Is there a role for placental histopathology in predicting the recurrence of preterm birth?

Purpose: Spontaneous preterm birth (sPTB) is a major cause of neonatal morbidity and mortality with a relatively high rate to recurrence. Our aim was to study the role of placental histopathology in predicting recurrence of sPTB. Methods: We conducted a retrospective cohort study. The medical records and placental pathologic reports of all women with sPTB (gestational age 23^0/7–36^6/7 weeks), during 2008–2015, were reviewed. Only women who had a subsequent delivery were included. Multiple pregnancies and women with known uterine anomalies were excluded. Placental histopathology lesions were classified into maternal and fetal vascular malperfusion lesions, acute maternal and fetal inflammatory responses lesions, and chronic inflammatory lesions. Placental lesions were compared between patients with and without recurrent sPTB on their subsequent pregnancies. Results: Maternal characteristics, gestational age, birthweight, and the rate of preterm rupture of membrane at index delivery were similar between the recurrent sPTB (n = 72) and the non-recurrent sPTB (n = 167) groups. The incidence of placental vascular malperfusion lesions, or inflammatory lesions did not differ between the study groups. However, on multivariate logistic regression analysis, the presence of only acute inflammatory response lesions was associated with recurrence of early sPTB (< 34 weeks) (adjusted OR 3.16; 95% CI 1.22–8.18). Conclusion: The presence of isolated placental acute maternal or fetal inflammatory response in index sPTB may be associated with recurrence of early sPTB.