Abstract. OBJECTIVES: Data on rates of cesarean delivery among pregnancies diagnosed with genetic syndromes remains limited. We examined the cesarean delivery rates for Down syndrome pregnancies over a 10-year period in the US. METHODS: We used data from the 1995–2004 US delivery data files to examine cesarean delivery rates in singleton pregnancies (at ≥20 weeks' gestation) with and without Down syndrome. We further examined if the rates of cesarean deliveries in primary and repeat cesarean deliveries among Down syndrome pregnancies differed based on the presence or absence of major structural abnormalities or stillbirth or gestational age at delivery. RESULTS: There were 35 million singleton deliveries of which 19186 were diagnosed at birth with Down syndrome (1 in 2000 births after 20 weeks gestation). The primary cesarean delivery rates were higher among Down syndrome pregnancies (17.5% in 1995 and 21.5% in 2004) compared to non-Down syndrome pregnancies (12.3% in 1995 and 16.6% in 2004). Temporal trends for cesarean deliveries were steeper among Down syndrome pregnancies with gastrointestinal and heart abnormalities than in Down syndrome cases without abnormalities. Higher cesarean delivery rates were also noted among Down syndrome pregnancies ending in third trimester live born than in control. CONCLUSION: In the US, cesarean deliveries in Down syndrome pregnancies increases over time and is greater when Down syndrome is associated with structural abnormalities and delivered during the third trimester of pregnancy.