This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ng, P. C. Articles by Chan, D. C. F. Search for Related Content PubMed PubMed Citation Articles by Ng, P. C. Articles by Chan, D. C. F.

Pituitary-Adrenal Response in Preterm Very Low Birth Weight Infants after Treatment with Antenatal Corticosteroids

Departments of Pediatrics (P.C.N., G.W.K.W., C.H.L., T.F.F., W.W.) and Chemical Pathology (C.W.K.L., D.C.F.C.), Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong; and the Department of Mathematics (M.Y.W.), The Hong Kong University of Science and Technology, Hong Kong

Address all correspondence and requests for reprints to: P.C. Ng, Associate Professor in Pediatrics and Honorary Consultant Neonatologist, Department of Pediatrics, Level 6, Clinical Sciences Building, Princes of Wales Hospital, Shatin, N.T., Hong Kong.

Antenatal corticosteroids have been widely used for the prevention of respiratory distress syndrome in preterm neonates, yet little is known about their effects on the hypothalamic-pituitary-adrenal axis in these infants. We prospectively evaluated pituitary-adrenal function in 61 preterm (<32 gestational weeks), very low birth weight (<1500 g) infants on days 7 and 14 of life using the human CRH stimulation test.

The baseline and poststimulation plasma ACTH and serum cortisol concentrations did not differ significantly between infants whose mothers received no antenatal corticosteroids, and those whose mothers received 1–2 doses or >2 doses (mean 7.2 doses) of prenatal dexamethasone (P = > 0.12). The number of doses of dexamethasone and the time intervals between the last dose of drug and delivery did not significantly affect the pituitary-adrenal responsiveness on days 7 and 14 of life. Among infants who did not require mechanical ventilation at the time of the human CRH test, significantly higher plasma ACTH (P < 0.014) and lower serum cortisol concentrations (P < 0.02) were found on day 14 than on day 7. In contrast, none of the poststimulation hormone concentrations were significantly different in ventilated infants between days 7 and 14.

The relationship between the blood hormone concentrations in each time epoch (day 7 and day 14) and possible confounding factors including gestational and postconceptional age, birth weight, sex, Apgar scores, mode of delivery, single or higher order births, and mode of ventilation were determined. Plasma ACTH concentrations on day 7 were found to be significantly higher in ventilated than in nonventilated infants (P = 0.006). However, none of the aforementioned factors correlated significantly with plasma ACTH concentrations on day 14. Serum cortisol concentrations on day 7 were significantly higher in infants of greater gestational age (P = 0.039) and birth weight (P = 0.013), with lower Apgar scores at 1 and 5 min (P = 0.021 and P = 0.049, respectively), and in those delivered vaginally (P = 0.047). Similarly, serum cortisol concentrations on day 14 were found to be significantly higher in infants with lower Apgar scores at 1 and 5 min (P = 0.011 and P = 0.014, respectively) and in infants requiring mechanical ventilation (P = 0.014).

Our results suggest that single or multiple courses of antenatal dexamethasone have no long-lasting suppressive effects on pituitary-adrenal function in preterm, very low birth weight infants. Maturation of pituitary function appears to be more advanced than adrenal function. The organ’s ability to respond appropriately to various stressful stimuli indicates that the pituitary-adrenal axis is highly responsive at these early gestational ages.

This article has been cited by other articles:

				O. M. Peltoniemi, M. A. Kari, O. Tammela, L. Lehtonen, R. Marttila, E. Halmesmaki, P. Jouppila, M. Hallman, and for the Repeat Antenatal Betamethasone Study Group Randomized Trial of a Single Repeat Dose of Prenatal Betamethasone Treatment in Imminent Preterm Birth Pediatrics, February 1, 2007; 119(2): 290 - 298. [Abstract] [Full Text] [PDF]

				R. E. Grunau, J. Weinberg, and M. F. Whitfield Neonatal Procedural Pain and Preterm Infant Cortisol Response to Novelty at 8 Months Pediatrics, July 1, 2004; 114(1): e77 - e84. [Abstract] [Full Text] [PDF]

				P C Ng, C H Lee, C W K Lam, K C Ma, T F Fok, I H S Chan, and E Wong Transient adrenocortical insufficiency of prematurity and systemic hypotension in very low birthweight infants Arch. Dis. Child. Fetal Neonatal Ed., March 1, 2004; 89(2): F119 - F126. [Abstract] [Full Text] [PDF]

				G. MASTORAKOS and I. ILIAS Maternal and Fetal Hypothalamic-Pituitary-Adrenal Axes During Pregnancy and Postpartum Ann. N.Y. Acad. Sci., November 1, 2003; 997(1): 136 - 149. [Abstract] [Full Text] [PDF]

				P. C. Ng, C. W. K. Lam, C. H. Lee, K. C. Ma, T. F. Fok, I. H. S. Chan, and E. Wong Reference Ranges and Factors Affecting the Human Corticotropin-Releasing Hormone Test in Preterm, Very Low Birth Weight Infants J. Clin. Endocrinol. Metab., October 1, 2002; 87(10): 4621 - 4628. [Abstract] [Full Text] [PDF]

				R. J. Bolt, M. M. van Weissenbruch, C. Popp-Snijders, C. G. J. Sweep, H. N. Lafeber, and H. A. Delemarre-van de Waal Fetal Growth and the Function of the Adrenal Cortex in Preterm Infants J. Clin. Endocrinol. Metab., March 1, 2002; 87(3): 1194 - 1199. [Abstract] [Full Text] [PDF]

				A. Nordenstrom, A. Wedell, L. Hagenfeldt, C. Marcus, and A. Larsson Neonatal Screening for Congenital Adrenal Hyperplasia: 17-Hydroxyprogesterone Levels and CYP21 Genotypes in Preterm Infants Pediatrics, October 1, 2001; 108(4): e68 - 68. [Abstract] [Full Text] [PDF]

				P C Ng, C W K Lam, T F Fok, C H Lee, K C Ma, I H S Chan, and E Wong Refractory hypotension in preterm infants with adrenocortical insufficiency Arch. Dis. Child. Fetal Neonatal Ed., March 1, 2001; 84(2): 122F - 124. [Abstract] [Full Text]

				R. Karlsson, J. Kallio, K. Irjala, S. Ekblad, J. Toppari, and P. Kero Adrenocorticotropin and Corticotropin-Releasing Hormone Tests in Preterm Infants J. Clin. Endocrinol. Metab., December 1, 2000; 85(12): 4592 - 4595. [Abstract] [Full Text]

				P C Ng, C W K Lam, C H Lee, G W K Wong, T F Fok, I H S Chan, K C Ma, and E Wong Leptin and metabolic hormones in preterm newborns Arch. Dis. Child. Fetal Neonatal Ed., November 1, 2000; 83(3): 198F - 202. [Abstract] [Full Text]

				P C Ng The fetal and neonatal hypothalamic-pituitary-adrenal axis Arch. Dis. Child. Fetal Neonatal Ed., May 1, 2000; 82(3): 250F - 254. [Full Text]

				M. Heckmann, S. A Wudy, D. Haack, and F. Pohlandt Reference range for serum cortisol in well preterm infants Arch. Dis. Child. Fetal Neonatal Ed., November 1, 1999; 81(3): 171F - 174. [Abstract] [Full Text]

				P C Ng, G W K Wong, C W K Lam, C H Lee, T F Fok, M Y Wong, and K C Ma Effect of multiple courses of antenatal corticosteroids on pituitary-adrenal function in preterm infants Arch. Dis. Child. Fetal Neonatal Ed., May 1, 1999; 80(3): 213F - 216. [Abstract] [Full Text]