Timothy J M Moss1, Ilias Nitsos, Richard Harding, John P Newnham. 1. Lotteries Commission Perinatal Research Laboratories, School of Women's and Infants' Health, University of Western Australia, Box M094, 35 Stirling Highway, Crawley, WA 6009, Australia. tmoss@cyllene.uwa.edu.au
Abstract
OBJECTIVE: To determine the effects of single or repeated intramuscular injections of betamethasone, given maternally or directly to the fetus, on chronically catheterized, late-gestation fetal sheep. METHODS: Fetal or maternal sheep received either repeated intramuscular injections of betamethasone (0.5 mg/kg body weight at 104, 111, and 118 days' gestation), single betamethasone injection (at 104 days' gestation, followed by saline at 111 and 118 days' gestation), or repeated saline injections; n = 6 or 7 per group. At approximately 130 days' gestation fetuses were catheterized for serial measurements of heart rate, arterial pressure, blood gases, metabolites, and electrolytes. RESULTS: Repeated maternal betamethasone injections reduced birth weight (P =.03) without fetal hypoxemia or hypoglycemia. Circulating fetal calcium and lactate concentrations were reduced (P =.002 and P =.014, respectively) by repeated maternal betamethasone only. Fetal hematocrit tended to be lower after fetal (P =.3) and maternal (P =.07) betamethasone. CONCLUSION: Growth restriction caused by repeated maternal betamethasone treatments is not due to overt chronic placental insufficiency but may be caused by alterations in hormonal mediators of fetal growth or impairment of placental transport of specific nutrients.
OBJECTIVE: To determine the effects of single or repeated intramuscular injections of betamethasone, given maternally or directly to the fetus, on chronically catheterized, late-gestation fetal sheep. METHODS: Fetal or maternal sheep received either repeated intramuscular injections of betamethasone (0.5 mg/kg body weight at 104, 111, and 118 days' gestation), single betamethasone injection (at 104 days' gestation, followed by saline at 111 and 118 days' gestation), or repeated saline injections; n = 6 or 7 per group. At approximately 130 days' gestation fetuses were catheterized for serial measurements of heart rate, arterial pressure, blood gases, metabolites, and electrolytes. RESULTS: Repeated maternal betamethasone injections reduced birth weight (P =.03) without fetal hypoxemia or hypoglycemia. Circulating fetal calcium and lactate concentrations were reduced (P =.002 and P =.014, respectively) by repeated maternal betamethasone only. Fetal hematocrit tended to be lower after fetal (P =.3) and maternal (P =.07) betamethasone. CONCLUSION: Growth restriction caused by repeated maternal betamethasone treatments is not due to overt chronic placental insufficiency but may be caused by alterations in hormonal mediators of fetal growth or impairment of placental transport of specific nutrients.
Authors: Kathryn L Gatford; Julie A Owens; Shaofu Li; Timothy J M Moss; John P Newnham; John R G Challis; Deborah M Sloboda Journal: Am J Physiol Endocrinol Metab Date: 2008-05-20 Impact factor: 4.310
Authors: Maureen Keller-Wood; Xiaodi Feng; Charles E Wood; Elaine Richards; Russell V Anthony; Geoffrey E Dahl; Sha Tao Journal: Am J Physiol Regul Integr Comp Physiol Date: 2014-06-11 Impact factor: 3.619
Authors: Zarqa Saif; Rebecca M Dyson; Hannah K Palliser; Ian M R Wright; Nick Lu; Vicki L Clifton Journal: PLoS One Date: 2016-02-03 Impact factor: 3.240