A routine third trimester growth ultrasound in the obese pregnant woman does not reliably identify fetal growth abnormalities: A retrospective cohort study
Web of Science
AuthorNeel, A; Cunningham, CE; Teale, GR
Source TitleAustralian and New Zealand Journal of Obstetrics and Gynaecology
AffiliationObstetrics and Gynaecology
Rural Clinical School
Document TypeJournal Article
CitationsNeel, A., Cunningham, C. E. & Teale, G. R. (2020). A routine third trimester growth ultrasound in the obese pregnant woman does not reliably identify fetal growth abnormalities: A retrospective cohort study. AUSTRALIAN & NEW ZEALAND JOURNAL OF OBSTETRICS & GYNAECOLOGY, 61 (1), pp.116-122. https://doi.org/10.1111/ajo.13256.
Access StatusOpen Access
BACKGROUND: In response to the challenges of assessing fetal growth in obese women, guidelines recommend routine third trimester ultrasound scans. AIM: The aim of this study was to assess the diagnostic performance of this routine scan in obese women (body mass index (BMI) ≥ 35 kg/m2 ). METHODS: A retrospective cohort study of 1008 pregnancies with maternal BMI ≥ 35 kg/m2 born after 37 weeks gestation at a Victorian hospital from 2015 to 2017. Multiple pregnancies and those affected by diabetes were excluded. Growth ultrasounds were performed between 34 + 0 and 36 + 6 weeks gestation. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the detection of large for gestational age (LGA > 90%) and small for gestational age (SGA < 10%) were calculated using ultrasound estimated fetal weight (EFW) or abdominal circumference (AC) and compared with gestational age and gender-based birthweight percentiles. RESULTS: Using EFW, sensitivity for detecting SGA at birth was 8.1% (six of 74) with a PPV of 100%. Sensitivity for detecting LGA at birth was 61.0% (119 of 195), PPV 54.8%. Sensitivity, specificity, PPV and NPV percentages were all lower using AC. Only 40% of actual birthweight percentiles (405/1008) were within ±10 percentiles of their growth ultrasound EFW percentile. CONCLUSION: The performance of a routine third trimester ultrasound in women with BMI ≥ 35 kg/m2 suggests limited utility in helping identify aberrant fetal growth. This has important implications for the management of obese pregnant women.
- Click on "Export Reference in RIS Format" and choose "open with... Endnote".
- Click on "Export Reference in RIS Format". Login to Refworks, go to References => Import References