What is Prematurity?
A Premature/Preterm Infant is an infant born before completion of 37 weeks of pregnancy REGARDLESS of birth weight.
A premature newborn has underdeveloped organs that may not be ready to function outside of the uterus. As a result, most premature infants spend some time in a special ICU for babies called the neonatal intensive care unit or NICU.
The earliest, smallest premature newborns are at far greater risk for complications, but even so, the majority of survivors have no permanent problems.
Extreme prematurity is the single most common cause of death in newborns.
What Are Some of the Risk Factors or Causes Associated with Premature Birth?
- Age of the mother - if the mother is an adolescent or an older woman, the risk of having a premature infant is higher.
- Women with lower socioeconomic status who have had inadequate prenatal care.
- Multiple births
- Poor nutrition
- Untreated infections
- Previous premature birth
- Life-threatening maternal disorders including heart disease, preeclampsia, eclampsia, kidney disease or infection of the uterus.
Survival Rates Per Gestational Age:
Survival rates for premature infants vary greatly upon numerous factors beyond gestational age.
- 26 Weeks: about an 80% survival rate
- 28 Weeks: about an 80% survival rate.
- 28-31 Weeks: about a 96% survival rate.
- 32-33 Weeks: about a 98% survival rate.
- 34-36 Weeks: greater than 99% survival rate.
General Signs of Premature Birth:
- Thin, smooth, shiny skin that may or may not be transparent.
- Soft, flexible ear cartilage
- Small scrotum and undescended testes
- Enlarged clitoris
- Lower muscle tone
- Less active than full-term infants
- Decreased body fat
- Lanugo (soft, silky body hair)
- Problems with feeding
- Problems with breathing
Symptoms of Prematurity as Divided by Organ Symptoms:
- Inconsistent breathing - the part of the brain that controls breathing may be immature, therefore newborns breathe with short pauses in between respirations or periods of apnea.
- Brain hemorrhage. A brain hemorrhage is most likely to occur in newborns before twenty-eight weeks gestation and can be anywhere from small to large. The germinal matrix and the ventricles are the areas typically involved with brain hemorrhages. An infant with a small bleed may experience no symptoms, newborns with very large bleeds may develop cerebral palsy or other developmental delays.
- Difficulty feeding. The parts of the brain that control the mouth and throat are immature, therefore a premature newborn may have trouble coordinating the suck/swallow of feeding.
- Underdeveloped structures: The lungs of premature infants are underdeveloped; they have decreased numbers of functioning aveoli, they may lack surfactant, they may have a greater risk for collapse or obstruction of respiratory passages.
- Respiratory Distress Syndrome: Because the lungs of a preemie aren't designed to efficiently move air, respiratory distress syndrome is common in the premature infant. Respiratory distress syndrome causes visibly labored breathing, flared nostrils, grunting sound while breathing out, and cyanosis (bluish skin tone) if blood oxygen levels are low.
- Apnea: As the area of the brain responsible for regulating breathing is immature, premature infants may experience periods of apnea - or periods when breathing stops entirely.
Underdeveloped digestive tract and liver:
- Spitting up: A premature infant has frequent episodes of spitting up because their small stomach empties slowly.
- Jaundice: The liver of a premature infant is slow to breakdown bilirubin from the blood, therefore the yellowish pigment accumulates in the skin and eyes of the preemie.
- Intestinal damage: Very premature infants may develop a highly serious condition called "necrotizing entercolitis" in which parts of the intestine die from lack of oxygen.
Underdeveloped immune system:
- Premature infants have very low levels of maternal antibodies (those passed from mother to fetus through the placenta).
- The risk for developing infections - especially the very dangerous infection of the blood, sepsis, is far greater for premature infants.
- Premature infants are more likely to have invasive devices such as IV ports, blood draws, and endotracheal tubes, which further increases their exposure to potential pathogens
- In utero, waste products produced by the fetus are removed by the placenta and excreted by the mother's kidneys. After delivery, the newborn must excrete their own wastes.
- Premature infants may have difficulty regulating the amount of salt and water in their bodies.
Difficulty regulating body temperature:
- Premature infants are much thinner than their full-term counterparts, therefore they tend to lose heat easily.
- They must work extra-hard to bring their bodies back up to normal temperature, increasing their metabolism and making it more challenging for them to gain weight.
- Premature infants have difficulty regulating their body temperature, which is why they spend their first few months in a tightly controlled incubator.
Difficulty regulating blood sugar levels:
- As premature infants have difficulty feeding and maintaining normal blood sugar levels, they're often given an IV glucose solution or frequent small feeds.
- Without regular feeds, preemies may develop hypoglycemia, which presents with very few symptoms.
- Premature infants are also prone to developing hyperglycemia if they receive too much IV glucose.
General Exams and Tests Performed on Premature Infants:
- Chest x-ray
- Blood tests to check levels of glucose, calcium and bilirubin
- Blood gas analysis
- Continuous cardiorespiratory monitoring
Additional Resources For Prematurity
March of Dimes - A national organization that works globally to help mothers take charge of their health and provide resources when something goes wrong. The organization has a wealth of information for health care providers and parents on all areas of prenatal and neonatal health, including prematurity.
National Dissemination Center for Children with Disabilities - everything from developmental milestones, disabilities in children, educational laws for special education and state-by-state resources for children with disabilities.
Ronald McDonald House - The Ronald McDonald House program provides a “home-away-from-home” for families so they can stay close by their hospitalized child at little or no cost.
KidsHealth.org has a Primer on Preemies.
The American Academy of Pediatrics has developed a brochure to help parents monitor the milestones of their premature babies.