SCIENCE
ABORTION
Defining Viability
In medicine, viability refers to the stage at which a fetus can survive outside the womb with medical support. It is not a fixed biological event, but a clinical judgment influenced by gestational age, physiological development, and available technology. The Royal College of Obstetricians and Gynaecologists explains that “viability is dependent upon gestational age, fetal development, and the level of neonatal care available,” and therefore “cannot be defined by a single universal gestational age” (Royal College of Obstetricians and Gynaecologists, Perinatal Management of Extreme Preterm Birth).
Medical authorities caution against equating viability with the beginning of life or with human value. The American College of Obstetricians and Gynecologists states that “viability does not define the beginning of life or personhood,” but instead reflects the limits of contemporary medical intervention (American College of Obstetricians and Gynecologists, Committee Opinion on Abortion and Ethical Care). Human development proceeds continuously throughout pregnancy, regardless of whether survival outside the womb is medically possible at a given moment.
The Changing Threshold of Viability
Historically, viability was often placed near 28 weeks of gestation, reflecting the limitations of neonatal care in the mid-20th century. At that time, neonatal researchers observed that “survival prior to 28 weeks was rare,” largely due to immature lungs and the absence of effective respiratory support (Stoll et al., New England Journal of Medicine).
Advances in neonatal medicine—including antenatal corticosteroids, surfactant therapy, advanced ventilation, and highly specialized neonatal intensive care—have steadily shifted this threshold earlier. Contemporary studies now document survival at 22–23 weeks of gestation, particularly in specialized care settings. While survival rates at 22 weeks remain limited, researchers consistently report that “outcomes improve substantially with each additional week of gestation,” underscoring the developmental continuum of early human life (Rysavy et al. 2015, New England Journal of Medicine).
As neonatal medicine continues to progress, the shifting boundary of viability illustrates that this standard is shaped by medical capability rather than biology itself. The changing threshold invites careful reflection on how society understands, protects, and values human life at its most vulnerable stages.
Surfactant Therapy
Surfactant replacement therapy has been a transformative advance in the care of premature infants with neonatal respiratory distress syndrome (RDS). RDS is closely linked to lung immaturity and surfactant deficiency; clinical literature explains that neonatal RDS “occurs from a deficiency of surfactant” in underdeveloped lungs (Avery and Mead 1959). Premature infants often lack sufficient functional surfactant to stabilize the alveoli, leading to breathing failure and life-threatening complications shortly after birth (Jobe and Bancalari 2001).
Following the development of exogenous surfactant, randomized clinical trials consistently demonstrated substantial improvements in outcomes for preterm infants with RDS. Reviews of this therapy report that surfactant administration “significantly reduced both neonatal mortality and pulmonary air leaks,” marking a major shift in neonatal survival (Soll 2000). Subsequent medical consensus has established surfactant therapy as a standard of care, with evidence showing it “reduces mortality and the risk of air leak” in vulnerable premature infants (Sweet et al. 2019). Large systematic reviews further conclude that early surfactant treatment lowers the risk of acute lung injury and decreases neonatal death when compared with delayed intervention (Soll and Morley 2001).
Together, these findings confirm that surfactant therapy dramatically improves survival and reduces serious complications in premature infants with RDS, underscoring the importance of providing life-sustaining care even in the most fragile and challenging circumstances.
Extracorporeal Membrane Oxygenation (ECMO)
Extracorporeal Membrane Oxygenation (ECMO) is an advanced life-support technology used in critically ill newborns when the heart or lungs cannot provide adequate oxygenation despite maximal treatment (Extracorporeal Life Support Organization [ELSO] 2017). ECMO works by circulating blood through an external circuit, where oxygen is added and carbon dioxide is removed, allowing the infant’s heart and lungs time to rest and recover (Daley et al. 2023).
In neonatal care, ECMO is most commonly used for severe respiratory failure, including persistent pulmonary hypertension of the newborn, meconium aspiration syndrome, overwhelming infection, and selected congenital conditions (ELSO 2017). Because ECMO requires anticoagulation and carries a significant risk of bleeding, it is generally reserved for late-preterm and term infants rather than very premature newborns (Daley et al. 2023).
Although ECMO does not determine fetal viability on its own, it demonstrates how advances in neonatal medicine continue to extend the limits of survival after birth. Each successful use of ECMO reflects the lifesaving potential of medical innovation for the most vulnerable infants.
Therapeutic Hypothermia (Cooling Therapy)
Therapeutic hypothermia (cooling therapy) is an evidence-based treatment for term and near-term newborns with moderate to severe hypoxic-ischemic encephalopathy (HIE), a form of brain injury caused by reduced oxygen and blood flow around the time of birth. Large randomized clinical trials have shown that lowering an infant’s body temperature shortly after birth slows metabolic injury in the brain and significantly improves outcomes. A landmark multicenter study reported that “whole-body hypothermia reduces the risk of death or disability” in infants with moderate or severe HIE (Shankaran et al. 2005).
Clinical guidance from the American Academy of Pediatrics affirms this conclusion, stating that “data from large randomized clinical trials indicate that therapeutic hypothermia…is an effective therapy for neonatal encephalopathy” when initiated within the appropriate therapeutic window (Papile et al. 2014). Systematic reviews further demonstrate that cooling therapy improves survival and neurodevelopment, with the Cochrane Collaboration concluding that therapeutic hypothermia “reduces mortality and major neurodevelopmental disability at 18 to 24 months of age” in eligible newborns (Jacobs et al. 2013).
High-Frequency Oscillatory Ventilation (HFOV)
High-Frequency Oscillatory Ventilation (HFOV) is a form of mechanical ventilation used in newborns with severe respiratory failure, often as a rescue strategy when conventional ventilation fails to provide adequate gas exchange (Keszler 2015). HFOV delivers extremely rapid oscillations using very small tidal volumes—often less than anatomical dead space—while maintaining a relatively constant mean airway pressure to keep the lungs recruited and evenly inflated (Froese and Kinsella 2005).
Because HFOV avoids large breath-to-breath volume changes, it is widely described as a lung-protective approach. Clinical reviews explain that HFOV uses low tidal volumes and constant distending pressure, reducing the repetitive opening and closing of alveoli associated with ventilator-induced lung injury (Greenough 2010). While experimental studies demonstrate reduced lung injury with this strategy, large clinical trials show mixed results when HFOV is compared with conventional ventilation, indicating that it is not universally superior but remains valuable in specific clinical circumstances (Johnson et al. 2002; Cools et al. 2015).
HFOV continues to play an important role in neonatal intensive care, reflecting ongoing medical innovation aimed at supporting the most fragile infants while carefully balancing life-sustaining respiratory support with protection of the developing lungs (Keszler 2015).
Real-World Survival Data
Viability—the ability of a preterm infant to survive outside the womb with medical support—has shifted in recent decades as neonatal care has advanced. Once commonly placed around 24 weeks’ gestation, survival is now documented at 22 and 23 weeks, particularly when active treatment is provided. (Bell et al. 2022)
Recent U.S. multicenter data from the NICHD Neonatal Research Network (2013–2018) show that “survival among actively treated infants was 30.0% at 22 weeks and 55.8% at 23 weeks” (Bell et al. 2022). When all live-born infants are included—regardless of treatment—survival is lower, reflecting the critical role that care decisions play: “Survival to discharge was 10.9% for live-born infants at 22 weeks” (Bell et al. 2022).
These gains are associated with established medical practices such as antenatal corticosteroids, surfactant therapy, advanced respiratory support, and specialized neonatal intensive care. Still, outcomes at these gestational ages remain uncertain, and long-term complications are common among survivors (Bell et al. 2022).
Survival also varies widely by location. Studies show that hospital policies strongly influence outcomes, with some centers actively treating most infants born at 22 weeks and others offering little or no intervention. One analysis found that rates of active treatment at 22 weeks ranged from 8% to 100% across U.S. hospitals (Mehler et al. 2016). Broader population studies confirm significant regional and institutional differences in care (Chen et al. 2022; Venkatesh et al. 2022).