Clinical yield of fetal echocardiography for suboptimal cardiac visualization on obstetric ultrasound

Suboptimal cardiac imaging on obstetric ultrasound is a frequent referral indication for fetal echocardiography, even in the absence of typical risk factors for fetal cardiac disease. The clinical profile of patients and findings of examinations performed for such an indication are not well defined. Given the increased cost, time and resource utilization of fetal echocardiography, we sought to determine the clinical findings of such referrals.

We performed a single-center review of such referrals from January 2010 to June 2016. Patients with commonly accepted indications for fetal echocardiography were excluded. Demographic variables and echocardiogram findings were collected. Findings were classified as (1) "normal," (2) "probably normal," if minor pathology could not confidently be excluded, or if minor findings were noted that were expected to resolve, or (3) "abnormal." Rates of pathology were determined with comparison of nonobese and obese populations.

A total of 583 gestations in 562 women were included (median gestational age 23.3 weeks, range 19.0-38.4). The median body mass index (BMI) was 34.6 kg/m² (range 17.2-66.3 kg/m² ). The majority of women were obese (BMI ≥ 30 kg/m² in 74.6%). Overall, 574 of 583 examinations (98.5%) were normal or "probably normal." Pathology was noted in 9 fetuses (1.5%), 3 of whom required intervention (0.5%). No ductal dependent lesions were diagnosed. There was no significant difference in pathology rates between nonobese and obese mothers.

We found a low fetal cardiac anomaly rate in studies performed for suboptimal views on obstetric ultrasound. The majority of women referred for this indication were obese. The practice of routine referral for this indication deserves further evaluation.