Placental pathology and neonatal outcome in small for gestational age pregnancies with and without abnormal umbilical artery Doppler flow.

Objective: To compare neonatal outcome and placental pathology in cases of small for gestational age (SGA) according to umbilical artery (UA) Doppler flow.

Study Design: Pregnancy and placental reports of SGA neonates (birth-weight <10th), born between 2008 and 2017 were compared between cases with normal and abnormal UA Doppler indices. Placental lesions were classified to malperfusion lesions and inflammatory responses.

Results: The abnormal Doppler group (n = 66) delivered at an earlier gestational age, compared to the normal Doppler group (n = 92). Placentas from the abnormal Doppler group were characterized by a higher rate of maternal malperfusion lesions, while placentas from the normal Doppler group exhibited a higher rate of chronic villitis. Neonatal outcome was independently associated with abnormal Doppler, gestational age and birth weight <5th percentile.

Conclusion: SGA may involve a vascular mechanism, associated with abnormal Doppler flow and placental malperfusion, and an inflammatory mechanism, with normal Doppler flow and chronic villitis.