Premature Birth

Last Updated August 2022 | This article was created by editorial staff and reviewed by Deepak S. Patel, MD, FAAFP, FACSM

Every woman dreams of an ideal pregnancy — a 40-week time where everything goes as planned. But 1 out of every 10 infants in the United States is born prematurely. And when a baby has had less time to develop in the womb, they are often born with problems. That’s because many organs, including the brain, lungs, and liver, are still developing in the final weeks of pregnancy. Preterm birth problems range from mild to severe. They can include breathing and feeding problems, cerebral palsy, developmental delays, and vision and hearing problems.

The earlier the delivery, the more likely it is that the baby will have more severe issues. Preterm is defined as babies born alive before the completion of 37 weeks of pregnancy. Premature birth sub-categories are based on gestational age (how far along the pregnancy is). It’s measured in weeks, from the first day of the woman’s last menstrual cycle to the current date:

  • Extremely preterm (born before 28 weeks)
  • Very preterm (28 to before 32 weeks)
  • Moderate to late preterm (32 to before 37 weeks)

Preterm birth is the greatest contributor to infant death. Most of the deaths occur among babies born prior to 32 weeks of pregnancy.

Doctors don’t always know why a woman gives birth before 37 weeks. But several factors can put women at a higher risk. They include:

  • Being younger than 19 or older than 40
  • Having a low maternal income or socioeconomic status
  • Having an infection or chronic condition, such as diabetes
  • Having a previous preterm birth
  • Being pregnant with twins, triplets, or more
  • Having high blood pressure during pregnancy
  • Using tobacco or alcohol during pregnancy
  • Abusing drugs during pregnancy
  • Beginning prenatal care late in the pregnancy
  • Going through a stressful event during pregnancy

Path to improved health

Can premature birth be prevented?

Some risk factors can’t be changed. But you can take certain steps to lower your risk of having a premature baby:

  • Don’t smoke. If you do, quit now. Talk with your doctor about how to do it.
  • Don’t use alcohol or drugs during pregnancy.
  • Go to your doctor for prenatal care as soon as you think you’re pregnant. Keep all your appointments throughout your pregnancy.
  • Be treated for any chronic conditions you have.
  • Reduce your stress.
  • Know the signs. If you think you may be in labor, call your doctor right away. Signs of labor include:
    • Contractions
    • Change in vaginal discharge
    • Pelvic pressure
    • Low, dull backache
    • Cramps that feel like a menstrual period
    • Abdominal cramps with or without diarrhea

Premature babies (preemies) need special care. A neonatal intensive care unit (NICU) is a nursery in the hospital that specializes in the care of preemies. The doctors and nurses who work in the NICU have specialized training and equipment to care for these infants. This ensures your baby will get the best possible care for their proper growth and development.

You’ll be able to get involved in your baby’s care, even if they are in the NICU. Premature babies are unable to feed from the breast or bottle until they’re 32 to 34 weeks gestational age. But breast milk can be pumped by the mother and fed to the infant through a tube. Breast milk has a distinct advantage over formula. It contains antibodies to help protect your baby from infections his or her underdeveloped immune system can’t fight off. Premature infants may also need an antibody injection to reduce the risks from a certain viral infection.

Because premature babies need more nutrition than full-term infants, vitamins and minerals may be added to breast milk or formula.

At home with your premature baby

Once your baby’s systems are developed and can work on their own, they will be able to go home. The baby may still require special care, especially if they were very small at birth.

Within a few days of being released from the hospital, you’ll need to take your baby to the doctor. They will check your baby’s weight and make sure everything is going well at home. At each of your baby’s well visits, your doctor will check your baby’s growth using a special growth chart for premature babies. Growth for your baby may be slower than a full-term baby’s growth. Don’t worry, though. Most premature babies catch up with full-term babies after the first 2 years.

Talk with your doctor about feeding your baby. Breast milk is always best. But premature babies can have issues with sucking or latching on. Ask your doctor for help, or for a recommendation of a lactation consultant if necessary.

Things to consider

Certain vision and hearing issues are more common in premature babies. Crossed eyes (or strabismus), for example, will often go away on its own. Retinopathy of prematurity (ROP), a condition in which the small blood vessels in the eye grow abnormally, can occur in babies who were born at or before 32 weeks of pregnancy. Ask your doctor if you should take your baby to an eye doctor.

Premature babies are also more likely to have hearing issues. Speak to your doctor if your baby fails to react to loud noises.

Your doctor will also pay careful attention to your baby’s developmental milestones. Motor skills like smiling, sitting, and walking will be closely monitored as they grow.

Questions to ask your doctor

  • How much should my baby be eating and how often?
  • How much should my baby be sleeping and how often?
  • What is my baby’s gestational age?
  • What developmental milestones should I be looking for and when?
  • How do I protect my baby from getting sick?
  • Will my baby need an antibody injection to protect against a specific infection?
  • Should others in the house get any special vaccinations?
  • When can I take my baby out in public?
  • How can I properly position my baby in his car seat?
  • Are there any special concerns about vaccinations since my baby was born prematurely?


Centers for Disease Control and Prevention: Preterm Birth
March of Dimes: Preterm Labor & Premature Birth
March of Dimes: The Newborn Intensive Care Unit (NICU)


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