Comparison of the Autopsy and Placental Findings in Second vs Third Trimester Stillbirth

Background: The pathology of second trimester fetal loss is not well-characterized due to lack of comprehensive autopsy studies. The purpose of this study is to compare autopsy pathology of second trimester and third trimester stillbirth. Methods: In this retrospective cohort study, fetal autopsies performed in-house with complete placental examination were included. From autopsy reports, maternal demographics, gestational age, sex, body and placental weight, congenital anomalies, and cause of death (COD) were obtained. Immediate COD was coded probable or possible according to Initial Causes of Fetal Death (INCODE). Results: Among 68 second trimester and 54 third trimester fetal autopsies, at least 1 probable COD was identified in 59/68 (87%) second trimester and 44/54 (81%) third trimester cases. 42/68 (62%) second trimester and 28/54 (52%) third trimester fetuses had probable COD secondary to placental pathology. Among placental causes, 29/42 (69%) second trimester and 14/28 (50%) third trimester stillbirths were related to compromised fetal microcirculation with umbilical cord abnormality. Conclusions: Among stillborn first and second trimester fetuses who undergo autopsy, the most prevalent COD is pathologic placental conditions, particularly those associated with umbilical cord obstruction. This study stresses the importance of placenta examination for establishing COD in both second and third trimester fetuses.

Automated summary

This study compares the autopsy findings of second trimester and third trimester stillbirths and finds that the most common cause of death is pathologic placental conditions, particularly those associated with umbilical cord obstruction. The study emphasizes the importance of placenta examination in determining the cause of death in both second and third trimester fetuses.