Huang 2014.
| Study characteristics | |||
| Patient sampling | Study design: blinded, prospective cohort study. Participants: pregnant women selected at high risk of fetal aneuploidy (as real clinical samples). Inclusion criteria: twin pregnancies with live fetuses and karyotype result. Exclusion criteria: singleton pregnancies, twins with intrauterine fetal demise at the time of sampling or without fetal karyotype result. | ||
| Patient characteristics and setting | Number enrolled: 189 pregnant women.
Number available for 2 x 2 table: 189 pregnant women (whole cohort included in analyses).
Setting: 7 centres. Hospitals in China.
Recruitment period: April 2012 to April 2013.
Ethnicity: most Asian.
Median gestational age (range): 19 (11 to 39) weeks.
Median maternal age (range): 31 (22 to 44) years.
Chorionicity: 17% monochorionics (33/189), 80% dichorionics (152/189) and 2% unknown (4/189). Relevant tests carried out prior to index test: ultrasonography (nuchal translucency measurement) and biochemical screening. Language of the study: English. |
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| Index tests | gNIPT by MPSS on Illumina Genome Analyzer IIx or HiSeq 2000 platform. Fetal fraction DNA: not reported. Blood samples for gNIPT were collected 30 minutes before reference standard. Cutpoint: positive if t score > 2.5 and L score risk > 1 (warning zone if t score > 2.5 or L score > 1). Commercial test: BGI's prenatal test. |
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| Target condition and reference standard(s) | Target conditions: T21 and T18. Reference standard: fetal karyotype of chorionic villi (2.1%), amniotic fluid (94.2%) or cord blood (3.7%). | ||
| Flow and timing | Blood samples were obtained prior to the invasive procedure (reference standard). gNIPT was a second‐tier test. No failed sample reported. No repeated test reported. |
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| Comparative | |||
| Aim to study | To assess the performance of noninvasive prenatal testing for trisomies 21 and 18 on the basis of MPSS of ccfDNA from maternal plasma in twin pregnancies. | ||
| Funding source or sponsor of the study | Funded by the Shenzhen Engineering Laboratory for Clinical Molecular Diagnostic, the China National GeneBank‐Shenzhen, the Medical Centre for Critical Pregnant Women in Guangzhou and Prenatal monitoring, In utero therapy and Follow‐up after birth in the complexity of Twin Pregnancy. Some authors worked for BGI‐Shenzhen. | ||
| Informations about the authors contacted | Author was contacted on: 10 February 2016. BGI‐Shenzhen were contacted on: 19 May 2016. No reply received from author. |
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| Notes | |||
| Methodological quality | |||
| Item | Authors' judgement | Risk of bias | Applicability concerns |
| DOMAIN 1: Patient Selection | |||
| Was a consecutive or random sample of patients enrolled? | Yes | ||
| Was a case‐control design avoided? | Yes | ||
| Did the study avoid inappropriate exclusions? | No | ||
| High | Low | ||
| DOMAIN 2: Index Test MPSS | |||
| Were the index test results interpreted without knowledge of the results of the reference standard? | Yes | ||
| If a threshold was used, was it pre‐specified? | Yes | ||
| Low | Low | ||
| DOMAIN 3: Reference Standard | |||
| Is the reference standards likely to correctly classify the target condition? | Yes | ||
| Were the reference standard results interpreted without knowledge of the results of the index tests? | Yes | ||
| Low | Low | ||
| DOMAIN 4: Flow and Timing | |||
| Was there an appropriate interval between index test and reference standard? | Yes | ||
| Did all analysed patients receive the reference standard? | Yes | ||
| Were all patients included in the analysis? | Yes | ||
| Low | |||