Worldwide, the incidence of late preterm deliveries has been increasing. Late preterm newborns – those born between 34^0/7 and 36^6/7 weeks of gestation – comprised approximately 70% of preterm deliveries in the United States in 2018. These late preterm infants are sometimes overlooked due to their size and maturity, but those last few weeks in utero are crucial for organ development. Common medical issues for late preterm infants include respiratory distress, temperature instability, hypoglycemia, hyperbilirubinemia, apnea and feeding difficulties. 

Mortality risk

“Studies show that late preterm infants are at increased risk of mortality – not only in the first month or so, but in the whole first year when compared to infants born at full term,” says Sreenivas Karnati, MD, a neonatologist with Cleveland Clinic Children’s.

“Although mortality risk is much higher in extremely premature infants, those born late preterm have a 3-7x higher risk of death in the first year than term infants. One issue with these studies it that they don’t always pinpoint the specific cause of mortality, though congenital malformations, infection and respiratory distress are likely culprits,” Dr. Karnati explains.^1-3 

Best practices for the care of late preterm neonates

Each year, approximately 10,000 infants are born in Cleveland Clinic birthing centers. Of these, about 1,000 infants are born preterm, and about 650-700 of those are born late preterm.

At Cleveland Clinic Children’s, infants born at < 35 weeks gestation are admitted to the special care nursery automatically, and are discharged home when it is deemed safe, according to Dr. Karnati. Neonates born between 35-37 weeks gestation, who have no other issues, are admitted to the newborn nursery for observation.

During this hospital stay, lactation consultants address feeding problems and a multidisciplinary group of caregivers provide education to parents about possible complications, emphasizing the importance of prompt follow-up. The first visit to the pediatrician is scheduled prior to discharge.

Neurodevelopmental outcomes

“A lot of brain development occurs during the third trimester of pregnancy, and studies show that, at 34-35 weeks’ gestation, the brain is only two-thirds the size of term infants in terms of structure and maturity,” continues Dr. Karnati. “This puts these babies at higher risk for cerebral palsy or developmental delays.”^4-6

For these reasons, he says, it is important for pediatricians to identify patients born late preterm and keep a close eye on their development.

The role of the pediatrician

Pediatricians are key players in the care of these infants. They should educate parents about what to watch for, and take action at the first sign of any developmental delay. Interventions such as physical therapy, speech therapy and occupational therapy can be quite helpful when undertaken early in life.

Studies suggest that later preterm infants are at very high risk for hypothermia, hypoglycemia and jaundice, and increased odds of readmission.^7-11 Although these infants may be safely discharged home, it is extremely important that they are seen by a pediatrician within the first 48-72 after discharge. This visit helps pediatricians monitor weight gain and look for signs of jaundice or temperature dysregulation.

“Overall, these babies do fairly well, but they need to be watched closely by their parents and pediatricians for the first few years. Vigilance in outpatient clinics should help pediatricians to identify early signs of any developmental delays and promptly refer to appropriate therapies,” concludes Dr. Karnati.

References

1. Tomashek KM, Shapiro-Mendoza CK, Davidoff MJ, Petrini JR. Differences in mortality between late preterm and term singleton infants in the United States, 1995-2002 ICD international classification of diseases LMP last normal menstrual period NCHS national center for health statistics SIDS sudden infant death syndrome. J Pediatr. 2007 Jul;151(5)450-456.
2. McIntire DD, Leveno KJ. Neonatal mortality and morbidity rates in late preterm births compared with births at term. Obstet Gynecol. 2008;111:35e41.
3. Reddy UM, Ko C-W, Raju TNK, Willinger M, Branch P, Shriver EK. Delivery indications at late-preterm gestations and infant mortality rates in the United States. Pediatr. 2009;124:234e40.
4. Kinney HC: The near-term (late preterm) human brain and risk for periventricular leukomalacia: a review. Semin Perinatol. 30;(2)81-88:2006
5. Billiards SS, Pierson CR, Haynes RL, Folkerth RD, Kinney HC. Is the late preterm infant more vulnerable to gray matter injury than the term infant? Clin Perinatol. 2006 Dec;33(4):915-933.
6. Kelly CE, Cheong JLY, Gabra Fam L, et al. Moderate and late preterm infants exhibit widespread brain white matter microstructure alterations at term-equivalent age relative to term-born controls. Brain Imaging Behav. 2016;10:41-49.
7. Escobar GJ, Joffe S, Gardner MN, Armstrong MA, Flock BF, Carpenter DM. Rehospitalization in the first two weeks after discharge from the neonatal intensive care unit. Pediatr. 1999 Jul;104(1)e2.
8. Tomashek KM, Shapiro-Mendoza CK, Weiss J, Kotelchuck M, Barfield W, Evans S, et al. Early discharge among late preterm and term newborns and risk of neonatal morbidity. Semin Perinatol. 2006 Apr;30(2):61-68.
9. Oddie SJ, Hammal D, Richmond S, Parker L. Early discharge and readmission to hospital in the first month of life in the Northern Region of the UK during 1998: a case cohort study. Arch Dis Child. 2005 Feb;90(2):119-124.
10. Kuzniewicz MW, Parker SJ, Schnake-Mahl A, Escobar GJ. Hospital readmissions and emergency department visits in moderate preterm, late preterm, and early term infants. Clin Perinatol. 2013 Dec;40(4):753-775.
11. Medoff Cooper B, Holditch-Davis D, Verklan MT, Fraser-Askin D, Lamp J, Santa-Donato A, et al. Newborn clinical outcomes of the AWHONN late preterm infant research-based practice project. J Obstet Gynecol Neonatal Nurs. 2012 Nov-Dec;41(6)774-785.