Is Abdominal Circumference Associated With Poor Outcomes in Fetuses With Estimated Fetal Weights Between 10-20th%? [17P

Abstract

INTRODUCTION: Fetuses with intrauterine growth restriction (IUGR) are at increased risk for poor perinatal outcomes. Fetuses with estimated weights (EFW) between 10-20th percentile also have increased risk for poor outcomes. Abdominal circumference (AC) has been shown to have high specificity and sensitivity for IUGR. We aim to determine whether AC is associated with increased risk for poor outcomes with EFW between 10-20th percentile. METHODS: Retrospective cohort study assessing pregnancies with ultrasound EFW between 10-20th% between 2005 and 2016. AC, maternal demographics and perinatal outcomes were documented and compared. P less than .05 was considered statistically significant. RESULTS: Of 285 patients with EFW 10-20th%, 56 (20%) had follow up ultrasounds. Of these, 59% had evidence of IUGR on follow up fetal growth surveillance and over 60% were documented as small for gestational age (SGA) at birth, regardless of AC. Fetuses with AC on ultrasound less than 10th% showed no increased risk of poor perinatal outcomes including 5 minute Apgar less than 7, NICU admission, SGA or composite outcome, nor did those with AC less than the 5th% in unadjusted or adjusted analyses. CONCLUSION: While our cohort with EFW 10-20th% has a high rate of IUGR on follow up ultrasound and SGA at birth, AC does not appear to be associated with other investigated poor perinatal outcomes. Given the high incidence of IUGR and SGA, follow-up ultrasounds could be considered if delivery not otherwise indicated. Further investigation identifying those at highest risk is warranted.