Umbilical cord hemangiomas are rare lesions, for which data on pregnancy outcome is lacking. This study combines a multi-institution 4-case series with a systematic literature search (n = 52) to determine possible pathologic lesion parameters which may have an effect on pregnancy outcome. Of all 56 pregnancies, lesion size ranged from 0.2 to 23.0 cm with pregnancy outcomes ranging from healthy liveborns (58.9%), liveborns with severe complications largely due to prematurity and/or fluid overload (12.5%), intrauterine/neonatal demise (25.0%), and pregnancy termination (3.6%). Of the 52 cases included for statistical analysis, there was no significant association between fetal outcome and vascular lesion location (P = .12) or fetal outcome and single umbilical artery involvement versus involvement of other vasculature (P = .29). The mean length of vascular lesions that resulted in healthy liveborns did not significantly differ from those resulting in severe fetal complications and/or demise (P = .72). Cases resulting in severe complications and/or demise were significantly earlier at delivery than those resulting in healthy liveborns (P < .001). Combined findings suggest that functional lesion characteristics, such as the degree of turbulent flow generated, have more significance than size, especially in early gestation losses. Moving forward, standardized reporting of pathologic lesion characteristics is paramount to better predict pregnancy prognosis.