Use three original studies to provide evidence for or against three physical techniques to prepare for labor. 
Use Ovid or PubMed to find original peer-reviewed research. Studies should be current (published within the past 5-10 years). Study types include randomized control trial, cohort study, case-control study, systematic review, or literature review. Committee opinions and websites are not appropriate to use.
Techniques may include: antenatal perineal stretching, exercise, specific herbs used to prepare the cervix, specific herbs used to prepare the uterus, prenatal nutrition, dates, prenatal yoga, chiropractic care during pregnancy, or acupuncture during pregnancy. 
This 3-6 page essay should summarize evidence demonstrating effectiveness (or lack thereof) and safety (or lack thereof) of three techniques used to promote labor at term (37-42 weeks), increase maternal satisfaction with labor, increase rates of vaginal birth, decrease rates of complications, or any other parameters used to measure the experience of labor. Also appraise the quality of the evidence and consider the relevance of your findings for clinical practice.