1. Pratt WF, Bachrach CA. What do women use when they stop using the pill? Fam Plann Perspect. 1987;19:257-266.
2. Rosenberg MJ, Waugh MS. Oral contraceptive discontinuation: A prospective evaluation of frequency and reasons. Am J Obstet Gynecol. 1998;179:577-582.
3. Thorneycroft IH. Cycle control with oral contraceptives: A review of the literature. Am J Obstet Gynecol. 1999;180:S280-S287.
4. Speroff L, Darney PD. A Clinical Guide for Contraception. 3rd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2001.
5. Rosenberg MJ, Waugh MS, Burnhill MS. Compliance, counseling, and satisfaction with oral contraceptives: A prospective evaluation. Fam Plann Perspect. 1998;30:89-92-104.
6. Belsey EM, Machin D, d’Arcangues C. The analysis of vaginal bleeding patterns induced by fertility regulating methods. World Health Organization Special Programme of Research, Development and Research Training in Human Reproduction. Contraception. 1986;34:253-260.
7. ESHRE Capri Workshop Group. Ovarian and endometrial function during hormonal contraception. Hum Reprod. 2001;16:1527-1535.
8. Kaunitz AM. Oral contraceptive estrogen dose considerations. Contraception. 1998;58(Suppl):15S-21S.
9. Preston SN. A report of a collaborative dose-response clinical study using decreasing doses of combination oral contraceptives. Contraception. 1972;6:17-35.
10. Akerlund M, Rode A, Westergaard J. Comparative profiles of reliability, cycle control and side effects of two oral contraceptive formulations containing 150 mcg desogestrel and either 30 mcg or 20 mcg ethinyl oestradiol. Br J Obstet Gynaecol. 1993;100:832-838.
11. Gallo MF, Nanda K, Grimes DA, Schulz KF. Twenty micrograms vs >20 microg estrogen oral contraceptives for contraception: a systematic review of randomized controlled trials. Contraception. 2005;71:162-169.
12. Endrikat J, Hite R, Bannemerschult R, Gerlinger C, Schmidt W. Multicenter, comparative study of cycle control, efficacy and tolerability of two low-dose oral contraceptives containing 20 μg ethinyl estradiol/100 μg levonorgestrel and 20 μg ethinyl estradiol/50 μg noresthisterone. Contraception. 2001;64:3-10.
13. Hickey M, Fraser I, Dwarte D, Graham S. Endometrial vasculature in Norplant users: preliminary results from a hysteroscopic study. Hum Reprod. 1996;11(Suppl 2):35-44.
14. Smith SK. Steroids and endometrial breakthrough bleeding: future directions for research. Hum Reprod. 2000;15(Suppl 3):197-202.
15. Song JY, Markham R, Russell P, Wong T, Young L, Fraser IS. The effect of high-dose medium- and long-term progestogen exposure on endometrial vessels. Hum Reprod. 1995;10:797-800.
16. Hickey M, Dwarte D, Fraser IS. Superficial endometrial vascular fragility in Norplant users and in women with ovulatory dysfunctional uterine bleeding. Hum Reprod. 2000;15:1509-1514.
17. Rodriguez-Manzaneque JC, Graubert M, Iruela-Arispe ML. Endothelial cell dysfunction following prolonged activation of progesterone receptor. Hum Reprod. 2000;15(Suppl 3):39-47.
18. Lockwood CJ, Runic R, Wan L, Krikun G, Demopolous R, Schatz F. The role of tissue factor in regulating endometrial haemostsis: Implications for progestin-only contraception. Hum Reprod. 2000;15(Suppl 3):144-151.
19. Clark DA, Wang S, Rogers P, Vince G, Affandi B. Endometrial lymphoid cells in abnormal uterine bleeding due to levonorgestrel (Norplant). Hum Reprod. 1996;11:1438-1444.
20. Hatcher RA, Trussell J, Stewart FH. Contraceptive Technology. 18th ed. New York: Ardent Media; 2004.
21. Saleh WA, Burkman RT, Zacur HA, Kimball AW, Kwieterovich P, Bell W. A randomized trial of three oral contraceptives: comparison of bleeding patterns by contraceptive types and steroid levels. Am J Obstet Gynecol. 1993;168:1740-1747.
22. Lawson JS, Yuliano SE, Pasquale SA, Osterman JJ. Optimum dosing of an oral contraceptive. A report from the study of seven combinations of norgestimate and ethinyl estradiol. Am J Obstet Gynecol. 1979;134:315-320.
23. Stenchever MA, Ling FW. Comprehensive Gynecology. 4th ed. St Louis, Mo: Mosby; 2001.
24. Maitra N, Kulier R, Bloemenkamp KW, Helmerhorst FM, Gulmezoglu AM. Progestogens in combined oral contraceptives for contraception. Cochrane Database Syst Rev. 2004;(3):CD004861.-
25. Corson SL. Efficacy and clinical profile of a new oral contraceptive containing norgestimate. US clinical trials. Acta Obstet Gynecol Scand Suppl. 1990;152:25-31.
26. Anderson FD, Hait H. A multicenter, randomized study of an extended cycle oral contraceptive. Contraception. 2003;68:89-96.
27. Miller L, Hughes JP. Continuous combined oral contraceptive pills to eliminate withdrawal bleeding: a randomized trial. Obstet Gynecol. 2003;101:653-661.
28. Upton GV. The phasic approach to oral contraception: the triphasic concept and its clinical application. Int J Fertil Steril. 1983;28:121-140.
29. Mishell DR, Jr. Oral contraception: past, present, and future perspectives. Int J Fertil Steril. 1991;37(Suppl):s7-s18.
30. Van Vliet H, Grimes D, Helmerhorst F, Schulz K. Biphasic versus triphasic oral contraceptives for contraception. Cochrane Database Syst Rev. 2006;3:CD003283.-
31. Van Vliet H, Grimes D, Helmerhorst F, Schulz K. Biphasic versus monophasic oral contraceptives for contraception. Cochrane Database Syst Rev. 2006;3:CD002032.-
32. Rosenberg MJ, Waugh MS, Meehan TE. Use and misuse of oral contraceptives: Risk indicators for poor pill taking and discontinuation. Contraception. 1995;51:283-288.
33. Potter L, Oakley D, de Leon-Wong E, Canamar R. Measuring compliance among oral contraceptive users. Fam Plann Perspect. 1996;28:154-158.
34. Stubblefield PG. Menstrual impact of contraception. Am J Obstet Gynecol. 1994;170:513-1522.
35. Talwar PP, Dingfelder JR, Ravenholt RT. Increased risk of breakthrough bleeding when one oral-contraceptive tablet is missed. N Engl J Med. 1977;296:1236-1237.
36. Wallach M, Grimes DA. Modern Oral Contraception: Updates from the Contraceptive Report. Totowa, NJ: Emron; 2000.
37. Murphy PA, Kern SE, Stanczyk FZ, Westhoff CL. Interaction of St. John’s Wort with oral contraceptives: effects on the pharmacokinectics of norethindrone and ethinyl estradiol, ovarian activity and breakthrough bleeding. Contraception. 2005;71:402-408.
38. Baron JA, Greenberg ER. Cigarette smoking and estrogen related disease in women. In: Smoking and Reproductive Health, ed. Rosenberg MJ. Boston: PSG; .1987:149–160.
39. Jusko WJ. Influence of cigarette smoking on drug metabolism in man. Drug Metab Rev. 1979;9:221-236.
40. Basu J, Mikhail MS, Palan PR, Thysen B, Bloch E, Romney SL. Endogenous estradiol and progesterone concentrations in smokers on oral contraceptives. Gynecol Obstet Invest. 1992;33:224-227.
41. Faculty of Family Planning and Reproductive Health Care Clinical Effectiveness Unit FFPRHC Guidance (October 2003): First prescription of combined oral contraception. J Fam Plann Reprod Health Care. 2003;29:209-222.
42. Sparrow MJ. Pregnancies in reliable pill takers. NZ Med J. 1989;102:575-577.
43. Kanarkowski R, Tornatore KM, D’Ambrosio R, Gardner MJ, Jusko WJ. Pharmacokinetics of single and multiple doses of ethinyl estradiol and levonorgestrel in relation to smoking. Clin Pharmacol Ther. 1988;43:23-31.
44. Rosenberg MJ, Waugh MS, Stevens CM. Smoking and cycle control among oral contraceptive users. Am J Obstet Gynecol. 1996;174:628-632.
45. Vessey MP, Villard-Makintosh L, Jacobs HS. Anti-estrogenic effect of cigarette smoking. N Engl J Med. 1987;317:769-770.
46. Darney PD. OC practice guidelines: minimizing side effects. Int J Fertil Womens Med. 1997;42(suppl 1):158-169.
47. Krettek JE, Arkin SI, Chaisilwattana P, Monif GR. Chlamydia trachomatis in patients who used oral contraceptives and had intermenstrual spotting. Obstet Gynecol. 1993;81:728-731.
48. Gaudet LM, Kives S, Hahn PM, Reid RL. What women believe about oral contraceptives and the effect of counseling. Contraception. 2004;69:31-36.
49. Belsey EM. The association between vaginal bleeding patterns and reasons for discontinuation of contraceptive use. Contraception. 1988;38:207-225.
50. Jung-Hoffman C, Kuhl H. Intra- and interindividual variations in contraceptive steroid levels during 12 treatment cycles: no relation to irregular bleedings. Contraception. 1990;(42):423-438.
51. Rosenberg MJ, Waugh MS, Long S. Unintended pregnancies and use, misuse and discontinuation of oral contraceptives. J Reprod Med. 1995;40:355-360.