Table 4 Search strategy for Web of Science

#1

Population = pregnant women

TS=(pregnant OR pregnanc* OR gestation* OR fetal OR foetal OR fetus OR foetus OR foetuses OR fetuses) OR TI=(pregnant OR pregnanc* OR gestation* OR fetal OR foetal OR fetus OR foetus OR foetuses OR fetuses)

#2

Index test = ultrasound

TS=(ultrasonograph* OR ultrasound OR “ultra sound” OR scan OR Doppler OR sonograph* OR echograph*) OR TI=(ultrasonograph* OR ultrasound OR “ultra sound” OR scan OR Doppler OR sonograph* OR echograph*)

#3

Reference test = small for gestational age measured by birth weight

TS=(“small for gestational age” OR “small for age infant” OR SGA OR “birth weight” OR birth-weight OR birthweight OR “growth restriction” OR “growth retardation” OR IUGR OR ((fetal OR foetal OR fetus OR foetus OR newborn OR infant OR neonatal) NEAR/2 (weight OR size OR growth))) OR TI=(“small for gestational age” OR “small for age infant” OR SGA OR “birth weight” OR birth-weight OR birthweight OR “growth restriction” OR “growth retardation” OR IUGR OR ((fetal OR foetal OR fetus OR foetus OR newborn OR infant OR neonatal) NEAR/2 (weight OR size OR growth)))

#4

Outcome = predictive value

TS=(Sensitivit* OR specificity OR “predictive value*” OR “predictive model*” OR “false-positive rate” OR “detection rate” OR “ROC curve” OR “receiver operating characteristic” OR “AUC” OR “area under the curve” OR screening)

#5

Human filter

TS=(Microorganisms OR Plants OR Invertebrates OR Protochordates OR “Nonhuman Vertebrates”)

#6

Combination of concepts

#1 AND #2 AND #3 AND #4 NOT #5