March 15, 2019 by John Fernandez
Extreme Preemies: Survival of the Tiniest
Big advances in maternal and neonatal care over the last 20 years are helping the tiniest infants survive. In the early 1990s, just over one half of extremely premature babies in the U.S. – those born earlier than 28 weeks and weighing less than 3 pounds – survived. Today, the average national survival rate is about 63 percent. The outcomes are documented in a research study published recently in the Journal of the American Medical Association (JAMA). Worldwide Prematurity Day, facilitated on November 17 by the March of Dimes, helps raise awareness about the issues related to preterm birth.
“The improved outcomes for extremely premature infants are encouraging,” says Jorge Perez, M.D., medical director of neonatal intensive care at South Miami Hospital and chairman of the hospital’s Center for Women & Infants. “Being able to buy extra days and weeks to keep these babies in the womb is translating into much better survival rates and lower severities of morbidities.”
Babies born before 28 weeks of gestation are considered extremely premature. Low birth weight, immature lungs and brain hemorrhages are among the most common reasons they do not survive.
The study examined nearly 35,000 extremely preterm infants born at between 22 and 28 weeks from 1993 to 2012. The most significant increase in survival rate was seen in infants born at 23 and 24 weeks gestation and survival without major morbidity increased for infants aged 25 to 28 weeks.
Dr. Perez validates the interventions and treatments the researchers conclude are making the biggest difference:
- Refinement of ventilation strategies.
- Enhanced nutritional support.
- Avoidance of neonatal infections.
- Increased use of antenatal corticosteroids.
“By far, the intervention that has made the biggest difference is the antenatal corticosteroids,” said Dr. Perez, who has been practicing high-level neonatal intensive care for 25 years. “We give them to more than 90 percent of mothers expecting to deliver preterm. The ways the steroids enhance lung maturation and strengthen the blood vessels that connect to the brain are keys to increasing these babies’ survival.”
Stronger lungs mean less likelihood the newborn will need artificial ventilation once born or develop respiratory distress syndrome, one of the most common complications in premature infants. Adequate blood supply to the brain wards off neurodevelopmental impairment.
More than 550,000 premature babies are born each year in the United States. Women who are considered high risk for delivering extremely premature babies include those who have delivered a preterm infant before, are pregnant with multiples (twins, triplets) or have reproductive system abnormalities, such as a short cervix. Premature birth can also result from medical conditions that develop during pregnancy, such as diabetes, high blood pressure and urinary tract infections.
Ethnicity, age and lifestyle also play a role. African-American babies are 50 percent more likely to be born preterm than are infants of white mothers, according to the U.S. Centers for Disease Control and Prevention. Women younger than age 18 and older than 35 and those with an unhealthy lifestyle that includes activities, such as limited prenatal care, drugs or alcohol use, smoking or exposure to environmental pollutants, also are at risk of delivering prematurely.
The neonatal intensive care units (NICU) at Baptist Hospital of Miami and South Miami Hospital care for more than 1,500 premature babies annually. Over the last two years, the survival rate of extreme preemies at these hospitals has been between 82 and 89 percent, above national benchmarks. South Miami Hospital holds Gold Seals of Approval for pre-term labor and prematurity from The Joint Commission, the largest, individual, not-for-profit healthcare accrediting body in the U.S.
“The way our NICU specialists communicate with other doctors, nurses and caregivers, sharing data to discuss each patient individually, is making a tremendous impact on outcomes,” said Dr. Perez. “With a truly multi-team approach, medical advances and high-quality care, the fruits of our hard work are starting to show.”