Week By Week Premature Baby Survival Rates And Statistics

Week By Week Premature Baby Survival Rates And Statistics

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During pregnancy, the baby undergoes various stages of growth and development. In the case of preterm birth, the baby loses on comprehensive development and might need medical interventions after birth. Preterm birth is a common issue prevalent across the world. Every year about 15 million babies are born preterm (1); in the US alone, one out of ten babies is born prematurely (2).

The survival rate and development depends on how early the baby has born before the due date. A birth nearer to the due date ensures better growth of the baby. Read this post to know about premature birth, its risk factors, what to expect after birth, and the preterm survival rates.

Definition Of Premature Birth

According to the World Health Organization, preterm or premature birth is defined as when babies are born alive before the completion of 37 weeks of pregnancy (1). Based on the gestational age or age of the pregnancy, preterm birth can be further divided into the following categories (1).

  • Extremely preterm: When a baby is born before 28 weeks
  • Very preterm: When a baby is born between 28 and 32 weeks
  • Moderate or late preterm: When a baby is born between 32 and 37 weeks

It is usually recommended that unless there is a medical emergency or a serious health condition, cesarean birth or induced labor (induction) should not be planned before 39 weeks of gestation. However, with advances in medical sciences, it is estimated that about 9 out of 10 babies born prematurely survive and have normal growth (3).

Factors Affecting Survival Of Preterm Babies

A National Institutes of Health study that observed 4,000 newborns found that the following factors affect the survival and disability in preterm babies (4).

  • Baby’s gender
  • Maternal age
  • Birth weight
  • multiple pregnancies
  • Whether the mother was given medication to stimulate the development of fetus
  • Infections and chronic conditions (eg. diabetes, hypertension, etc.)

The researchers found that there were better chances of survival without a disability when the baby was a female, was of older gestational age, had higher birth weight, was born as a single baby, and the mother received medication, such as antenatal steroids, to stimulate fetal growth (4).

Since preterm babies are not able to meet growth milestones during pregnancy, they may have serious health problems. In 2018, preterm birth and low-birth weight accounted for 17% mortality in newborns  (2). However, babies who survive may develop respiratory problems, digestive problems, or bleeding issues in the brain.

They may also have a higher risk of developing long-term health conditions, such as cerebral palsy, learning disabilities, developmental delay, or lower performance in schools (2) (5)

What To Expect After An Extremely Premature Birth?

The extremely preterm babies require advanced care from specialized experts, including obstetricians, neonatologists, maternal-fetal-medicine specialists, and other specialized pediatricians  (6).

The first thing to consider after an extremely premature birth is whether the baby is capable of breathing and whether the parents and doctors decide to resuscitate the baby. When resuscitation doesn’t work, doctors try to make the baby comfortable instead of using treatment to help them survive (7).

The treatment, in such cases, is dependent on the following factors (7).

  • Whether the brain of the baby has incurred any damage, which can occur due to lack of oxygen or bleeding in the brain
  • Physical health of the baby
  • Gestational age at which the baby is born

The first month after birth is the most crucial period because that is when the baby experiences major problems (7).

Very rarely, babies born before 23 weeks survive. Babies born between 23 and 25 weeks may survive but may experience long-term disabilities (6). This happens because the vital organs are not completely formed.

Preterm Survival Rates

Below are the survival rates for preterm babies born at different gestational ages.

  • Babies born less than 24 weeks: Babies born before 24 weeks have a rare chance of survival, their chance of survival is usually less than 50% However, if they do survive, they may have life-long health complications.
  • Babies born at 24 weeks: Babies born at 26 weeks have about a 78% chance of survival. Moreover, in the long-term 4 out of 10 children develop problems with vision, hearing or, intellectual development (8) (9).
  • Babies born at 28 weeks: Babies born at 28 weeks have an 80% to 90% chance of survival. Statistically, they only have a 10% chance of developing long-term health problems, which include breathing problems, infections, digestive problems, and blood-related problems (8).
  • Babies born at 30 to 32 weeks: When a baby is born at 32 weeks, the chances of survival can be as high as 95%.  Also, the chances of mortality and development of long-term health problems decrease drastically (8).
  • Babies born at 34 to 36 weeks: A baby born at or after 34 weeks has similar health outcomes as that of a baby born after a complete gestation period of 40 weeks. Thus, the baby is more likely to be as healthy as the baby who was not born prematurely. Also, in the long-term, the babies do well and are generally as healthy as full-term babies. However, doctors may still recommend hospital (neonatal) care for one or two more weeks  (8).

It is important to note that statistics may not apply to all babies. Every baby is different. Also, survival rate factors, mentioned earlier, have a significant role to play in the prognosis.

Risk Of Disabilities At Each Stage

Due to immature organs, babies who survive preterm birth develop both short-term and long-term complications. Preterm babies may develop various health problems, including (7):

  • Respiratory problems: May range from transient tachypnea of newborns to bronchopulmonary dysplasia.
  • Neurologic outcomes: Neurosensory impairments such as deafness, blindness, hypo- or hypertonia, poorer cognitive performances, as well as neurodevelopmental abnormalities.
  • Cerebral palsy: A non-progressive motor disability that results in plegias, spasticity and dystonia. Its signs may appear when the child is between one and three years old.
  • Learning disabilities: These may appear when the child starts school.

The chances of developing health problems may vary according to the age (7) (9).

  • For babies born at 24 weeks, 60% of them may not have a disability at three years of age.
  • For babies born at 25 weeks, 70% of them may not have a disability at three years of age.
  • For babies born at 26 weeks, 80% of them may not have a disability at three years of age.

About 50% of babies born between 23 and 25 weeks may develop behavior- and attention-related problems by the age of six years. They may also have difficulty adjusting to school (7).

Nearly 40% of babies born between 25 and 26 weeks may develop problems related to hearing, vision, and intellectual development. These problems may carry on to adulthood (7).

What To Ask Your Doctor?

During pregnancy, you should make sure to visit your doctor for antenatal care during the first 12 weeks. The doctor can compute for your due date, using your last menstrual period or based on your earliest ulttasound, and perform necessary physical exams, and discuss risk factors or concerns, if any (8). The doctor can also monitor for presence of any infection or inflammation across the entire duration of pregnancy to avoid any risk factors that would greatly affect the baby.

Knowing about the following can help you prepare well for taking care of the baby. You may ask the following questions to the doctor to dispel your doubts.

  • What is the gestational age at which my baby will be born?
  • Does the baby have any developmental issues before birth? What are the associated complications of it? What tests were run to check the severity?
  • What treatments will be used in my baby’s care before birth? What are the risks and benefits of each of these treatments? Are there any alternatives?
  • What consequences should I look out for after discharge from the hospital? What can be the potential health problems in the first year or when the child starts school?
  • What type of follow-up will my baby need after birth? How many revisits might be required after birth?

The earlier the baby is born, the lower the chances of survival. Thankfully, advancements in medical technology may help the doctor determine the risks earlier, thus letting you prepare better. The age threshold at which a preterm baby is free of any danger may vary, and the child may still require long-term monitoring. Adequate prenatal care, understanding and avoidance of risk factors, and regular checkups could help improve the survival rate of the baby in case they are born prematurely.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Preterm birth: World Health Organization
2. Premature birth: Centers for Disease Control and Prevention
3. Premature baby: Pregnancy, Birth, and Baby
4. NIH Study Reveals Factors That Influence Premature Infant Survival, Disability: National Institute of Health
5. Preterm labor and birth FAQs: American College of Obstetricians and Gynecologists
6. Extremely preterm birth FAQs: American College of Obstetricians and Gynecologists
7. What to expect when you have an extremely premature infant: HealthLinkBC
8. When is it safe to deliver your baby?: University of Utah
9. Definition of premature birth: Irish Neonatal Health Alliance
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Maria Carmela Villania-Mamauag

Maria Carmela Villania-Mamauag is a board certified diplomate of the Philippine Pediatric Society with a degree of Doctor of Medicine from Our Lady of Fatima University, Valenzuela City and a Bachelor in Science in Psychology from Saint Louis University, Baguio City which was augmented by a year of Bachelor in Science in Family Life and Child development at the University... more

Dr Bisny T. Joseph

Dr. Bisny T. Joseph is a Georgian Board-certified physician. She has completed her professional graduate degree as a medical doctor from Tbilisi State Medical University, Georgia. She has 3+ years of experience in various sectors of medical affairs as a physician, medical reviewer, medical writer, health coach, and Q&A expert. Her interest in digital medical education and patient education made... more