A baby born at 28 weeks of gestation has roughly a 90 to 95 percent chance of survival in a well-equipped neonatal intensive care unit in a high-income country. That figure, while reassuring compared with earlier gestational ages, comes with important caveats: the baby’s birth weight, sex, prenatal treatments received by the mother, and the quality of neonatal care all shift the odds. And survival alone does not capture the full picture, because 28-weekers face weeks to months of intensive hospital care and a meaningful risk of complications that can affect health for years.
Why Birth Weight and Sex Matter at the Same Gestational Age
Not every 28-week baby arrives in the same condition. One of the strongest predictors of how well a baby does is birth weight relative to gestational age. A population-based study of births in England and Wales found that at 28 weeks, predicted survival ranged from about 63 percent for infants weighing 500 to 749 grams (well below average for that age) up to about 90 percent for those weighing 1,250 to 1,499 grams.1BMJ. Prediction of survival for preterm births by weight and gestational age: retrospective population based study Those figures date from the 1990s, and survival rates have improved since then, but the pattern still holds: a 28-weeker who is small for gestational age faces steeper odds than one who has been growing on track.
Sex also plays a role. In the same study, female infants had an overall survival advantage. At earlier gestational ages the gap was stark, and while it narrows somewhat by 28 weeks, girls still tend to do a bit better on average. The reasons are not fully settled, but female infants tend to have slightly more mature lungs at any given gestational age and may be less susceptible to certain inflammatory complications. Infants from multiple births (twins or triplets) also showed a small survival advantage over singletons of the same weight and gestational age in that dataset, possibly because being smaller within a multiple pregnancy reflects a different growth trajectory than being small as a singleton.
Prenatal Treatments That Improve the Odds
Some of the most consequential interventions for a 28-weeker happen before the baby is even born. When preterm delivery is anticipated, obstetricians typically administer two treatments to the mother: antenatal corticosteroids (usually betamethasone) and magnesium sulfate. Corticosteroids speed lung maturation and reduce the risk of severe breathing problems after birth. Magnesium sulfate, given during labor, protects the developing brain. A Cochrane review of six randomized trials involving more than 6,000 infants found that prenatal magnesium sulfate reduced the risk of cerebral palsy by about 29 percent compared with placebo.2PubMed Central. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus
The combination of both treatments appears to be more effective than either one alone. A study of extremely preterm infants found that those exposed to both corticosteroids and magnesium sulfate had a rate of severe neurodevelopmental impairment or death of about 36 percent, compared with roughly 48 percent among infants who received neither.3PubMed Central. Association of Antenatal Corticosteroids and Magnesium Sulfate Therapy With Neurodevelopmental Outcome in Extremely Preterm Infants That study focused on extremely preterm infants as a group (born well before 28 weeks), so the absolute numbers skew worse than what you would see at 28 weeks specifically. But the relative benefit of receiving both treatments appears consistent across the preterm spectrum. One caveat: the evidence for these interventions is less clear for small-for-gestational-age fetuses, where trials have either yielded conflicting results or excluded this subgroup entirely.4PubMed. Antenatal glucocorticoids, magnesium sulfate, and mode of birth in preterm fetal small for gestational age
Breathing Support After Birth
The lungs are the organ system most likely to cause immediate trouble for a 28-weeker. At this gestational age, the lungs are producing surfactant, a slippery substance that keeps the tiny air sacs from collapsing, but they are not producing enough of it reliably. Many 28-week infants develop respiratory distress syndrome and need help breathing within minutes of birth.
Surfactant replacement therapy has been one of the biggest advances in neonatal care over the past few decades. Giving surfactant directly into the lungs improves survival and reduces long-term lung damage.5PubMed Central. Guidelines for surfactant replacement therapy in neonates The way surfactant is delivered has evolved. In earlier eras, it was given routinely to nearly all very preterm infants right after birth (prophylactic use). Current practice favors starting babies on gentler breathing support, such as continuous positive airway pressure (CPAP), and administering surfactant only if the baby shows worsening distress. A large trial of infants born at 26 to 29 weeks compared three approaches: prophylactic surfactant with continued ventilation, prophylactic surfactant with rapid extubation to CPAP, and CPAP alone without surfactant.6Pediatrics. Surfactant Replacement Therapy for Preterm and Term Neonates With Respiratory Distress None of these approaches was dramatically better than the others for mortality, but starting with CPAP and adding surfactant when needed reduces the time a baby spends on a mechanical ventilator, which is itself a risk factor for chronic lung disease.
Newer techniques for delivering surfactant are also gaining ground. Instead of intubating the baby with a breathing tube, clinicians can thread a thin catheter into the airway while the infant breathes on CPAP, deliver the surfactant, and avoid intubation altogether.5PubMed Central. Guidelines for surfactant replacement therapy in neonates Research suggests that for preterm infants of 30 weeks or less with worsening respiratory distress, surfactant should be considered when supplemental oxygen requirements reach about 40 percent or higher.7Journal of Pediatric and Maternal Medicine. Clinical decision thresholds for surfactant administration in preterm infants: a systematic review and network meta-analysis
Infection in the NICU
A 28-week baby’s immune system is not ready for the outside world. The transfer of maternal antibodies across the placenta ramps up significantly during the third trimester, and a baby born at 28 weeks misses most of that transfer. Compounding the problem, these infants often need intravenous lines, breathing tubes, and other devices that provide a route for bacteria to enter the body. The result is a meaningful risk of late-onset sepsis, which is a bloodstream infection that develops after the first few days of life.
An international comparison across ten high-income countries found that about one in five extremely preterm infants (24 to 28 weeks) developed late-onset sepsis, though rates varied dramatically from about 7 percent in Japan to more than 44 percent in Spain.8PubMed Central. Late-Onset Sepsis among Extremely Preterm Infants of 24-28 Weeks Gestation: An International Comparison in 10 High-Income Countries Among infants who developed the infection, about 11 percent died from it or in close temporal relation to it. That wide range between countries suggests that infection-control practices and unit protocols make a substantial difference, and that the risk is not simply baked into the biology.
Within the 24-to-28-week range, the risk falls with each additional week of gestation. A separate study of extremely premature infants in the United States found that infants born at 23 through 26 weeks were significantly more likely to develop late-onset sepsis compared with 28-weekers, who served as the reference group.9PubMed Central. Late-Onset Sepsis in Extremely Premature Infants: 2000–2011 Being born at 28 weeks, in other words, puts a baby at the lower-risk end of the extremely preterm window for sepsis.
Feeding, Gut Health, and Necrotizing Enterocolitis
The gastrointestinal tract of a 28-week baby is fragile. One of the most feared complications in the NICU is necrotizing enterocolitis (NEC), in which portions of the intestinal lining become severely inflamed and can die. NEC can require emergency surgery and is sometimes fatal. It tends to strike the most premature infants, but babies born between 28 and 32 weeks are far from immune.
Human milk, whether the mother’s own or from a donor, is the single most protective factor against NEC. A study of very preterm infants found that when donor milk was available as a supplement or alternative to formula, the incidence of NEC dropped, and the effect was especially pronounced in infants born between 28 and 32 weeks, where NEC rates went from about 5 percent to essentially zero.10PubMed Central. Availability of Donor Milk for Very Preterm Infants Decreased the Risk of Necrotizing Enterocolitis without Adversely Impacting Growth or Rates of Breastfeeding This is not because formula contains something toxic. A review of the evidence concluded that it is the absence of human milk, rather than harmful components in formula, that raises NEC risk.11Journal of Perinatology. The fifty billion dollar question: does formula cause necrotizing enterocolitis? Human milk contains immune factors, beneficial bacteria, and growth signals that formula cannot replicate. Still, formula remains a critical alternative when human milk is unavailable.
Eye Problems From Premature Birth
Retinopathy of prematurity (ROP) is a condition in which the blood vessels of the retina grow abnormally, sometimes threatening vision. The retina is one of the last organs to finish developing, and in preterm infants, exposure to fluctuating oxygen levels outside the womb can derail the normal pattern of blood vessel growth. A screening study in Cyprus found that the severe prematurity group born between 24 and 28 weeks had the highest risk of vision-threatening ROP, with each additional week of gestational age correlating with a meaningful reduction in risk.12PubMed. One-Year Review of Retinopathy of Prematurity in Cyprus: Risk Factors and Screening Effectiveness Low birth weight, prolonged supplemental oxygen use, and sepsis were the strongest risk factors.
Most ROP resolves on its own as the baby matures. When it does not, treatments including laser therapy and injections of anti-growth-factor medications can usually prevent vision loss. All infants born before 31 weeks are routinely screened for ROP before they leave the hospital, with follow-up eye exams continuing for weeks or months afterward. For a 28-weeker, being at the upper edge of the highest-risk window means the chances of needing treatment are real but much lower than for a baby born at 24 or 25 weeks.
Long-Term Brain Development
Survival is the first question parents ask. The second is usually about whether their child will develop normally. The honest answer at 28 weeks is that most survivors do well, but the risk of neurodevelopmental problems is higher than in babies born at term. A review of outcomes after preterm birth found that about 5 percent of survivors born between 26 and 31 weeks developed cerebral palsy, compared with roughly 10 percent among survivors born before 26 weeks.13PubMed Central. Neurodevelopmental outcomes after preterm birth Cognitive difficulties are more common than cerebral palsy: somewhere between a quarter and half of children born very or extremely preterm show cognitive deficits, perform poorly at school, or need special educational support.
Those numbers cover a broad range of gestational ages and include babies born much earlier than 28 weeks, so the figures for 28-weekers specifically are likely at the lower end of that range. Many 28-week survivors attend mainstream school without any support. Others may need help with attention, learning, or motor coordination that only becomes apparent once academic demands increase in the early school years. Prenatal magnesium sulfate, as noted earlier, reduces the risk of cerebral palsy and is one reason why outcomes have improved over time.
Coming Home and Going Back
Leaving the NICU is a milestone, but it is not the end of medical attention. Babies born this early have high rates of rehospitalization during their first couple of years. A French cohort study found that about 47 percent of infants born before 29 weeks were readmitted to the hospital at least once before the age of two, and more than half of those admissions were for respiratory problems.14Acta Paediatrica. Re‐hospitalization in infants younger than 29 weeks’ gestation in the EPIPAGE cohort Chronic lung disease from the NICU stay was the strongest predictor of readmission. Seasonal timing mattered too: babies discharged during the fall and winter months, when respiratory viruses circulate heavily, were two to three times more likely to be readmitted.
Respiratory infections remain the main driver of hospital returns in the first two years. A risk-assessment study of infants born before 29 weeks found that each additional respiratory infection roughly doubled the odds of readmission, and babies who needed surgical intervention for severe reflux were at dramatically higher risk of repeated hospital stays.15PubMed. Rehospitalization in Infants Born < 29 Weeks' Gestation during the First 2 Years of Life: Risk Assessment Practical steps like avoiding crowded indoor spaces during RSV season, ensuring vaccinations are up to date, and limiting contact with other young children can reduce the risk.
How Outcomes Differ Around the World
The survival figures discussed so far reflect care in well-resourced neonatal units. The picture looks very different in many parts of the world. A systematic review and meta-analysis comparing extremely preterm survival across income levels found that survival was about 69 percent in high-income countries but only about 44 percent in low- and middle-income countries.16PubMed Central. Global inequities in the survival of extremely preterm infants: a systematic review and meta-analysis That review focused on extremely preterm infants as a whole, most of whom were born before 28 weeks, so the gap at 28 weeks specifically may be narrower. Still, the message is clear: access to NICU technology, trained staff, and prenatal care is the biggest single determinant of whether a preterm baby survives. The treatments described in this article, from antenatal steroids to surfactant to donor milk, are routine in some settings and unavailable in others.
The Financial and Emotional Weight
NICU care for very preterm infants is expensive. A Canadian population-based study estimated that the median cost of the initial hospitalization for infants born before 29 weeks was roughly $100,000 (Canadian dollars), and costs correlated strongly with how early the baby was born.17PubMed. Costs of Neonatal Intensive Care for Canadian Infants with Preterm Birth Health care costs remain elevated well beyond discharge. A separate study found that cumulative hospitalization costs for very preterm infants were significantly greater than for term infants not just in the first year of life, but also between ages one and six.18PubMed. Survival, Hospitalization, and Acute-Care Costs of Very and Moderate Preterm Infants in the First 6 Years of Life: A Population-Based Study In countries without universal health coverage, these costs can be financially devastating for families.
The emotional toll on parents often gets less attention but can be equally significant. A study that followed families for seven years after very preterm birth found that parents of preterm children reported higher levels of anxiety and depression than parents of children born at term.19PubMed Central. Very preterm birth influences parental mental health and family outcomes seven years after birth The difference in anxiety was modest on average, but parents of preterm children were more likely to fall into the moderate-to-severe range. The prolonged uncertainty of the NICU stay, the medical fragility of the first years, and the worry about long-term development all compound. Many NICUs now employ social workers and psychologists to support parents, and peer support groups connect families going through similar experiences. If you are in this situation, asking for that support is not a sign of weakness. The evidence suggests you are more likely to need it than parents who had full-term births, and there is no reason to go it alone.