Serpentine Aneurysm of the Placenta with Good Fetal Outcome

We report an exceedingly rare case of placental serpentine aneurysm. A 21-year-old gravida 3 para 1-0-1-1 with the history of a prior C-section presented at 35 weeks of gestation with the complaint of decreasing or absent fetal movements, previously there were no complications during her pregnancy. She underwent an emergent C-section due to non-reassuring fetal heart tones and delivered a female infant weighing 2145 grams without malformation and Apgar scores of 6 and 8 at 1 and 5 minutes. The premature neonate was admitted to the neonatal intensive care unit (NICU) and was discharged a few days later in good health and has done well since. The placenta weighed 768 grams with a three-vessel umbilical cord. The fetal surface was blue-gray and had multiple markedly dilated tortuous vessels (ranging in diameter from 0.5-1.4 cm) which were attached to a single area on the fetal surface. A Verhoeff-Van Gieson stain was negative for elastic fibers. The placental disc had a 7.1 cm peripheral infarct involving approximately 10% of the disc. There have been 3 cases reported previously in which two were associated with intrauterine growth restriction and one with molar transformation. In conclusion, placental serpentine aneurysm is a rare finding and unlike prior cases was associated with prematurity, decreased fetal movements, and nonreassuring fetal heart tones; a good outcome occurred because of prompt medical intervention.