When Will My Preemie Learn to Sit Up?

Smililng baby sitting up
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Many parents worry that their preemies aren't meeting developmental milestones on time. Remember that charts of developmental milestones are general guidelines that give parents an idea of when their children will learn new skills. There is a wide range of ages at which children will meet new milestones, whether they were born early or on time.

If your preemie is now a healthy baby who had a smooth NICU course and no serious long-term effects of prematurity, he should learn to sit up according to normal developmental milestones for his corrected age:

  • By 6 to 9 Months: By the time preemies reach 9 months corrected age, they should be able to sit up without support from pillows or a parent.
  • By 10 to 12 Months: By 12 months corrected age, preemies should be able to play with a toy with both hands while sitting up without support.

Remember to use corrected age when comparing preemies to a chart of developmental milestones. Corrected age is the age your baby would be if he was born at term. If your baby is 8 months old but was born 2 months early, his corrected age would be 6 months old.

Why Some Preemies Learn to Sit Later Than Others

Although most preemies will learn to sit up within the normal time frame, very low birth weight babies tend to meet developmental milestones later than full-term babies, even after adjusting for corrected age.

Babies who are born very early or who have many health problems tend to meet milestones, including learning to sit up, later than other babies.

Your preemie may learn to sit up later, even after correcting for gestational age, if he or she:

  • Was born before 27 weeks gestation
  • Weighed less than 750 grams at birth
  • Suffers from bronchopulmonary dysplasia or chronic lung disease
  • Has been hospitalized frequently
  • Still needs significant medical support (feeding tubes, help breathing, etc)

When Should Parents Should Worry

Although preemies might learn to sit up a little later than their full-term peers, most preemies will learn to sit up by 9 months corrected age. If your baby is not sitting up for 9 months or is not using both hands to play while sitting by 12 months corrected age, talk to your pediatrician.

What Can Parents Do to Help?

A close relationship with your pediatrician can help you ensure that your preemie thrives. Pediatricians who know their patients and their families well can help decide if a baby who is late meeting milestones is showing normal effects of prematurity or has signs of a developmental delay. They may be able to recommend therapies, such as occupational or physical therapy, that can help preemies catch up to their peers.

Also, if your baby was born early, ask as soon as you can if your baby qualifies for early intervention. Early intervention is a group of programs that help babies and toddlers who are at risk for developmental delays to thrive. Some babies will qualify for early intervention from the moment they leave the NICU.

Getting help so early can minimize the long-term effects of prematurity.

3 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Important Milestones: Your Baby By Nine Months.

  2. Marín gabriel MA, Pallás alonso CR, De la cruz bértolo J, et al. Age of sitting unsupported and independent walking in very low birth weight preterm infants with normal motor development at 2 years. Acta Paediatr. 2009;98(11):1815-21. doi:10.1111/j.1651-2227.2009.01475.x

  3. Centers for Disease Control and Prevention. Developmental Monitoring and Screening.

By Cheryl Bird, RN, BSN
Cheryl Bird, RN, BSN, is a registered nurse in a tertiary level neonatal intensive care unit at Mary Washington Hospital in Fredericksburg, Virginia.