Placental Sonolucencies in the First Trimester: Incidence and Clinical Significance

The aims of this study were to determine the incidence of placental sonolucencies on first-trimester screening sonograms in a general obstetric population and assess whether these findings are associated with adverse obstetric outcomes.

A retrospective cohort analysis of 201 pregnant patients screened at a high-risk prenatal diagnostic center was conducted with first-trimester cine clips reviewed by 2 radiologists. Placental sonolucencies were defined as intraplacental anechoic or heterogeneous areas 0.7 cm or greater. Obstetric and neonatal outcomes were collected by chart review.

Placental sonolucencies 0.7 cm or greater were seen in 45 (22.4%) of first-trimester ultrasound examinations. The ultrasonographic presence of a placenta previa, marginal sinus, and subchorionic hemorrhage was not more common in those with placental sonolucencies 0.7 cm or greater (P > 0.05). Sonolucencies were not associated with prior cesarean deliveries (P > 0.05). Both the groups with and without sonolucencies 0.7 cm or greater had similar rates of antepartum hemorrhage, preeclampsia, preterm delivery, cesarean delivery, postpartum hemorrhage, and delivery of small-for-gestational-age infants. One placenta accreta and no fetal demises occurred in the study population.

Placental sonolucencies detected on first-trimester screening sonograms in the general obstetric population are not predictive of poor obstetric outcomes.