Your infant's "age"

Age is both a measure of time and a marker of development. Unlike with a full-term infant, a premature infant's age and development can be defined in different ways. This can be confusing to any parent. When following your premature infant's growth and development, it can be helpful to know the difference between the following "ages":

• Gestational age is the fetus's age, as measured from the first day of the mother's last period. This figure is used to define your premature infant's age and point of development at the time of birth. This is the same as the length of your pregnancy.
• Postconceptual age is the infant's age, also measured from the first day of the mother's last period (the same as gestational age, but with a different name). This figure may be used early in your premature infant's life and is useful for estimating his or her point of growth and development.
• Chronological age is measured from the day of birth. Your child's birthdays are celebrations of his or her chronological age.
• Corrected age is the infant's or child's chronological age minus the amount of weeks or months he or she was born early. For example, if your 1-year-old was born 3 months early, you can expect him or her to look and act like a 9-month-old (corrected age). You may find this figure to be most reassuring when following your child's growth and development for the first 2 years after birth.

Your infant's development

Most premature infants who are born between 32 and 37 completed weeks' gestation do well after birth. If your infant does well after birth (has no oxygen deprivation, severe infection, or brain or lung damage), his or her risk of disability or developmental delay is low.

During your child's first 2 years of life, he or she will appear to be developmentally behind full-term children of the same age. But you can expect your infant and young child to achieve the same sequence of developmental milestones as any other child. For more information about infant and child developmental milestones, see Growth and Development, Newborn, Growth and Development, Ages 1 to 12 Months, and Growth and Development, Ages 12 to 24 Months.

Expect that your premature infant's "lag" in development will catch up at about 2 years of chronological age. As your child grows into the preschool years, a 2- to 4-month difference in age or development blends right in among a group of preschoolers. For more information about preschooler development, see the topic Growth and Development, Ages 2 to 5 Years.

As your child begins formal schooling, be alert for signs of learning problems. Learning, reading, and math disabilities due to prematurity may first become apparent during the early school years.

Severe delays and disability