A baby born at 23 weeks of gestation arrives roughly 17 weeks early, weighing somewhere around 500 to 600 grams and small enough to fit in an adult’s hand. Survival is possible but far from guaranteed, and the journey through the neonatal intensive care unit will be long, medically complex, and emotionally grueling for families. What happens in the hours, weeks, and months ahead depends on a web of factors, from what medications the mother received before delivery to how the baby’s lungs and brain respond to life outside the womb.
Survival at 23 Weeks
The honest picture of survival at 23 weeks is complicated by one stubborn reality: outcomes vary enormously depending on where a baby is born and how aggressively the medical team intervenes. A large analysis of U.S. national data found that among infants born before 24 completed weeks, about 24% survived overall.1PubMed Central. Survival of infants born at periviable gestation: The US national database But that number lumps together babies who received full intensive care with those who received only comfort care, which drags the average down significantly. At centers that routinely offer active treatment to 23-weekers, survival rates are considerably higher.
A 2025 study comparing 11 international neonatal networks found that adjusted survival to discharge for 23-week infants ranged from 16% to 80% depending on the network.2JAMA Pediatrics. Outcomes of Preterm Infants Born at 22 to 23 Weeks’ Gestation in 11 International Neonatal Networks That is an enormous spread, and it reflects not just differences in biology but differences in institutional philosophy, staffing, equipment, and willingness to intervene. A family’s location and the hospital’s approach to periviable births may matter as much as the baby’s gestational age itself.
What Happens Before Delivery
When doctors know a delivery at 23 weeks is imminent, two medications given to the mother can meaningfully shift the odds. Antenatal corticosteroids, typically betamethasone, help accelerate fetal lung maturation. Even a partial course given hours before birth can reduce the risk of death in the newborn. Observational data show that corticosteroids administered before deliveries at or after 22 weeks are associated with lower neonatal mortality, though survival with severe complications remains common.3PubMed Central. Antenatal Corticosteroids at 21-23 Weeks of Gestation
The second medication is magnesium sulfate, given intravenously to the mother to protect the baby’s developing brain. One study of extremely preterm infants found that those exposed to both corticosteroids and magnesium sulfate before birth had lower rates of severe neurodevelopmental impairment or death compared to those who received only one or neither treatment.4PubMed Central. Association of Antenatal Corticosteroids and Magnesium Sulfate Therapy With Neurodevelopmental Outcome in Extremely Preterm Infants These interventions are not magic bullets, but they represent the first in a long chain of medical decisions that compound to influence the baby’s trajectory.
The First Minutes in the Delivery Room
A 23-weeker’s arrival is nothing like a typical birth. The baby emerges limp, often with translucent skin, and the medical team must immediately begin stabilization. Infants this early are profoundly vulnerable to respiratory and circulatory instability because their lungs, blood vessels, and temperature-regulation systems are drastically underdeveloped.5PubMed Central. Delivery Room Care for Premature Infants Born after Less than 25 Weeks’ Gestation-A Narrative Review The delivery room team typically includes neonatologists, respiratory therapists, and specialized nurses, all working in coordinated steps rehearsed many times.
The immediate priorities are establishing breathing support, often through gentle positive-pressure ventilation delivered via a tiny mask or nasal prongs, and preventing heat loss. The baby may be placed in a plastic wrap or bag right at birth to reduce evaporative cooling, because their skin is so thin that body heat escapes rapidly. An umbilical line may be placed within minutes for medication and fluid delivery. How well this initial stabilization goes has lasting consequences: a low five-minute Apgar score and the need for intubation at birth are both associated with higher risk of severe brain bleeds later on.6PubMed. Improving incidence trends of severe intraventricular haemorrhages in preterm infants <32 weeks gestation: a cohort study
Breathing and Lung Support
The lungs are the most immediately critical organ system for a 23-weeker. At this stage of development, the lungs have barely begun producing surfactant, the slippery substance that keeps air sacs from collapsing with each breath. Without it, every exhale is like trying to peel apart two wet sheets of glass. Surfactant replacement therapy, delivered directly into the lungs through a breathing tube, has been a cornerstone of neonatal care for decades. Giving surfactant early cuts the hours a baby needs on a mechanical ventilator roughly in half and trends toward lower rates of chronic lung disease.7PubMed Central. Prophylactic Administration of Surfactant in Extremely Premature Infants
Even with surfactant, most 23-weekers will need mechanical ventilation for days to weeks, and many will develop bronchopulmonary dysplasia, the chronic lung disease of prematurity. This happens because the lungs are so immature that the very oxygen and pressure needed to keep the baby alive also damage the developing tissue. Babies with evolving lung disease often require carefully calibrated ventilator settings over a prolonged period.8Early Human Development. Ventilation settings in preterm neonates with ventilator-dependant, evolving bronchopulmonary dysplasia Over weeks, the goal is to gradually wean ventilator support as the lungs mature, transitioning from a ventilator to gentler forms of breathing assistance like nasal continuous positive airway pressure and eventually to supplemental oxygen through small prongs. Some babies go home on oxygen; others eventually breathe independently.
Skin, Temperature, and the Incubator
A 23-weeker’s skin is strikingly different from a full-term baby’s. It is gelatinous, nearly transparent, and lacks the protective outer barrier that normally prevents water and heat from escaping. This means the baby loses fluid and body heat at alarming rates through the skin surface, a process called transepidermal water loss. The skin is also fragile enough that adhesive tape, routine handling, or even a diaper can cause injury and open a pathway for infection.9Neoreviews. Skin Care of Infants Born at 21–23 Weeks’ Gestation
To manage this, babies are placed in closed humidified incubators that deliver humidity levels of 70% to 100% in the first days of life. This high humidity dramatically reduces water loss and helps stabilize body temperature. Over the first week, the skin gradually begins to mature, and the humidity can be slowly lowered. Research shows that after about seven days at high humidity, reducing the humidity actually helps accelerate the skin’s natural toughening process.10Journal of Perinatology. Seeing beyond the obvious: pragmatic skin care guidance for infants 22–24 weeks gestational age Nurses handling a 23-weeker use minimal adhesive, apply emollient barriers where needed, and perform careful, clustered care to limit the number of times the incubator is opened.
The Heart and Patent Ductus Arteriosus
Before birth, a blood vessel called the ductus arteriosus connects two major arteries, allowing blood to bypass the lungs since the fetus gets oxygen from the placenta. After a full-term birth, this vessel normally closes on its own within a few days. In very preterm babies, it frequently stays open, a condition called patent ductus arteriosus, or PDA. This is extremely common at 23 to 24 weeks: one study found that a significant PDA occurred in about 70% of infants born at that gestational age, compared to roughly 59% of those born between 25 and 28 weeks.11PubMed. Patent ductus arteriosus in preterm infants born at 23-24 weeks’ gestation: Should we pay more attention?
A large open PDA floods the lungs with extra blood, making breathing harder and potentially affecting blood flow to the gut and brain. The first line of treatment is usually medication, but closure with the initial round of drug therapy fails in close to 70% of 23- to 24-weekers, a much higher rate than in slightly older preterm infants.11PubMed. Patent ductus arteriosus in preterm infants born at 23-24 weeks’ gestation: Should we pay more attention? When medication does not work, surgical ligation or a newer catheter-based closure procedure may be needed. Over the past decade, surgical ligation has become less common while transcatheter closure has grown as an option for these very small infants.12Journal of Perinatology. Management of the patent ductus arteriosus among infants born at 23 to 32 weeks’ gestation between 2011 to 2022: a report from in the Children’s Hospitals Neonatal Consortium
Brain Bleeds and Neurological Risk
One of the most feared complications at 23 weeks is intraventricular hemorrhage, or bleeding into the fluid-filled spaces of the brain. The blood vessels in an extremely preterm baby’s brain are thin-walled and fragile, and changes in blood pressure or oxygen levels can rupture them. Severe brain bleeds are graded on a scale from I to IV, with grades III and IV carrying the highest risk of lasting neurological damage. Extremely low gestational age is the strongest predictor of severe bleeding, carrying about a fourfold increase in risk compared to older preterm infants. Other risk factors include not receiving antenatal steroids, needing intubation at birth, and being born outside a specialized center.6PubMed. Improving incidence trends of severe intraventricular haemorrhages in preterm infants <32 weeks gestation: a cohort study
Head ultrasounds are performed routinely in the NICU, typically within the first week and repeated at intervals, to monitor for bleeding. When severe hemorrhage does occur, it can lead to a buildup of fluid in the brain that sometimes requires a surgical drain. Not every bleed leads to disability, and mild bleeds often resolve without lasting harm, but severe hemorrhage remains one of the major determinants of long-term neurological outcomes for 23-weekers.
Feeding, the Gut, and Necrotizing Enterocolitis
A 23-week baby cannot coordinate sucking, swallowing, and breathing, so all nutrition initially comes through intravenous lines. Parenteral nutrition, a carefully mixed bag of proteins, fats, and sugars delivered into the bloodstream, is the sole source of calories for the first stretch. The goal is to maintain a minimum protein intake to support brain and body growth during this critical window.13PubMed Central. Preterm Nutrition Parenteral Nutrition Consensus Statement Over days to weeks, tiny amounts of breast milk are introduced through a feeding tube that runs through the nose or mouth into the stomach. These “trophic feeds” are not primarily for calories at first but to prime the gut lining and encourage it to mature.
The intestines of a 23-weeker are dangerously vulnerable to necrotizing enterocolitis, a condition where patches of the gut wall become inflamed and can die. NEC is one of the most serious gastrointestinal emergencies in the NICU and can require surgery if the bowel perforates. Feeding with breast milk, whether from the mother or a pasteurized donor, is one of the most effective protections. A retrospective study found NEC rates of about 5% in babies fed predominantly mother’s own milk and about 4% with pasteurized donor milk, compared to roughly 11% with preterm formula.14PubMed. Necrotizing Enterocolitis and Growth in Preterm Infants Fed Predominantly Maternal Milk, Pasteurized Donor Milk, or Preterm Formula: A Retrospective Study This is one reason NICU teams place so much emphasis on pumping and milk supply for mothers of extremely preterm babies.
Infection Risk
Preterm infants have immune systems that are not simply immature versions of an adult’s but functionally distinct, responding to threats in ways that leave them highly susceptible to bacterial, viral, and fungal infections. The combination of a barely formed skin barrier, invasive lines running into their bloodstream, and a prolonged hospital stay creates persistent opportunities for pathogens. Late-onset sepsis, meaning infection acquired after the first 72 hours of life, is one of the leading causes of morbidity and death in extremely preterm babies. NICU teams guard against this with meticulous hand hygiene, antibiotic stewardship, and protocols to minimize how long central lines stay in place. Even so, most 23-weekers will be treated with antibiotics at least once during their stay, and some will face serious bloodstream infections.
Eyes and Retinopathy of Prematurity
The blood vessels that supply the retina are among the last structures to finish growing before a full-term birth. In a 23-weeker, these vessels are barely started, and the combination of supplemental oxygen and prematurity can cause them to grow abnormally, a condition called retinopathy of prematurity (ROP). In its mildest forms, ROP resolves on its own. In severe cases, the abnormal vessels can pull on the retina and cause detachment and blindness if untreated.
Babies born this early are screened with regular eye exams starting around 31 weeks postmenstrual age. Treatment for severe ROP has improved substantially. Laser therapy has long been the standard, but injections of anti-VEGF drugs into the eye are increasingly used, particularly for disease in the most central zone of the retina.15Cochrane Database of Systematic Reviews. Anti-vascular endothelial growth factor (VEGF) drugs for treatment of retinopathy of prematurity Among the international networks studied, the proportion of 23-week survivors needing ROP treatment ranged from about 16% to 48%.2JAMA Pediatrics. Outcomes of Preterm Infants Born at 22 to 23 Weeks’ Gestation in 11 International Neonatal Networks The good news is that with timely screening and modern treatment, most cases of ROP can be managed to preserve functional vision.
How Long the NICU Stay Lasts
Parents of a 23-weeker should expect a NICU stay measured in months, not weeks. A common rough estimate is that the baby will be in the hospital until around the original due date, which for a 23-weeker means approximately four months. In practice, many stay longer. Data from U.S. NICUs show that the average postmenstrual age at discharge for very preterm infants has actually increased slightly over the past decade and a half, partly because centers have become more cautious about sending fragile babies home before they are ready.16Pediatrics. Discharge Age and Weight for Very Preterm Infants: 2005–2018
Before discharge, the baby generally needs to meet several milestones: maintaining body temperature outside an incubator, feeding by mouth well enough to gain weight, breathing independently or stable on home oxygen, and passing a car seat tolerance test. Some babies reach these milestones at 36 or 37 weeks postmenstrual age; others take considerably longer, especially those with chronic lung disease or feeding difficulties.
Long-Term Neurodevelopment
Among the hardest questions parents face is what life will look like years down the road. The data here are honest but not hopeless. A review of neurodevelopmental studies found that roughly half of survivors born at 23 weeks had moderate to severe impairment, with that proportion improving for each additional week of gestation. A separate analysis of children assessed between ages four and ten showed similar rates, with about 41% of 23-week survivors having moderate to severe neurodevelopmental issues.17PubMed Central. Neurodevelopmental outcomes of preterm infants That means roughly half of 23-week survivors do not have major impairments, though many will need developmental support services at some point during childhood.
“Impairment” covers a wide spectrum. It can mean cerebral palsy ranging from mild to severe, cognitive delays, learning disabilities, attention difficulties, or sensory losses in vision or hearing. Many children born at 23 weeks attend mainstream schools with support. Others need more intensive services. Early intervention programs, physical and occupational therapy, and consistent developmental follow-up all play roles in maximizing each child’s potential, and outcomes continue to improve as neonatal care advances.
The Emotional Weight on Parents
Nothing about having a baby in the NICU for months is easy. Parents of extremely preterm infants face higher rates of depression, acute stress disorder, and post-traumatic stress disorder than parents of healthy full-term babies, and the smaller and sicker the baby, the higher the risk.18Journal of Perinatology. Trauma-informed care in the newborn intensive care unit: promoting safety, security and connectedness The NICU environment itself contributes: alarms sounding constantly, the sight of your baby connected to machines, the feeling of helplessness when you cannot hold or feed your own child in a normal way.
One of the most powerful tools available to parents is skin-to-skin care, also called kangaroo care. Holding the baby chest-to-chest, even while monitors and tubes are attached, has been shown to reduce parental anxiety, improve the baby’s stress physiology, strengthen the parent-infant bond, and support cognitive development into childhood.18Journal of Perinatology. Trauma-informed care in the newborn intensive care unit: promoting safety, security and connectedness NICUs that promote kangaroo care early and often tend to see better outcomes for both babies and families.19PubMed Central. Continuing Education Module-Kangaroo Mother Care 2: Potential Beneficial Impacts on Brain Development in Premature Infants Parents should feel empowered to ask when they can start skin-to-skin, and NICU staff should help make it happen as soon as the baby is stable enough.
Where You Deliver Matters More Than You Might Think
International guidelines on whether and how to treat babies born at 23 weeks differ dramatically. A structured comparison of position statements from ten countries found that at 23 weeks, six countries recommended an individualized assessment to decide between active treatment and comfort care, three still recommended comfort care as the default, and Japan recommended intensive care for all.20Frontiers in Pediatrics. A structured comparison and reflection on international position statements and professional guidance for the management of periviable infants Even within a single country, hospital-to-hospital variation can be stark. Some centers have dedicated teams with years of experience caring for 22- and 23-weekers; others may only encounter a handful of cases a year and approach them with less confidence.
This variation drives a fierce ethical debate. Centers that actively treat 23-weekers point to improving survival data and argue that many survivors do well. Those that are more conservative cite the high rates of severe morbidity and question whether aggressive intervention serves the baby’s best interests.21PubMed. Ethics of care for the micropreemies. Just because we can, should we? The emerging consensus among ethicists and neonatologists is that shared decision-making between clinicians and parents, guided by the baby’s specific circumstances rather than gestational age alone, represents the most defensible approach.22PubMed. From “can we treat?” to “should we treat?”: a narrative review on resuscitation limits at the threshold of viability Factors like the baby’s sex, estimated weight, whether antenatal steroids were given, and whether the pregnancy involved a single baby or multiples all influence prognosis and should factor into the conversation.
After the NICU
Going home does not mean the medical chapter is over. Babies born before 29 weeks have a very high rate of rehospitalization in the first year of life. In one large cohort, nearly half were readmitted at least once, and more than half of those admissions were for respiratory problems.23Acta Paediatrica. Re‐hospitalization in infants younger than 29 weeks’ gestation in the EPIPAGE cohort The risk was especially high for children who had chronic lung disease, those discharged during fall or winter when respiratory viruses circulate, and those living with other young children who bring home infections.
Post-discharge life typically involves a schedule of follow-up appointments with a neonatologist or developmental pediatrician, eye exams to monitor for late ROP progression, hearing tests, and assessments through early intervention programs. Many families also contend with home medical equipment like oxygen tanks, apnea monitors, or specialized feeding supplies. The practical burden is real, and so is the financial one. For families navigating this, connecting with social workers and parent support groups during the NICU stay can help set up the resources and community they will need once they leave.