Sepulveda 2007.
| Clinical features and settings | Routine screening | |
| Participants | 1287 participants Chile ‐ fetal medicine centre January 2003 ‐ January 2006 Pregnant women Median maternal age 33 years (range 14‐47 years), 35.4% ≥ 35 years Singleton pregnancies 11‐14 weeks' gestation |
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| Study design | Prospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 31 cases Reference standards: CVS, amniocentesis, cordocentesis or follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT and nasal bone assessment (Accuvix XQ, Medison or Voluson 730, GE Healthcare) (only included in study if scanned by 1 of 2 fetal medicine specialists following FMF guidelines) |
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| Follow‐up | Cases of chromosomal abnormality were identified from the cytogenetics laboratory logbook, which recorded all the cytogenetic studies performed prenatally, after a spontaneous abortion or fetal death, or in neonates with physical abnormalities. Information from the remaining cases was obtained from the delivery records and neonatal discharge summaries, which recorded the condition of the neonate at birth and the physical examination performed by a neonatologist | |
| Aim of study | To report their experience with first trimester screening for trisomy 21 by using the combination of NT thickness and nasal bone assessment | |
| 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 | No | No details given for test failures/uninterpretable measurements |
| Withdrawals explained? All tests | No | No details of withdrawals given |