Low-Lying Placenta: Is a 32 Weeks Transvaginal Ultrasound Needed? [36A]. (May 2020)

• Record Type: Journal Article
• Authors: Eid, Joe; Wang, Amanda; Moutos, Christopher; Saade, George R.; Saad, Antonio
• Is Part Of: Obstetrics and gynecology. Volume 135(2020)Supplement 1
• Publication Date: 2020-05
• Subjects: Obstetrics -- Periodicals; Gynecology -- Periodicals; 618
• DOI: 10.1097/01.AOG.0000663080.40529.3c
• Languages: English
• ISSNs: 0029-7844

Abstract

Abstract : INTRODUCTION: Women with low-lying placenta (LLP) on second trimester ultrasound, are routinely followed up with a transvaginal ultrasound (TVUSG) at 32 weeks gestational age (GA), and if persistent, at 36 weeks. In this study, we describe outcomes of patients with initial diagnosis of LLP and evaluate its rate of resolution. METHODS: After IRB approval, we retrospectively reviewed cases of LLP diagnosed via second trimester ultrasound between August 2013 and June 2019. Patients' characteristics, ultrasound reports, maternal and neonatal outcomes were recorded. Descriptive statistics, receiver-operating characteristic (ROC), and logistic regression analysis were performed. Data were reported as median [range] or n (percentage). P <.05 was considered significant. RESULTS: Six hundred forty-six cases of LLP were identified at a median GA of 19 [16–25] weeks. A follow up TVUSG was performed at a median GA of 32 [29–34] weeks; 28 (4%) were found to be persistent and underwent a TVUSG at a median GA of 36 [35–37] weeks. Only 5 (0.7%) were persistent at 36 weeks. No significant difference was found in patients' characteristics, estimated blood loss, need for blood transfusions, nor neonatal outcomes between the persistent and non-persistent groups ( P >.05). Second trimester ultrasound was a poor predictor of LLP (ROC analysis; area under curve: 0.67, 95% CI 0.5–0.8; P =.16). CONCLUSION: Our data showed favorable outcomes for LLP with a 99% resolution rate at 36 weeks. A follow up at this GA is suggested rather than 32 weeks TVUSG. This might avoid unnecessary patient discomfort with TVUSG and decrease health care costs. Further prospective trials are needed to validate this approach.