Sonographic evaluation of retained products of conception within 48 h following delivery: a retrospective cohort study

Abstract

Objective Early diagnosis of retained products of conception (RPOC) is critical for directing clinical management and for preventing associated complications. This study aimed to evaluate the utility of post-delivery ultrasound in patients with risk factors for RPOC. Study design A retrospective cohort-study was conducted in a single tertiary university-affiliated hospital (January 2016–September 2022). Sonographic evaluation, including endometrium thickness measurement and color Doppler, were reviewed of women with risk factors for RPOC: postpartum hemorrhage, a hemoglobin drop > 4 g/dl, manual removal of the placenta, and suspicious placenta. Results of early postpartum ultrasound (within 48 h), misoprostol administration and hysteroscopies were evaluated. Results Of the 591 women included, RPOC was suspected in 141 (24%). Endometrial thickness > 5 mm was associated with sonographic RPOC diagnosis in 58%. Suspected sonographic RPOC was concluded for 100%, 92% and 7% of the women with marked, moderate, and undetectable vascularity, respectively, p < 0.001. Misoprostol 1000 mcg per rectum (PR) was administered to 86% of those with suspected RPOC; only 11% of them needed an operative hysteroscopy for removal of the RPOC. RPOC on a pathology report was confirmed for 71% of those who underwent hysteroscopy. Conclusions Postpartum transabdominal ultrasonography within 48 h of delivery was effective for assessing RPOC. For appropriate triage, color Doppler grading increased the accuracy of RPOC diagnosis. Misoprostol treatment was successful in 88% of women with suspected sonographic RPOC. The combination of sonographic evaluation and misoprostol treatment for suspected RPOC might lower the rate of unnecessary invasive procedures.