The recent saga of cardiovascular disease and safety of oral contraceptives

Human Reproduction Update

Volumn 5, Issue 6, 1999, Pages 565-620

  Edwards, R G ^a   Cohen, Jean ^b  

^a Editorial Office   (United Kingdom)

^b Clinique Marignan   (France)

Author keywords

Cardiovascular disease; Epidemiology; Oral contraception; Pill scare; Safety

Indexed keywords

ORAL CONTRACEPTIVE AGENT;

CARDIOVASCULAR DISEASE; DRUG SAFETY; ORAL CONTRACEPTION; PRIORITY JOURNAL; REVIEW; SIDE EFFECT;

EID: 0033374723     PISSN: 13554786     EISSN: None     Source Type: Journal    
DOI: 10.1093/humupd/5.6.565     Document Type: Review

References (150)

1. Administrative Court of Berlin 1997, decision. December 18, 1997. Administrative Court, Berlin, Germany
2. Badimon, L. and Bayés-Genis, A. (1999) Effects of progestogens on thrombosis and arteriosclerosis. Hum. Reprod. Update, 5, 191-199.
3. Bardin, C.W. and Sivin, I. (1989) Lessons learnt from clinical trials. In Michal, F. (ed.), Safety Requirements for Oral Steroids. Cambridge University Press, Cambridge, pp. 400-413.
4. Beard, J. (1898) The rhythm of reproduction in mammalian species. Anat. Anz., 14, 97.
5. Benagiano, G. (1998) Learning from the past, venous thromboembolism and the pill: an endless saga. Hum. Reprod., 13, 1115.
6. Bhathena, R.K. (1998) The 1995 pill scare and its aftermath: lessons learnt. J. Obstet. Gynaecol., 18, 215-217.
7. Bishop, A. and Oldershaw, P. (1996) Thromboembolism in primary pulmonary hypertension. Br. Med. J., 313, 1418.
8. Bloemenkamp, K.W.M., Rosendaal, F.R., Helmerhorst, F.M. et al. (1995) Enhancement by factor V Leiden mutation of risk of deep vein thrombosis associated with oral contraceptives containing a third-generation progestagen. Lancet, 346, 1593-1596.
9. Bottiger, I.E., Borman, G., Eklund, G. and Westerholme, B. (1980) Oral contraceptives and thromboembolic disease: effects of lowering oestrogen content. Lancet, i, 1097-1101.
10. Bradford Hill, A.B. (1965) The environment and disease: association or causation? Proc. R. Soc. Med., 58, 295-300.
11. Cano, A (1999) Progestins and coronary heart disease. An introduction. Hum. Reprod. Update, 5, 189-190.
12. Child, T.J. (1996) Terminations of pregnancy, not unplanned deliveries, increased as a result of the pill scare. Br. Med. J., 313, 1005.
13. Cohen, J. (1996) Epidemiological disasters. Hum. Reprod., 11, 689.
14. Cohen, J. (1998) Recommendations on the safety of oral contraceptives are too important for the regulating authorities alone. Hum. Reprod., 13, 116.
15. Cohen, J. and Edwards, R.G. (1999) Conclusions: the relative safety of modern oral contraceptives. Hum. Reprod. Update, 5, 756-771.
16. Collins, J.A. (1997) Guides for practitioners: meta-analysis. Clinical research evidence and clinical practice. Hum. Reprod., 12, 1847-1850.
17. Committee on Safety of Medicines (1995) Combined Oral Contraceptives and Thromboembolism. London.
18. Cramer, D.W. (1996) Safety of combined oral contraceptive pills. Lancet, 347, 546-547.
19. Crook, D. and Godsland, I. (1998) Safety evaluation of modern oral contraceptives: Effects on lipoprotein and carbohydrate metabolism. Contraception, 57, 189-201.
20. Crosignani, P.G. and La Vecchia, C (1999) Condordant and discordant effects on cardiovascular risks exerted by oestrogen and progestogen in women using oral contraception and hormone replacement therapy. Hum. Reprod. Update, 5, 681-687.
21. Diczfalusy, E. (1989) The history of oral contraception: what is past and what is present? In Safety Requirements for Contraceptive Steroids, pp. 21-37. Cambridge University Press, Cambridge.
22. Edwards, R.G., Beard, H.K. and Bradshawe, J.P. (1997) Balancing risks and benefits of oral contraception. Hum. Reprod., 12, 2339-2440.
23. Ehrenstein, M. (1944) Investigations on steroids. J. Org. Chem., 9, 435.
24. ESHRE Capri Workshop (1998) Hormones and cardiovascular diseases: oral contraceptives and hormone replacement therapy: differential effects on coronary heart disease, deep vein thrombosis and stroke. Hum. Reprod., 13, 2325-2333.
25. Farley, T.M.M., Meirik, O., Poulter, N.R. et al. (1996) Oral contraceptives and thrombotic disease: impact of new epidemiological studies. Contraception, 54, 193-195.
26. Farley, T.M.M., Collins, J. and Schlesselman, J.J. (1998a) Hormonal contraception and risk of cardiovascular disease: An international perspective. Contraception, 57, 211-230.
27. Farley, T.M.M., Meirik, O., Marmot, M.G. et al. (1998b) Oral contraceptives and risk of venous thromboembolism: Impact of duration of use. Contraception, 57, 61-65.
28. Farley, T.M.M., Meirik, O., Chang, C. et al. (1998c) Combined oral contraceptives, smoking, and cardiovascular risk. J. Epidemiol. Community Health, 52, 775-785.
29. Farmer, R.D.T. (1996) Safety of modern oral contraceptives. Lancet, 347, 259.
30. Farmer, R. and Preston, T. (1995) The risk of venous thromboembolism associated with low oestrogen dose oral contraceptives. J. Obstet. Gynecol., 15, 195-200.
31. Farmer, R.D.T. and Lawrensen, R.A. (1997) Third generation oral contraception and venous thromboembolism. Lancet, 349, 732-733.
32. Farmer, R.D.T., Lawrensen, R.A. and Hambleton, I.R. (1996) Oral contraceptive switching patterns in the U.K.: an important potential confounding variable in studies of venous thromboembolism. Eur. J. Contracept. Public Health Care, 1, 31-37.
33. Farmer, R.D.T., Lawrensen, R.A., Thompson, J.G. and Hambleton, I.R. (1997a) Population-based study of risk of venous thromboembolism associated with various oral contraceptives. Lancet, 349, 83-88.
34. Farmer, R.D.T., Newson, R.B., MacRae, K. et al. (1997b) Mortality from venous thromboembolism among young women in Europe: no evidence for any effect of third generation oral contraceptives. J. Epidemiol. Comm. Health, 51, 630-635.
35. Farmer, R.D.T., Todd, J.-C., Lewis, M.A. et al. (1998) The risks of venous thromboembolic disease among German women using oral contraceptives: A database study. Contraception, 57, 67-70.
36. Fotherby, K. (1998) Metabolic interrelationships, cardiovascular disease and sex steroids. Contraception, 57, 183-187.
37. Furedi, F. and Furedi, A. (1996) The international impact of a pill panic in the UK. Birth Control Trust, 16 Mortimer Street, London W1N 7RD.
38. Furedi, A, and Paintin, D. (1998) Conception and termination after the 1995 warning about oral contraceptives. Lancet, 352, 323-324.
39. Garcia, C.R., Goldzieher, J.W. and Massey, J.B. (1975) Oral contraceptives. In Hafez, E.S.E. and Evans, T.N. (eds), Human Reproduction, Chapter 15. Harper and Row, Hagerstown, MD.
40. Guillebaud, J. (1995a) Advising women which pill to take. Br. Med. J., 311, 1111.
41. Guillebaud, J. (1995b) If a woman has not had a thrombotic event in years of use she is unlikely to have one now. Br. Med. J., 311, 1638-1639.
42. Guillebaud, J. (1997a) The Pill. Oxford University Press, Oxford.
43. Guillebaud, J. (1997b) Combined oral contraceptives. In Contraception Today. Martin Dunitz, London, p. 18.
44. Hagemann, U. (1998) Role of reguatory authorities and safety of the pill. Hum. Reprod., 13, 2660-2661.
45. Hannaford, P. (1998) The collection and interpretation of epidemiological data about the cardiovascular risks associated with the use of steroid contraceptives. Contraception, 57, 137-142.
46. Hannaford, P.C., Croft, P.R. and Kat, C.R. (1994) Oral contraception and stroke. Evidence from the Royal College of General Practitioners Oral Contraception Study. Stroke, 25, 935-942.
47. Heinemann, L.A.J., Lewis, M.A., Affmann, A. et al. (1996) Could preferential prescribing and referral behaviour of physicians explain the elevated thrombosis risk found to be associated with third generation oral contraceptives. Pharmacoepidiol. Drug Safety, 5, 285-294.
48. Heinemann, L.A.J., Lewis, M.A., Thorogood, M. et al. (1997) Oral contraceptives and risk of thromboembolic stroke: results for the Transnational Study on Oral Contraceptives and Health of Young Women. Br. Med. J., 315, 1502-1503.
49. Heinemann, L.A.J., Lewis, M.A., Spitzer, W.O. et al. (1998) Thromboembolic stroke in young women. A European case-control study on oral contraception. Contraception, 57, 29-37.
50. Helmerhorst, F.M., Rosendaal, F.R. and Vandenbroucke, J.P. (1998) The WHO Technical Report on cardiovascular disease and steroid hormone contraception: state-of-the-art. Hum. Reprod., 13, 2981-2983.
51. Jamin, C. and de Mouzon, J. (1996) Selective prescribing of third generation oal contraceptives. Contraception, 54, 55-56.
52. Jick, H., Jick, S.S., Gurewich, V. et al. (1995) Risk of idiopathic cardiovascular death and nonfatal venous thromboembolism in women using oral contraceptives with differing progestagen components, Lancet, 346, 1589-1593.
53. Jick, H., Jick, S.S., Myers, W. and Vasilakis, C. (1996) Risk of myocardial infarction and low dose combined oral contraceptives. Lancet, 347, 627.
54. Jick, H., Jick, S.S., Myers, M.W. and Vasilakis, C. (1997) Third generation oral contraception and venous thromboebolism. Lancet, 349, 731-732.
55. Jick, H., Garcia Rodriguez, A.A. and Pérez-Gutthann, S. (1998a) Principles of epidemiological research on adverse and beneficial drug effects. Lancet, 352, 1767-1770.
56. Jick, S.S., Vasilakis, C. and Jick, H. (1998b) Pregnancies and terminations after 1995 warning about third-generation oral contraceptives. Lancet, 351, 1404-1405.
57. Jordan, W.M. (1961) Pulmonary embolism. Lancet, ii, 1146-1147.
58. Jung-Hoffmann, C. and Kuhl, H. (1989) Interaction with the pharmacokinetics of ethinylestradiol and progestagens contained in oral contraceptives. Contraception, 40, 299-312.
59. Kaper, R.F. (1996) Differences in venous thromboembolism risk are related to causes other than product characteristics. Hum. Reprod., 11, 690-691.
60. Leader, A. (1996) The public warnings on cardiovascular disease and third-generation oral contraceptives were not justified. Hum. Reprod., 11, 693.
61. Leader, A. (1998) Incomplete compensation following the ban on third generation oral contraceptives. Hum. Reprod., 13, 1118.
62. Lewis, M.A. and Heinemann, L.J. (1997) Oral contraception and venous thromboembolism. Lancet, 349, 1621-1622.
63. Lewis, M.A. and Spitzer, W.O. (1997) The role of bias in observational studies on oral contraceptives. Contraception, 55, 192-194.
64. Lewis, M.A., Heinemann, L.A.J., MacRae, K.D. et al. (1996a) The increased risk of venous thromboembolism and the use of third generation progestagens: role of bias in observational research. Contraception, 54, 5-13.
65. Lewis, M.A., Spitzer, W.O., Heinemann, L.A.J. et al. (1996b) Third generation oral contraceptives and risk of myocardial infarction: an international case-control study. Br. Med. J., 312, 89-90.
66. Lewis, M.A., Spitzer, W.O. and Macrae, K.D. (1996c) Third generation oral contraceptives. Br. Med. J., 312, 577-578.
67. Lewis, M.A., Heinemann, L.A.J., Spitzer, W.O. et al. (1997a) The use of oral contraceptives and the occurrence of myocardial infarction in young women: results for the Transnational Study on oral contraceptives and the health of young women. Contraception, 56, 129-140.
68. Lewis, M.A., Spitzer, W.O., Heinemann, L.A.J. et al. (1997b) Lowered risk of dying of heart attack with third generation pill may offset risk of dying of thromboembolism. Br. Med. J., 330, 679-680.
69. Lidegaard, O. (1993) Oral contraceptives and risk of cerebral thromboembolic attack: results of a case-control study. Br. Med. J., 306, 956-963.
70. Lidegaard, O. (1997) The influence of thrombotic risk factors when oral contraceptives are prescribed. Acta Obstet. Gynecol. Scand., 76, 252-260.
71. Lidegaard, O. and Milsom, I. (1996a) Oral contraceptives and thrombotic disease: impact of new epidemiological studies. Contraception, 53, 135-139.
72. Lidegaard, O. and Milsom, I. (1996b) Oral contraceptives and thrombotic disease: impact of new epidemiological studies. Response to the Editor. Contraception, 54, 195-198.
73. Lidegaard, O., Edstrom, B. and Kreiner, S. (1998a) Oral contraceptives and venous thromboembolism. A case control study. Contraception, 57, 291-301.
74. Lidegaard, O., Edstrom, B. and Kreiner, S. (1998b) Oral contraceptives and venous thromboembolism. Contraception, 58, 199-200.
75. Lidegaard, O. and Milsom, I. (1997) Oral contraception and venous thromboembolism. Lancet, 349, 1621.
76. Lorenz, I.T. (1962) Parietal lesion and Enovid. Br. Med. J., 2, 119.
77. Lowe, G.D.O., Rumley, A., Woodward, M. and Reid, E. (1997) Oral contraceptives and venous thromboembolism. Lancet, 349, 1623.
78. McGuire, A. and Hughes, D. (1995) The economics of family planning services: a report prepared by the Contraceptive Alliance. Family Planning Association, London.
79. McPherson, K. (1996) Third generation oral contraception and venous thromboembolism. Br. Med. J., 312, 68-69.
80. Mann, J.I., Vessey, M.P., Thorogood, M. and Doll, R. (1975) Myocardial infarction in young women with special reference to oral contraceptive practice. Br. Med. J., 2, 241-245.
81. Mann, J.I. and Inman, W.H.W. (1975) Oral contraceptives and death from myocardial infarction. Br. Med. J., 2, 245-248.
82. Meirik, O. (1998) Cardiovascular safety and combined oral contraceptives. Contraception, 57, 135-136.
83. Michaels, M.A. and Norpoth, T. (1996) Health policy and third-generation oral contraceptives. Hum. Reprod., 11, 691-692.
84. Mills, A. (1997) Combined oral contraception and the risk of venous thromboembolism. Hum. Reprod., 12, 2595-2598.
85. Mills, A. (1999) Avoiding problems in clinical practice after the pill scare. Hum. Reprod. Update, 5, 639-653.
86. Office for National Statistics (1997) Legal abortions, June quarter 1996. Office for National Statistics, London.
87. Pettiti, D.B., Sidney, S. and Queensbury, C.P. (1998) Oral contraceptive use and myocardial infarction. Contraception, 57, 143-155.
88. Pincus, G. (1965) The Control of Fertility. Academic Press, New York.
89. Plu-Bureau, G., Amirat, J., Guize, L. and Scarabin, P.Y. (1996) Safety of combined oral contraceptive pills. Lancet, 347, 549.
90. Poulter, N.R., Chang, C.L., Farley, T.M.M. and Marmot, M.G. (1995) World Health Organisation Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. A multinational case-control study of cardiovascular disease and steroid hormone contraceptives. Description and validation of methods. J. Clin. Epidemiol., 48, 1513-1547.
91. Poulter, N.R., Farley, T.M.M., Chang, C.L. et al. (1996) Safety of modern oral contraceptive pills. Lancet, 347, 547.
92. Poulter, N.R., Chang, C.L., Marmot, M. et al. (1997) Third generation oral contraceptives and venous thrombosis. Lancet, 349, 732.
93. Rawlins, M. (1995) Combined oral contraceptives and thromboembolism. Br. Med. J., 311, 1232.
94. Rawlins, M. (1998) Learning from the past: a response from the Committee on the Safety of Medicines. Hum. Reprod., 13, 1781-1782.
95. Rekers, H., Norpoth, T. and Michaels, M.A. (1996) Oral contraceptive use and venous thromboembolism: a consideration of the impact of bias and confounding factors on epidemiological studies. Eur. J. Contracept. Reprod. Health Care, 1, 21-30.
96. Rice, C., Killick, S., Hickling, D. and Coelingh Benninck, H. (1996) Ovarian activity and vaginal bleeding patterns with a desogestrel-only preparation at three different doses. Hum. Reprod., 11, 737-740.
97. Rosenberg, L., Kaufman, D.W., Helmrich, S.P. et al. (1985) Myocardial infarction and cigarette smoking in women younger than 50 years of age. J. Am. Med. Assoc., 253, 2965-2969.
98. Rosenberg, L., Begaud, B., Bergman, U. et al. (1996) Are third-generation oral contraceptives safe? Hum. Reprod., 11, 687-688.
99. Rosing, J., Hemker, H.C. and Tans, G. (1997a) Oral contraceptives and venous thromboembolism: acquired APC resistance. Br. J. Hematol., 98, 491-492.
100. Rosing, J., Tans, G., Nicolaides, G.A.F. et al. (1997b) Oral contraceptives and venous thrombosis: different sensitivities to activated protein C in women using second and third generation oral contraceptives. Br. J. Haematol., 97, 233-238.
101. Rouse, A. (1995) Risk of delay was small. Br. Med. J., 311, 1228.
102. Royal College of General Practitioners (1978) Oral Contraceptives and Health. Pitman Medical, London.
103. Sarrel, P.M. (1999) The differential effects of oestrogens and progestins on the vascular tone. Hum. Reprod. Update, 5, 205-209.
104. Sartwell, P.E., Masi, A.T., Arthes, F.G. et al. (1969) Thromboembolism and oral contraceptives: an epidemiological case-control study. Am. J. Epidemiol., 90, 365-380.
105. Schramm, W. and Heinemann, L.A.J. (1997) Oral contraceptives and venous thromboembolism: acquired APC resistance. Br. J. Hematol., 98, 491.
106. Sidney, S., Pettiti, D.B., Queensferry, C.P. Jr. et al. (1996) Myocardial infarction in users of low-dose oral contraceptives. Obstet. Gynecol., 88, 939-944.
107. Simpson, A. and Elstein, J.-L. (1996) The safety or oral contraceptives. Lancet, 347, 257.
108. Skegg, D.C.G. (1989) The epidemiological assessment of the safety of hormonal contraceptives: a methodological review. In Safety Requirements for Contraceptive Steroids, pp. 21-37. Cambridge University Press, Cambridge.
109. Slone, D., Shapiro, S., Kaufman, D.W. et al. (1981) Risk of myocardial infarction in relation to current and discontinued use of oral contraceptives. New Engl. J. Med., 305, 420-424.
110. Speroff, L. (1999) A clinician's response to the oral contraceptive thrombosis controversy. Hum. Reprod. Update, 5, 654-663.
111. Speroff, L., De Cherney, A. and the Advisory Board for the New Progestins (1993) Evaluation of a new generation of oral contraceptives. Obstet. Gynecol., 81, 1034-1047.
112. Spitzer, W.O. (1995) Data from transnational study of oral contraception have been misused. Br. Med. J., 311, 1162.
113. Spitzer, W.O. (1996) The future of oral contraceptives: research priorities. Hum. Reprod., 11, 688-689.
114. Spitzer, W.O. (1997) The pill scare revisited: anatomy of a non-epidemic. Hum. Reprod., 12, 2347-2357.
115. Spitzer, W.O. (1998) Thromboembolism and the pill: the saga must end. Hum. Reprod., 13, 1117.
116. Spitzer, W.O., Lewis, M.A., Lothar, A.J. et al. (1996) on behalf of the Transnational Research Group (1996) Third generation oral contraceptives and risk of venous thromboembolic disorders: an international case-control study. Br. Med. J., 312, 83-88.
117. Stolley, P.D., Tonascia, J.A., Tockman, M.S. et al. (1975) Thrombosis with low-estrogen oral contraceptives. Am. J. Epidemiol., 102, 197-208.
118. Suissa, S. and Spitzer, W.O. (1998) Methodological limitations in comparing the risks of newer oral contraceptives. Contraception, 57, 64-65.
119. Suissa, S., Blais, L., Spitzer, W.O. et al. (1997) First-time use of newer oral contraceptives and the risk of venous thromboembolism. Contraception, 56, 141-146.
120. Szarewski, A and Mansour, D. (1999) The 'pill scare': the responses of authorities, doctors and patients using oral contraception. Hum. Reprod. Update, 5, 627-632.
121. Szarewski, A., Hollingworth, B., Mansour, D. et al. (1997) Oral contraception and venous thromboembolism. Lancet, 349, 1622.
122. Thorogood, M. (1998) Stroke and steroid hormonal contraception. Contraception, 57, 157-167.
123. Thorogood, M., Man, J., Murphy, M. and Vessey, M. et al. (1992a) Fatal stroke and use of oral contraceptives: findings from a case-control study. Am. J. Epidemiol., 136, 35-45.
124. Thorogood, M., Mann, J., Murphy, M. and Vessey, M. (1992b) Risk factors for fatal venous thromboembolism in young women: a case-control study. Int. J. Epidemiol., 21, 48-52.
125. Vandenbroucke, J.P. and Rosendaal, F.R. (1997a) End of line for 'third generation pill' controversy. Lancet, 349, 1113-1114.
126. Vandenbroucke, J.P. and Rosendaal, F.R (1997b) Oral contraceptives and venous thromboembolism. Lancet, 349, 1622-1623.
127. Vandenbroucke, J.P., Koster, T., Briar, E. et al. (1994) Increased risk of venous thrombosis in oral contraception users who are carriers for factor V Leiden mutation. Lancet, 344, 1453-1457.
128. Vandenbroucke, J.P., Bloemenkamp, K.W.M., Helmerhorst, F.M. et al. (1996) Safety of combined oral contraceptive pills. Lancet, 347, 547-548.
129. Vandenbroucke, J.P., Bloemenkamp, K.W.M., Helmerhorst, F.M., Rosendaal, F.R. (1997a) Risk of oral contraceptives and recency of market introduction. Contraception, 35, 191-192.
130. Vandenbroucke, J.P., Helmerhorst, F.M., Bloemenkamp, K.W.M. and Rosendaal, F.R. (1997b) Third generation oral contraception and venous thromboembolism. Lancet, 349, 731.
131. Vessey, M.P. (1969) Lessons learnt from epidemiology. In Mical, F. (ed.), Safety Requirements for Contraceptive Steroids. Cambridge University Press, Cambridge, pp. 148-156.
132. Vessey, M.P. and Doll, R. (1968) Investigation of relation between between use of oral contraceptives and thromboembolic disease. Br. Med. J., 2, 199-205.
133. Vessey, M.P. and Doll, R. (1969) Investigation of relation between use of oral contraceptives and thromboembolic disease. A further report. Br. Med. J., 2, 651-657.
134. Vessey, M.P. and Lawless, M. (1984) The Oxford Family Planning Association contraceptive study. Clin. Obstet. Gynaecol., 11, 743-757.
135. Walker, A.M. (1998a) Newer oral contraceptives and the risk of venous thromboembolism. Contraception, 57, 169-181.
136. Walker, A.M. (1998b) Oral contraceptives and venous thromboembolism: Response to Editor. Contraception, 58, 200.
137. Walters, D.E. (1996) Risk of third generation oral contraceptives. Hum. Reprod., 11, 2565-2566.
138. Walters, D.E. (1998) IFFS meeting on Safety of Oral Contraception, Gothenburg.
139. Watson, C. (1995) Scare over oral contraceptives. Doctors should take warning seriously. Br. Med. J., 311, 1638.
140. Watt, A.H. (1995) Regulatory consideration of issues concerning drug safety in U.K. fall short of acceptable standards. Br. Med. J., 311, 1640.
141. Weiss, N.S. (1997) Bias in studies of venous thromboembolism in relation to the use of new formulations of oral contraceptives. Contraception, 35, 189-190.
142. Westoff, C.L. (1996) Oral contraceptives and venous thromboembolism: should epidemiological associations drive clinical decision making? Contraception, 54, 1-3.
143. Winkler, U.H. (1998) Blood coagulation and oral contraceptives: a critical review. Contraception, 57, 203-209.
144. Winkler, U.H. (1999) Effects of progestins on cardiovascular diseases: the haemostatic system. Hum. Reprod. Update, 5, 200-204.
145. World Health Organization (1995a) WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Venous thromboembolic disease and combined oral contraceptives: results of international muticentre case-control study. Lancet, 346, 1575-1582.
146. World Health Organization (1995b) WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Effect of different progestagens in low oestrogen oral contraceptives on venous thromboembolic disease. Lancet, 346, 1582-1588.
147. World Health Organization (1996a) WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Ischaemc stroke and combined oral contraceptives: results of an international, multicentre, case-control study. Lancet, 348, 498-505.
148. World Health Organization (1996b) WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception, haemorrhagic stroke, overall stroke risk, and combined oral contraceptives: results of an international, multicentre, case-control study. Lancet, 348, 505-510.
149. World Health Organization (1997) WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Acute myocardial infarction and combined oral contraeptives: results of an international, multicentre, case-control study. Lancet, 349, 1202-1209.
150. World Health Organization (1998) Cardiovascular disease and steroid hormone contraception. WHO Technical Report Series, 877, 1-89. WHO, Geneva.