Indeterminate Prenatal Ultrasounds and Maternal Anxiety: A Prospective Cohort Study.

Introduction: Prenatal ultrasounds often yield indeterminate (incomplete or minor abnormality) findings with limited clinical utility. We evaluate impact of indeterminate findings on maternal anxiety.

Methods: A single-U.S.-center prospective cohort study administered the Perinatal Anxiety Screening Scale (PASS; control mean = 13.4; > 20 denotes clinically significant anxiety) before and after prenatal ultrasounds in February-May 2017. Ultrasound reports were coded as: normal; indeterminate; or major abnormality. Primary outcome was anxiety after indeterminate vs. normal ultrasounds. Secondary outcomes included anxiety change from pre-to-post-ultrasound and relative to women's characteristics. Linear regression adjusted for confounders.

Results: Of 286 ultrasounds, 51.0% were normal, 40.5% indeterminate (22.0% incomplete; 18.5% minor abnormality), and 8.0% major abnormalities. Indeterminate findings were unrelated to age, race, parity, infertility, or psychiatric history, but associated with gestational age (26.6%/45.0%/52.5% for first/second/third trimesters; p < 0.001), and obesity (48.8 vs. 37.0%; p = 0.031). Pretest anxiety was highest in second/third trimesters (p = 0.029), and in subjects aged age ≤ 24 or younger(p < 0.001), with a history of anxiety (p < 0.001),) or with prior pregnancy loss (p = 0.011). Mean anxiety score decreased pre-to-posttest across all groups. Indeterminate findings were associated with higher PASS scores than normal findings: pretest 20.1 vs. 16.4 (p = 0.026) and posttest 16.9 vs. 12.2 (p = 0.009; adjusted-p = 0.01). Versus normal ultrasounds, incomplete findings were associated with higher post-ultrasound anxiety (p = 0.007; adjusted-p = 0.01) and smaller decreases from pre-to-posttest (adjusted-p = 0.03), whereas minor abnormalities had higher pretest anxiety (p = 0.029) with larger pre-to-posttest decreases (adjusted-p =0.010).

Discussion: Indeterminate ultrasounds, especially incomplete findings, are associated with significantly higher anxiety than normal findings, suggesting need for evidence-based counseling, management and strategies for decreasing number of indeterminate results.