Should an Early Anatomy Ultrasound Scan Be Offered Routinely to Obese Pregnant Women?

OBJECTIVE

The primary objective of this study was to determine whether an early anatomic scan (EAS), either on its own or in combination with the routine transabdominal scan (R-TAS), would improve overall completion rates of the fetal anatomic survey in the obese pregnant woman. The study's secondary objectives were to compare patients' and sonographers' satisfaction with EAS versus R-TAS.

METHODS

A prospective observational study was carried out over a 2.5-year period including consecutive pregnant women with a pre-pregnancy BMI ≥30 kg/m who consented at a dating ultrasound appointment to undergo EAS at 15 ± 1 GA in addition to the second trimester R-TAS. Anatomic structures were categorized as normal, not well seen, or abnormal by using the institutional 26-item anatomic standardized reporting template. Examination completion and study duration were recorded. Neonatal follow-up was performed to evaluate for any missed diagnoses. Patients' and sonographers' satisfaction questionnaires were completed.

RESULTS

A total of 120 pregnant women completed the study. Visualization of all anatomic components was complete in 14% at EAS and in 61% at R-TAS (combined completion rate, 90%). Mean scan time was 30.4 minutes at EAS and 51 minutes at R-TAS. No missed diagnoses of structural anomalies were identified at neonatal follow-up. EAS and R-TAS differed in terms of sonographers' reports of difficult or suboptimal scans (9% vs. 58%), well-seen anatomy (85% vs. 78%), and good visibility (44% vs. 12%). Most sonographers expressed a preference for performing EAS in future pregnancies, rather than the R-TAS (96% vs. 6%). Although patients reported greater satisfaction with EAS (93% vs. 74%), for reasons that could not be determined, they expressed a preference for R-TAS in a subsequent pregnancy (23% vs. 63%).

CONCLUSION

Performing EAS along with R-TAS improves completion rates for anatomic evaluation in the obese gravida and is associated with greater patient and sonographer satisfaction.