Micro Preemie Survival Rates and Health Concerns

Premature baby.

Science Photo Library / Brand X Pictures / Getty Images

A micro preemie is a baby who is born weighing less than 1 pound, 12 ounces (800 grams), or before 26 weeks gestation. Since micro preemies are born months before their due dates, they face long stays in the neonatal intensive care unit (NICU). Although many extremely premature babies grow up with no long-term effects of premature birth, some face severe health problems throughout life.

Premature Baby vs. Micro Preemie

To give you some context, any baby who is born before 37 weeks gestation is considered to be premature (also known as preterm).

Stages of Prematurity

Babies who are born between 34 and 37 weeks gestation are named "late preterm." Those who are born between 31 weeks and 34 weeks gestation are labeled "moderately premature," while babies who are born between 27 weeks and 30 weeks gestation are called "very premature."

Micro Preemies

Micro preemies are the most premature babies of all, born on or before 26 weeks. Many people are surprised by how small micro preemies are. Their skin is thin, with visible veins, and it may look sticky or gelatinous. If you are visiting a micro preemie in the NICU, you can expect to see the following:

  • Respiratory support: Micro preemies usually have endotracheal tubes (ET Tubes) coming from their mouths. The tube is attached to a ventilator that helps your baby breathe. Some micro preemies can breathe on their own and will be on continuous positive airway pressure (CPAP) instead. These babies will have CPAP masks strapped firmly over their noses.
  • Intravenous lines (IVs): If a micro preemies' digestive system is too immature to absorb nutrition, they will be fed intravenously. Most will have lines in their umbilical cord stumps (called umbilical lines) for the first week or two of life, and a PICC line or peripheral IV later.
  • Monitoring equipment: All NICU patients are closely monitored. Micro preemies may have wired stickers on their chests, feet, wrists, arms, and legs. They're used to check blood pressure, breathing rates, and oxygen levels in the blood.
  • NG/OG tube: Because micro preemies are too immature to eat from a bottle or from the breast, a tube will go from their mouths (OG tube) or noses (NG tube) into the stomach.

Micro Preemie Health Concerns

When a baby is born very prematurely, they are at risk for a number of health conditions. Some of the health concerns are short-term, while others may impact them for the rest of their lives.

Short-Term Health Concerns

Immediately after birth and during a micro preemie's NICU stay, doctors and nurses watch closely for several serious medical conditions, such as these, below.

  • Respiratory distress syndrome (RDS): Most micro preemies (about 85%) have difficulty breathing after birth. RDS is treated with respiratory support and medication.
  • Patent ductus arteriosus (PDA): Just over half of micro preemies have a PDA. A PDA is a persistent connection between the large blood vessels near the heart. The connection is normal for a fetus but should close when a baby is born and begins to breathe. PDAs are treated with medication or surgery.
  • Sepsis: Premature babies are prone to infection for several reasons. Micro preemies have immature immune systems and face many invasive procedures in the NICU, each of which can allow bacteria to enter the body. About 40% of micro preemies need antibiotics to treat bacterial infections.
  • Intraventricular hemorrhage (IVH): IVH is bleeding into parts of the brain. Micro preemies have fragile blood vessels in their brains, and these vessels can rupture easily. About a quarter of micro preemies have serious IVH. Most cases of IVH resolve on their own, but some babies may need surgery to help drain the extra fluid.
  • Retinopathy of Prematurity (ROP): The blood vessels in a micro preemie's eyes are not fully formed at birth. When the vessels develop, they may grow so rapidly that they damage the retina. Just under 15% of micro preemies develop ROP, which usually resolves on its own. Surgery may be required in severe cases.
  • Necrotizing Enterocolitis (NEC): Since micro preemies have immature digestive systems, their intestines are susceptible to infection. In NEC, the linings of the bowels become infected and begin to die. About 7% of micro preemies develop NEC, which can be extremely serious. NEC is treated with IV fluids and medication. Surgery may be required.

Long-Term Health Concerns

Many micro preemies show no long-term effects of prematurity. In fact, by age 8, about 60% have normal IQs. However, other micro preemies may have lifelong health issues, including the ones listed below.

  • Cognitive problems: Developmental delays, trouble in school, and other cognitive problems are common effects of prematurity. About 20% of micro preemies have severe cognitive disabilities by age 8, and another 20% have mild to moderate cognitive problems.
  • Cerebral palsy: About 10% of micro preemies have moderate to severe cerebral palsy.
  • Chronic lung disease: About half of micro preemies need oxygen at NICU discharge. Micro preemies may also have asthma or other respiratory problems, including bronchopulmonary dysplasia, or BPD.
  • Digestive problems: Micro preemies are prone to digestive problems such as gastroesophageal reflux disease (GERD), food refusal, or poor feeding.
  • Vision or hearing loss: Between 2% and 3% of micro preemies have permanent vision or hearing problems due to complications of prematurity.

Survival Rate for Micro Preemies

Micro preemies are very fragile, and every day that you spend pregnant increases your baby's chance of survival.

Birth Week Average Survival Rate
22 weeks About 10% of babies survive
23 weeks 50% to 66% of babies survive
24 weeks 66% to 80% of babies survive
25 weeks 75% to 85% of babies survive
26 weeks More than 90% of babies survive

Improve Your Baby's Chances

Although micro premies may face serious health problems, there are many things that you can do as a parent to give your baby the best possible start.

  • Get early prenatal care: When you become pregnant, talk to your doctor early about how to minimize your risk of premature birth. Early prenatal care can help you avoid early delivery.
  • Have your baby in a hospital with a NICU: If you know that your baby will be premature, delivering in a hospital with a level 3 NICU with 24-hour neonatology coverage can give your baby the best possible start.
  • Learn the signs of preterm labor: While you're pregnant, make sure that you understand the signs of preterm labor, and seek medical care immediately if you develop any of them.
  • Seek early intervention: Babies born early may qualify for state-run early intervention programs. Starting these programs as soon as possible can help minimize any cognitive effects of prematurity.
Was this page helpful?
0 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Hoekstra, R et al. "Survival and Long-Term Neurodevelopmental Outcome of Extremely Premature Infants Born at 23-26 Weeks' Gestational Age at a Tertiary Center." Pediatrics Jan 2004; 113, c1-c7.
  • Qiu, X et al. "Comparison of Singleton and Multiple-Birth Outcomes of Infants Born at or Before 32 Weeks of Gestation." Obstetrics & Gynecology Feb 2008; 111, 365-371.
  • Vohr, B et al. "Neurodevelopmental Outcomes of Extremely Low Birth Weight Infants <32 Weeks' Gestation Between 1993 and 1998." Pediatrics Sept 2005; 116, 635-643.