Cicero 2006.
| Clinical features and settings | Routine screening | |
| Participants | 20, 418 participants UK ‐ Fetal Medicine Centre October 2001‐2004 Pregnant women Singleton pregnancies Median age 35 years (18‐50 years) 11‐13 weeks' gestation |
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| Study design | Prospective cohort study | |
| Target condition and reference standard(s) | Down's syndrome: 140 cases Reference standards: CVS or amniocentesis in high‐risk women, or follow‐up to birth |
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| Index and comparator tests | Maternal age Presence of nasal Bone (FMF methods) First trimester NT (FMF methods) First trimester serum free ßhCG (Kryptor analyser, Brahms AG) First trimester serum PAPP‐A (Kryptor analyser, Brahms AG) |
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| Follow‐up | Data on pregnancy outcome from cytogenetics laboratory and by letters and telephone calls to patients, GPs and maternity units 656 patients excluded because karyotype was not known due to miscarriage (n = 185), termination of pregnancy (n = 85) or loss to follow‐up (n = 386) |
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| Aim of study | To investigate the impact of incorporating assessment of the nasal bone into first trimester combined screening by fetal nuchal translucency thickness and maternal serum biochemistry | |
| 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 | Yes | 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 | Reported that fetal NT and serum markers were successfully measured in all cases |
| Withdrawals explained? All tests | Yes | Patients lost to follow‐up reported |