Birthweight to placental weight ratio and placental pathology in clinically unanticipated stillbirths: a retrospective cohort study.
Unanticipated stillbirths show abnormal birthweight-to-placental-weight ratios as often as placental-cause stillbirths
Birthweight to placental weight ratio and placental pathology in clinically unanticipated stillbirths: a retrospective cohort study.
Clinically unanticipated stillbirths may result from placental dysfunction that is not detected during pregnancy.
We investigated the association between clinically unanticipated stillbirths and placental dysfunction assessed by the birthweight-to-placental-weight (birthweight-to-placental-weight) ratio and placental histopathology.
This retrospective cohort study included placentas from 295 stillbirths at ≥24 weeks' gestation (2000-2017) at a tertiary referral centre.
most unanticipated stillbirths had abnormal weight ratios, similar to placental-cause cases
Of 295 stillbirths, 109 (36.9%) were due to placental causes, 57 (19.3%) to other causes, and 129 (43.7%) were clinically unanticipated.
Birthweight-to-placental-weight ratio distributions were similar between placental cause and clinically unanticipated stillbirths.
Histological review (n = 182) showed maternal vascular malperfusion predominated in placental cause stillbirths, while fetal vascular malperfusion was more frequent in clinically unanticipated stillbirths (16.9% vs 5.7%).
Clinically unanticipated stillbirths show placental abnormalities comparable to placental cause stillbirths, despite later gestation and often normal birthweight.
These findings suggest that many unanticipated stillbirths result from unrecognized placental dysfunction.
Systematic macroscopic and histological placental examination may aid postmortem classification and risk assessment in subsequent pregnancies.