PURPOSE: Describe practice patterns among obstetrician/gynecologists (OB/GYNs) when caring for women with pregnancy complicated by fetal trisomy 13 (T13) or 18 (T18) and compare these between maternal-fetal medicine (MFM) and non-MFM providers. MATERIALS AND METHODS: We conducted an electronic survey using the American College of Obstetricians and Gynecologists database. Using simple statistics, we describe demographics and practice patterns among respondents and compare those of MFM practitioners with non-MFM providers. RESULTS: The survey was sent to 300 individuals, 161 individuals verified email receipt, and 105 had complete response and were included. The median age was 58 (IQR 53,62). Sixty percent were female, 69% were private practice, and 38% were MFM. All providers were more likely to offer than to recommend antenatal and intrapartum interventions. MFMs were more likely to offer growth ultrasounds and neonatal hospice consults (53% vs. 29%, p = .02; 88% vs. 60%, p < .01). During labor, MFMs were more likely offer no fetal heart rate monitoring, (90% vs. 52%, p < .01), 60% of all providers offer breech vaginal delivery; 32% offer cesarean delivery for fetal distress. CONCLUSION: Many providers offer antepartum and intrapartum interventions for pregnancies complicated by T13/18. We recommend that providers elicit each woman's goals for pregnancies complicated by T13/18 and tailor management options to meet these goals.