In this study the investigators hypothesize that infused combinations of oxytocin and
ergometrine will exhibit fewer cardiac and neurological side effects than equipotent infusion
of oxytocin alone. In order to perform this study the investigators perform the following
steps:
1. The investigators validate a quantitative measure of uterine tone as our primary
endpoint.
2. The investigators use this endpoint measure in order to determine equipotential doses of
different tocotonic drug regimens, based on the ED50 for each.
3. Using equipontial ratios based on the ED50, the investigators compare hemodynamic and
other side effects of these tocotonic drug regimes. Plasma levels of oxytocin will be
measured.