Batra 2014.

Study characteristics
Patient Sampling	Study design: prospective observational study Recruitment: unclear Study start and end date: April 2012 to April 2013
Patient characteristics and setting	Setting: private hospital/fertility clinic (CIMAR Fertility Centre) Region(s) and country/countries from which participants were recruited: Cochin, India Sample size: 353 Study eligibility criteria: pregnant women were enrolled after taking informed consent Number of participants with the target condition: 5 Population type: not reported Prior testing: nuchal translucency measurement at the time of the first trimester scan
Index tests	Type: two‐stage screening First‐trimester scan: Timing (weeks and days gestation): 11 weeks to 13 weeks and 6 days of gestation Ultrasound scanning protocol: detailed Mode of examination: transabdominal and transvaginal Cardiac screening: extended Single or multiple operators: not reported Staff qualification and/or operator experience level: not reported Second‐trimester scan: Timing: 18 weeks to 22 weeks of gestation Ultrasound scanning protocol: not reported Cardiac screening: not reported Mode of examination: not reported Single or multiple operators: not reported Staff qualification and/or operator experience level: not reported
Target condition and reference standard(s)	Target condition(s): cardiac anomalies (any type) Definitions used for major and minor congenital abnormalities: not reported Reference standard (live birth): follow‐up at delivery Reference standard (fetal or neonatal demise): not reported Postnatal follow‐up duration: until delivery
Flow and timing	Eligible patients: 355 Exclusions (study investigator): none reported Exclusions (review team): 2 (1 abnormal karyotype, 1 lost to follow‐up after the second trimester anomaly scan ‐ excluded on no reference standard)
Comparative
Notes	Funding source: CIMAR Fertility Centre, Kochi, Kerala, India
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
Could the selection of patients have introduced bias?		Unclear risk
Are there concerns that the included patients and setting do not match the review question?			Unclear
DOMAIN 2: Index Test (First‐trimester scan)
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
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 2: Index Test (First + second‐trimester scan)
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
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 2: Index Test (Single second‐trimester scan)
DOMAIN 3: Reference Standard
Is the reference standard likely to correctly classify anomalies that are externally visible, present with clinically relevant symptoms shortly after birth, or that are considered to be lethal/incompatible with life?	Yes
Is the reference standard likely to correctly classify anomalies that may present after discharge from postnatal care?	No
Were the reference standard results interpreted without knowledge of the results of the index test?	No
Could the reference standard, its conduct, or its interpretation have introduced bias?		High risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
DOMAIN 4: Flow and Timing
Did all live‐born infants receive a reference standard?	Yes
Did all live‐born infants receive the same reference standard?	No
Did all cases of fetal or perinatal loss receive the reference standard (including termination of pregnancy, intra‐uterine death, stillbirth, perinatal mortality)?	Unclear
Were all patients included in the analysis?	Yes
Could the patient flow have introduced bias?		Unclear risk