FIRST PLACE Heparin Use is Associated With an Increased No-Call Rate of Cell-Free DNA Testing [22OP

Abstract

INTRODUCTION: To determine if the no-call rate for cell-free DNA testing is higher in pregnant women with hypertension, diabetes, or those taking aspirin and/or heparin. METHODS: This IRB approved, retrospective cohort study included 1395 patients with cell-free DNA testing performed between 2014-2018. Weight, gestational age at collection, cell-free DNA platform, parity, presence/absence of chronic hypertension, pre-gestational diabetes, or autoimmune disease, and use of heparin, aspirin, or immune modulating drugs, was gathered for each patient. Univariate and multivariate logistic regressions were performed to determine if chronic hypertension, pre-gestational diabetes, and use of heparin and/or aspirin affected the no-call rate. RESULTS: In the univariate analyses there was a significant increase in the odds of a no-call for chronic hypertension, pre-gestational diabetes, and heparin and/or aspirin use. The unadjusted odds ratios (OR) and 95% confidence intervals were 6.1 (3.3-11.1), 3.3 (1.5-7.3), and 13.9 (7.6-25.2), respectively. After adjustment for confounding factors including weight, gestational age at collection, cell-free DNA platform, autoimmune disease, and use of immune modulating drugs, only heparin and/or aspirin use remained a significant predictor of a no-call. The adjusted ORs were 1.5 (0.7-3.3), 0.7 (0.3-1.8), and 6.1 (3.0-12.6), for chronic hypertension, pre-gestational diabetes, and heparin and/or aspirin use, respectively. CONCLUSION: On multivariate analysis heparin and/or aspirin use increased the odds of a no-call following cell-free DNA testing. Based on this result, clinicians should consider other genetic testing options in patients taking heparin and/or aspirin, especially those with other conditions known to decrease cell-free DNA level.