None, One, or Both Placentas Involved with Malperfusion Lesions in Twin Pregnancies Complicated by Preeclampsia—Does It Matter?

We aimed to study the association between the number of placentas with vascular malperfusion lesions in dichorionic twin pregnancies complicated by preeclampsia and the severity of the disease and pregnancy outcomes. Dichorionic twin pregnancies with preeclampsia (n = 125), from January 2007–June 2018, were reviewed. Affected placenta was defined as the presence of maternal/fetal vascular malperfusion lesions. Maternal demographics, pregnancy characteristics, and neonatal outcomes were compared between three groups: no pathological placentas, one pathological placenta, and two pathological placentas. Composite adverse neonatal outcome was defined as ≥ 1 early neonatal complication. Regression analysis models were used to recognize independent associations with the number of involved placentas. The two pathological placenta group (n = 57 pregnancies), the one pathological placenta group (n = 40 pregnancies), and the no pathological placenta group (n = 28 pregnancies) differed in terms of gestational age (GA) at delivery (p < 0.001, p = 0.008) and the rates of severe features (p = 0.028, p = 0.047). Neonates born to the two pathological placenta group (n = 114), the one pathological placenta group (n = 80), and the no pathological placenta group (n = 56) were characterized by lower birth weights (p < 0.001, p = 0.031), higher rates of small for gestational age (SGA) (p = 0.017, p = 0.748), neonatal intensive care unit admission (p = 0.004, p = 0.013), and composite adverse neonatal outcome (p < 0.001, p = 0.025). By regression analyses, the presence of two pathological placentas was found to be independently associated with severe features (aOR = 5.1), GA at delivery < 32 weeks (aOR = 2.0), SGA (aOR = 2.5), and composite adverse neonatal outcome (aOR = 2.7). In dichorionic twin pregnancies, there is an association between the presences of placental vascular malperfusion lesions in none, one, or both placentas and the development of early and severe preeclampsia, as well as with SGA and adverse neonatal outcome.