Babies and Breathing – Cry It Out Method and Waterboarding (Part 1)
Many parents have read about the controversy on the Ferber method, more famously known as the “cry-it-out” method. The goal of this method essentially claims to help the baby soothe him/herself to sleep. This article will not try to attempt to explain the pros and cons for using this method for sleep training. Rather it will scientifically focus on the implications of using such a method. This article is a two-part series which will first focus on the anatomic and physiological changes in respiration. Part two will focus on the importance of maintaining an unrestricted airway and why prolonged crying is not recommended especially during the first six months after birth.
A very important concept to keep in mind is that anatomic development precedes functional development. Putting it in more simple terms, in order for something to work, it must first be built. In most cases, crafting a masterpiece requires time. As with the human body, maturation of organs require time for it to function properly and to be at its full capacity.
There are four important changes in respiration that occurs from childbirth to six months.
1. Maturation and number of air sacs in the lung nearly quadruples (conservatively speaking) from birth to six months of age.
Alveoli is where the exchange of gas (ie. oxygen and carbon dioxide) occurs. It is the single most important part of the human body which is responsible for respiration and for that matter the continuation of life. At full term, a newborn at birth has 20 to 70 million air spaces in the lung – a combination of both terminal air sacs and alveoli. This represents less than 25% of functioning respiration in comparison with the adult. By the end of six months, up to 270 million of alveoli have formed – approximately 90% of maturation. Additional alveoli will continue to form until about two years of age. Afterwards lung growth is proportional to body growth. Alveolar diameter will also double in size during maturation. Increase in size improves the oxygen-diffusing capacity of the lung. In other words, the lungs will be more efficient in bringing more oxygen to the blood with each breath taken.
2. Blood composition changes from fetal hemoglobin to adult hemoglobin.
The composition of the red blood cells are changing during the first six months of life. Fetal hemoglobin has a higher oxygen affinity than adult hemoglobin. This may confuse the readers that it would be better for the infant but actuality it is the opposite. Inside the mother’s womb, having a higher affinity for oxygen in fetal hemoglobin is needed because the fetus has to compete with the mother’s blood for oxygen. However, outside the womb, the baby does not compete for oxygen. Rather, a lower affinity of oxygen would serve better - oxygen transferred from blood cells to the tissues will be easier. Approximately 90% of the hemoglobin is the adult type by the end of six months and improved oxygenation to the tissues is the result.
4. Changes in airway resistance which is greatly due to anatomic and physiologic maturity of the airways.
Finally, airway resistance is 16 times the average adult in a newborn. Fortunately this is dramatically decreased as the baby grows older. Peripheral airways contribute most to airway resistance in children under 5 years of age. As for babies, it takes much more effort to breathe in air versus the adult.
So what does this all mean and why is it important to understand this? What does this have to do with the “cry-it-out” method and waterboarding? Having a brief background in anatomical and physiological changes that occur will make understanding easier. The second part of this series will address those questions and discuss the importance of unrestricted breathing in an infant from birth to six months of age.