Developmental Milestones for Premature Babies

Premature babies develop at a slightly different rate than full-term babies. Here is your guide to all the developmental milestones for premature babies.

Waiting for a baby’s milestones is a source of excitement for parents everywhere, but for parents of premature babies, it is also a source of stress and confusion. On one hand, there’s the worry about whether the prematurity will affect the baby’s normal development, and on the other hand, there’s the confusion about how to check if their baby’s hitting all their milestones at the right time.

The confusion is understandable since the calculation for premature babies’ milestones is a little different from that of full-term babies. Here, there is some math to do in calculating the baby’s adjusted age.

Calculating the Adjusted Age for Premature Babies

A foetus is programmed to develop a certain way, according to a specific schedule which usually ends by 40 weeks in the womb. Even when the baby is born before that, the development proceeds the way it would as if the baby were still in the womb. This is why doctors don’t rely only on the baby’s actual birth date to track development; the baby’s estimated due date is also important. The baby’s age based on this due date is called the ‘adjusted age’ or ‘corrected ‘age’.

For instance, if the baby was born 2 months early and is now 6 months old, she can’t be compared to a full-term 6-month-old baby, since she has missed out on 2 months in the womb. As a result, her adjusted age will be 4 months – the age she would have been if she had spent her full 40 weeks in the womb. Now, her milestones and development will be tracked with the 4 month age in mind.

Doctors use the adjusted age when tracking anything related to the baby’s development, usually, till about 2 years of age since most preemies catch up with their full-term peers by then. However, even with the adjusted age, some other factors may affect a premature baby’s milestones.

Factors affecting Milestones of Premature Babies

Birth Date

A baby is considered premature if she is born before 37 weeks in the womb. However, how early the baby is born affects her rate of development. Premature babies are divided into four categories based on their gestational age at birth:

  • Late preterm – Born from 34 weeks – 37 weeks
  • Moderately preterm – Born from 32 -34 weeks
  • Very preterm – Born from 25 – 32 weeks
  • Extremely preterm – Born before 25 weeks

The earlier the prematurity, the longer it will take for the baby to catch up with her milestones and it’s also likely that she will have other medical issues which slow down development. Late preterm babies catch up quite fast, and many of them don’t need to be tracked with their adjusted age for long.

Birth Weight

Along with how preterm the baby is, the weight of the baby also plays an important role in her development. A lower birth weight indicates a higher chance of health problems and slower development. Heavier babies are more likely to be stronger and achieve milestones faster. Babies in the NICU are also fed very slowly and carefully, and this can lead to slow weight gain.

Time spent in Hospital

Premature babies often spend some weeks in the hospital, especially extremely preterm to moderately preterm babies.  A long hospital stay can delay milestones since babies in the NICU don’t have the opportunity to develop their muscle tone, which can delay all their motor development.

Other Medical Conditions

Premature babies have missed out on a lot of crucial development in the final months of pregnancy, and this can lead to various medical issues and infections. Even if they are treated and the baby is healthy, it can cause a slowdown in development and it can take longer for babies to get strong and catch up.

Based on these factors, we can understand that a premature baby will have developmental delays compared to full-term babies, but most of them will catch up in due time. Yet, it helps to know what to expect at every stage, so parents can keep a close eye on their babies and offer the right support when needed.

As mentioned above, premature babies continue to develop outside the womb, just as they would inside. The difference is that they are now exposed to much more stimuli, for which they are not yet ready. Here is a quick look at what to expect in babies born at different stages of prematurity.

26 Weeks

  • Opens eyes sometimes but can’t focus yet
  • Has poor muscle tone and can’t curl up
  • Cannot suck or feed on his own

28 Weeks

  • Starts to blink eyes, opening it occasionally
  • Can’t focus eyes or move them together
  • Can respond to the mother’s voice

30 Weeks

  • Has better muscle tone and can move and stretch
  • Responds to pleasant sounds
  • Starts to develop the rooting reflex

33 Weeks

  • Has more controlled movements
  • Can bend arms and legs
  • Can focus on a single object at a time
  • Starts to suck more strongly

36 Weeks

  • Can move the head from side to side
  • Has good muscle tone
  • Can close eyes and turn away
  • Starts breastfeeding

Before looking at what to expect at each age, it helps to get a general idea by looking at the top 3 developmental milestones in premature babies.

Sitting – In most cases, premature babies learn to sit up on their own somewhere around 6-7 months, and this is usually the first significant milestone noticed by parents.

Walking – Premature babies learn to walk somewhere around 18 months, though many do walk later. When a preemie walks depends largely on how much exercise their muscles get.

Talking – Preemies usually talk around the same time as full-term babies, as long as they’ve had enough exposure to speech and language in their environment.

Article courtesy of My little moppet