Skin so translucent and fragile it tears like tissue paper. Faces obscured by oxygen masks. Alarms going off very few minutes. Bassinets covered in plastic wrap.
This is the world of babies born extremely preterm—at less than 28 weeks of pregnancy. Yet for all the almost sinister machines surrounding these tiny humans–tubes and incubators, oxygen masks and respirators–they really represent medical miracles.
Just 40 years ago, birth before 28 weeks, a full twelve weeks early, was a death sentence. When Jackie Kennedy went into labor just 6 weeks early in 1962, doctors gave her preemie son, Patrick Bouvier, a 50-50 shot at survival. With the nation watching, Patrick’s condition deteriorated rapidly. He lived for just 39 hours, dying from Respiratory Distress Syndrome, a lung condition which remains common among premature babies. (Lungs are one of the last organs to fully develop – more on this below.)
In low-income countries, babies born at 34 weeks like Patrick Bouvier continue to face only a 50-50 shot at survival.
But in developed countries, like most of Western Europe and the United States, the age at which most babies survive, sometimes known as the age of viability, has crept earlier and earlier. A full-term baby is born between 37 and 42 weeks. Today, just over a third of babies born at 23 weeks, and over half of those born at 24 weeks, will survive. A baby born at 28 weeks has nearly a 90% chance of survival. Babies born at 34 weeks have survival rates topping 99%. (1) Which, is pretty incredible!
Yet, preterm birth is by no means “solved”. Even in the U.S., it remains the second leading cause of death in children under the age of 5, and even if babies are surviving, roughly half of all childhood disabilities are connected to preterm birth. (2)
We are so impressed by the work our partners at Bloomlife are doing to highlight this issue. Learn more from them here!
How Modern Medicine Transformed Preemie Survival
When it comes to boosting survival, nearly all of the recent medical advances involve the lungs.
UNDERSTANDING FETAL LUNG DEVELOPMENT
Inside the womb, the fetus doesn’t use their lungs to breathe. In fact, there is no air inside that fluid-filled amniotic sac in which the fetus lives. Instead, they get the oxygen they need through that matrix-like umbilical cord plugged into their future belly button. (Thanks, Mom!) The oxygen bypasses the fetal lungs and goes directly to the fetal heart, where it is pumped throughout their body.
But when the baby is born, everything changes. The cord is cut, and the baby is suddenly cut off from the pregnant person’s blood supply. This means their lungs need to start getting to work.
To enact this dramatic switch—from passively receiving oxygen to extracting it from the air—the lungs undergo a series of critical preparatory steps while in the womb.
In the second trimester, the fetus begins practicing breathing, “inhaling” and “exhaling” amniotic fluid. Then, around 24 weeks, of pregnancy the lungs begin to coat themselves with a mixture of carbohydrates, proteins, and fats known as surfactant.
Surfactant is critical for breathing air. It decreases surface tension inside the lungs. Without it, the lungs will collapse when exhaling air. (3)
Lung development the main reason very few babies born before 23 weeks survive, but the majority born after 24 weeks do. This window of time represents a critical juncture. These weeks are when the fetal lungs become able to take in oxygen, release carbon dioxide, and produce surfactant.
MEDICAL ADVANCES BOOSTING PREEMIE SURVIVAL
In the 1980s, doctors developed machines that could force air into preemies’ lungs, which provided babies who could not breathe on their own with life-sustaining oxygen.
In the 1990’s, continuous air pressure devices to aid breathing and artificial surfactant given after birth spurred further increases in survival, especially among the very youngest preemie. (4) Doctors of the ’90’s also began to give women at risk of premature delivery, steroids to hasten fetal lung development. A single dose of steroids at least 24 hours before birth dramatically raises the chances of preemie survival. It also lowers the risk of major complications like respiratory distress syndrome and bleeding in the brain.
But the timing of these steroids is key. Given too close to delivery, they do not have sufficient time to boost lung development. Given too early, on the other hand, and their beneficial effects fade. The ideal is between 1-7 days before birth. (4)
Complicating matters is the fact that, ideally, steroids are given only once, as multiple doses have been linked with poorer long-term cognitive outcomes. (5)
Lungs = survival… with health complications. So now what?
Despite survival rates rising dramatically, the rates of major complications have remained stubbornly high. Extremely premature babies face serious physical challenges. Compared to full-term babies, these babies have a much higher risk of cerebral palsy, blood and brain infections, blindness, deafness, brain bleeds, and respiratory distress syndrome (RDS). They also are more prone to mental challenges, suffering elevated rates of ADHD, autism, and developmental delays. (2)
Researchers are testing multiple treatments that may eventually improve preemies’ long-term health, such as administering antioxidants and anti-inflammatory medications.
Yet, more than any likely medical advance, the most dramatic improvements might simply come from more time inside the womb.
A baby born at 23 weeks has a less than 1 in 10 chance of survival without any major disability, such as blindness, deafness, or severe cerebral palsy. These dire odds, however, improve rapidly with each extra week inside the womb. By 25 weeks of pregnancy, a baby’s chances of avoiding a major disability has more than doubled to 1 in 3. (2) By 27 weeks, the majority of babies will survive without any major disability. (7)
So how do we get babies to stay in the womb longer?
Right now, medicine cannot yet accurately predict when labor will start, nor stall labor once it has begun. (8) Current labor-delaying drugs like magnesium sulfate can hold off labor by at most a few precious days. These extra hours are invaluable. They allow time to transfer to a hospital with a specialized neonatal intensive care units (NICU) and to treat pregnant people with steroids to speed up fetal lung development. But the extra time inside is not long enough to give these preemies the best shot at a full, healthy life.
Imagine if we solved this puzzle. Consider the dramatic impact of being able to stall labor by a week or more. One week or even two weeks seems like a mere drop in the bucket of a lifetime, but it is a vast span of time for a fetus. The difference in the health outcomes for a preemie born at 23 weeks and those born at 25 weeks is enormous. In one fell swoop, we could significantly lower preemies’ risk of severe disabilities, transforming their lives and the lives of their families. Bloomlife is working to bring awareness to the wider public of how valuable this extra time during pregnancy is. For Prematurity Awareness Month, Bloomlife is bringing attention to the maternal health perspective of preterm birth, and the value of every single week. Check out valueofoneweek.com or read more about how the Bloomlife research team is making incremental change towards impacting preterm birth.
And let’s do our part! Let’s educate ourselves and reset the conversation around premature birth from solving the preterm birth crisis to valuing incremental progress and the impact that seemingly small changes can make in the lives of pregnant people and their babies. Check out more information from Bloomlife here.
All content found on this Website, including: text, images, audio, or other formats, was created for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
(1). “Definition of Premature Birth – INHA – Irish Neonatal Health Alliance.” INHA, November 25, 2015. http://www.inha.ie/definition-of-premature-birth/.
(2). Glass, Hannah C., Andrew T. Costarino, Stephen A. Stayer, Claire M. Brett, Franklyn Cladis, and Peter J. Davis. “Outcomes for Extremely Premature Infants.” Survey of Anesthesiology 59, no. 6 (2015): 272–73. https://doi.org/10.1097/01.sa.0000471763.32127.3c.
(3). Chakraborty, Mallinath, and Sailesh Kotecha. “Pulmonary Surfactant in Newborn Infants and Children.” Breathe 9, no. 6 (2013): 476–88. https://doi.org/10.1183/20734735.006513.
(4) Roberts, Devender, Julie Brown, Nancy Medley, and Stuart R Dalziel. “Antenatal Corticosteroids for Accelerating Fetal Lung Maturation for Women at Risk of Preterm Birth.” Cochrane Database of Systematic Reviews, 2017. https://doi.org/10.1002/14651858.cd004454.pub3.
(5) Blickstein, Isaac. “Antenatal Corticosteroids: Current Controversies.” Journal of Perinatal Medicine 45, no. 1 (January 2017). https://doi.org/10.1515/jpm-2015-0405.
(6) Crowther, Caroline A, and Jane E Harding. “Repeat Doses of Prenatal Corticosteroids for Women at Risk of Preterm Birth for Preventing Neonatal Respiratory Disease.” Cochrane Database of Systematic Reviews, 2007. https://doi.org/10.1002/14651858.cd003935.pub2.
(7) Pierrat, V., L. Marchand-Martin, C. Arnaud, M. Kaminski, M. Resche-Rigon, C. Lebeaux, F. Bodeau-Livinec, et al. “Neurodevelopmental Outcome at 2 Years for Preterm Children Born at 22 to 34 Weeks’ Gestation in France in 2011.” Obstetric Anesthesia Digest 38, no. 1 (2018): 38–39. https://doi.org/10.1097/01.aoa.0000530002.37979.4c.
(8) Bloomlife. “Study: Current Preterm Birth Screening Tests Don’t Work.” Medium. Bloomlife News, April 6, 2018. https://blog.bloomlife.com/preterm-birth-screening-tests-ea590a964b52.