Efficacy of Using Mesenchymal Stem Cells With Therapeutic Hypothermia in Infants With Perinatal Hypoxic-Ischemic Encephalopathy: A Double Blind, Randomized Controlled Trial

Perinatal hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal death and long-term disability worldwide. Therapeutic hypothermia (TH) is the established standard of care for term and near-term infants with moderate to severe HIE. Large randomized trials and systematic reviews have demonstrated that TH significantly reduces the combined outcome of death or major neurodevelopmental disability at 18 months of age (relative risk 0.75; 95% confidence interval 0.68-0.83). However, despite this benefit, many infants continue to have poor outcomes. Importantly, a recent meta-analysis indicated that in upper-middle-income countries, the effect of TH was smaller and did not reach statistical significance (RR 0.67; 95% confidence interval 0.41-1.09), underscoring the need for effective adjunctive treatments.

Mesenchymal stem cells (MSCs) derived from Wharton's jelly of the human umbilical cord have emerged as a promising adjunctive therapy. Preclinical studies demonstrate that MSCs exert neuroprotective and regenerative effects via anti-inflammatory, anti-apoptotic, and trophic mechanisms. Early-phase clinical studies of cord blood or MSC products in neonatal HIE have shown feasibility and acceptable safety, with signals suggesting improved neurological recovery. Nevertheless, controlled trials specifically testing MSCs after completion of TH in neonates are lacking.

This study is a pilot, randomized, double-blind, placebo-controlled trial to evaluate the feasibility, safety, and potential efficacy of repeated intravenous infusions of Wharton's jelly-derived allogeneic MSCs in neonates with moderate to severe perinatal HIE who have completed TH. Forty infants (gestational age ≥34 weeks, postnatal age ≤10 days) will be randomized in a 1:1 ratio to receive either MSCs or placebo.

The intervention group will receive three intravenous doses of MSCs (2 × 10^6 cells/kg per dose, suspended in normal saline) administered over approximately 30 minutes. The control group will receive equivalent volumes of placebo (normal saline). Infants, parents, and treating clinicians will remain blinded to allocation.

All cell products are prepared in a GMP-compliant cleanroom facility with rigorous quality control testing, including sterility, endotoxin, mycoplasma, viability, morphology, immunophenotype, and karyotype. Donor placental tissue undergoes standard infectious disease screening.