Fetal growth retardation, particularly within lymphoid organs, following repeated maternal injections of betamethasone in sheep.
OBJECTIVE
To examine the effect of single or repeated injections of maternally administered corticosteroids on fetal growth in sheep.


METHODS
Forty-six date-mated singleton gestation ewes were allocated at random to one of 3 groups: a single, or repeated injections of betamethasone, or a control group which received saline. On days 125 (preterm) or 145 (term) caesarean section delivery was performed. After lambs were killed, measures of size and weight were recorded. Data were analysed using Fishers Exact test and the Student's t-test.


RESULTS
Significant betamethasone dose dependent reductions in body and organ weights and biometry were found at preterm and term gestational ages (p < 0.05). There was little catch up growth in those in whom delivery was delayed until term. Thymus, spleen and liver were particularly targeted.


CONCLUSIONS
Repeated injections of betamethasone to the pregnant ewe cause significant reductions in fetal growth with little evidence of catch up by term. The effect of repeated maternal injections of corticosteroids in human pregnancy will await the results of randomized controlled trails.
Department of Obstetrics and Gynaecology, University of Western Australia, Australia.
J A
JA
Quinlivan
M A
MA
Archer
S A
SA
Dunlop
S F
SF
Evans
L D
LD
Beazley
J P
JP
Newnham
D000818:Animals; D001623:Betamethasone / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects / Q000196:embryology; D004305:Dose-Response Relationship, Drug; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D005069:Evaluation Studies as Topic; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011897:Random Allocation; D012756:Sheep
D005938:Glucocorticoids; D001623:Betamethasone