Relatively little is published on pregnancy in adolescents with HIV despite concerns regarding the U.S. epidemiology of HIV, youth, and pregnancy. This single-center retrospective study examined demographic and socio-behavioral characteristics, viral suppression, and pregnancy outcomes in adolescents compared to adults at a large urban academic HIV pregnancy clinic. Chart review was performed for 90 adolescents and 250 adults receiving care from 2003 to 2015. 29 percent of adolescents and 19 percent of adults were first diagnosed with HIV during the current pregnancy. Although 73 percent of pregnancies were unintended (83.6% for adolescents vs. 68.7% for adults), the majority were pleased to be pregnant and had involvement of the father of the baby. Homelessness and history of sexual/physical abuse were not more common among adolescents; adolescents were more likely to report marijuana use history. Among individuals with known HIV who became pregnant after universal ART recommendations, adolescents were significantly less likely to have viral load suppression (27.8% vs. 68%) and had lower CD4 (383 vs. 616 cells/mm³) at pregnancy entry. At delivery, adolescents were less likely to have viral suppression (50% vs. 69.7%). Over a third of adolescents and adults were discharged without contraception plan documentation, and approximately two-thirds of both adolescents and adults attended a postpartum visit.