Objective: To compare placental pathology from term singleton live births conceived with fresh embryo transfer vs. those conceived without assisted reproductive technology (ART).

Design: Retrospective cohort study.

Setting: Academic fertility center.

Patient(s): Women with a term singleton live birth who conceived after fresh autologous in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles (ART group) and those who conceived without ART.

Intervention(s): An experienced placental pathologist categorized placental pathology as anatomic, inflammatory, or vascular. Patient characteristics were compared by chi-squared tests, Student's t-test, or nonparametric tests. Multivariate logistic regression models were used to compare placental pathology between pregnancies conceived with and without ART.

Main outcome measure(s): Incidence of anatomic, inflammatory, and vascular placental pathology.

Result(s): There was a higher incidence of placental pathology in the ART group (n = 511) than in the non-ART group (n = 121), specifically anatomic (adjusted odds ratio [aOR] 2.50, 95% confidence interval [CI] 1.42-4.40) and vascular (aOR 2.00, 95% CI 1.13-3.53) pathology. These findings were driven primarily by the significantly higher odds of anatomic (aOR 2.97, 95% CI 1.55-5.66) and vascular (aOR 1.98, 95% CI 1.04-3.75) pathology observed in ICSI pregnancies. Single blastocyst transfers remained associated with increased anatomic pathology (ART: aOR 4.89, 95% CI 2.28-10.49; ICSI: aOR 3.38, 95% CI 1.49-7.71).

Conclusion(s): Fresh embryo transfer is associated with increased anatomic and vascular placental pathology in term singleton live births compared with conception without ART. This finding should be investigated prospectively in a larger cohort of patients.