• Subject's self-rated nausea level on a scale of 0-3 at multiple points immediately before, during, and after the surgery [ Time Frame: before surgery, multiple times during & after surgery ] [ Designated as safety issue: No ]
• Investigator's rating of the incidence of vomiting or retching on a scale of 0-3 at multiple points immediately before, during, and after the surgery [ Time Frame: before surgery, multiple times during & after surgery ] [ Designated as safety issue: No ]

• Subject's self-rated nausea level on a scale of 0-3 at multiple points immediately before, during, and after the surgery
• Anesthesiologist's rating of the incidence of vomiting or retching on a scale of 0-3 at multiple points immediately before, during, and after the surgery

• Non-invasive blood pressure measurements made during the procedure [ Time Frame: once each minute for at least 10 minutes and then at least every 2.5 minutes for the duration of the surgery ] [ Designated as safety issue: No ]
• Total amount of vasopressors (total IV ephedrine and total IV phenylephrine) administered during the procedure [ Time Frame: throughout the surgery ] [ Designated as safety issue: No ]
• Cord Blood Gas Results following delivery of the placenta [ Time Frame: one time, after delivery of placenta ] [ Designated as safety issue: No ]

• Non-invasive blood pressure measurements made during the procedure (once each minute for at least 10 minutes and then at least every 2.5 minutes for the duration of the surgical procedure)
• Total amount of vasopressors (total IV ephedrine and total IV phenylephrine) administered during the procedure
• Cord Blood Gas Results following delivery of the placenta

The purpose of this research study is to investigate if the incidence of nausea and vomiting that subjects experience during and after a Cesarean section can be reduced by giving a shot of the drug ephedrine into the thigh muscle at the time of spinal anesthesia administration.

This research project is designed to study the medication ephedrine, when it is given as a routine part of the anesthesia for elective Cesarean section. Ephedrine is a medication that is widely used in labor and in vaginal and operative (Cesarean section) deliveries to help maintain a woman's blood pressure within its normal range, especially after spinal and epidural anesthesia has been administered. The purpose of this study is to determine if ephedrine, when given intramuscularly (<IM> as a shot in the muscle), at the time of spinal anesthesia administration, can help to decrease the incidence of nausea and vomiting subjects experience during and after a Cesarean section. This study will compare women who receive ephedrine to a similar group of women who receive a normal saline placebo. In addition to looking at the difference in the incidence of nausea and vomiting perioperatively, this study will also evaluate if the administration of IM ephedrine helps the baby to receive more blood from the placenta after anesthesia has been administered to the mother. This will be evaluated by performing a simple blood test, drawn from the umbilical cord, after the baby is born.

• Nausea
• Vomiting
• Cesarean Section

• Drug: Ephedrine [Synonyms: Ephedra, Ephedrinum]
• Drug: Saline Placebo

Inclusion Criteria:

• Must be pregnant with a single baby
• Must be at term in their pregnancy (estimated gestational age of at least 38 weeks)
• Must be scheduled for an elective Cesarean section
• Must be between 60-70" tall
• Must be free of severe systemic disease (ASA class I or II)

Exclusion Criteria:

• Contraindication to spinal anesthesia
• Any allergy to any of the medications included in the study
• History of pregnancy-induced hypertension or preeclampsia
• History of preexisting hypertension
• Diabetes mellitus
• Hyperemesis gravidum
• Previous perioperative nausea and vomiting
• History of motion sickness
• Women carrying a fetus with a known abnormality will also be excluded from the study