Abstract Background Umbilical artery Doppler plays a central role in the diagnosis and management of placenta-mediated early-onset fetal growth restriction. However, interpreting available data on the rate of umbilical artery Doppler progression remains challenging, primarily because many prior studies included patients with varying degrees of fetal growth restriction severity. Consequently, the aggregated data resulted in estimates of umbilical artery Doppler progression that are often too broad for clinical use. Therefore, there is a need for more robust data to define the deterioration rate of umbilical artery Doppler abnormalities in more homogeneous patient cohorts with definitive evidence of severe placenta-mediated early-onset fetal growth restriction. Objective To quantify the rate of progression of umbilical artery Doppler abnormalities, time to delivery, and risk of fetal death in a homogeneous cohort of singleton pregnancies with severe placenta-mediated early-onset fetal growth restriction that ultimately progressed to late umbilical artery Doppler abnormalities (defined as intermittent or persistent absent or reversed end-diastolic flow). Study Design We conducted a retrospective descriptive study of singleton pregnancies with severe early-onset fetal growth restriction that ultimately progressed to late umbilical artery Doppler abnormalities in a single tertiary center (2014–2024). Umbilical artery Doppler findings at each visit were categorized according to the following order of progression: normal (umbilical artery pulsatility index <95th percentile), elevated umbilical artery-pulsatility index (>95th percentile), intermittent absent end-diastolic flow, persistent absent end-diastolic flow, intermittent reversed end-diastolic flow, and persistent reversed end-diastolic flow. The primary outcomes were the timing of progression between successive umbilical artery Doppler abnormalities and the interval from each Doppler abnormality to either delivery or fetal death. Results A total of 241 patients met the study criteria and underwent 1835 Doppler assessments. The mean gestational age at which late umbilical artery Doppler abnormalities were first observed was 27.5±3.2 weeks, and the mean gestational age at birth was 28.6±3.1 weeks. Fetal death was observed in 11 pregnancies (4.6%), although the majority of these cases (10/11) were either previable (4/11) or occurred because the parents declined intervention due to poor prognosis (6/11). The mean±standard deviation time of umbilical artery Doppler progression was 7±8 days from elevated umbilical artery-pulsatility index to intermittent absent end-diastolic flow, 6±6 days from intermittent absent end-diastolic flow to absent end-diastolic flow, 6±6 days from absent end-diastolic flow to intermittent reversed end-diastolic flow, and 4±5 days from intermittent reversed end-diastolic flow to reversed end-diastolic flow. The time to delivery was greatest in cases of elevated umbilical artery-pulsatility index >95th percentile (median 6 [interquartile range, 3–12] days) or abnormal cerebral Doppler (5 [2–11] days) and was shorter for intermittent absent end-diastolic flow (4 [2–10] days), absent end-diastolic flow (3 [1–8] days), intermittent reversed end-diastolic flow (0 [0–3] days), and reversed end-diastolic flow (0 [0–1] days). The risk of observed fetal death increased progressively with the severity of umbilical artery Doppler abnormalities, from 0.6% in cases with intermittent absent end-diastolic flow to 11.5% in cases with reversed end-diastolic flow. All cases of observed fetal death showed evidence of either reversed end-diastolic flow in the umbilical artery or abnormal ductus venosus Doppler at the examination preceding fetal death. Conclusion In this study, we provided estimates of umbilical artery Doppler deterioration rate, stage-specific fetal death risk, and time to delivery. Given the high-risk case mix, these intervals likely represent worst-case timelines and can therefore guide the minimum surveillance frequency, the timing of antenatal corticosteroid administration, and delivery timing planning. Patients and care providers can be reassured that the risk of fetal growth restriction–related fetal death between visits is low when neither reversed end-diastolic flow in the umbilical artery nor abnormal ductus venosus Doppler is present.