Head off complications in late preterm infants

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Applied Evidence

Head off complications in late preterm infants

J Fam Pract. 2013 April;62(4):E3-E8

By

Steven D. Schrock, MD

Kimberly Stuckey-Schrock, MD

Late preterm infants may look like their full-term counterparts, but they face many more challenges. Here’s what to keep in mind.

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References

1. Martin JA, Hamilton BE, Sutton PD, et al. Birth: final data for 2008. Natl Vital Stat Rep. 2010;59:1, 3-71.

2. Engle WA, Tomashek KM, Wallman C. Committee on Fetus and Newborn. “Late-preterm” infants: a population at risk. Pediatrics. 2007;120:1390-1401.

3. Gabbe SG, Niebyl JR, Simpson JL. eds. Obstetrics Normal and Problem Pregnancies. Philadelphia, Pa: Churchill Livingstone; 2007.

4. Murthy K, Grobman WA, Lee TA, et al. Obstetricians’ rising liability insurance premiums and inductions at late preterm gestations. Med Care. 2009;47:425-430.

5. Wang ML, Dorer DJ, Fleming MP, et al. Clinical outcomes of near-term infants. Pediatrics. 2004;114:372-376.

6. Melamed N, Klinger G, Tenenbaum-Gavish K, et al. Short-term neonatal outcome in low-risk, spontaneous, singleton, late preterm deliveries. Obstet Gynecol. 2009;114:253-260.

7. Garg M, Devaskar SU. Glucose metabolism in the late preterm infant. Clin Perinatol. 2006;33:853-870.

8. Laptook A, Jackson G. Cold stress and hypoglycemia in the late preterm (“near-term”) infant: impact on nursery of admission. Semin Perinatol. 2006;30:24-27.

9. Cornblath M, Hawdon JM, Williams AF, et al. Controversies regarding definition of neonatal hypoglycemia: suggested operational thresholds. Pediatrics. 2000;105:1141-1145.

10. Adamkin D. Late preterm infants: severe hyperbilirubinemia and postnatal glucose homeostasis. J Perinatol. 2009;29(suppl):S12-S17.

11. Clark R. The epidemiology of respiratory failure in neonates born at an estimated gestational age of 34 weeks or more. J Perinatol. 2005;25:251-257.

12. Kalyoncu O, Aygun C, Cetinoglu E, et al. Neonatal morbidity and mortality of late-preterm babies. J Matern Fetal Neonatal Med. 2010;23:607-612.

13. Watchko J. Hyperbilirubinemia and bilirubin toxicity in the late preterm infant. Clin Perinatol. 2006;33:839-852.

14. Bhutani V. Kernicterus in late preterm infants cared for as term healthy infants. Semin Perinatol. 2006;30:89-97.

15. Tomashek KM, Shapiro-Mendoza CK, Weiss J, et al. Early discharge among late preterm and term newborns and risk of neonatal morbidity. Semin Perinatol. 2006;30:61-68.

16. Sarici SU, Serdar MA, Korkmaz A, et al. Incidence, course, and prediction of hyperbilirubinemia in near-term and term newborns. Pediatrics. 2004;113:775-780.

17. Shapiro-Mendoza CK, Tomashek K, Kotelchuck M, et al. Risk factors for neonatal morbidity and mortality among “healthy” late preterm newborns. Semin Perinatol. 2006;30:54-60.

18. Meier PP, Furman LM, Degenhardt M. Increased lactation risk for late preterm infants and mothers: evidence and management strategies to protect breastfeeding. J Midwifery Women’s Health. 2007;52:579-587.

19. American Academy of Pediatrics, Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2004;114:297-316.

20. Thoyre S, Shaker CS, Pridham KF. The early feeding skills assessment for preterm infants. Neonatal Netw. 2005;24:7-16.

21. Adams-Chapman I. Neurodevelopmental outcomes of the late preterm infant. Clin Perinatol. 2006;33:947-964.

22. Morse SB, Zheng H, Tang Y, et al. Early school age outcomes of late preterm infants. Pediatrics. 2009;123:622-629.

23. Cohen-Wolkowiez M, Moran C, Benjamin D, et al. Early and late onset sepsis in late preterm infants. Pediatr Infect Dis J. 2009;28:1052-1056.

PRACTICE RECOMMENDATIONS

• Delay discharge of late preterm infants to a minimum of 48 hours to prevent readmission. B

• Perform transcutaneous or total serum bilirubin testing before discharging late preterm infants. C

• Perform a formal feeding assessment of breastfed infants prior to discharge. C

• Ensure that a follow-up appointment is made for 24 to 48 hours after discharge. C

Strength of recommendation (SOR)

A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series

CASE Laura M delivers her third baby at 35 weeks 4 days after an uneventful spontaneous labor. Julia, 5 lb 1 oz, has Apgar scores of 8 and 9. You see them on the mother-baby unit Friday afternoon, 36 hours after the delivery.

Ms. M has successfully breastfed her other 2 children and is planning to breastfeed Julia as well. She says the infant is nursing well today but seemed sleepy yesterday. The nursing notes say that Julia went to the nursery overnight because her mother was tired, and the infant spit up after receiving a formula bottle. Ms. M is asking you to discharge her because tomorrow is her son’s birthday. After considering this and her experience with breastfeeding, you decide to discharge her with follow-up on Monday instead of checking her out to your partner for the weekend.

Ms. M returns to your office on Monday with Julia, whose weight is down 10% and is “glowing yellow.” The baby is not latching well at the breast and is spitting up when Ms. M tries to supplement with formula. After examining Julia and checking lab work (bilirubin, 20 mg/dL), you decide to readmit her for feeding difficulties and hyperbilirubinemia.

Complications are common with late preterm infants, which refers to babies born between 34 weeks 0 days and 36 weeks 6 days of pregnancy. Between 1990 and 2006, there was a dramatic (25%) increase in the rate of late preterm infants in the United States, although more recently this number has leveled off.¹

Several factors have been linked to increased late preterm births: maternal obesity, increased maternal age, and the increasing rate of multiple gestation pregnancies that have resulted from the expanded use of reproductive technology.² Similarly, treatment of severe preeclampsia and premature rupture of membranes often includes delivery after 34 weeks of gestation,³ further contributing to the problem. Finally, higher rates of antenatal screening have contributed to more inductions and cesarean sections at earlier gestational ages. One study even found a correlation between higher malpractice premiums and more frequent late preterm inductions.⁴

Don’t let their appearance fool you

At first appearance, late preterm infants are similar to term infants in terms of Apgar scores,⁵ size, and weight.² However, the care of these infants can be complex. They are often placed in well-infant nurseries under the same protocols as term infants and discharged before an adequate observation period. These infants have both increased short- and long-term morbidity and mortality and use a significant amount of health care resources.⁵ Morbidity in these infants decreases with each week of gestation from 34 weeks to a nadir at 39 weeks and can be unrelated to maternal and pregnancy complications.⁶

The following are some important issues to keep in mind when caring for these infants.

Hypothermia and hypoglycemia
Late preterm infants experience increased cold stress because of their limited fat stores, reduced brown fat, an immature epidermal barrier, and increased surface area to body mass ratio.² Hypothermia increases the metabolic demands on the neonate and can worsen hypoglycemia as well as respiratory distress.⁷

Ideally, clinicians should dry these infants with warm blankets, place them skin-to-skin with their mother, and cover them with a warm blanket and cap to avoid excess energy expenditure.⁸ If conditions necessitate, neonates can be placed in a radiant warmer. Infants’ temperature needs to be monitored within the first 30 minutes of life and frequently reassessed during the first 12 hours of life—the “transition period.”⁸ The infant’s axillary temperature should be maintained between 36.5°C and 37.4°C (97.7-99.3°F); the temperature should remain stable in an open crib for the 12 hours before discharge.²

Decreased glycogen stores, increased glucose utilization, and immature hepatic enzymes help to explain the fact that hypoglycemia is 3 times more common in late preterm infants compared with full-term neonates.⁷ In all newborns, glucose levels decrease to their nadir between 30 and 90 minutes of life and normally trigger the breakdown of glycogen if the infant does not eat.⁷ Hypoglycemia can manifest as a change in level of consciousness, apnea, cyanosis, tachypnea, hypothermia, and seizures.⁹ The evidence is limited and there is controversy as to what level of hypoglycemia and over what duration of time is harmful.⁹