Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis

BACKGROUND: Fetal macrosomia is associated with an increased risk of adverse maternal and neonatal outcomes.

OBJECTIVES: To compare the accuracy of antenatal two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, and magnetic resonance imaging (MRI) in predicting fetal macrosomia at birth.

SEARCH STRATEGY: Medline (1966-2013), Embase, the Cochrane Library and Web of Knowledge.

SELECTION CRITERIA: Cohort or diagnostic accuracy studies of women with a singleton pregnancy, who had third-trimester imaging to predict macrosomia (>4000 g, >4500 g or >90th or >95th centile).

DATA COLLECTION AND ANALYSIS: Two reviewers screened studies, performed data extraction and assessed methodological quality. The bivariate model was used to obtain summary sensitivities, specificities and likelihood ratios.

MAIN RESULTS: Fifty-eight studies (34 367 pregnant women) were included. Most were poorly reported. Only one study assessed 3D ultrasound volumetry. For predicting birthweight >4000 g or >90th centile, the summary sensitivity for 2D ultrasound (Hadlock) estimated fetal weight (EFW) >90th centile or >4000 g (29 studies) was 0.56 (95% CI 0.49-0.61), 2D ultrasound abdominal circumference (AC) >35 cm (four studies) was 0.80 (95% confidence interval [95% CI] 0.69-0.87) and MRI EFW (three studies) was 0.93 (95% CI 0.76-0.98). The summary specificities were 0.92 (95% CI 0.90-0.94), 0.86 (95% CI 0.74-0.93) and 0.95 (95% CI 0.92-0.97), respectively.

CONCLUSION: There is insufficient evidence to conclude that MRI EFW is more sensitive than 2D ultrasound AC (which is more sensitive than 2D EFW); although it was more specific. Further primary research is required before recommending MRI EFW for use in clinical practice. Tweetable abstract Systematic review of antenatal imaging to predict macrosomia. MRI EFW is more sensitive than ultrasound EFW.