Survival expectations for very low birth weight (VLBW) infants have transformed remarkably over the past decade. While a 500-gram infant at 22 weeks sits at the boundary of gestational age viability, an infant weighing 2 lbs (typically born between 26 and 28 weeks) enters the hospital system with substantially higher clinical stability.
Recent network data from international neonatal research consortia shows that neonatal survival rates for infants born at 27 to 28 weeks now track between 88% and 94% in high-volume, tertiary centers.
Mortality, however, is only one metric. The broader medical focus centers on intact neurological survival, avoiding severe cerebral palsy, profound hearing loss, and chronic lung disease. Clinicians continuously balance supplemental oxygen concentration. Too little oxygen risks hypoxic tissue injury; too much induces oxidative stress that triggers retinopathy of prematurity (ROP), an abnormal proliferation of retinal blood vessels that can cause scarring and retinal detachment if left untreated. Laser photocoagulation or anti-VEGF injections remain standby interventions when weekly indirect ophthalmoscope exams detect stage 3 disease.
