Placental Histopathology and Adverse Perinatal Outcomes in ART Pregnancies: A Comparative Analysis of Homologous and Heterologous Techniques.

Background: Assisted Reproductive Technology (ART) is associated with increased maternal and fetal complications. This study compared adverse outcomes and placental histopathology findings between ART and spontaneous conceptions, with a novel focus on homologous versus heterologous techniques. Methods: This retrospective cohort study included 80 singleton ART pregnancies (45 homologous, 35 heterologous) and 80 matched spontaneous controls delivered at A. Gemelli Hospital. Clinical data and placental lesions, classified via the Amsterdam criteria and Benton framework, were statistically analyzed. Results: ART pregnancies showed higher rates of preterm birth (mean Gestational Age: 37.97 vs. 38.72 weeks), NICU admissions (15% vs. 0%), and maternal vascular malperfusion (MVM). Heterologous ART was associated with significantly higher maternal age (42.6 vs. 37.8 years; p = 0.007) and lower gestational age at delivery (p = 0.006) compared with homologous cycles. A higher frequency of placental hypoplasia was observed among heterologous pregnancies (55% vs. 14%; p = 0.03). A near-universal prevalence (95-100%) of MVM and fibrinoid deposition was observed across all ART placentas. Discussion: ART pregnancies, particularly those achieved through heterologous cycles, appear to represent a higher-risk category associated with accelerated placental aging and impaired placental growth. These findings highlight the importance of comprehensive counseling and informed consent, and suggest that routine histopathological placental examination may be valuable to improve neonatal surveillance and clinical management.