Neonatal care: Incubation for preterm babies explained

Preterm birth in layman terms is used for babies born before 37 weeks of gestation is completed or fewer than 259 days since the first day of a woman’s last menstrual period. Premature babies are naturally smaller than full-term babies and many weigh less than two pounds. Preterm birth is a major cause of death and a significant cause of long-term loss of human potential among survivors all around the world.

There are sub-categories of preterm birth, based on gestational age:

• Extremely preterm (less than 28 weeks)
• Very preterm (28 to 32 weeks)
• Moderate to late preterm (32 to 37 weeks)

A special category of preterm babies is termed Extreme Preterm Babies (EPB), because they are so immature that bacteria in the “air” can cause infection. Premature babies do not get immunoglobulins from their mothers and are therefore prone to infection. It is important that such babies are taken care of during the first two weeks to a month of their birth.

Reasons for admission of an infant in an NICU

• Prematurity (24 weeks gestation or more)
• Intrauterine growth retardation/small for gestational age
• Low blood sugar
• Respiratory (breathing) problems
• Infections
• Seizures
• Temperature instability
• Assistance with feeding

Why do premature newborns need special care?

Premature babies are little bodies that have underdeveloped parts, which include the lungs, digestive system, immune system and skin. The advancements in medical technology have made it possible for preemies to survive the first few days, weeks or months of life until they are strong enough to make it on their own. Hospitals have equipped themselves with Neonatal Intensive care Units (NICU) where infants are cared for in incubators or “open warmers”. Some low birth weight infants need respiratory support ranging from extra oxygen (by head hood or nasal cannula) to continuous positive airway pressure (CPAP) or mechanical ventilation. Public access is limited, and staff and visitors are required to take precautions to reduce transmission of infection.

When babies are born less than 32 weeks, they need to be cared for “almost like they are in the womb” so that they grow “as expected” and for this, we need an “artificial womb”, which is nothing but an incubator. But babies more than 32 weeks probably can do well without the need of an incubator in an open care system.

Baby incubation

Incubators are self-contained units roughly the size of a crib equipped with a plastic dome. Because premature babies lack body fat, they are less able to regulate body temperature. To this end, the incubator ensures the ideal environmental conditions by either allowing the temperature to be adjusted manually or providing auto-adjustments based on changes in the baby’s temperature. An incubator also protects the premature babies from infection, allergens, or excessive noise or light levels that can cause harm. It can regulate air humidity to maintain the integrity of the skin (which is very important for extremely preterm babies) and even be equipped with special lights to treat neonatal jaundice which is common in these babies.

Types of incubators in a NICU

• Closed box incubators have a fresh air filtration system which minimises the risk of infection and prevent the loss of moisture from the air.
• Double-walled incubators have two walls that can further prevent heat and air moisture loss.
• Servo-control incubators are automatically programmed to adjust temperature and humidity levels based on skin sensors attached to the baby.
• Open box incubators, also known as Armstrong incubators, provide radiant heat below the baby but are otherwise open to the air, allowing for easy access.
• Portable incubators, also known as transport incubators, are used to move the newborn from one part of the hospital to another or from one hospital to another.

At the Neonatal Intensive Care Unit, through incubators, specialised medical, surgical and cardiology care is given to newborn babies. It is well-equipped with a protective environment which is home for a limited period of time with a caring staff, monitoring and alarm systems, respiratory and resuscitation equipment, access to physicians in every pediatric specialty, 24-hour laboratory service.

Premature babies often have breathing problems because their lungs are not fully developed. Full-term babies also can develop breathing problems due to complications of labor and delivery, birth defects and infections.

For extreme preterm infants, no matter how disheartening it may sound, the incubator provides the best opportunity to grow into the healthy, happy baby we’ve always dreamed of. A better technology for better survival.

(The writer is Chairman & Neonatologist, Cloudnine Group of Hospitals, Bengaluru.)