579 after
plasma infusion. The
nature
of this
inhibitory factor
remains iinknnwn-
M. DUPUY M. TARDIEU C. HÉRY
J.
I.N.S.E.R.M. U 56 and Hôpital d’Enfants, Université Paris-Sud, F-94270 Bicêtre, France
NATURAL FAMILY PLANNING
SIR Professor Marshall has reported a trial of a symptothermal method of natural family planning (Aug. 7, p. 282) and has used his analysis to attack the ovulation method. Unfortunately Professor Marshall does not follow the established technique of instruction in the ovulation method,’ nor has he reminded us of his inability to help more than 75% of women understand their cervical mucous pattern.2 He makes the assumption, based on an earlier study of the basal body temperature method,’that 17 "unplanned pregnancies" in this symptothermal trial resulted from an act of coitus in the preovulatory phase of the cycle, but the two groups were not closely matched either by age or by parity. In any case, the act of coitus responsible for pregnancy needs to be determined in the individual case, having reference to the peak symptom of the mucus4 and to the temperature record, keeping in mind also the information he published previously about his clients’-namely, that 88% of the husbands engaged in love-making during the fertile phase of the cycle when there should have been total abstinence, leading to a climax often (20%), sometimes (42%), and rarely (22%). His judgment would involve sperm survival for up to 12 days, in contradiction of the knowh facts regarding sperm survival time, which embrace much more than the penetrability or otherwise of a cervical plug. Professor Marshall also assumes that a combination of two methods will give better results than either method alone, and presumably that three methods are better than two, and so on. In fact, his assessment of this combination of methods has given worse results than the Ball trial of the ovulation method alone, which he supervised.6 In reporting his trial of the B.B.T. method,3 Professor Marshall did that method a disservice by not recording the length of usage of the method previously by those participating; he did not contradict the possibility that he was studying a group of lower than average fertility or with unusually reliable temperature records. Additionally, he reported an "unplanned pregnancy" rate of 66% for the post-ovulatory phase, but included 4.2% who broke the rules. Similarly he spoke of a 15% "unplanned pregnancy" rate in the Ball trial whereas the true failure-rate was 2.9%. He has a curious way of defining an "unplanned pregnancy", and uses the term in such a way that others may conclude that he means what they might mean as the true failure-rate. That Professor Marshall has consistently devalued natural family planning is evident also in his criticism of the results of the trial of the ovulation method in Tonga.’ His study of that report led him to the conclusion that there was an "unplanned pregnancy" rate of 25%. The true failure-rate in the Tongan trial was 1.4%. If he is disturbed by those persons who break the rules of the method, it is all the more important for him to emphasise the information of primary importance (i.e., the number of pregnancies which occur amongst those couples who follow the rules of the method exactly). Natural
Family Planning Centre, Family Life Centre, East Melbourne 3002, Australia
J. J. BILLINGS
SIR,-Professor Marshall’s field trial of what amounts to so called symptothermic rhythm is misleading. It has been put forward-and accepted as such in the lay Press1—as a trial of Billings’ ovulation method.2 I know of no ovulation method (O.M.) teaching centres in England, although there are at least 30 in Ireland. The Catholic Marriage Advisory Council (C.M.A.C.) has discouraged the teaching of o.M. until the efficacy of the method has been established to its satisfaction. Professor Marshall’s survey has done nothing to clarify the situation. The C.M.A.C. clings doggedly to the thermometer, at best a dubious aid and highly suspect when used alone as an indicator of ovulation. Moghissi3 has shown that 20% of normally ovulating women, as demonstrated by hormonal profile, have monophasic B.B.T. graphs. If a woman is properly to identify her cervical mucus symptom she needs to be freed from, the distraction of the thermometer. Again, it seems incredible to an Australian that a country as compact as the U.K. finds it necessary to conduct a natural family planning service by correspondence, presided over by doctors. It is an even greater mystery that this practice persists when it has been shown repeatedly that a very adequate service can be provided by women in countries of widely differing cultures such as New Guinea, Korea, Guatemala, and the U.S.A.4 The existence of so many centres in Ireland linked under the Ovulation Method Advisory Service, operating to the satisfaction of clients all over that country and parallel to the C.M.A.C. service, is an indication of what can be achieved by intelligent women enjoying minimal professional support. A proper evaluation of o.M. is still needed. It is doubtful whether the C.M.A.C. can ever meet that need without a radical restructuring of its present commitments. 38
Judge Street, Randwick, New South Wales 2031, KEVIN HUME
Australia
PULMONARY ŒDEMA
SIR,—Iread with interest your editorial on pulmonary cedema (Aug. 14, p. 350). I should like to add that the singular effectiveness of intermittent positive-pressure respiration (I.P.P.R.) in preventing and treating pulmonary oedema of cardiac origin may help in explaining the mechanism of its occurrence at high altitude. It is likely that I.P.P.R. suppresses pulmonary oedema in more than one way. The increased respiratory pressure directly opposes fluid leakage at alveolar/terminal-bronchiolar level; and rhythmic compression of the interstitial tissue and lymphatic channels of the lungs conceivably expedites the passage of lymph. But possibly the main mode of action of I.P.P.R. is to raise mean intrathoracic pressure and thereby to shift a significant amount of blood from the pulmonary to the systemic reservoirs: as a result, hydrostatic pressure in the lung capillaries is reduced and leakage through stretched intercellular capillary pores’ is stopped. If pulmonary oedema can be suppressed by raising intrathoracic pressure, might it not be promoted by reduced intrathoracic pressure? Perhaps, as barometric pressure falls, blood is attracted to the atmospherically vulnerable pulmonary bed, leading directly to capillary congestion, overdistension, and
leakage. 1. Billings, E. L., Billings, J. J., Catarinich,
M. Atlas of the Ovulation Method.
Melbourne, 1976. 2. Marshall J. J. biosoc. Sci. 1975, 7, 49. 3. Marshall, J. Lancet, 1968, ii, 8. 4. Billings, E. L., Billings, J. J., Brown, J. B., Burger, H. G. ibid. 1972, i, 282. 5. Marshall, J., Rowe, B. in Proceedings of the Research Conference on Natural Family Planning; p. 213. Human Life Foundation, 1973. 6. Ball. M. Eur. J. Obstet. Gynœc. reprod. Biol. 1976, 6, 63. 7. Weissman, C., Foliaki, L., Billings, E. L., Billings, J. J. Lancet, 1972, ii, 813.
Northern Regional Cardiothoracic Seaham Hall Hospital, Seaham, Co. Durham SR7 7AQ
Surgical Service, H. E. BELL
1. Irish Times, Aug. 13, 1976. 2. Billings, E. L., Billings, J. J. Aust. Family Physn, 1973, 2, no. 2. 3. Moghissi, K. S. Fertil. Steril. (in the press). 4. Second International Institute of the Ovulation Method, Los Angeles, 1976. 5. Robin, E. D., Cross, C. E., Zelis, R. New Engl.J. Med. 1973, 288, 292.
plasma infusion. The
nature
of this
inhibitory factor
remains iinknnwn-
M. DUPUY M. TARDIEU C. HÉRY
J.
I.N.S.E.R.M. U 56 and Hôpital d’Enfants, Université Paris-Sud, F-94270 Bicêtre, France
NATURAL FAMILY PLANNING
SIR Professor Marshall has reported a trial of a symptothermal method of natural family planning (Aug. 7, p. 282) and has used his analysis to attack the ovulation method. Unfortunately Professor Marshall does not follow the established technique of instruction in the ovulation method,’ nor has he reminded us of his inability to help more than 75% of women understand their cervical mucous pattern.2 He makes the assumption, based on an earlier study of the basal body temperature method,’that 17 "unplanned pregnancies" in this symptothermal trial resulted from an act of coitus in the preovulatory phase of the cycle, but the two groups were not closely matched either by age or by parity. In any case, the act of coitus responsible for pregnancy needs to be determined in the individual case, having reference to the peak symptom of the mucus4 and to the temperature record, keeping in mind also the information he published previously about his clients’-namely, that 88% of the husbands engaged in love-making during the fertile phase of the cycle when there should have been total abstinence, leading to a climax often (20%), sometimes (42%), and rarely (22%). His judgment would involve sperm survival for up to 12 days, in contradiction of the knowh facts regarding sperm survival time, which embrace much more than the penetrability or otherwise of a cervical plug. Professor Marshall also assumes that a combination of two methods will give better results than either method alone, and presumably that three methods are better than two, and so on. In fact, his assessment of this combination of methods has given worse results than the Ball trial of the ovulation method alone, which he supervised.6 In reporting his trial of the B.B.T. method,3 Professor Marshall did that method a disservice by not recording the length of usage of the method previously by those participating; he did not contradict the possibility that he was studying a group of lower than average fertility or with unusually reliable temperature records. Additionally, he reported an "unplanned pregnancy" rate of 66% for the post-ovulatory phase, but included 4.2% who broke the rules. Similarly he spoke of a 15% "unplanned pregnancy" rate in the Ball trial whereas the true failure-rate was 2.9%. He has a curious way of defining an "unplanned pregnancy", and uses the term in such a way that others may conclude that he means what they might mean as the true failure-rate. That Professor Marshall has consistently devalued natural family planning is evident also in his criticism of the results of the trial of the ovulation method in Tonga.’ His study of that report led him to the conclusion that there was an "unplanned pregnancy" rate of 25%. The true failure-rate in the Tongan trial was 1.4%. If he is disturbed by those persons who break the rules of the method, it is all the more important for him to emphasise the information of primary importance (i.e., the number of pregnancies which occur amongst those couples who follow the rules of the method exactly). Natural
Family Planning Centre, Family Life Centre, East Melbourne 3002, Australia
J. J. BILLINGS
SIR,-Professor Marshall’s field trial of what amounts to so called symptothermic rhythm is misleading. It has been put forward-and accepted as such in the lay Press1—as a trial of Billings’ ovulation method.2 I know of no ovulation method (O.M.) teaching centres in England, although there are at least 30 in Ireland. The Catholic Marriage Advisory Council (C.M.A.C.) has discouraged the teaching of o.M. until the efficacy of the method has been established to its satisfaction. Professor Marshall’s survey has done nothing to clarify the situation. The C.M.A.C. clings doggedly to the thermometer, at best a dubious aid and highly suspect when used alone as an indicator of ovulation. Moghissi3 has shown that 20% of normally ovulating women, as demonstrated by hormonal profile, have monophasic B.B.T. graphs. If a woman is properly to identify her cervical mucus symptom she needs to be freed from, the distraction of the thermometer. Again, it seems incredible to an Australian that a country as compact as the U.K. finds it necessary to conduct a natural family planning service by correspondence, presided over by doctors. It is an even greater mystery that this practice persists when it has been shown repeatedly that a very adequate service can be provided by women in countries of widely differing cultures such as New Guinea, Korea, Guatemala, and the U.S.A.4 The existence of so many centres in Ireland linked under the Ovulation Method Advisory Service, operating to the satisfaction of clients all over that country and parallel to the C.M.A.C. service, is an indication of what can be achieved by intelligent women enjoying minimal professional support. A proper evaluation of o.M. is still needed. It is doubtful whether the C.M.A.C. can ever meet that need without a radical restructuring of its present commitments. 38
Judge Street, Randwick, New South Wales 2031, KEVIN HUME
Australia
PULMONARY ŒDEMA
SIR,—Iread with interest your editorial on pulmonary cedema (Aug. 14, p. 350). I should like to add that the singular effectiveness of intermittent positive-pressure respiration (I.P.P.R.) in preventing and treating pulmonary oedema of cardiac origin may help in explaining the mechanism of its occurrence at high altitude. It is likely that I.P.P.R. suppresses pulmonary oedema in more than one way. The increased respiratory pressure directly opposes fluid leakage at alveolar/terminal-bronchiolar level; and rhythmic compression of the interstitial tissue and lymphatic channels of the lungs conceivably expedites the passage of lymph. But possibly the main mode of action of I.P.P.R. is to raise mean intrathoracic pressure and thereby to shift a significant amount of blood from the pulmonary to the systemic reservoirs: as a result, hydrostatic pressure in the lung capillaries is reduced and leakage through stretched intercellular capillary pores’ is stopped. If pulmonary oedema can be suppressed by raising intrathoracic pressure, might it not be promoted by reduced intrathoracic pressure? Perhaps, as barometric pressure falls, blood is attracted to the atmospherically vulnerable pulmonary bed, leading directly to capillary congestion, overdistension, and
leakage. 1. Billings, E. L., Billings, J. J., Catarinich,
M. Atlas of the Ovulation Method.
Melbourne, 1976. 2. Marshall J. J. biosoc. Sci. 1975, 7, 49. 3. Marshall, J. Lancet, 1968, ii, 8. 4. Billings, E. L., Billings, J. J., Brown, J. B., Burger, H. G. ibid. 1972, i, 282. 5. Marshall, J., Rowe, B. in Proceedings of the Research Conference on Natural Family Planning; p. 213. Human Life Foundation, 1973. 6. Ball. M. Eur. J. Obstet. Gynœc. reprod. Biol. 1976, 6, 63. 7. Weissman, C., Foliaki, L., Billings, E. L., Billings, J. J. Lancet, 1972, ii, 813.
Northern Regional Cardiothoracic Seaham Hall Hospital, Seaham, Co. Durham SR7 7AQ
Surgical Service, H. E. BELL
1. Irish Times, Aug. 13, 1976. 2. Billings, E. L., Billings, J. J. Aust. Family Physn, 1973, 2, no. 2. 3. Moghissi, K. S. Fertil. Steril. (in the press). 4. Second International Institute of the Ovulation Method, Los Angeles, 1976. 5. Robin, E. D., Cross, C. E., Zelis, R. New Engl.J. Med. 1973, 288, 292.
