FASTER - First-trimester or Second-trimester Screening or Both, for Downs Syndrome

Question 1

Journal

Year

Answer 1

The New England Journal of Medicine 2005

Question 2

Aims

Answer 2

To investigate the best way to screen women for fetal Down’s syndrome

Question 3

Study Design

Answer 3

Observational study

Question 4

Participants

Answer 4

38,167 women with singleton pregnancies

Question 5

Inclusion Criteria:

Answer 5

● Maternal age of 16 years or older

● Singleton pregnancy with a live fetus and a fetal CRL of 36-79mm at study entry

Question 6

Exclusion Criteria

Answer 6

● Prior measurement of nuchal translucency

● Previously diagnosed anencephaly of the fetus

Question 7

Intervention

Answer 7

Women underwent first-trimester combined screening (NT + PAPP-A + B-HCG) and second trimester quadruple screening (AFP + B-HCG + estriol + inhibin A) comparing the results of step-wise screening, fully integrate screening, and serum integrated screening.

Question 8

Primary end-points

Answer 8

● High risk was defined as:
○ 1 in 150 for 1st trimester screening
○ 1 in 300 for 2nd trimester screening

Question 9

Summary of results

Answer 9

● With a 5% false positive rate, detection of Down’s Syndrome were as follows:
○ 1st trimester combined 87% at 11w, 85% at 12w, 82% at 13w
○ Second-trimester quadruple screening 81%
○ Stepwise sequential screening 95%
○ Serum integrated screening 88%
○ Fully integrated screening 96%

Question 10

Conclusion

Answer 10

First trimester combined screening at 11w is better than second trimester quadruple screening but at 13 w has similar results. Both stepwise sequential screening and fully integrated screening have high rates of detection of Down’s syndrome, with low false positive rates.