B. B. Matonhodze, L. C. Katsoulis, G. Justus Hofmeyr
Labor induction and meconium: in vitro effects of oxytocin, dinoprostone and misoprostol on rat ileum relative to myometrium
Background. Oxytocin and various prostaglandin preparations
are commonly used for pharmacological induction
of labor at term. Some prostaglandin preparations
appear to be associated with more fetal meconium passage
and maternal gastrointestinal side effects than is
oxytocin. These adverse effects may be caused by stimulation
of bowel smooth muscle in the mother and in the
fetus.
Aim. To determine whether the in vitro ileal contractile
activities of dinoprostone, misoprostol and oxytocin are in
keeping with the variation in rates of meconium staining
observed during labor induction with these substances.
Methods. The contractile activity of the drugs was tested
on isolated rat uterus and ileum mounted in Tyrode's solution.
Results. Uterine contractions were stimulated by all
three drugs, whereas ileal contractions were only stimulated
by dinoprostone and misoprostol. Oxytocin had no
contractile activity on the ileum. Dinoprostone and
misoprostol stimulated significantly (p < 0.05) larger
uterine contractions than ileal contractions.
Conclusion. These results provide a pharmacological basis
for the increased rate of maternal gastrointestinal
complaints and meconium passage with labor induction
using dinoprostone and misoprostol compared to oxytocin.
Based on the above findings, we postulate that the
difference in the rates of meconium passage following
misoprostol and dinoprostone administration is caused
by pharmacokinetic rather than pharmacodynamic differences
between the two drugs.
Journal of Perinatal Medicine, Walter de Gruyter
Print ISSN: 1619-3997
Volume: 30, 09/2002
Pages: 405 - 410
Show full article (external site)
Show all available items of this journal
Search
