600
VIEWPOINT Can
we
abandon
A pregnant woman may become anxious if she has not delivered by the date given to her by her physician. Much anxiety would be alleviated if a range of dates (38-42 weeks) was substituted for a specific date of delivery.1
Naegele’s rule?
opinion on this subject it is better to mention some time beyond that which we really suppose or on the whole it would perhaps be better that labour should always come on unexpectedly". 200 years later this dilemma is just as evident. A given necessary to
give
EDD leads
most women to
an
believe that the date is an of some considerable prediction importance. It can be extremely difficult to allay the anxiety of a pregnant woman and her relatives if she remains undelivered 281 days or more after the date of her last menstrual period. accurate
Introduction "I cannot imagine why gestation should be the only process connected with reproduction for which a total exemption from 1 any variation in its period should be claimed".
The duration of human pregnancy is a matter of considerable social and scientific importance. Both ancient Hindu and Roman cultures recognised that the average duration of pregnancy was about 9 months but allowed some latitude, especially with respect to prolonged gestation. In more modem times the legal process has been called upon to settle questions of legitimacy and inheritance in relation to the maximum possible duration of human pregnancy. For example, during the Gardner peerage trial (House of Lords, 1816), five eminent physicians testified that under no circumstances could the duration of pregnancy exceed 40 weeks’ gestation, whereas five of their colleagues presented the opposite view. The laws of some countries have defmed an upper limit of gestation consistent with legitimate birth after the death or departure of a husband, whereas English law does not set a precise limit. In judicial practice, it is usual to accept the most recently agreed ruling and to inquire whether to go beyond it is reasonable.2 The aim of the law is peace rather than justice; therefore, the scientific validity of such judgments is questionable.
Naegele’s rule Although most so-called prolonged pregnancies are due delayed ovulationin clinical practice the time of ovulation is rarely known with certainty. Assessment of gestational age is helped by antenatal ultrasonography, but for most women an estimated date of delivery (EDD) is calculated according to Naegele’s rule-ie, add 7 days and 9 months to the date of the last menstrual period. This formula, generally credited to Franz Carl Naegele (17781851), was proposed by Hermann Boerhaave, professor of medicine and botany at the University of Leyden (1709), and was merely quoted by Naegele.4 Furthermore, the original latin text is ambiguous with respect to whether the calculation should be based on the first or last day of menstruation. Many women (if not most) deliver after their EDD calculated by Naegele’s rille.5 In 1782, Thomas Denman6 noted "some inconveniences are produced by attempts to make exact reckonings for pregnant women: for when the time fixed for their delivery is past the mistake creates much solicitude and impatience. When therefore it is to
Proportion of patients undelivered by EDD maternal height.
in relation to
Data derived from more than 23 000 consecut!ve pregnancies which onset of labour occurred spontaneously.
in
Furthermore, it is likely that decisions about induction of are occasionally influenced by such worries. Even if prolonged pregnancy does carry an increased risk of perinatal mortality (and the data are by no means consistent), few would argue that this risk is substantial before 42 weeks’ gestation in an otherwise uncomplicated labour
pregnancy. The mean duration of pregnancy may be influenced by raciaF and social factors. For example, in the UK North West Thames health region in 1988 the proportion of pregnant women undelivered by their EDD was strikingly influenced by maternal height (figure). Whatever the underlying mechanism, this example illustrates the fallacy of applying the present calculation to an entire population.
The alternative In 1837 Montgomery1 stated "a very common calculation among women themselves is to reckon 42 weeks from the last menstruation or 40 weeks from the middle day of the interval". If we were to follow that suggestion, and substitute this calculation for Naegele’s rule, much anxiety ADDRESS Department of Obstetrics and Gynaecology, St Mary’s Hospital Medical School, Norfolk Place, London W2 1PG, UK (N. Saunders, MD, C. Paterson, MRCOG). Correspondence to Mr N. Saunders.
601
would be alleviated and a potential stimulus for unnecessary obstetric intervention would be removed. An alternative solution would be to give women a range of dates (ie, from 38 to 42 weeks) during which they would probably go into labour, rather than a definite date. The final word should go to Boerhaave: he kept an elaborately bound volume, which was said to contain all the secrets of medicine. When it was opened after his death, all the pages were found to be blank--except one. Inscribed on this page was only the one sentence, which read, "Keep the head cool, the feet warm and the bowels open".
BOOKSHELF Spinal Cord Injuries: Anaesthetic and Associated Care Edited by J. D. Alderson and E. A. M. Frost. Guildford: Butterworth Scientific. 1990. Pp 258. L50. ISBN 040701148X.
Long-term survival after spinal-cord injury has improved dramatically over the last 30 years. Previously, when most survivors of the acute phase died within a year, the concern to improve immediate management techniques was small. Nowadays, greater emphasis on the early management of injured patients, before the phase of long-term rehabilitation, is appropriate and necessary. Ambulance men and women are usually the first trained staff on the scene of an accident and it is they, with their advanced skills, who can provide appropriate immediate management to improve the chance of survival and to avoid further deterioration. In the UK an injured person is then transferred to the local accident and emergency department; few of these have a spinal injuries centre on site, so casualty department and other local staff must also be aware of the special problems involved in the early care of such injuries, with effective channels of communication with the nearest spinal injuries centre. It is now recognised that the first few hours after injury is a critical period; there is often instability of the spine and the patient’s clinical state may deteriorate rapidly. Recognition and avoidance of such dangers requires a high level of training of ambulance and casualty staff, as well as of those who offer first-aid at sporting and other organised events. In addition to these aspects of treatment, preventive measures must not be neglected. Alderson and Frost have assembled 17 contributors from the UK and the USA, of whom seven are from Sheffield and eight are anaesthetists, and provide a comprehensive account of the management of spinal-cord injuries from the scene of the accident to long-term rehabilitation. Anaesthetic aspects are emphasised but, as is observed, anaesthetists are not now to be found only in operating theatres; their skills and expertise are too valuable to be so constrained. The editors have largely avoided repetition, the individual chapters are well written, and there is an interesting contribution on the moral and legal issues in the management of these patients. The book would benefit from a clearer exposition of the relations between casualty departments and spinal injuries centres, how and when the specialists should become involved, and appropriate
REFERENCES
Montgomery WF. An exposition of the signs and symptoms of pregnancy and the period of human gestation and the signs of delivery. London: Sherwood, Gilbert, and Piper, 1837. 2. Nesbitt REL. Prolongation of pregnancy. Obstet Gynecol Surv 1955; 10: 1.
311-62. 3. Stewart HL. Duration of pregnancy and postmaturity. JAMA 1952; 148: 1079-83. 4. Speert H. Essays in eponymy. New York: Macmillan, 1958. 5. Park GL. The duration of pregnancy. Lancet 1968; ii: 1388-89. 6. Denman T. Introduction to the practice of midwifery. London, 1782. 7. Henderson M, Kay J. Differences in duration of pregnancy. Arch Environ Health 1967; 14: 905-11.
transfer arrangements. But do not be misled by the title: this good general account of the acute management of spinalcord injuries will be of use to paramedics, nurses, and casualty and spinal injuries centre staff, as well as to anaesthetists. Department of Neurology, Radcliffe Infirmary, Oxford OX2 6HE, UK
RICHARD GREENHALL
Regulating for Competition: Government, Law, and the Pharmaceutical Industry in the United Kingdom and France Leigh Hancher. Oxford: Oxford University Pp 429. 45. ISBN 0-198275706.
Press. 1990.
the last forty years the pharmaceutical industry has marketed a range of new chemicals which have enhanced the quality and length of life of many millions of people world wide. Yet because of its secrecy and affluence the industry is treated with suspicion, if not dislike, by many health-care workers and by society at large. Although often regarded as the epitome of capitalism, the pharmaceutical industry is the product of government regulation which ensures an absence of price competition. It may take up to twelve years for a company to negotiate the demands of the Medicines Act 1968 and to prove that a compound is safe and efficacious, but this leaves at least eight years of patent protection, during which the company has a monopoly and can generate substantial profits to recoup the investment costs of research and development. Innovation can be a hazardous process; the industry asserts that only a small minority of new products are successful, so creation of a marketable drug may cost c 100 million when all failures are taken into account.
During
But patents are only one way in which the industry is protected: since 1957 there have been various forms of covert schemes to guarantee a return on capital. In the UK the Pharmaceutical Price Regulation Scheme (PPRS) requires firms to reveal trading details to the Department of Health; in exchange, Government permits the industry to adjust its prices to achieve a high target return (rumoured to be around 18-20% at present) on historical capital. This protection is administered by one part of the Department of Health; another branch increases development costs by overseeing the process of taking a drug from the laboratory to the patient. Hancher’s book offers an excellent analysis of the development of regulatory policies in both France and the UK. Despite differences in culture and approach, there are several similarities between the ways in which the pharmaceutical industry has been regulated in the two countries. Can the UK learn from experiences overseas? UK regulatory policy evolved because of the discretionary power vested in the Executive; the PPRS is a voluntary agreement and firms have
VIEWPOINT Can
we
abandon
A pregnant woman may become anxious if she has not delivered by the date given to her by her physician. Much anxiety would be alleviated if a range of dates (38-42 weeks) was substituted for a specific date of delivery.1
Naegele’s rule?
opinion on this subject it is better to mention some time beyond that which we really suppose or on the whole it would perhaps be better that labour should always come on unexpectedly". 200 years later this dilemma is just as evident. A given necessary to
give
EDD leads
most women to
an
believe that the date is an of some considerable prediction importance. It can be extremely difficult to allay the anxiety of a pregnant woman and her relatives if she remains undelivered 281 days or more after the date of her last menstrual period. accurate
Introduction "I cannot imagine why gestation should be the only process connected with reproduction for which a total exemption from 1 any variation in its period should be claimed".
The duration of human pregnancy is a matter of considerable social and scientific importance. Both ancient Hindu and Roman cultures recognised that the average duration of pregnancy was about 9 months but allowed some latitude, especially with respect to prolonged gestation. In more modem times the legal process has been called upon to settle questions of legitimacy and inheritance in relation to the maximum possible duration of human pregnancy. For example, during the Gardner peerage trial (House of Lords, 1816), five eminent physicians testified that under no circumstances could the duration of pregnancy exceed 40 weeks’ gestation, whereas five of their colleagues presented the opposite view. The laws of some countries have defmed an upper limit of gestation consistent with legitimate birth after the death or departure of a husband, whereas English law does not set a precise limit. In judicial practice, it is usual to accept the most recently agreed ruling and to inquire whether to go beyond it is reasonable.2 The aim of the law is peace rather than justice; therefore, the scientific validity of such judgments is questionable.
Naegele’s rule Although most so-called prolonged pregnancies are due delayed ovulationin clinical practice the time of ovulation is rarely known with certainty. Assessment of gestational age is helped by antenatal ultrasonography, but for most women an estimated date of delivery (EDD) is calculated according to Naegele’s rule-ie, add 7 days and 9 months to the date of the last menstrual period. This formula, generally credited to Franz Carl Naegele (17781851), was proposed by Hermann Boerhaave, professor of medicine and botany at the University of Leyden (1709), and was merely quoted by Naegele.4 Furthermore, the original latin text is ambiguous with respect to whether the calculation should be based on the first or last day of menstruation. Many women (if not most) deliver after their EDD calculated by Naegele’s rille.5 In 1782, Thomas Denman6 noted "some inconveniences are produced by attempts to make exact reckonings for pregnant women: for when the time fixed for their delivery is past the mistake creates much solicitude and impatience. When therefore it is to
Proportion of patients undelivered by EDD maternal height.
in relation to
Data derived from more than 23 000 consecut!ve pregnancies which onset of labour occurred spontaneously.
in
Furthermore, it is likely that decisions about induction of are occasionally influenced by such worries. Even if prolonged pregnancy does carry an increased risk of perinatal mortality (and the data are by no means consistent), few would argue that this risk is substantial before 42 weeks’ gestation in an otherwise uncomplicated labour
pregnancy. The mean duration of pregnancy may be influenced by raciaF and social factors. For example, in the UK North West Thames health region in 1988 the proportion of pregnant women undelivered by their EDD was strikingly influenced by maternal height (figure). Whatever the underlying mechanism, this example illustrates the fallacy of applying the present calculation to an entire population.
The alternative In 1837 Montgomery1 stated "a very common calculation among women themselves is to reckon 42 weeks from the last menstruation or 40 weeks from the middle day of the interval". If we were to follow that suggestion, and substitute this calculation for Naegele’s rule, much anxiety ADDRESS Department of Obstetrics and Gynaecology, St Mary’s Hospital Medical School, Norfolk Place, London W2 1PG, UK (N. Saunders, MD, C. Paterson, MRCOG). Correspondence to Mr N. Saunders.
601
would be alleviated and a potential stimulus for unnecessary obstetric intervention would be removed. An alternative solution would be to give women a range of dates (ie, from 38 to 42 weeks) during which they would probably go into labour, rather than a definite date. The final word should go to Boerhaave: he kept an elaborately bound volume, which was said to contain all the secrets of medicine. When it was opened after his death, all the pages were found to be blank--except one. Inscribed on this page was only the one sentence, which read, "Keep the head cool, the feet warm and the bowels open".
BOOKSHELF Spinal Cord Injuries: Anaesthetic and Associated Care Edited by J. D. Alderson and E. A. M. Frost. Guildford: Butterworth Scientific. 1990. Pp 258. L50. ISBN 040701148X.
Long-term survival after spinal-cord injury has improved dramatically over the last 30 years. Previously, when most survivors of the acute phase died within a year, the concern to improve immediate management techniques was small. Nowadays, greater emphasis on the early management of injured patients, before the phase of long-term rehabilitation, is appropriate and necessary. Ambulance men and women are usually the first trained staff on the scene of an accident and it is they, with their advanced skills, who can provide appropriate immediate management to improve the chance of survival and to avoid further deterioration. In the UK an injured person is then transferred to the local accident and emergency department; few of these have a spinal injuries centre on site, so casualty department and other local staff must also be aware of the special problems involved in the early care of such injuries, with effective channels of communication with the nearest spinal injuries centre. It is now recognised that the first few hours after injury is a critical period; there is often instability of the spine and the patient’s clinical state may deteriorate rapidly. Recognition and avoidance of such dangers requires a high level of training of ambulance and casualty staff, as well as of those who offer first-aid at sporting and other organised events. In addition to these aspects of treatment, preventive measures must not be neglected. Alderson and Frost have assembled 17 contributors from the UK and the USA, of whom seven are from Sheffield and eight are anaesthetists, and provide a comprehensive account of the management of spinal-cord injuries from the scene of the accident to long-term rehabilitation. Anaesthetic aspects are emphasised but, as is observed, anaesthetists are not now to be found only in operating theatres; their skills and expertise are too valuable to be so constrained. The editors have largely avoided repetition, the individual chapters are well written, and there is an interesting contribution on the moral and legal issues in the management of these patients. The book would benefit from a clearer exposition of the relations between casualty departments and spinal injuries centres, how and when the specialists should become involved, and appropriate
REFERENCES
Montgomery WF. An exposition of the signs and symptoms of pregnancy and the period of human gestation and the signs of delivery. London: Sherwood, Gilbert, and Piper, 1837. 2. Nesbitt REL. Prolongation of pregnancy. Obstet Gynecol Surv 1955; 10: 1.
311-62. 3. Stewart HL. Duration of pregnancy and postmaturity. JAMA 1952; 148: 1079-83. 4. Speert H. Essays in eponymy. New York: Macmillan, 1958. 5. Park GL. The duration of pregnancy. Lancet 1968; ii: 1388-89. 6. Denman T. Introduction to the practice of midwifery. London, 1782. 7. Henderson M, Kay J. Differences in duration of pregnancy. Arch Environ Health 1967; 14: 905-11.
transfer arrangements. But do not be misled by the title: this good general account of the acute management of spinalcord injuries will be of use to paramedics, nurses, and casualty and spinal injuries centre staff, as well as to anaesthetists. Department of Neurology, Radcliffe Infirmary, Oxford OX2 6HE, UK
RICHARD GREENHALL
Regulating for Competition: Government, Law, and the Pharmaceutical Industry in the United Kingdom and France Leigh Hancher. Oxford: Oxford University Pp 429. 45. ISBN 0-198275706.
Press. 1990.
the last forty years the pharmaceutical industry has marketed a range of new chemicals which have enhanced the quality and length of life of many millions of people world wide. Yet because of its secrecy and affluence the industry is treated with suspicion, if not dislike, by many health-care workers and by society at large. Although often regarded as the epitome of capitalism, the pharmaceutical industry is the product of government regulation which ensures an absence of price competition. It may take up to twelve years for a company to negotiate the demands of the Medicines Act 1968 and to prove that a compound is safe and efficacious, but this leaves at least eight years of patent protection, during which the company has a monopoly and can generate substantial profits to recoup the investment costs of research and development. Innovation can be a hazardous process; the industry asserts that only a small minority of new products are successful, so creation of a marketable drug may cost c 100 million when all failures are taken into account.
During
But patents are only one way in which the industry is protected: since 1957 there have been various forms of covert schemes to guarantee a return on capital. In the UK the Pharmaceutical Price Regulation Scheme (PPRS) requires firms to reveal trading details to the Department of Health; in exchange, Government permits the industry to adjust its prices to achieve a high target return (rumoured to be around 18-20% at present) on historical capital. This protection is administered by one part of the Department of Health; another branch increases development costs by overseeing the process of taking a drug from the laboratory to the patient. Hancher’s book offers an excellent analysis of the development of regulatory policies in both France and the UK. Despite differences in culture and approach, there are several similarities between the ways in which the pharmaceutical industry has been regulated in the two countries. Can the UK learn from experiences overseas? UK regulatory policy evolved because of the discretionary power vested in the Executive; the PPRS is a voluntary agreement and firms have
