ULTRASOUND ASSESSMENT FOR PLACENTA ACCRETA SPECTRUM PRIOR TO SECOND TRIMESTER DILATION AND EVACUATION

Abstract

Objectives

Ultrasound (US) markers for placenta accreta spectrum (PAS) are often undetectable until late second trimester, increasing the risk of complications during dilation and evacuation. We assessed the prevalence of these markers and their predictive value for complications in patients with prior cesarean delivery (CD) undergoing dilation and evacuation.

Methods

We included patients with prior CD who underwent dilation and evacuation between 14 0/7 and 23 6/7 weeks’ gestation from 05/2020-12/2021. We abstracted obstetric history, placental US findings, and perioperative data from electronic records. We compared complications between those with and without PAS-associated US markers defined by the Society of Maternal-Fetal Medicine. Bleeding complications were defined as ≥2 uterotonics use, blood transfusion, intrauterine balloon placement, uterine artery embolization, and hysterectomy.

Results

Of 770 patients undergoing dilation and evacuation, 209(27%) had one or more prior CDs. On US, 24(11%) patients had lacunae, 20(10%) had placenta previa, 12(6%) had abnormal flow, 7(3%) had bridging vessels, and 6(3%) had an abnormal uteroplacental interface. Based on these markers, 16(8%) were considered moderate risk for PAS. Complications occurred in 25(12%) patients, most commonly use of ≥2 uterotonics (10, 40%), blood transfusion (6, 24%), and intrauterine balloon placement (5, 20%). Patients with pre-procedure US indicating moderate risk for PAS were not more likely to have complications compared to those considered low risk [4(25%) vs 18 (9%); p=0.07].

Conclusions

US assessment for PAS did not predict higher bleeding complications during dilation and evacuation. Enhanced early second-trimester PAS risk characterization is necessary for improved perioperative readiness.