Trophoblast inclusions (TIs) are placental abnormalities of the trophoblast bilayer. Present in 2-8% of full-term placentas, they are associated with poor neurodevelopment, including autism. Although previously unstudied, examination of chorionic villi from 108 preterm births revealed a ∼4 fold increase in the frequency of TIs (30.5%). Frequency of TIs was inversely related to gestational age (GA); 43% of placentas <30 weeks and 20% of placentas ≥32 weeks had TIs (χ2 = 4.41, p = 0.036). This increased prevalence in preterm infants suggests that TIs may indicate adverse intrauterine processes or undetected genetic abnormalities and could identify infants at risk for poor neurodevelopment.