There are few moments in life as precious, as critical and as celebrated as baby's first breath. New research from the University of Virginia School of Medicine sheds light on the lifelong changes in breathing systems that occur precisely with that first breath -- and may offer important insights into Sudden Infant Death Syndrome (SIDS). Show
A team of researchers led by UVA's Yingtang Shi, MD; Patrice Guyenet, PhD; and Douglas A. Bayliss, PhD, have discovered a signaling system within the brainstem that activates almost immediately at birth to support early breathing. That first gasp that every parent cherishes appears to trigger this support system. "Birth is traumatic for the newborn, as the baby has to independently take control over various important body functions, including breathing," said Bayliss, chairman of UVA's Department of Pharmacology. "We think that activation of this support system at birth provides an extra safety factor for this critical period." Regulating Baby's Breathing The new findings help researchers understand how breathing transitions from a fragile state susceptible to brain-damaging and potentially deadly pauses early in development to a stable and robust physiological system that flawlessly supplies the body with oxygen for the rest of our lives. Before a baby is born, breathing is not required and breathing movements occur only intermittently, so the transition at birth can be a highly vulnerable time. Bayliss and his colleagues at UVA, working with researchers at the University of Alberta and Harvard University, found that a specific gene is turned on immediately at birth in a cluster of neurons that regulate breathing selectively in mice. This gene produces a peptide neurotransmitter -- a chain of amino acids that relays information between neurons. This transmitter, called PACAP, starts to be released by these neurons just as the baby emerges into the world. The scientists determined that suppressing the peptide in mice caused breathing problems and increased the frequency of apneas, which are potentially dangerous pauses in breathing. These apneas further increased with changes in environmental temperature. These observations suggest that problems with the neuropeptide system may contribute to SIDS. Understanding SIDS SIDS, also known as crib death, is the sudden unexplained death of a child less than a year of age. It is the leading cause of infant mortality in Western countries. SIDS is attributed to a combination of genetic and environmental factors, including temperature. UVA's new research suggest that problems with the neuropeptide system may increase babies' susceptibility to SIDS and other breathing problems. PACAP is the first signaling molecule shown to be massively and specifically turned on at birth by the breathing network, and it has been linked genetically to SIDS in babies. The causes of SIDS likely are complex, and there may be other important factors to discover, the researchers note. "These finding raise the interesting possibility that additional birth-related changes may occur in the control systems for breathing and other critical functions," Bayliss said. "We wonder if this could be a general design principle in which fail-safe support systems are activated at this key transition period, and that understanding those may help us better treat disorders of the newborn." Story Source: Materials provided by University of Virginia Health System. Note: Content may be edited for style and length. During pregnancy, babies receive 100% of their oxygen from their mother. As she inhales, oxygen enters her bloodstream then flows to the placenta, and is transported to the baby through the umbilical cord. Carbon dioxide (CO2) and waste products from the baby travel back through the cord to the placenta. From there they are transferred back into the maternal system to be disposed of. Babies get everything they need for their growth and development through this amazing system. But what about when your baby is born? When do babies take that first breath and how do they adapt to breathing for themselves? Let’s explore this more. When do babies start breathing in the womb?Babies don’t breathe their own oxygen when they’re in the womb. Instead, they receive it from their mother, via the placenta. We call this fetal circulation, and the process can be described simply, like this:
Baby’s first breath physiologyThe process that happens at birth, when a baby switches from fetal circulation to breathing independently (newborn circulation) is complex but amazing. The following information will help you understand what happens physically when a baby takes its first breath:
This process completes the successful conversion from fetal to newborn circulation. The baby’s muscles, organs, and brain are now oxygenated by the baby’s own system. How long does it take for a baby to take its first breath?Your baby takes the first breath usually within ten seconds of birth. These first few breaths, initiated by the newborn, are the most difficult. Most full-term infants will gasp spontaneously within seconds of birth. 90-95% of newborns will complete this transformation without any help. What stimulates a newborn’s first breath?How do babies know when to take their first breath? The reality is that babies, like all mammals, are primed for survival. Taking the first breath is a primal reflex essential for keeping the baby alive and is triggered by the change in air temperature and environment. Research suggests:
For more information be sure to read How Do Babies Breathe During Labor? Factors that initiate respiration in newbornThere are a number of factors that can aid or hinder your baby’s ability to take the first breath and establish respiration. These factors include:
Why do preterm babies have trouble breathing?Preterm babies haven’t had as much time produce surfactant – a substance that keeps the air sacs in the lungs from sticking together when exhaling. Surfactant also helps the lungs to inflate and prevents them collapsing in on themselves, which makes breathing harder. A baby normally begins to produce surfactant from 24-28 weeks of pregnancy. Most will produce enough to breathe normally by week 34. Some babies born at this point, however, will still struggle to maintain breathing for themselves and might require respiratory support from a breathing machine or ventilator. The lungs aren’t considered mature until around 36 weeks. Generally the longer the gestation, the better it is for the health of newborn babies, as they are better equipped to deal with their new world. Why is the first breath of a newborn the most difficult?The first breath immediately after birth is mechanically the most difficult for a newborn because it’s the first time the lungs are being used. Within a couple of breaths, the baby’s lungs will inflate. They become filled with air, and push out the fluid inside them. Only after this is done can the lungs effectively take in oxygen and eliminate carbon dioxide. Imagine blowing up a balloon for the first time. The balloon is like the newborn’s lungs. Your first attempt to blow up the balloon takes a lot of effort, but once you get started it becomes easier. The next time you blow it up, it’s easier still. The process is similar for the baby. Once their lungs have begun working, the muscles involved in breathing don’t have to work so hard to keep them inflated. Can a baby breathe with the umbilical cord attached?Most babies will breathe spontaneously immediately after birth, even when they are still connected to the cord. Because blood is still flowing to the placenta, babies will still receive oxygen from their mother, even when breathing for themselves. This will continue until the cord naturally stops pulsing. This is known as delayed cord clamping. Doctors usually clamp and cut the cord after three minutes but you can request to leave it for longer. Ways to support babies in their newborn transitionsThe first moments after birth are incredibly precious as you meet your baby for the first time. While your newborn is adjusting to life outside the womb, you can support this transition by:
The first hour after birth should always be about you and your baby getting to know each other and helping your baby make this incredible transition. Find out more in 7 Huge Benefits of An Undisturbed First Hour After Birth. When newborns take their first breath impacts the circulatory system Why do you think this might be?Once the baby takes the first breath, a number of changes occur in the infant's lungs and circulatory system: Increased oxygen in the lungs causes a decrease in blood flow resistance to the lungs. Blood flow resistance of the baby's blood vessels also increases. Fluid drains or is absorbed from the respiratory system.
Why is taking the first breath hard work for the newborn?Your baby will need to work very hard to take their first breath, and their first few breaths may be shallow and irregular. With each breath after birth, more air will accumulate in their lungs, which will make it easier for them to breathe.
Why is the first breath of a newborn the most important?The oxygen from a baby's first breath decreases pulmonary vascular resistance, allowing the lungs to open and expel amniotic fluid. Appropriate oxygenation in the first minutes of life stimulates brain, kidney, endocrine, and digestive function.
What closes when a baby takes its first breath?When newborns take their first breath, a new flow direction happens. The blood now needs to go to the baby's lungs. This new flow helps push the patent foramen ovale closed.
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