Has 2008.
| Clinical features and settings | Routine screening | |
| Participants | 1807 participants with successful scans Turkey September 2003 ‐ December 2005 Pregnant women Singleton pregnancies Median maternal age 28.3 years (range 17‐45 years) 11‐14 weeks' gestation |
|
| Study design | Cohort study | |
| Target condition and reference standard(s) | Down's syndrome: 9 cases Reference standards: karyotyping or follow‐up to birth |
|
| Index and comparator tests | Maternal age First trimester NT (FMF methods) First trimester fetal nasal bone (experienced maternal fetal specialists) First trimester PAPP‐A and free ßhCG (details not reported) Combined cut‐point 1:300 |
|
| Follow‐up | Findings recorded in a computer database. Karyotype results obtained directly from the genetics department. Pregnancy outcomes obtained from hospital records or from parents via telephone interview. 110 women (5%) with terminations, miscarriages or malformations and unknown outcome were excluded from the study | |
| Aim of study | To evaluate the contribution of nasal bone assessment in first trimester Down's syndrome screening | |
| Notes | ||
| Table of Methodological Quality | ||
| Item | Authors' judgement | Description |
| Representative spectrum? All tests | Yes | Routine screening of typical pregnant population |
| Acceptable reference standard? All tests | Yes | Karyotyping or follow‐up to birth |
| Partial verification avoided? All tests | Unclear | Unclear if all women received a reference standard |
| Differential verification avoided? All tests | No | Choice of reference standard depended on index test results |
| Incorporation avoided? All tests | Yes | Reference standard was independent of the index test |
| Reference standard results blinded? All tests | No | Reference standard interpreted with knowledge of index test results |
| Index test results blinded? All tests | Yes | Index test interpreted without knowledge of reference standard results |
| Relevant clinical information? All tests | Yes | Information available as would be in standard clinical practice |
| Uninterpretable results reported? All tests | Yes | Evaluation of nasal bone was not possible in 9 (0.5%) cases |
| Withdrawals explained? All tests | No | No details of withdrawals given |