What is the accuracy of an early third trimester sonogram for identifying LGA infants born to GDM patients diagnosed with the one-step approach?

Abstract

Purpose: The one-step approach for screening of GDM will increase the incidence 2- to 3-fold. These larger cohorts may need to target high-morbidity subsets to be cost-effective. We asked whether ultrasound could stratify the GDM patients with the highest risk for a large for gestational age (LGA) infant.

Materials and methods: A retrospective analysis was performed on 413 GDM patients diagnosed using the one-step approach. Ultrasound data from 28 weeks 0 day to 34 weeks 6 days was studied. The abdominal circumference (AC) and EFW at thresholds between 70 and 95% were examined for their prognostic utility. The primary outcome was an LGA infant.

Results: Both the AC and EFW at all gestational ages were predictive of a LGA infant. The AC and EFW at 28–32 weeks 6 days using a threshold of ≥70% showed the following test characteristics: sensitivity (73 versus 66%), specificity (61 versus 77%), positive predictive value (PPV) (30 versus 40%), and negative predictive value (NPV) (91 versus 91%). The specificity of the EFW was significantly higher than the AC (p < .001).

Conclusion: Among GDM patients diagnosed using the one-step approach, an elevated AC and EFW in the early third trimester are predictive of a LGA infant. This is a possible cost-effective way to stratify the one-step GDM pregnancies at highest risk for neonatal morbidity.

Keywords:

• One-step
• gestational diabetes
• IADPSG
• neonatal outcomes

Acknowledgements

Authors thank Norma Turner for preparation and editing of the manuscript.

Disclosure statement

There are no conflict of interest to report for the authors of the manuscript submission.