Which group of infants has the highest mortality rate?

• A. Term infants
• B. Moderately preterm infants
• C. Extremely preterm infants
• D. Full-term infants

Answer: (C)

The group of infants with the highest mortality rate is extremely preterm infants. Extremely preterm infants are defined as those born before 28 weeks of gestation. This group is at significant risk due to several factors, including underdeveloped organs, particularly the lungs and brain, which can lead to severe complications such as respiratory distress syndrome, infections, and neurodevelopmental disorders. These risks significantly increase the likelihood of mortality in this population compared to infants born at later gestational ages.

As gestational age increases, the likelihood of survival improves due to better organ development and maturity. Term infants and full-term infants, being born at 37 weeks or later, generally have lower mortality rates attributed to their more developed physiological state. Moderately preterm infants, born between 32 to 36 weeks of gestation, also face risks, but these are typically less severe than those faced by extremely preterm infants. Thus, while all preterm infants are more vulnerable than their full-term counterparts, it is the extremely preterm infants who experience the highest mortality rates due to their critical developmental stage at birth.