Diagnostic accuracy of biochemical tests of placental function versus ultrasound assessment of fetal size for stillbirth and small-for-gestational age infants

This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows: The primary objective of this review is to assess and compare the diagnostic accuracy of ultrasound assessment of fetal growth and placental biomarkers alone and in any combination used after 24 weeks of pregnancy in the identification of placental dysfunction as evidenced by either stillbirth or born small‐for‐gestational age (SGA). Accuracy is described by the proportion of fetuses who are subsequently stillborn or who have a SGA baby detected by a positive test result (the presence of placental dysfunction) (sensitivity) and by the proportion of fetuses that have an uncomplicated pregnancy following a negative index tests result (absence of placental dysfunction) (specificity).