After a decade of steady decline in late preterm birth rates, the birth rate in this at-risk group has been inching upward since 2015. Because late preterm infants account for approximately 70% of preterm births in the U.S., this is an important public health matter — and a costly one.
An updated clinical report summarizes the initial progress and potential reasons for the trends in late preterm and early term birth rates, along with suggestions for research.
The report, Updates on an At-Risk Population: Late Preterm and Early Term Infants, from the AAP Committee on Fetus and Newborn, is available at https://doi.org/10.1542/peds.2019-2760 and will be published in the November issue of Pediatrics.
Change in terminology
The AAP published a clinical report on late preterm infants in 2007 based on a 2005 workshop at the Eunice Kennedy Shriver National Institute of Child Health and Development at which a change in terminology from “near term” to “late preterm” was proposed. This paradigm-shifting recommendation had a major impact on federal and professional organizations. A nationwide initiative ensued in which monitoring and educational plans had a significant effect on decreasing the rates of iatrogenic late preterm deliveries.
Unfortunately, that trend did not continue. In the third quarter of 2018, the preterm birth rate rose to 9.97%, up from 9.57% in 2014.
Neurodevelopmental sequelae
Evidence revealed by population health research demonstrates that being born as an early-term infant (37 0/7- 38 6/7 weeks’ gestational age) poses a significant risk to the infant’s survival, growth and development. These early term infants represent 25% of all live births and 28% of all term births.
Late preterm newborns are at an increased risk for a number of adverse events, including respiratory distress, hypoglycemia, feeding difficulties, hypothermia, hyperbilirubinemia, apnea, seizures and a higher rate of readmission after initial discharge compared to term infants. In addition, late preterm infants have higher rates of pulmonary disorders during childhood and adolescence, learning difficulties and subtle, minor deficits in cognitive function. They also are at increased risk for acute bilirubin encephalopathy (kernicterus) as well as auditory neuropathy spectrum disorder.
As adults, individuals born preterm and early term have higher blood pressure and more often require treatment for diabetes. A review of 126 publications concluded that the overwhelming majority of adults born at preterm gestation remain healthy and well (Raju TNK, et al. Acta Paediatr. 2017;106:1409-1437, (https://onlinelibrary.wiley.com/doi/abs/10.1111/apa.13880). Still, adult outcomes in a small but significant fraction of infants born late preterm are concerning. This is due to the increased risk for neuropsychological and behavioral problems, hypertensive disorders and metabolic syndrome, which develops at an earlier age when compared to term infants.
Together, late preterm and early term births account for about 32% of nearly 4 million live births annually. This remains a challenge, especially with the recent increases in U.S. rates.
Recommendations
- Late preterm and early term infants have increased risks of adverse medical, neurodevelopmental, behavioral and social sequelae into and throughout adulthood. Pediatricians and neonatologists should always obtain a patient’s clinical history, including gestational age at birth, and should continue to understand and inform parents, educators and adult care clinicians of these risks.
- The use of population data within hospitals, states, regions and networks will help clinicians monitor rates of late preterm and early term births for trends, changes in practice and need for intervention.
- Multidisciplinary discussions and planning with obstetric providers can improve the understanding of the causes of and indications for late preterm and early term deliveries with the intention of preventing iatrogenic deliveries.
- Because late preterm and early term infants are at risk for adverse health outcomes, these groups should be added to payment models that better finance practitioners who have to increase their outreach, screening and treatment to provide appropriate care to these patients.
Dr. Stewart, a lead author of the clinical report, is a former member of the Committee on Fetus and Newborn.
