LIMITS OF VIABILITY: SHOULD WE PLAY GOD?

Area of Science:

• Perinatal Medicine
• Neonatology
• Public Health

Background:

• The definition of "limits of viability" for newborns is inconsistent across countries.
• Infant mortality and morbidity increase with decreasing gestational age, while survival rates decrease.
• Existing definitions of viability lack scientific consensus and vary based on available resources.

Purpose of the Study:

• To demonstrate that the definition of infant viability is influenced by socioeconomic and medical conditions.
• To highlight the variability in defining viability even within countries with advanced neonatal care.
• To explore the challenges in establishing a universal scientific definition of viability.

Main Methods:

• Comparative analysis of viability definitions and outcomes across different countries and healthcare settings.
• Review of existing literature and World Health Organization (WHO) guidelines on viability.
• Examination of factors influencing survival rates, including gestational age, birth weight, and access to neonatal intensive care.

Main Results:

• Survival rates for preterm infants vary dramatically, with 95% mortality in developing countries ( <28 weeks gestation) versus up to 90% survival in developed countries (22-25 weeks gestation).
• The WHO currently defines the lower limit of viability at 22 weeks gestation, 500g birth weight, or 25cm length.
• Significant disparities exist in neonatal intensive care availability and organization, impacting survival rates.

Conclusions:

• A universal definition of the limits of viability is not feasible due to individual, setting-specific, and community variations.
• Social and medical conditions significantly impact the definition and practical application of infant viability.
• Further research is needed to establish more standardized, yet adaptable, criteria for defining neonatal viability.