Full Term Vs. Premature Infant Development

Most pregnancies result in a healthy, full-term baby, which is a baby born after 38 to 40 weeks gestation. Infants born before the 37th week of pregnancy are premature, which places them at a higher risk for complications than full-term babies, explains HealthyChildren.org, a website published by the American Academy of Pediatrics 23. For a time, preemies lag behind developmentally, but eventually they do catch-up with their full-term peers.


Unlike full-term newborns, premature infants have a number of special needs. Preemies often spend the first weeks of life in the hospital's neonatal intensive care unit, where hospital staff closely watch the newborn for potential problems. The NICU also provides a low-stress environment, and hospital nurses place preemies in incubators for warmth, since preemies do not have the natural insulation of body fat that full-term babies have.

Growth and Development

Full-term babies generally weigh between 6 and 9 pounds at birth, but preemies usually weigh 5 pounds or less at birth, according to the American Pregnancy Association 12. Even though all newborns lose about 5 percent to 10 percent of their birth weight during the first week of life, full-term babies will regain the lost weight in about 10 to 14 days, whereas a preemie may not return to his birth weight for up to 21 days. Premature babies grow at a slower pace than full-term infants do for the first 24 months. For this reason, your preemie’s development is based on his "corrected" age, which is his age in weeks minus the number of weeks he was born early, rather than on his date of birth. For example, if your baby was born eight weeks prematurely, your baby’s age at 6 months would have a corrected age of 4 months, explains MayoClinic.com. If a full-term baby is able to at crawl on her belly at 8 months, a preemie may not be able to do so until 10 months.

Nutritional Needs

Breast milk is generally the best food for all babies, but infant formula will suffice when breastfeeding is not possible. Your doctor may recommend vitamin D supplements for your baby, since breast milk may lack sufficient amounts of the so-called "sunshine vitamin.” Vitamin D also helps your baby absorb bone-strengthening nutrients like calcium and phosphorus. Premature babies may also need extra iron for proper growth and development, since they do not have the same adequate iron reserves of full-term infants.

Going Home

Most healthy newborns go home after two or three days, but preemies may stay in the hospital for days, weeks or even months. A premature baby’s discharge date depends upon how early he was born and on which medical problems he may have. The NICU staff wants to be certain that your baby can breathe easily and retain her body temperature before she’s released, explains Vinod K. Bhutani, M.D., FAAP, professor of pediatrics at Lucile Packard Children’s Hospital at Stanford University School of Medicine.

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