Why doesn the baby breathe under water?
A combination of 4 different factors stop the baby from taking a first breath while still underneath the water: • A hormone secreted by the placenta, Prostaglandin E2, causes the baby’s breathing movements to slow before, during, and right after labor. While these levels stay high, the baby is prevented from breathing. All the baby’s oxygen will continue to be supplied by the placenta, not the lungs. • Babies will not gasp or try to breathe as long as the umbilical cord is not clamped nor cut and is still pulsing regularly. All babies are born with slightly low levels of oxygen which causes them to swallow, not inhale. • The baby’s lungs contain a hypertonic solution which is dense while water is a hypotonic solution. If water were to move past the protective larynx, the lung fluids would not allow it to pass since they prevent hypotonic solutions like water from mixing or pushing past them. • The larynx, or voice box, provides an important protective function called the Dive Reflex. T
