Earliest Gestational Age for Fetal Survival

Survival Rates by Gestational Age

The American College of Obstetricians and Gynecologists notes that at 22 weeks gestation, survival rates are approximately 5-6% with nearly universal significant morbidity (98-100%) 1, 2
At 23 weeks gestation, survival rates range from 23-27% 1, 2
At 24 weeks gestation, survival rates increase to 42-59% 1, 2
At 25 weeks gestation, survival rates further improve to 67-76% 1, 2

Long-term outcomes for survivors show high rates of impairment that decrease with increasing gestational age, with 43% having moderate-to-severe neurodevelopmental impairment at 22 weeks 1
At 23 weeks, 40% have moderate-to-severe neurodevelopmental impairment 1
At 24 weeks, 28% have moderate-to-severe neurodevelopmental impairment 1
At 25 weeks, 24% have moderate-to-severe neurodevelopmental impairment 1

Institutional practices regarding resuscitation and active treatment, particularly at 22-23 weeks, influence survival 1, 2
Administration of antenatal corticosteroids affects survival 1, 2
Birth weight and fetal growth impact survival 3
Multiple gestations influence survival 1
Fetal genetic diseases and anomalies affect survival 4
Location of delivery, with tertiary care centers having better outcomes, impacts survival 1, 2

From the 1950s through 1980, newborn death was virtually assured with delivery at or before 24 weeks gestation 1, 2
There has been a progressive increase in survival rates for infants born at 22-25 weeks over the past three decades 1, 2

The periviable period is defined as delivery occurring from 20 0/7 weeks to 25 6/7 weeks of gestation 5, 4
Outcomes at the extremes of each gestational week may be closer to those of the adjacent week 1
Counseling should include accurate, individualized information regarding short-term and long-term outcomes 1, 2
Variation in practices regarding resuscitation and active treatment at very early gestational ages explains some differences in survival between hospitals 1, 2