Improve your odds
Having a doula
is no guarantee of achieving a natural birth, but a large body of research shows those with doulas are less likely to require pain meds/anesthesia
or need a c-section, forceps or vacuum extraction, so i highly recommend a doula (or friend who will act as a doula) to all women giving birth.
See http://www.Dona.Org/resources/research.Php for references to the research if interested.