All patients are fully informed of the research objectives and will only be included in the study if they agree to participate and sign the Instrument of Consent. The project was designed following the recommendations of Resolution 196/96 of the National Health and the Declaration of Helsinki for research involving human subjects (2000). In addition, the project was submitted to the Ethics Committee in Research of the Institute of Integrative Medicine Professor Fernando Figueira, is approved. The study will be conducted from June 2011 to July 2012. The study variables are: consumption of metaraminol and ephedrine before and after birth, the occurrence of nausea and vomiting, incidence of maternal hypotension, the occurrence of reactive hypertension, occurrence of bradycardia, pH of umbilical cord, Apgar score 5 minutes, need for face mask ventilation and ICU admission.