The Pill: Abortifacient or Contraceptive? A Literature Review

Congregatio Pro Doctrina Fidei “Instructio: De Observantia Erga Vitam Humanam Nascentem Deque Procreationis Dignitate Tuenda: Responsiones ad quasdam quaestiones nostris temporibus agitatas” Acta Apostolica Sedis — Commentarium Officiate 1988 I. 1. p. 78 (footnote) [Congregation for the Doctrine of the Faith “Instruction on Respect for Human Life in its Origin and on the Dignity of Procreation: Replies to Certain Questions of the Day (Donum Vitae)” published also in English by St. Paul Publications but there are significant errors in the translation, particularly in regard to the definition of a zygote. This problem was the subject of some correspondence between the Australian Catholic Bishops Conference and the Congregation resulting in the Congregation referring the Bishops to the Italian version and indicating what would be included in the official Latin text. There remains some confusion however as to whether the fusion of the gametes referred to in the definition of “zygote” has occurred at the time that the contents of the head of the sperm are absorbed into the ovum and the second polar body is extruded, or whether fusion has not really occurred until later at syngamy when the two pro-nuclei from the sperm and ovum fuse to form one nucleus and the chromosomes line up on the mitotic spindle for the first time, immediately prior to the first cell division. The difference is about sixteen hours. The medical literature tends to take the later stage as the formation of the zygote. This is not a major issue in this discussion as the anti-implantation effects we are concerned about take place much later than this.]

Acta Apostolica Sedis — Commentarium Officiate 1988, p. 79

1994 MIMS Annual, MIMS Australia 1994, p. 817

Kane Penny , and Porter Jane Choice Guide to Birth Control Penguin Books. Australia 1988

1994 MIMS Annual, MIMS Australia 1994, pp. 817–838

1994 MIMS Annual, p. 817

Kumar T.C Anand , Dhah RS , Chitlange CM , Hazari KT , Gopalkrisan K , Vadigoppula AD , Vernekar VJ , Borkar DM , and Puri CP “Effects of Intranasal Administration of Morthisterone on Follilulargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Function Profile in Women” Contraception September 1991, Vol 44 No 3 R.W. Rebar and K Zeserson “Characteristics of the New Progestogens in Combination Oral Contraceptives” Contraception July 1991 Vol 44 no 1 H. Refn, A Kjaer, A.M. Lebech, B. Borggaard, L. Schierap “Clinical and Hormonal Effects of Two Contraceptives: correlation to Serul Concentration of Lenonogestrel and Gestodene” Contraception March 1990 Vol 41 No.3 pp. 259-271 I. Spona, I Huber “Inhibition of ovulation with Gestodene” Gestodene Patheneon Publishing 1987: pp. 47-54

Crook D. , Godsland I.F. , Forthington M , Felton C.V. , Proudler A.J. , Stevenson J.C. “A Comparative Metabolic Study of two low-dose estrogen contraceptives containing desogestrel or gestodene progestins” American Journal of Obstetrics and Gynaecology November 1993, Vol 169 no. 5 pp. 1183–9

Fotherby K. , Caldwell A.D. “New Progestogens in Contraception” Contraception January 1994 Vol 49 no. 1 pp. 1–32 I.Y. Wang, I.S. Fraser “Reproductive function and contraception in the postpartum period” Journal of Obstetrics and Gynecology - Survey 1994 Vol 49 no. 1 1994 D.J. Hemrika, E.H. Slaats, J. Schoemaker “The Response of the Pituitary - ovarian axis to pulsatile administration of gonadotrophin releasing hormone in long term oral contraceptive users” American Journal of Obstetrics and Gynecology February 1994 Vol 170 no. 2 pp 462-8

Spona I. , Huber I “Inhibition of ovulation with Gestodene” Gestodene Patheneon Publishing 1987: pp. 47–54

Aref I. , Hefnawi F. , Kandl O. , Abdel Aziz T. “Effect of Minipills on Physiologic Responses of Human Cervical Mucus, Endometrium, and Ovary” Journal of Fertility and Sterility August 1973 Vol 24, no. 8 pp. 578–583

Aref I. , Hefnawi F. , Kandl O. , Abdel Aziz T. “Effect of Minipills on Physiologic Responses of Human Cervical Mucus, Endometrium, and Ovary” Journal of Fertility and Sterility August 1973 Vol 24, no. 8 pp. 578–583

Anand Kumar T.C. , Dhah R.S. , Chitlange C.M. , Hazari K.T. , Gopalkrisnan K. , Vadigopppula A.D. , Vernekar V.J. , Borkar D.M. , and Puri C.P. “Effects of Intranasal Administration of Norethisterone on Folliculargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Profile in Women” Contraception September 1991, Vol 44 No. 3

YoungKin E.Q. “Progestogens: a look at the “other” hormone” Journal of Nursing Practice November 1993 Vol 18 no. 11 pp 35–40 P.A. Rogers C.L. Au, B. Affandi “Endometrial microvascular density during the normal menstrual cycle and following exposure to long term levonorgestrel” Journal of Human Reproduction September 1993 Vol 8 No. 9 pp. 1396-404

Safro E. , O'Neill C. , Saunders O.M. “Elevated luteal phase estradiol: progesterone ratio in mice causes implantation failure by creating a uterine environment that suppresses embryonic metabolism” Journal of Fertility and Sterility December 1990 Vol 54 No. 6 pp. 1150–3

Kane Penny , and Porter John Choice Guide to Birth Control Penguin Books, Australia 1988 p. 48

Choice Guide to Birth Control, pp. 49–50.

de la Rey N. , Schall R. , Luus H.G. , Meyer B.H. , Fuller M.O. “Assessing the risk of ovulation in interaction studies of drugs and oral contraceptives” International Journal of Clinical Therapeutic Toxicology September 1993 Vol 31 no. 9 pp 435–9

John J. Billins in personal correspondence dated 9 August 1994.

1994 MIMS Annual, MIMS Australia 1994, p. 818

Kane , and Porter Op Cit, p. 7–8

1994 MIMS Annual, MIMS Australia 1994, p. 817

1994 MIMS Annual, p. 835

Wang I Y , Fraser I S “Reproductive function and contraception in the postpartum period” Journal of Obstetrics and Gynecology Jan 1994 Vol 49 no. 1 pp 56–63

Aref I. , Hefnawi F. , Kandl O. , Abdel Aziz T. “Effect of Minipills on Physiologic Responses of Human Cervical Mucus, Endometrium, and Ovary” Journal of Fertility and Sterility August 1973 Vol 24, no. 8 pp. 578–583

Shi J.P. , Wu X.R. “Levonorgestrel levels in serum and uterine flushings in women bearing LNG-CU-IUD” Journal of Thgji Medical University 1993 Vol 13 No. 2 pp 126–8

Okulwicz W.C. , Balsamo M. “A double immunoflourescent method for simultaneous analysis of progesterone-dependant changes in proliferation and the estrogen receptor in endometrium of rhesus monkeys” Journal of Reproductive Fertility November 1993 Vol 99 no. 2 pp 545–9 P.A. Rogers C.L. Au, B. Affandi “Endometrial microvascular density during the normal menstrual cycle and following exposure to long term levonorgestrel” Journal of Human Reproduction September 1993 Vol 8 No. 9 pp. 1396-404

Rebar R.W. , and Zeserson K. “Characteristics of the New Progestogens in Combination Oral Contraceptives” Contraception July 1991 Vol 44 no. 1 H. Refn, A. Kjaer, A.M. Lebech, B. Borggaard, L. Schierap “Clinical and Hormonal Effects of Two Contraceptives: Correlation to Serum Concentration of Levonogestrel and Gestodene” Contraception March 1990 Vol 41 No. 3 pp 259-271

Anand Kumar T.C. , Dhah R.S. , Chitlange C.M. , Hazari K.T. , Gopalkrisnan K. , Vadigopppula A.D. , Vernekar V.J. , Borkar D.M. , and Puri C.P. “Effects of Intranasal Administration of Norethisterone on Folliculargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Profile in Women” Contraception September 1991, Vol 44 No. 3 I. Aref, F. Hefnawi, O. Kandl, T. Abdel Aziz “Effect of Minipills on Physiologic Responses of Human Cervical Mucus, Endometrium, and Ovary” Journal of Fertility and Sterility August 1973 Vol 24, no. 8 pp. 578-583 P.A. Rogers C.L. Au, B. Affandi “Endometrial microvascular density during the normal menstrual cycle and following exposure to long term levonorgestrel” Journal of Human Reproduction September 1993 Vol 8 No. 9 pp. 1396-404 I Ben-nun, Y Ghetler, R. Jaffa, A. Siegal, H. Kaneti, M. Fejgin “Effect of preovulatory progesterone administration on the endometrial maturation and implantation rate after in vitro fertilization and embryo transfer.” Journal of Fertility and Sterility February 1990 Vol 53 No. 2 pp. 276-81

Anand Kumar T.C. , Dhah R.S. , Chitlange C.M. , Hazari K.T. , Gopalkrisnan K. , Vadigopppula A.D. , Vernekar V.J. , Borkar D.M. , and Puri C.P. “Effects of Intranasal Administration of Norethisterone on Folliculargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Profile in Women” Contraception September 1991, Vol 44 No. 3

1994 MIMS Annual, MIMS Australia 1994, p. 817

Darney P. “Safety and efficacy of a triphasic oral contraceptive containing desogestrel: results of three multi-centre trials” Contraception October 1993 Vol 48 No. 4 pp. 323–337 F. Weber-Diehl, J Lehnery, U. Lachnit “Comparison of two triphasic oral contraceptives containing either gestodene or norethindrone: a randomized controlled trial” Contraception October 1993 Vol 48 No. 4 pp 291-301 Penny Kane and John Porter Choice Guide to Birth Control Penguin Books, Australia 1988

1994 MIMS Annual Annual, MIMS Australia 1994, p. 817

Fotherby K. , and Caldwell ADS “New Progestogens in Contraception Contraception vol 49 1994 No. 1 pp. 1–9

Contraception, Thomas K.H. , Vanrieken L. “Inhibition of ovulation by low-dose contraception containing gestodene” American Journal of Obstetrics and Gynaecology 1990, Vol 163 pp. 1404–10 V. De Leo, D. Lanzetta, A.L. Vanni et al “Low Dose estrogen oral contraceptives and the hypothalamic-pituitary axis Contraception 1991 Vol 44 pp. 155-161

Anand Kumar T.C. , Dhah R.S. , Chitlange C.M. , Hazari K.T. , Gopalkrisnan K. , Vadigopppula A.D. , Vernekar V.J. , Borkar D.M. , and Puri C.P. “Effects of Intranasal Administration of Norethisterone on Folliculargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Profile in Women” Contraception September 1991, Vol 44 No. 3 I. Aref, F. Hefnawi, O. Kandl, T. Abdel Aziz “Effect of Minipills on Physiologic Responses of Human Cervical Mucus, Endometrium, and Ovary” Journal of Fertility and Sterility August 1973 Vol 24, no. 8 pp. 578-583

1994 MIMS Annual, MIMS Australia 1994, p. 817

Cachrimanidou A.C. , Hellberg D. , Nilsson S. , Waldenstrom U. , Olsson S.E. , Sikstrom B. “Long-interval treatment regimen with a desogestrel-containing oral contraceptive” Contraception September 1993 Vol 48 No. 3 pp. 205–16

Kane Penny , and Porter John Choice Guide to Birth Control Penguin Books, Australia 1988 pp. 95–97

Russell-Brown P. , Piedrahita C. , Foldesy R. , Steiner M. , Townsend J. “Comparison of Condom Breakage During Human Use with Performance in Laboratory Testing” Contraception 1992, Vol 49, pp. 429–437

Cahill L S. “‘Abortion pill’ RU486: ethics, rhetoric, and social practice.” Hastings Cent Rep 1987, Oct-Nov; 17(5): 5–8.

Dubois C ; Ulmann A ; Baulieu E E. “Contrageston with late luteal administration of RU486 (Mifepristone)” Fertil Steril 1988 Oct; 50(4): 593–6 Baulieu, E.E. “A novel approach to human fertility control: contragestion by the anti-progesterone RU486.” Eur J Obstet Gynecol Reprod Biol 1988 June; 28(2): 125-9

Evidence given to the Senate Estimates Committee, Hansard 21st June 1994, Parliament of the Commonwealth of Australia 1994

Bygdeman M ; Van Look P F. “Anti-progesterones for the interruption of pregnancy” Baillieres Clin Obstet Gynaecol 1988 Sep; 2(3) 617–29

Baulieu E. “Fertility control in women: Results with RU486 by the end of 1985.” J Steroid Biochem 1986 Bov; 25(5B): 847–51 (B) Baulieu E E; Ulmann A. “Antiprogesterone activity of RU486 and its contragestive and other applications.” Hum Reprod 1986 Feb; 1(2): 107-10 (A)

A plain language statement is a written statement which is approved by an ethics committee and which explains the research project and its dangers in simple, non-technical language for use by research subjects.

Evidence given to the Senate Estimates Committee, Hansard 21st June 1994, Parliament of the Commonwealth of Australia 1994

Cameron I T ; Michie A F ; Baird D T. “Therapeutic abortion in early pregnancy with antiprogestogen RU486 alone or in combination with prostaglandin analogue (gemeprost).” Contraception 1986 Nov; 34(5): 459–68.

Ulmann A ; Dubois C ; Philibert D. “Fertility control with RU486.” Horm Res 1987: 28(2-4): 274–8 Maria B; Stampf; Goepp A; Ulmann A. “Termination of early pregnancy by a single dose of mifepristone (RU486), a progesterone antagonist.” Eur J Obstet Gynecol Reprod Biol 1988 Jul; 28(3): 249-55 Dubois C; Ulman A; Baulieu E E. “Contragestion with late luteal administration of RU486 (Mifepristone).” Fertil Steril 1988 Oct; 50(4): 593-6

Bygdeman M ; Van Look P F. “Anti-progesterones for the interruption of pregnancy.” Baillieres Clin Obstet Gynaecol 1988 Sep; 2(3): 617–29 Cameron I T; Michie A F; Baird D T, “Therapeutic abortion in early pregnancy with antiprogestogen RU486 alone or in combination with prostaglandin analogue (gemeprost).” Contraception 1986 Nov; 34(5): 459-68 Ulmann A; Dubois C; Philibert D. “Fertility control with RU486” Horm Res 1987: 28(2-4): 274-8 Dubois C; Ulmann A; Baulieu E E. “Contragestion with late luteal administration of RU486 (Mifepristone).” Fertil Steril 1988 Oct; 50(4): 593-6 Rodger M W; Baird D T. “Induction of therapeutic abortion in early pregnancy with mifepristone in combination with prostaglandin pessary.” Lancet 1987 Dec 19; 2(8573): 1415-8 Baird D T; Rodger M; Cameron I T; Roberts I. “Prostaglandins and antigestagens for the interruption of early pregnancy.” J Reprod Fertil Suppl 1988; 36: 173-9

el-Refaey H. , Hinshaw K. , Templeton A. “The Abortifacient effect of misoprostol in the second trimester. A radomized comparison with gemeprost in patients treated with mifepristone” Journal of Human Reproduction October 1993 Vol 8 no 10 pp 1744–6

Frydman R ; Fernandez H ; Pons J C ; Ulmann A “Mifepristone (RU486) and therapeutic late pregnancy termination: a double-blind study of two different doses.” Hum Reprod 1988 Aug; 3(6): 803–6 Urquhart D R; Bahzad C; Templeton A A. “Efficacy of the antiprogestin mifepristone (RU486) prior to prostaglandin termination of pregnancy.” Hum Reprod 1989 Feb; 4(2): 202-3 Wolf J P; Sinosich M; Anderson T L; Ulmann A; Baulieu E E; Hodgen G D. “Progesterone antagonist (RU486) for cervical dilation, labor induction, and delivery in monkeys: effectiveness in combination with oxytocin.” Am J Obstet Gynecol 1989 Jan; 160(1): 45-7

Ghosh D. , De P. , Sengupta J. “Luteal phase contraception with mifepristone (RU486) in the rhesus monkey” Indian Journal of Physiology and Pharmacology January 1994 Vol 38 no. 1 pp 17–22

Nieman L K ; Choate T M ; Chrousos G P ; Healy D L ; Morin M ; Renquist D ; Merriam G R ; Spitz I M ; Bardin C W ; Baulieu E E “The progesterone antagonist RU486. A potential new contraceptive agent” N Engl J Med 1987 Jan 22; 316(4): 187–91 Swahn M L; Wang G; Aedo A R; Cekan S Z; Bygdeman M “Plasma levels of antiprogestin RU486 following oral administration to non-pregnant and early pregnant women”. Contraception 1986 Nov; 34(5): 469-81 Baulieu E E; Ulmann A; Philibert D. “Contragestion by antiprogestin RU486: a review.” Arch Gynecol Obstet 1987; 241 (2): 73-85

van Santen M R ; Haspels A A. “Interception. IV: Failure of mifepristone (RU486) as a monthly contragestive, “Lunarette”.” Contraception 1987 May; 35(5): 433–8 Nieman L K; Loriaux D L. “The use of anti-progesterones as a medical IUD.” Baillieres Clin Obstet Gynaecol 1988 Sep; 2(3): 609-16

Cameron I T ; Michie A F ; Baird D T. “Therapeutic abortion in early pregnancy with antiprogestogen RU486 alone or in combination with prostaglandin analogue (gemeprost).” Contraception 1986 Nov; 34(5): 459–68.

Nieman L K ; Loriaux D L. “The use of anti-progesterones as a medical IUD.” Baillieres Clin Obstet Gynaecol 1988 Sep; 2(3): 609–16.

Couzinet B ; Le Strat N ; Ulmann A ; Baulieu E E ; Schaison G. “Termination of early pregnancy by the progesterone antagonist RU486 (Mifepristone).” N Engl J Med 1986 Dec 18; 315(25): 1565–70.

Gao J : Qiao G M ; Wu Y M ; Wu M E ; Zheng S R ; Han Z B ; Fan H M ; Yao G Z ; Meng U ; Dubbois C ; “Pregnancy interruption with RU486 in combination with dl-15-methyl-prostaglandin-F2 alpha-methyl ester: the Chinese experience.” Contraception 1988 Dec; 38(6): 675–83 Couzinet B; Le Strat N; Ulmann A; Balieu E E; Schaison G. “Termination of early pregnancy by the progesterone antagonist RU486 (Mifepristerone).” N Engl J Med 1986 Dec 18; 315(25) 1565-70

Indian Council for Medical Research Task Force on Contraception “A multicentre clincial trial with RU486 followed by 9-methylene-PGE2 vaginal gel for termination of early pregnancy: a doser finding study” Contraception January 1994 Vol 49 no. 1 pp 87–98 Maria B; Stampf; Goepp A; Ulmann A. “Termination of early pregnancy by a single dose of mifepristone (RU486), a progesterone antagonist.” Eur J Obstet Gynecol Reprod Biol 1988 Jul; 28(3): 249-55 Gao J; Qiao G M; Wu Y M; Wu M E; Zheng S R; Han Z B; Fan H M; Yao G Z; Meng U; Dubbois C;, et al. “Pregnancy interruption with RU486 in combination with dl-15-methyl-prostaglandin-F2 alpha-mthyl ester: the Chinese experience. Contraception 1988 Dec; 38(6): 675-83

Das C ; Catt K J. “Antifertility actions of the progesterone antagonist RU486 include direct inhibition of placental hormone secretion.” Lancet 1987 Sep 12; 2 (8559): 599–601 Bischof P; Sizonenko M T; Herrmann W L. “Trophoblastic and decidual response to RU486: effects on human chorionic gonadotrophin, human placental lactogen, prolactin and pregnancy-associated plasma protein-A production in vitro.” Hum Reprod 1986 Jan; 1(1): 3-6 Bygdeman M; Van Look P F. “Anti-progesterones for the interruption of pregnancy.” Ballieres Clin Obstet Gynaecol 1988 Sep; 2(3): 617-29

Baulieu E E ; Ulmann A ; Philibert D. “Contragestion by antiprogestin RU486: a review.” Arch Gynecol Obstet 1987; 241(2): 73–85.

Cekan S ; Aedo A R ; Segersteen E ; Van Look P ; Messinis I ; Templeton A. “Levels of the antiprogestin RU486 and its metabolites in human blood and follicular fluid following oral administration of a single dose.” Hum Reprod 1989 Feb; 4(2): 131–5.

Durlot F ; Dubois C ; Brunerie J ; Frydman R. “efficacy of progesterone antagonist RU486 (mifepristone) for pre-operative cervical dilation during first trimester abortion.” Hum Reprod 1988 Jul; 3(5): 583–4.

Romieu G ; Maudelonde T ; Ulmann A ; Pujol H ; Grenier J. , Cavalie G ; Khalaf S ; Rochefort H. “The antiprogestin RU486 in advanced breast cancer: preliminary clinical trial.” Bull Cancer (Paris) 1987; 74(4): 455–61 Baulieu E E; Ulmann A; Philibert D. “Contragestion by antiprogestin RU486: a review.” Arch Gynecol Obstet 1987; 241(2): 73-85

Screenivasulu S. , Singh M.M. , Dwivedi A. , Setty B.S. , Kamboj V.P. CDRI-85/287, a novel antestrogen and anti-implantation agent: biological profile and interaction with the estrogen receptors in immature rat uterus” Contraception January 1992 Vol 45 No. 1 pp. 81–92

Hafex E.S.E. , and Evans T.N. Human Reproduction: Conception and Contraception Harper and Row 1973

Screenivasulu S. , Singh M.M. , Setty B.S. , Kamboj V.P. “Effect of a pure non-steroidal antiestrogen, CDRI-85/287, on implantation-associated histological and biochemical changes in the rat uterus” Contraception December 1993 Vol 48 No. 6 pp. 597–609

Chattergee S. , Johnson D.C. “Contrasting action of antiestrogen (ICI-182780) for preventing initiation of embryo implantation by estradiol or epidermal growth factor (EGF)” Life Science 1993 Vol 53 No. 1 pp. 1625–30 W. Xie, Q. Ziheng, G. Lei, D. Qiu, S. Hanz. Han “Anti-implantation action of nylestriol and its effect on uterine ctosol estrogen and progesterone receptor in rabbits” Hua-Hui-I-Ko-Ta-Haueh-Haueh-Pao June 1993 Vol 24 n. 2 pp. 163-6

Alexander N J “The effects of anti-body sperm-egg interaction” Annals of the New York Academy of Sciences 1988; 541: 317–23

Tsukui S ; Noda Y ; Fukuda A ; Matsumoto H ; Tatsumi K ; Mori T “Blocking effect of sperm immobilizing antibodies on sperm penetration of zonae pellucidae” J In Vitro Fert. Embryo Transf. 1988 Jun; 5(3): 123–8 Bamezai A K; Mahi-Brown C A; Talway G P “Inhibtion of penetration of canine zonae pellucidae by homologous spermatozoa in vitro using monoclonal antibodies raised against procine zonae” J. M. Reprod Immunol 1988 June; 13(1): 85-95 Moore H O; Hartman T D; Bye A P; Lutjen P; De Witt; Trounson A O. “Monoclonal Antibody against a sperm Antigen Mr 95,000 inhibits attachment of human spermatozoa to the zona pellucida” J. Reprod Immunol 1987 Jul; 11(3): 157-66

Bronson R A , Cooper G W “Detection in human sera of antibodies against hamster egg oolemma” Fertil Steril 1988 Mar; 49(3): 493–6.

Talway G P ; Gaur A “recent developments in immunocontraception” American Journal of Obstetrics and Gynecology 1987 Oct; 157 (4 Pt. 2): 1075–8

Shanti M Shehani , Patel K.C. “Use of hCG Stimulation Test in Women Immunized with B-hCG Vaccine Contraception October 1991 Vol 44 No, 4 pp. 453–460

Williams B L ; Wendell-Smith C P , Treadgold S , Basic Human Embryology Pitman 1969 p. 38

Kane Penny , and Porter John Choice Guide to Birth Control Penguin Books, Australia 1988, p. 122

Wonodirekso S. , Au C.L. , Hadisaputra W. , Affandi B. , Rogers P.A. “Cytokeratins B, 18 and 19 in endometrial epithelial cells during the normal menstrual cycle and in women receiving norplant” Contraception November 1993 Vol 48 No. 5 pp. 481–93

Anand Kumar T.C. , Dhah R.S. , Chitlange C.M. , Hazari K.T. , Gopalkrisnan K. , Vadigoppula A.D. , Vernekar V.J. , Borkar D.M. , and Puri C.P. “Effects of Intranasal Administration of Norethisterone on Folliculargenesis, Cervical Mucus, Vaginal Cytology, Endometrial Morphology and Reproductive-Endocrine Profile in Women” Contraception September 1991, Vol 44 No. 3

“Facts about once-a-month injectable contraceptives: memorandum from a WHO meeting Bulletin World Health Organization 1993, Vol 71 No. 6 pp. 677-89 Weisman C.S. “Comparison of contraceptive implant adopters and pill users in a family planning clinic in Baltimore” Family Planning Perspectives September-October 1993 Vol 25 No. 5 pp 224–6

Dr John J Billings personal correspondence 9th August 1994.

Kane Penny , and Porter John CHoice Guide to Birth Control Penguin Books, Australia 1988, p. 115–116

Wu J.C. , Sealfron S.C. , Miller W.L. “Gonadal hormones and gondotrophin-releasing hormone (GnRH) alter messenger ribonucelic acid levels for GnRH receptors in sheep Journal of Endocrinology April 1994 Vol 134 No. 4 pp 1846–50 8393 Vol 25 No. 5 pp 224-6

Kane Penny , and Porter John Choice Guide to Birth Control Penguin Books, Australia 1988, p. 69–82

Donum Vitae. See the discussion in this document at footnote one.

Bishops’ Conference of England and Wales Joint Committee on Bioethical Issues “The Morning After Pill” Briefing 86 January 31 1986 Vol 16 No. 3

cf. Benedict M Ashley and Kevin O'Rourke Health Care Ethics: A Theological Analysis The Catholic Health Care Association of the United States 1982 p. 281–2

Congregation for the Doctrine of the Faith Donum Vitae Part III, 1987

1994 MIMS Annual, MIMS Australia 1994, p. 835

World Health Organiztion, Task Force on Methods for the Determination of the Fertile Period, Special Programme of Research, Development and Research Training in Human Reproduction, ‘A prospective Multi-centre Trial of the Ovulation Method of Natural Family Planning. 1. The Teaching Phase’ Fertility and Sterility, 36, 152, 1981