Babies breathe in utero
Do babies breathe when they are still in the uterus?
Indeed babies do practice breathing while they are growing in the uterus. Breathing movements can be seen on ultrasound as early as 11 weeks gestation. Some scientists speculate that these early breathing movements are essential for the development of the chest wall muscles and the lungs. The first breath of life is a gasp in response to chemical, tactile (skin), thermal and mechanical changes associated with birth. These changes allow the alveoli, which are grape like clusters in the lungs, to open.
When you blow up a balloon sometimes it is hard to make the material expand; however, the more it is done the easier it becomes. Babies are initially a purplish color and gradually become pinker as they become more efficient at breathing. This begins the transition from a fluid-filled environment to an air-breathing, independent life.
One of the mechanical changes is the result of the cord being clamped. This changes the pH and oxygen level of the blood. The temperature in the womb is warm, the same as the mother’s temperature. Room air is much cooler. This change in temperature also acts as a stimulator to the baby. However if the baby gets too cool it may actually cause the respiratory system to not function correctly. We dry the baby and place the baby on the mother’s chest to keep the baby warm. If the mother and baby have to be separated for any reason we have special warming beds for the infant.
Babies start getting ready for their birthday even before they are born. The last couple of days in the womb, the fluid in the baby’s lungs starts to diminish. However some fluid does remain. The removal of the fluid from the lungs occurs as the baby passes through the birth canal. This is why babies born via Cesarean section have more fluid in their lungs when they are born. They also sometimes take longer to adjust their breathing after delivery. With each breath the lungs expand more.
Babies that are born before they complete the 38-40 week gestation period have more difficulties with breathing after delivery. A dramatic and exciting discovery was made in the 1990s. Research proved that giving the mother injections of betamethasone or dexamethasone 24-48 hours apart can speed up the maturity of a baby’s lungs. This is just one of many reasons why it is so important for every woman to know the signs of labor. Preterm labor can have lifetime complications that might have been avoided if treated promptly.
Most babies sleep a lot after they are born. The first couple of hours they are usually awake and alert and then they enter a sleep period. Giving birth is a lot of work for the mother, but also for the baby. Appreciate all the adjustments that your baby is making as you adjust to being a mother.
Katie Powers, R.N., is a board-certified lactation consultant and perinatal educator at Manatee Memorial Hospital’s Family BirthPlace. Her column appears every other week in Family & Friends. Contact her at katie.powers@mmhhs.com.
This story was originally published November 9, 2010 at 12:00 AM with the headline "Babies breathe in utero."