RESULTS	As the proportion of phenylephrine decreased and proportion of ephedrine increased among the groups , the following significant trends were detected : the incidences of hypotension and nausea/vomiting increased , the median magnitude of deviations of SBP above or below baseline and the bias for SBP to be above baseline increased , maternal heart rate was faster , fetal pH and base excess decreased , umbilical arterial oxygen content decreased and umbilical venous Po2 increased .\