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OBJECTIVE To compare composite neonatal and maternal adverse outcomes among low-risk singleton pregnancies at 37-41 weeks among conception methods: spontaneously-conceived (SC) pregnancy; infertility medications and/or intrauterine insemination (IFM/IUI); and assisted reproductive technology (ART). DESIGN Population-based retrospective cohort study. SETTING US Vital Statistics datasets 2013-2017. PATIENT(S) Low-risk pregnancies (without hypertensive disorders, pregestational or gestational diabetes, or history of preterm birth) of women ≥20 years with nonanomalous singletons, who labored, delivered at 37-41 weeks, and had data on pregnancy conception method. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) The primary outcome was the composite neonatal adverse outcome (CNAO). The secondary outcome was the composite maternal adverse outcome (CMAO). RESULT(S) Of the 19.7 million deliveries during the study period, 54.0% (N = 10,676,184) met the inclusion criteria, with 99.0% (N = 10,573,741) being conceived spontaneously, 0.4% (N = 47,227) by IFM/IUI, and 0.5% (N = 55,216) by ART. The overall rate of CNAO was 6.68 per 1,000 live births. Compared with SC, the risk of CNAO was significantly higher among IFM/IUI (adjusted relative risk [aRR], 1.29; 95% CI, 1.18-1.41) and ART (aRR, 1.29; 95% CI, 1.18-1.39). The overall rate of CMAO was 2.50 per 1,000 live births. Compared with SC, the risk of CMAO was significantly increased among IFM/IUI (aRR, 1.72; 95% CI, 1.50-1.97) and ART (aRR, 2.40; 95% CI, 2.17-2.65). CONCLUSION(S) Among low-risk term singleton pregnancies, IFM/IUI and ART have modestly higher rates of adverse outcomes to maternal-neonatal dyad than SC.