Document Detail

Fetal sciatic nerve growth is delayed following repeated maternal injections of corticosteroid in sheep.
MedLine Citation:
PMID:  10765511     Owner:  NLM     Status:  MEDLINE    
AIMS: A single course of prenatal corticosteroid reduces the mortality and morbidity of preterm birth. Repeated courses of prenatal corticosteroids are widely prescribed despite a lack of safety data. Repeated corticosteroids delay myelination in the ovine central nervous system at the time of preterm delivery but with catch-up at term. We aimed to evaluate their effect in the peripheral nervous system. METHODS: Thirty date-mated ewes were administered either saline, a single injection of betamethasone, or four injections of betamethasone between 104 and 124 days' gestation, with delivery on day 125 or 145 (term = 150 days). Sciatic nerves were dissected and fixed in modified Karnovsky's fixative and prepared for light and electron microscopy to determine the proportion of myelinated axons and mean axon diameter. RESULTS: Repeated, but not single, corticosteroid administration resulted in significant decreases in the total cross-sectional and fascicle-containing areas of the sciatic nerve, and in the mean diameter of myelinated and unmyelinated axons. Deficits persisted at term. The proportion of myelinated axons was unaffected. CONCLUSION: Repeated prenatal corticosteroids have the capacity to affect the growth of peripheral nerve axons in sheep. Documentation of their effects in human pregnancy await randomized trials.
J A Quinlivan; M A Archer; S F Evans; J P Newnham; S A Dunlop
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of perinatal medicine     Volume:  28     ISSN:  0300-5577     ISO Abbreviation:  J Perinat Med     Publication Date:  2000  
Date Detail:
Created Date:  2000-06-08     Completed Date:  2000-06-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0361031     Medline TA:  J Perinat Med     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  26-33     Citation Subset:  IM    
University Department of Obstetrics and Gynecology, University of Western Australia, Australia.
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MeSH Terms
Adrenal Cortex Hormones / administration & dosage*,  adverse effects
Axons / physiology,  ultrastructure
Microscopy, Electron
Myelin Sheath / physiology,  ultrastructure
Sciatic Nerve / drug effects*,  embryology*,  ultrastructure
Sheep / embryology*
Reg. No./Substance:
0/Adrenal Cortex Hormones

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