Results of full postmortem examination in a cohort of clinically unexplained stillbirths: undetected fetal growth restriction and placental insufficiency are prevalent findings

Objective To analyze a cohort of clinically unexplained stillbirths (CUS) referred for postmortem. Study Design In total, 258 CUS were referred for full postmortem between 2009 and 2015. Relevant Condition at Death (ReCoDe) classification was applied. Statistical analysis included chi-square test and multiple logistic regression. Results In all, 386 ReCoDe categories identified corresponded to: fetus (99); umbilical cord (48); placenta (165); amniotic fluid (55), and mother (1). No condition was identified in 18 cases. Prevalent conditions were placental insufficiency (101 cases, 39%) and fetal growth restriction (96 cases, 37%), frequently presenting together (41 cases, 15.9%). Significant associations were found between fetal growth restriction and gestational age, asymmetrical fetal growth and placental insufficiency. Conclusions In total, 60.5% of CUS were diagnosed at postmortem to have fetal growth restriction and/or placental insufficiency. The mean gestational age of death in which these conditions presented was 32.7 weeks and 35.5 weeks, respectively, suggesting a critical time-frame to monitor to potentially reduce stillbirth occurrence.