Fetal viability refers to the earliest gestational age at which a baby can survive outside the womb with medical support. Understanding these milestones helps parents and doctors make informed decisions about preterm birth management.
What Viability Means
The threshold of viability is typically set at 22–24 weeks, but this is a spectrum — not a sharp line. At 22 weeks, survival is rare and neurological outcomes are uncertain. At 24 weeks, survival with intensive care is possible for many babies. At 28+ weeks, outcomes improve dramatically.
Survival Rates by Gestational Age
| Gestational Age | Approximate Survival Rate | Intact Survival (No Major Disability) |
|---|---|---|
| 22 weeks | 5–15% with maximal intervention | Rare |
| 23 weeks | 20–35% with maximal intervention | 15–25% |
| 24 weeks | 40–70% | 30–50% |
| 25 weeks | 60–80% | 50–60% |
| 26–27 weeks | 75–90% | 65–75% |
| 28–29 weeks | 85–95% | 75–85% |
| 30–32 weeks | 95%+ | 90%+ |
| 34–36 weeks | Near normal | Near normal |
Note: These figures are averages from high-income country NICUs. Singapore's KKH and NUH have outcomes comparable to the best global centres.
What NICU Care Involves
- Respiratory support: CPAP or mechanical ventilation for immature lungs
- Synthetic surfactant administration for RDS
- Temperature regulation in a warmed incubator
- IV nutrition (TPN) until gut matures enough for feeding
- Infection monitoring and treatment
- Kangaroo care (skin-to-skin) as soon as stable — improves outcomes
Long-Term Outcomes for Premature Babies
The risk of long-term disability depends heavily on gestational age and on whether complications like severe intraventricular haemorrhage (IVH), necrotising enterocolitis (NEC), or severe BPD occurred. Many babies born at 28+ weeks with uncomplicated courses do very well developmentally.
Singapore
At KKH, babies from 24+0 weeks are offered full resuscitation. At 22–23 weeks, decisions are made on an individual basis with parents.