Abnormal Doppler and perinatal outcomes according to the placental lesions of maternal and fetal vascular malperfusion in preterm fetal growth restriction.

OBJECTIVES

We aimed to identify the associations between specific pathologic placental findings and abnormal Doppler results as well as perinatal outcomes in preterm fetal growth restriction (FGR).

METHODS

This retrospective study included 465 consecutive singleton pregnancies with FGR delivered between 22+0 and 36+6 weeks of gestation. Abnormal Doppler was defined as absent or reversed end-diastolic flow in the umbilical artery (UA) and a pulsatility index less than the 10th percentile in the middle cerebral artery (MCA). Placental pathology was evaluated focusing on villous or vascular findings of maternal (MVM) and fetal vascular malperfusion (FVM) based on Amsterdam criteria.

RESULTS

The average gestational age at delivery and neonatal birth weight were 32 weeks (±4 weeks) and 1,299 g (±575 g), respectively. Placental MVM lesions were observed in the majority of cases (90.3 %) and were significantly related to abnormal UA and MCA Doppler. Meanwhile, FVM lesions was observed in about half of the cases (44.8 %) and were significantly related to abnormal MCA Doppler, but not abnormal UA Doppler. Both villous and vascular lesions of MVM and FVM were associated with lower neonatal birth weight. Among specific key findings of MVM and FVM, distal villous hypoplasia was highly associated with abnormal UA Doppler (crude OR 5.01, 95 % CI 1.27-19.68), while intramural fibrin deposition in large fetal vessels was significantly associated with abnormal MCA Doppler (crude OR 2.49, 95 % CI 1.01-6.13). Of note, intramural fibrin deposition of large fetal vessels was associated with neonatal mortality (crude OR 3.25, 95 % CI 1.52-6.92).

CONCLUSIONS

We identified key findings among placental MVM and FVM associated with abnormal UA and MCA Doppler as well as neonatal mortality in preterm FGR.