This is a Phase 1 clinical trial that constitutes two time points cohorts with participants who will receive intravenous autologous umbilical cord blood and 0.9% sodium chloride respectively. The timing of treatment is any time after the diagnosis of autism spectrum disorder. The investigator will proceed the groups during the same period.~Demographic Data and Baseline Characteristics of the Studied Group were collected:~Basic patient's information survey~Medical history~Physical examination~Basic blood test result~Autism Behavior Checklist,CARS before the treatment~Brain Magnetic Resonance Imaging-Diffusion Tensor Imaging (MRIDTI) before the treatment~Neurocognitive function test before the treatment~Assessment of clinical condition in the course by measurement of blood pressure, heart and respiratory rates, temperature and adverse events was recorded.~Autologous cord blood doses is 20-30ml (total Mononuclear cells# 1*10^7/kg)#the infusion speed is 1ml/min, and with same volume of 0.9% sodium chloride as placebo.~The follow-up: clinical test until 24th month in 3 month gaps.
To study the clinical efficacy and safety of autologous umbilical cord blood transfusion in the treatment of autism spectrum disorder.