At what gestational age does a fetus typically become viable outside the womb?

A fetus is generally considered viable outside the womb at around 24 weeks of gestation. This timing corresponds to the development of several critical physiological systems that are necessary for independent survival, particularly the lungs and brain. Around 24 weeks, the lungs begin to produce surfactant, which is essential for proper lung function after birth, reducing the risk of respiratory distress syndrome.

Prior to 24 weeks, although there may be some cases of survival with extensive medical intervention, the chances of successful survival are significantly lower, and the risks of severe complications increase. By about 28 weeks, the chances for survival improve even further, but clinical guidelines and the majority of medical literature cite 24 weeks as the threshold for viability. Thus, 24 weeks is the standard gestational age referenced in medical practice when discussing viability.