternal age, fetal NT and maternal serum free β -hCG and PAPP-A was 1 in 300 or greater in 6.8% (967 of 14 240) normal pregnancies, in 91.5% (75 of 82) of those with trisomy 21 and in 88.5% (54 of 61) of those with other chromosomal defects. For a fixed false-positive rate of 5% the respective detection rates of screening for trisomy 21 by maternal age alone, maternal age and serum free β -hCG and PAPP-A, maternal age and fetal NT, and by maternal age, fetal NT and maternal serum biochemistry were 30.5%, 59.8%, 79.3% and 90.2%, respectively. Conclusion Screening for trisomy 21 by a combination of maternal age, fetal NT and maternal serum biochemistry at 11-14 weeks can be provided in an OSCAR setting and is associated with a detection rate of about 90% for a false-positive rate of 5%.