EP16.34: Placental cysts and atypical placental sonolucencies at 11–13 weeks of gestation: sonographic features and clinical significance

To determine the sonographic features, prenatal course, and pregnancy outcome in pregnancies in which a placental cyst or an atypical placental sonolucency (PCAPS) was detected in the first trimester. Pregnancies with a PCAPS were prospectively recorded in a dedicated database of women presenting for their first trimester sonographic screening for aneuploidy and major structural anomalies. Relevant information was obtained by reviewing ultrasound reports and medical records. Follow-up and pregnancy outcomes were obtained by contacting the referring obstetrician or the patients themselves. During a 9-year study period from June 2014 to June 2023, a PCAPS was identified in 10 out of 7,125 first trimester pregnancies undergoing sonographic screening, for a prevalence of 1/712 (0.14%). Median gestational age at evaluation was 12 (range 11-13) weeks. All women were asymptomatic at the time of evaluation and 1 case occurred in a multiple pregnancy. Median largest diameter of the cyst was 10 (range 7-26) mm; 8 were single and 2 multiple; and 6 were eccentric and 4 central in location. With the exception of two pregnancies complicated with multiple anomalies, the prognosis was universally good in the remaining cases, with resolution by the second trimester in all continuing pregnancies. PCAPS is a rare finding during the 11-13 weeks scan. This finding is usually incidental, transient, and probably has no clinical significance in isolated cases. When detected in fetuses with congenital anomalies, the final prognosis depends on the magnitude of the associated malformations.