Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Premature Baby

By

The Manual's Editorial Staff

Medically Reviewed Dec 2021 | Modified Sep 2022
VIEW PROFESSIONAL VERSION
Get the full details

What is a premature baby?

A premature baby is born too early. A full pregnancy lasts 37 to 40 weeks, so a premature baby is born anytime before the 37th week of pregnancy.

The more premature babies are, the more likely they are to have complications at birth and later. Babies born before 23 weeks probably won't live.

What causes a baby to be born prematurely?

Most of the time, there's no clear reason why a baby is born too early.

The chances of having a premature baby are higher if the mother:

What are symptoms of a premature baby?

Premature babies look a little different than full-term babies. They usually:

  • Weigh between 1 and 5.5 pounds (500 to 2500 grams)

  • Have a head that looks large compared to the rest of their body

  • Lack fat under their skin

  • Have thin, shiny, pink skin

  • Have veins visible through their skin

Premature babies often:

  • Breathe quickly and may pause for seconds at a time (apnea)

  • Have trouble regulating their body temperature

  • Have trouble sucking and swallowing

What complications do premature babies have?

Premature babies get complications because their organs aren't fully developed. The more premature they are, the more complications they get.

Most complications go away after a while. But babies who had severe complications may keep having problems with their breathing or vision.

How do doctors treat premature babies?

Doctors will care for your baby in the hospital in a special unit for sick newborns. It's called a NICU, which stands for neonatal intensive care unit. They'll also:

  • Put your baby in an incubator to help keep the baby warm

  • Give medicine into your baby's lungs to help your baby breathe, and sometimes put a tube in the baby's nose or mouth attached to a breathing machine (ventilator)

  • Feed your baby through a vein or feeding tube until your baby can suck and swallow

  • Put the baby under special UV lights to treat jaundice

How can I keep my baby from being premature?

You can lower the chance of your baby being premature by:

  • Going to all of your prenatal doctors' visits

  • Following a healthy diet

  • Not drinking alcohol

  • Not using tobacco or drugs

If you go into labor early, your doctor may give you medicine to:

  • Slow down your labor

  • Help your baby’s lungs develop faster

NOTE: This is the Consumer Version. DOCTORS: VIEW PROFESSIONAL VERSION
VIEW PROFESSIONAL VERSION
quiz link

Test your knowledge

Take a Quiz!
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP