Showing papers in "Best Practice & Research in Clinical Obstetrics & Gynaecology in 1996"

3 The Cochrane Library

Abstract: Summary In the current era of patients seeking better information, managers seeking cost-effective treatments, clinicians struggling to keep up with the expanding medical literature, and professional groups requiring continuing medical education, there is a clear need for up-to-date and relevant systematic reviews of the effectiveness of treatment within our specialty. Such reviews will play an increasing role in the education of health professionals and lay people, in the evolution of the health service and in the direction of future research. The Cochrane Collaboration provides the infrastructure for the development and dissemination of these reviews. The specialty of obstetrics and gynaecology will benefit from several related groups already working within the Cochrane Collaboration (Pregnancy and Childbirth, Subfertility, Menstrual Disorders and Incontinence). Other groups are in the process of, or likely to, register in the near future (Fertility Control, Gynaecological Cancer). However, the need and demand for a large number of systematic reviews exceeds the current capacity of those who have committed themselves to prepare and maintain such reviews, and substantial challenges remain. However, there is every reason to believe that a concerted effort over many years will be worth while. Earlier in this commentary, obstetrics and gynaecology was referred to as the specialty most deserving of the ‘wooden spoon’ for its lack of evidence-based practice. With the development of various gynaecological groups within the Collaboration, we hope that the ‘wooden spoon’ can be discarded from our ranks for good.

2 Developments in CTG analysis

Abstract: Summary FHR monitoring has been the subject of many debates. The technique, in itself, can be considered to be accurate and reliable both in the antenatal period, when using the Doppler signal in combination with autocorrelation techniques, and during the intrapartum period, in particular when the FHR signal can be obtained from a fetal ECG electrode placed on the presenting part. The major problems with FHR monitoring relate to the reading and interpretation of the CTG tracings. Since the FHR pattern is primarily an expression of the activity of the control by the central and peripheral nervous system over cardiovascular haemodynamics, it is possibly too indirect a signal. In other specialities such as neonatology, anaesthesiology and cardiology, monitoring and graphic display of heart rate patterns have not gained wide acceptance among clinicians. Digitized archiving, numerical analysis and even more advanced techniques, as described in this chapter, have primarily found a place in obstetrics. This can be easily explained, since the obstetrician is fully dependent on indirectly collected information regarding the fetal condition, such as (a) movements experienced by the mother, observed with ultrasound or recorded with kinetocardiotocography (Schmidt, 1994), (b) perfusion of various vessels, as assessed by Doppler velocimetry, (c) the amount of amniotic fluid or (d) changes reflected in the condition of the mother, such as the development of gestation-induced hypertension and (e) the easily, continuously obtainable FHR signal. It is of particular comfort to the obstetrician that a normal FHR tracing reliably predicts the birth of the infant in a good condition, which makes cardiotocography so attractive for widespread application. However, in the intrapartum period, many traces cannot fulfil the criteria of normality, especially in the second stage. In this respect, cardiotocography remains primarily a screening and not so much a diagnostic method. As long as continuous monitoring of fetal acid-base balance has not been extensively tested in clinical practice, microblood sampling of the fetal presenting part (Saling, 1994) is a useful adjunct. The problem with non-normal tracings is that their significance is very often unclear. They may indicate serious fetal distress, finally resulting in preventable destruction of critical areas in the fetal brain and damage to various organs; or, on the contrary, they may indicate temporary changes in cardiovascular control as a reaction to the intermittent effects on fetal haemodynamics of, for example, uterine contractions, whether or not in combination with partial or complete compression of umbilical cord vessels or the vessels on the chorionic plate (van Geijn, 1994). Many factors influence the FHR and its variability, which further complicates the interpretation of FHR patterns; some have been discussed here in some detail. Undoubtedly, there is a need for quantitative and objective FHR analysis, as long as it does not lead to erroneous results. Close collaboration between engineers and clinicians is a prerequisite for further advances in this field. Decision support systems certainly have a future but only if they are able to take into account a large set of clinical data and can combine it with data obtained from FHR signals and other parameters referring to the fetal condition, such as fetal growth, Doppler velocimetry, amniotic fluid volume and biochemical and biophysical data obtained from the mother. Basic technical concepts inherent in computerized CTG analysis, such as sampling rate (Chang et al, 1995), signal loss, artefact detection (van Geijn et al, 1980), further processing of intervals, archiving in digitized format and monitor display, should receive considerable attention. There is still a long way to go until decision support systems find their way into obstetric practice. Further developments can only be achieved thanks to efforts of many basic and clinical researchers, working in a harmonious environment with adequate funding.

6 Evaluating diagnostic tests

Abstract: Summary Diagnosis-based decision-making is fundamental to clinical practice. In this chapter, we have seen how clinical symptoms can select a group of patients in whom diagnostic tests can then help the clinician to reach or exclude a diagnosis. Informed use of a diagnostic test requires identification of valid evaluations of its diagnostic abilities. Conventional measures of a test's effectiveness, such as sensitivity and specificity, are of limited use when applying diagnostic tests in clinical practice. Likelihood ratios provide an explicit tool for updating diagnostic probabilities according to test results, and can incorporate variations between individuals in their risk of disease. Their use may help both individual patient management and the appropriate allocation of diagnostic and therapeutic resources.

4 Urogenital effects of the menopause

Abstract: The mean age of cessation of menses is 51 years, with an average life expectancy of 27 years beyond that. Women can be expected to live a third of their lives in the post-menopausal state. By the year 2000, there will be 50 million post-menopausal women in the USA (Mishell, 1992). It is therefore expected that management of the gynaecological problems of the menopause will become an increasingly important aspect of routine gynaecological practice (Utian, 1990). Urogenital disorders are among the most common reasons why menopausal and post-menopausal women seek the aid of a physician (Brown and Hammond, 1987). The menopause occurs at a time when the incidence of degenerative and organic diseases of the urogenital system increases. It is not surprising therefore that associations have been observed between oestrogen deprivation (hypo-oestrogenism) and the urogenital disorders of the menopause. However, scientific evidence supporting many of these associations is lacking. This chapter will discuss the urogenital conditions associated with the menopause and the direct and indirect evidence connecting them to hypo-oestrogenism. Particular emphasis will be placed on the most common syndromes associated with the menopause, including lower genital tract atrophy/atrophic vaginitis, urinary tract infections (UTI) and urinary incontinence. Particular attention will be given to issues of clinical practice.

Psychological and sexual aspects of the menopause and HRT.

Abstract: Despite the clinical impressions that there are considerable psychological benefits from HRT, there is only clear evidence for amelioration of psychological symptoms (including improvement in cognitive function) in women who have undergone a surgical menopause. Otherwise in the natural menopause it remains unclear which, if any, non-sexual psychological symptoms respond directly to oestrogen except as a secondary response to reduction in physical symptoms. Overall, it has to be said that there is little scientific backing for hormonal treatment of psychological problems on their own around the time of the natural menopause. In most cases psychological treatment or counselling will be more appropriate than HRT. It must be remembered that the prevalence of psychological symptoms in the menopause and gynaecology clinic is high just as it is in all hospital settings. The task is to identify which women: 1. Have a predominance of psychological symptoms and might have psychiatric disorders. They may have presented in the clinic because they also happen to be menopausal, but it may well be that the psychiatric disorder has a quite independent aetiology. They will benefit from specific treatment for that disorder. 2. Have, and complain of, low moods or other non-specific psychological symptoms and have presented in the clinic because they are menopausal. They might benefit from practical, supportive help with current and ongoing stresses and strains. 3. Present appropriate menopausal complaints and only on enquiry reveal their psychological problems. In particular, disorders such as depressive illness, anxiety states and alcohol abuse can present with physical symptoms including ones which mimic vasomotor ones. This group may well be non-responders to HRT. Women requiring particular consideration might be those with other health problems (particularly chronic ones that might carry on in to old age) who are possibly more at risk of developing depression as they pass through the menopause. There is clearer evidence that HRT has beneficial effects on sexual function. When sexual symptoms are presented it is worth clarifying the exact features contributing to the complaint. Is it a problem of sexual interest, of infrequency of sexual activity, of vaginal dryness and dyspareunia, or is it a mixture of these complaints? Reduction of sexual interest and reduced sexual activity with the partner and possibly orgasm may accompany the menopause. Oestrogens have been shown to have some beneficial effect on sexual desire. Where oestrogen alone is ineffective, testosterone is usually beneficial. This treatment effect is particularly clear in surgically menopausal women. Non-menopausal aspects of the sexual relationship must be considered too. These aspects include the quality of the relationship, the sexual performance of the partner (since sexual desire decreases in both sexes with age), and age-related changes in self-image. These issues may need to be addressed at a simple health education level or with specific counselling. Although a woman's motivation or desire might change as a result of HRT, on its own this will not influence the frequency of intercourse or response during intercourse unless the partner variables permit this. The situation is more straightforward when problems of postmenopausal vaginal dryness and dyspareunia are the key issues. Oestrogens have been shown to be highly effective in such circumstances. It is also worth noting that regular and continued sexual activity has been found to protect against vaginal dryness.

5 Intrapartum assessment of uterine activity

Abstract: Summary Management of labour carries the responsibility of achieving safe delivery of the mother and baby, while avoiding prolonged labour and fetal distress. This requires close attention to uterine activity, which is particularly important in labours in which contractions are stimulated pharmacologically. Whether labour is induced or augmented for slow progress, the principal aim should be to make the use of oxytocin safe. Better awareness and understanding of the effects of oxytocin, aided by appropriate methods of monitoring, will minimize iatrogenic intervention and maximize the chances of normal delivery.

Post-partum contraception.

Abstract: The choice of a post-partum contraceptive method depends on many factors, including the need for a temporary versus a permanent method, the infant feeding choice and the extent to which informed consent is made prior to delivery. For maximum protection, the non-breast-feeding woman should be protected from the fourth week post-partum, even if that means using a temporary method, such as condoms or spermicides, until her method of choice is procured. Combined oestrogen/progestin methods should be avoided by all women for 2-3 weeks to avoid elevating the risk of thromboembolism. Preparations containing oestrogen should be avoided altogether during lactation because they have been associated with a reduction in milk production. POPs, implants and injectables are appropriate regardless of infant feeding choice. They can be administered immediately post-partum in bottle-feeding women, but should ideally be postponed for 6 weeks in breast-feeding women. It is best to insert IUDs within 10 minutes of delivery of the placenta, in order to minimize the risk of IUD expulsion. Insertion immediately after expulsion of the placenta requires special training, and expulsion rates are reduced with the insertion experience of the practitioner. Breast-feeding is not associated with an increase in IUD expulsion or uterine perforation, and it is associated with fewer removals for bleeding or pain. Tubal sterilization is safe, convenient and cost-effective when performed immediately after delivery, but it requires extensive counselling and fully informed consent prior to the onset of labour to avoid potential regret over post-partum tubal ligation. If the procedure is performed immediately, any effect on the establishment of lactation may be minimized. LAM is a method that can only be used by breast-feeding women. It may prove to be a useful way to time the commencement of a second, less temporary contraceptive method. Natural family planning methods require a period of abstinence for the establishment and identification of the new symptoms of fertility. When LAM is used during this interval, the need for abstinence may be reduced significantly for breast-feeding women. Breast-feeding provides health benefits for the woman and her infant, as well as the best possible nutrition for the baby. The International Planned Parenthood Federation (1990) (among others) recommends that, 'As far as is practicable, all women should be advised and encouraged to breastfeed fully'. The infant feeding decision affects the choice of a contraceptive method, and this is an important reason for the woman's physician to be interested in her infant feeding choice.

3 Metabolic acidosis and fetal reserve

Abstract: Dr Bailey, Director of the National Institute of Neurological Diseases and Blindness, Bethesda, Maryland, introduced the 1956 symposium on 'Neurological and psychological deficits of asphyxia neonatorum' by saying. 'Medical research in regard to cerebral palsy and other neurological disabilities has been relatively neglected. For a truly comprehensive attack on this problem we must focus a sharper scientific search for greater knowledge of those adverse biological factors which operate in the perinatal period. The proper point of departure in such a search is through controlled animal observations, for which purpose monkeys are best suited' (Windle, 1958). Our understanding of the significance of asphyxia is built on the foundation of the laboratory research that has followed upon this initiative. Laboratory studies in fetal monkeys and fetal lambs have clearly demonstrated that the fetus can initially compensate for an asphyxial insult and protect the vital organs. However, if the hypoxaemia progresses to a severe metabolic acidosis and cardiovascular decompensation with hypotension, brain damage will occur. There is a growing body of clinical evidence that supports the contention that the human fetus responds in a similar manner. The varied nature of hypoxic and ischaemic insults has been well demonstrated in animal studies. Total anoxia and isolated cerebral ischaemia are uncommon events in the human fetus. The common insult, particularly during labour, is a degree of hypoxia present over a variable period of time. This is fortunate in that such insults are associated with a period of fetal compensation that may last several hours, during which time a diagnosis of a developing metabolic acidosis can be made. This is the clinician's window of opportunity, when a definitive diagnosis of an asphyxial insult can be made and if necessary intervention made before the threshold of decompensation has been reached. A consensus on the threshold of decompensation has yet to be achieved. However, there is a growing body of evidence that the threshold is in the range of an umbilical artery base deficit of 12-16 mmol/l. Since the aim of the obstetrician during labour is the prevention of asphyxial morbidity and mortality, the determination of this threshold is important to provide criteria for clinical action. A blood gas and acid-base assessment with the determination of a metabolic acidosis is the best measure of an asphyxial insult that may be of clinical significance. The definition of the threshold of metabolic acidosis requiring intervention will continue to be clarified with future clinical research. However, there are many factors that will influence the fetal response to an asphyxial insult, which may require that a range of threshold be acknowledged. The effect upon the fetus will be influenced by whether the asphyxial event is the first or the last of a series of asphyxial episodes, and the duration of the asphyxial episode. The characteristics of the fetus, i.e. maturity (pre-term versus term), and fetal growth small for gestational age (SGA) or appropriate for gestational age (AGA) may influence the fetal response to an asphyxial insult. Improved understanding of these issues will provide a better rationale for clinical management.

9 Sexual behaviour in young people

Abstract: A review of the literature from the United Kingdom reveals a progressive reduction in recent decades in the age at first intercourse an increase in the prevalence of premarital sex to the point of near universality and a convergence of the sexual behavior of males and females. Over the past 30 years the median age at first intercourse in the UK has dropped from 16 to 14 years for females and from 15 to 13 years for males. Fewer than 1% of women 16-24 years of age had their first sexual experience within marriage compared with 40% of women 45-59 years old. These trends reflect biologic factors including earlier age at menarche and social factors such as liberalization of norms governing sex behavior and peer pressure. Age at first intercourse increases with educational level and social class status. Curiosity is the factor most commonly cited by males as motivating first intercourse while females identify romantic reasons. Nearly half of young women and over half of young men who have intercourse before the age of 16 years have unprotected sex. Contraceptive use is more likely with casual than steady sex partners. The condom is the most widely used contraceptive method in the early stages of sexual experience and its use is increasing as a result of awareness of acquired immunodeficiency syndrome. More than two-thirds of young people consider themselves inadequately prepared at first intercourse in terms of information on sexual matters. Although the majority gain their information about sexuality from friends schools are cited as a preferred source. The importance of sex education is confirmed by the positive association of predominantly school-based information and contraceptive use at first intercourse. There is no evidence that sex education hastens the onset of sexual activity.

1 The menopausal transition

Abstract: Summary The menopausal transition is that period beginning with the first indications of the approach of menopause and ending with the final menses. Its morphological basis is a rapidly declining number of primordial follicles within the ovary; a decline which appears to result from an increased rate of follicular atresia. The most characteristic hormonal change in the menopausal transition is a progressive, though often fluctuating, rise in the level of serum FSH. Oestradiol and inhibin levels fluctuate markedly when observed in individual subjects but remain relatively preserved during the follicular phase of the cycle, until late in the menopausal transition. The frequency of anovulatory cycles increases as the final menstrual period approaches. The rate of symptom reporting varies among different populations of women, with maximum symptom frequency being seen during the menopausal transition. There are some indications that cardiovascular and osteoporosis risk factors may change adversely during the menopausal transition and medical practitioners should be ready to offer hormonal supplementation to women at increased risk of cardiovascular disease and osteoporotic fracture.

7 Metabolic effects of the menopause and oestrogen replacement

Abstract: There is little doubt that the metabolic disturbances seen following the loss of ovarian function are most important in the development of cardiovascular disease in women. The loss of hormones at the menopause appears to reduce both insulin secretion and elimination, but increasing insulin resistance thereafter brings about an increase in circulating insulin concentrations. Changes in lipids and lipoproteins are in an adverse direction, as are changes in body fat distribution, and changes in haemostatic factors would tend to favour coagulation rather than fibrinolysis. HRT with oestrogen appears to improve most of the metabolic abnormalities related to the menopause, but this is in part dependent on the type of oestrogen used and the route of administration. The addition of progestogen may influence the metabolic changes induced by oestrogens, and this will vary according to the type of the progestogen. Overall, the metabolic effects of any of the current HRT regimens would seem likely to be beneficial for CHD. Nevertheless, future HRT regimens should ideally be tailored to produce the most favourable changes in CHD metabolic risk factors, particularly in the case of the regimens which attempt to avoid cyclical bleeding.

4 Fetal monitoring with lactate

Abstract: Summary Lactate is a metabolite that can safely and easily can be determined in fetal scalp blood using new microvolume (5–20 μl) lactate meters. However, new lactate analysing methods need their own reference values. There are factors other than hypoxia that might increase fetal lactate levels, although this does not disqualify this parameter for intrapartum surveillance. Available data on fetal lactate determination give support that it can simplify FBS in labour and is likely to predict fetal tissue hypoxia at least as well as is pH determination. Prospective randomized studies are needed before the method can be introduced into clinical practice. As a predictor of neonatal outcome, lactate can substitute pH in routine assessment of cord artery blood at delivery.

8 Fetal pulse oximetry

Abstract: Fetal pulse oximetry provides a tool for the surveillance of the fetus at risk of hypoxia. The experience of 150 deliveries monitored by pulse oximetry and the analysis of data may allow preliminary recommendations for clinical use in cases of suspected fetal hypoxia based on a suspicious FHR. In most cases, saturation values above 33% suggest fetal well-being. Further fetal evaluation, for example by fetal blood samples or other means, is necessary to assess alterations of FHR pattern or decreases in saturation values. Pulse oximetry may allow a differentiation between cases that need further evaluation, such as scalp blood sampling, and those which do not. The number of repeated assessments may be reduced as long as the oxygen saturation and FHR pattern do not worsen. The effect of therapeutic measures on fetal oxygenation can be directly observed. The positive preliminary experiences with fetal pulse oximetry predominate even if high expectations of easy detection of fetal hypoxia have so far not been fulfilled.

10 Treatments for menopausal and post-menopausal problems: present and future

Abstract: Probable developments in HRT and non-HRT treatments for menopausal and post-menopausal problems have been reviewed. More information is required on potential benefits and side-effects of HRT. The major potential benefit is prevention against stroke amelioration of Alzheimer's disease: the major potential side-effect discussed in this chapter is ovarian cancer. At present, techniques for delivering oestrogens are more varied and advanced than those for progestogens. Non-oral delivery systems for progestogens which minimize side-effects will be introduced during the next decade. It is not clear whether benefits expected with new progestational agents will be realized. Preliminary data suggest that SERMs and phytoestrogens are worthy of further evaluation. Their development will provoke intense interest over the next 10 years.

9 The menopause and the cardiovascular system

Abstract: Summary Combining the wealth of epidemiological, metabolic and recent mechanistic data, it would appear biologically plausible that HRT, either oestrogen alone or in combination with progestogen, is cardioprotective. Further research is required, as information is lacking on cardiovascular effects of HRT instigated at an older age. There is a need to identify cardiovascular benefit, indirect and/or direct, of combined oestrogen/progestogen therapy using randomized trials. The various progestogen types and doses also need to be investigated. Studies are also required to investigate the effect of HRT use in higher risk patients with established CVD. There is scant information on the effect of HRT on blood pressure of patients with hypertension. Cardiovascular risk factor profiles and incidence surveys need to be conducted in developing countries to characterize their female population and to identify the prevalence of CVD; this needs to be undertaken before widespread recommendations on CVD prevention and the role of HRT can be made. If HRT is to be used effectively in the future treatment of heart disease in women these questions need to be addressed. At present HRT is indicated for the relief of menopausal symptoms and the prevention of osteoporosis. In women without these indications, ORT may be recommended in those who have had a premature menopause, and possibly in those who have established CHD or who are at high risk of developing CHD. It is too early to suggest a blanket recommendation for the use of HRT in the treatment of the symptoms of women with established CVD, but HRT after the menopause may at least be safely used in the secondary prevention of CHD.

1 Male contraception

Abstract: Summary With the powerful tools of molecular investigation, the last decade has witnessed the most remarkable scientific advance in our history, yet no new leads for male contraception have been forthcoming. All the likely methods of male contraception discussed above were derived from relatively ‘old' physiological principles or serendipitous observations. The increasing gap between fundamental research (in the control of mammalian spermatogenesis) and the lack of clinical application are a testament to the low public funding priority afforded to male reproduction and the unwillingness of the pharmaceutical industry to invest in male reproductive research and development. Yet amidst such an unfavourable setting and with very limited support, it is heartening to note that the prospects of introducing a new systemic method for male contraception into the market by the end of this millenium has been greatly enhanced. Thus the results of recent studies have confirmed the contraceptive efficacy of sex steroid-induced oligozoospermia and unexpectedly revealed an ethnically distinct pattern of susceptibility to the hormonal suppression of spermatogenesis. Thus, Asian men are more responsive than are caucasian, and long-acting testosterone esters now being tested in that most densely populated part of the world may well hasten the large-scale application of this method. This is probably the most effective way to correct the misconceptions that men are unwilling or disinterested in sharing in family planning options with their partners. Together with the increased acceptance of novel non-surgical and reversible methods of vas deferens occlusion and the availability of improved non-latex condoms, the currently unfulfilled contraceptive needs of millions of men can be increasingly met in future years. The consequent increase in overall contraceptive prevalence could well make the telling difference between demographic catastrophe and maintaining good quality existence. Politicians, scientists and industrialists need to wake up to their responsibilities and the opportunities offered by this untapped resource and market potential.

1 Evidence-based obstetrics and gynaecology

Abstract: Summary ‘At present, many clinical decisions are based principally on values and resources—opinion-based decision making; little attention has been given or is paid to evidence derived from research—the scientific factor’ (Gray, in press). Our ultimate aim is to ensure the practice of effective medicine in which, quite simply, the benefits to an individual patient or population outweigh any associated harm to that same patient or population. To do this, we need the skills to produce and evaluate the evidence on which our decisions are based. Evidence-based practice can help us to incorporate those skills into our working day. It depends on good clinical skills, forming a concise relevant question, becoming efficient in searching for the information, appraising that information, implementing the information into our daily practice and, finally, closing the circle by auditing our efforts at implementation and the effects within our own practice population. There seems no doubt that our patient care should be rooted in the best external evidence. Despite obstetricians, in particular, already having a great deal of information critically appraised and summarized for them, our clinical practice risks becoming out of date because of a propensity to lag behind the evidence as it stands, whether in discarding the ineffective or in introducing effective care policies. We need the techniques of evidence-based medicine to equip us as self-directed learners in our quest to remain well-informed practitioners. We owe it to our patients to ensure that, in consultation with them, we are doing the right thing for them.

1 Historical perspectives: forgotten past, unpredictable future

Abstract: Intrapartum surveillance has in recent years become a matter of debate. Following its earlier development, first in auscultation and then 40 years ago in electronic monitoring, obstetricians accepted its use with great, perhaps too great, enthusiasm. Years later, attempts to evaluate the actual consequences of this use led to disappointment: although its benefit on perinatal mortality is acknowledged, two observations lead one to reconsider the legitimacy of its use. First the apparent lack of beneficial influence on neonatal long-term morbidity, and second the definite increase in the rate of caesarean section. Furthermore, recent comparative studies, despite some discrepancies, seem to indicate that clinical monitoring by auscultation leads to results as good as those from electronical monitoring, particularly with respect to fetal mortality and infant morbidity. These observations obviously merit careful consideration; some explanations may be put forward to explain these apparently surprising results. From a practical point of view, this discussion leads to two opposite choices for obstetric policy: either to 'go back' to auscultation or to try to identify indicators more specific to fetal asphyxia and increased risk of cerebral palsy, leading to more precise and fewer indications for caesarean section. This chapter on historical perspectives may be useful in pointing out what were the goals of the obstetric pioneers involved in electronic monitoring: definitely not to build theoretical considerations on the pathophysiology of fetal distress, but to gather continuous information about the fetal heart rate in the hope of detecting changes announcing fetal asphyxia before it becomes irremediable, and hence preventing fetal death. These promises have been fulfilled. It follows that continuous clinical monitoring, which provides the same kind of information, is quite likely to lead to similar clinical results. It also follows that this relatively cumbersome method has really nothing to do with the 'classical' clinical surveillance in use before the widespread acceptance of electronical monitoring. It may be beneficial to experiment with this specific type of clinical surveillance; it would be dangerous, however, to 'go back' to the type of monitoring practised 40 years ago.

6 New hormonal methods of contraception

Abstract: Summary Three types of new contraceptive delivery system have been discussed in this chapter. Each have novel methods of delivery and may be acceptable to certain groups of women. It is clear that subdermal contraceptive implants are extremely useful as a long-term method of contraception, and provided insertion occurs correctly, removal will then be easy. The second-generation implants using a single rod, compared with the first-generation ones using six capsules, would appear to offer advantages both to the patient and in relation to the training of medical and paramedical personnel who have to fit the subdermal implant. The main disadvantage is the incidence of irregular bleeding, which, by and large, can be overcome by pre-insertion counselling and by time. The second method of delivery, vaginal rings, offers high patient acceptability, but a usable ring for contraception has as yet to be developed. Two approaches appear to be the use of a continuous progestogen-only ring, or a combined ring releasing oestrogen and progestogen with a 21-day-in, 7-day-out cycle of use. Ongoing studies will indicate whether vaginal lesions are significant or related to the flexibility of the ring. If these studies prove satisfactory, further development of the vaginal rings, both as an alternative method for interval use or as a specific postpartum form of contraception using progesterone-releasing rings, will be developed. Significant developments in the use of a combined monthly injectable have led to the release of two preparations, Cyclofem and Mesigyna, which are now available in many countries. This combined approach offers a significant reduction in amenorrhoea rates and unacceptable bleeding, the majority of women having acceptable menstrual patterns even during the first 3 months of use. All three methods have low and acceptable rates of pregnancy, the lowest being seen with the subdermal implants and with combined monthly injectables. Due to the length of action of subdermal implants, these may find a niche for women wishing to use a long-acting method and not wishing to be sterilized. They also provide a useful method where medical intervention is not available on a regular basis. Monthly injectable preparations can be given by paramedical personnel, and introductory studies have indicated that in developing and developed countries, they are highly acceptable. All three methods offer an increased choice for women and safe and effective methods of contraception.

6 The breast and the menopause

Abstract: The breast is composed of numerous cells with differing functions which may vary from secretory activity, duct formation and myoepithelial contraction to fat cells, nerve fibres, vascular supply and production of fibrous tissue and collagen. The breast is capable of functioning as a source of nutritious food and as an endocrine gland, controlling cellular activity within the breast independently of outside influence, yet capable of responding to messages produced elsewhere in the body. Each breast is composed of millions of alveoli which have the capacity to secrete milk. Each alveolus is fined by a single layer of cells which, under the influence of specific hormones, is capable of producing milk which is secreted into the lumen of the alveolus. Contraction of myoepithelial cells then squeezes the milk into the collecting ducts which eventually pass to the nipple where 15 to 20 lacteals empty to the surface. The complex of alveolar cells, collecting ducts and myoepithelial cells is embedded in specialized fat cells through which pass the arteries, capillaries, veins, nerves and lymphatics. The fat cells in the breast have specialized functions including the ability to produce oestrogen locally (Blankenstein et al, 1992) as well as protecting delicate tissue within the breast. In young women, subject to the influence of a number of hormones including oestrogen and progestogen, the ducts and alveoli are relatively active and occupy a large portion of the total volume of the breast. Following the menopause, and withdrawal of sex hormones, the glands and ducts undergo atrophic changes so that the major proportion of breast cells are fat ceils. For that reason, post-menopausal breast tissue appears relatively translucent to X-rays, except in those women where hormonal therapy has been used to maintain cellular, ductal and alveolar activity.

7 The fetal electrocardiogram

Abstract: Summary Advances in microprocessing technology have made fetal ECG analysis a feasible adjunct to fetal surveillance. Time interval and morphology changes of the FECG occur during fetal hypoxia. The use of these changes to detect a fetus at risk of intrapartum asphyxia awaits validation in terms of both future and ongoing clinical trials. Recognition of FECG changes during decelerations may improve the sensitivity of EFM. Antepartum FECG analysis has potential for the detection of a number of pathological fetal conditions, including intrauterine growth retardation, but remains hampered by low signal-to-noise ratios, rendering successful signal acquisition unreliable.

8 Contraception for the older woman

Abstract: Summary Contraception presents particular problems for women over the age of 40. Although fertility is declining and the risk of pregnancy may be small, the consequences of an unplanned pregnancy may be socially devastating and medically ill-advised. Menstrual dysfunction and psychosexual difficulties increase with age and may exacerbate the side-effects of some methods of contraception. The long-term risks of combined hormonal contraception, particularly cardiovascular disease, become more pertinent to women whose natural risk of disease increases with age. Patterns of sexual activity and contraceptive use change with age. The advantages and disadvantages of currently available methods of contraception are difficult to quantify, and the choice of method is very much a matter for individual concern. The increasing prevalence of HRT may complicate matters for some women who are unsure for how long to continue using contraception. Contraceptives of the future may be designed to improve the reproductive health of all women, particularly those approaching the menopause.

10 Monitoring technology and the clinical perspective

Abstract: Summary Currently available technology requires a new look to reduce intervention as well as to improve the detection of the truly at-risk fetus. Iatrogenic causes of so-called fetal distress, in particular the administration of uterotonics without due attention to avoiding hyperstimulation, predominate as a reason for intervention. There needs to be a better definition of the starting point, i.e assessment of the fetal condition and identification of any risk factors, such as oligohydramnios and growth retardation, that might diminish fetal reserve. This will allow ‘customization' of surveillance and management according to the needs of each individual fetus. There also needs to be better training and better agreement about the end-point of monitoring. For prospective surveillance, the aim is to avoid rather than to identify damage, and the definition of the appropriate point for intervention needs to come from better consensus on what is and what is not acceptable management based on current knowledge. New technology holds the promise that it can give trended information during labour, allow early recognition of problems and reduce unnecessary intervention. However, there is a need to ensure reliability and reproducibility of the readings before a new method is released. Co-operation with industry is essential, but the roles need to be well defined and the ultimate responsibility for establishing the role of a new technique has to come from the clinicians involved in intrapartum care.

9 Near infrared spectroscopy applied to intrapartum fetal monitoring

Abstract: Summary NIRS as a technique for intrapartum fetal monitoring is at present only able to be used as an investigative research tool. We feel that it has enormous potential to give access to previously inaccessible information about fetal cerebral haemodynamic and oxygenation changes in labour. The major limitations at present are technological, and the problems addressed in this review need to be resolved before clinicians can advance the technique. In the future, standardized measurement parameters that truly reflect cerebral oxygenation, along with a range of normality need to be established. This would require the study of very large numbers of uncomplicated labours. Comparison with data from labours complicated by what we currently call ‘fetal distress’ and correlation with outcome measures in the neonate would then be needed to determine abnormal patterns of change related to intracerebral hypoxia-ischaemia. This is severely limited by the current inability to measure absolute levels of oxygenation necessary to validate the method. To use the technique for routine surveillance in labour would require considerable refinement of both the equipment and the data analysis systems to improve the acceptability of the technique. It is not possible to envisage a role for NIRS in routine surveillance of low-risk pregnancies, but it may in future prove to have a role in the management of high-risk pregnancies and may well improve our understanding of intracerebral pathology.

4 Modern intra-uterine devices

Abstract: Summary Modern intrauterine devices (IUDs) provide effective, safe and long-term contraception and could be recommended to most women. The mechanism of action of an IUD is still not fully understood, but most recent research suggests that copper-IUDs as well as hormone-releasing intrauterine systems (IUSs) prevent conception. In women in mutually monogamous relationships the risk of PID is low and related to the insertion procedure. IUD/IUS use should be discouraged if there is a suspicion of increased risk of sexually transmitted disease. The risk of ectopic pregnancy is extremely low if modern, highly effective IUDs/IUSs are used. Copper-IUDs increase menstrual blood loss by around 50%, whereas hormone-releasing IUSs substantially reduce menstrual blood loss. Careful patient selection and counselling are the most important tools in order to provide acceptable and safe IUD use.

6 Clinical role of amnio-infusion

Abstract: Summary Amnio-infusion is a simple, yet beneficial, technique for improving pregnancy outcome. Antepartum amnio-infusion has been shown to be beneficial as an aid to enhancing ultrasonographic fetal imaging and may have a role in the administration of antibiotic therapy or the prevention of pulmonary hypoplasia. There are considerable data to support the intrapartum use of amnio-infusion in the presence of oligohydramnios, variable decelerations or meconium. Numerous prospective clinical trials have shown a significant benefit of amnio-infusion in reducing the rate of emergency caesarean section for fetal distress and complications related to meconium when used for these indications. Additional research is needed to clarify further its intrapartum role in patients with premature rupture of membranes or chorio-amnionitis.

2 Finding the evidence

Abstract: Summary When the Cochrane Collaboration fulfils its quest to organize the available evidence in a registry of trials and systematic reviews, it will mean that our task to find the best evidence will be much less daunting than it may at present seem. Meanwhile, to be evidence-based practitioners, we must learn the techniques that will make our search both comprehensive and efficient. To find this evidence requires: o 1. the construction of a specific question based on the clinical problem; 2. the design of a search strategy that is inclusive but practical; 3. the search of the appropriate database(s); 4. the scan of the retrieved abstracts for the most useful papers for critical appraisal. Efficient searching for evidence does mean getting to grips with the manifold advantages that computerization can offer us. The use of a computer for this purpose needs, like any other new technique we take on, practice to gain competence and confidence. Within the UK, the National Health Service Research and Development Department has made the collation and dissemination of clinical evidence to practitioners a priority. Hence at present, there is an enormous effort within the UK to make sure that the evidence is in the clinical areas of need, in a format we can use it and available in a place where and when we want it, whether that is the ward or the general practitioner's surgery. The aim is to remove at least some of the barriers that prevent us from becoming individual evidence-based practitioners.

7 Evaluation of screening programmes

Abstract: Summary As with other public health interventions, the decision to adopt a screening programme will need to take account of both the benefits and the burdens, including both human and financial costs. A balanced view is called for, and this is best achieved by making explicit the scientific information underpinning the proposed screening programme. In normal medical practice, there is frequently also a conflict between the therapeutic and the iatrogenic, but the detailed justification for preferring a particular medical intervention is often not always made clear. However, in normal medical practice doctors act in response to the patient who seeks alleviation of symptoms, whereas screening is proactive. Consequently, there is a greater obligation to ensure that a proper justification can be made. It is fruitless to try to justify screening in general; each screening programme needs to be considered separately. Some will be found wanting and can be readily discarded. Others will show a clear-cut benefit and, provided sufficient funding were available, could become routine practice. In many cases, however, the balance may be more finely poised, and there is likely to be an element of value judgement.

8 The menopause and the skeleton: key issues

Abstract: Summary There is a persuasive rationale for the use of HRT at the time of the menopause, but there are a number of factors which limit its widespread application for osteoporosis. These relate partly to the long-term efficacy of HRT when given for a finite duration at the time of the menopause, and long-term prospective studies are warranted to address this issue. A further difficulty relates to the logic of targetting women at risk of osteoporosis at the time of the menopause when the benefits and risks of HRT are largely extraskeletal. Finally, the importance of the menopause to the problems of osteoporosis have probably been overemphasized and other factors are important in determining the geographical variation in hip fracture risk as well as the increase in age- and sex-specific incidence that has occurred in many countries. The causes for this are unknown, but are clearly not related to gonadal status since these phenomena are observed both in men and in women. A plausible hypothesis is the decrease in physical activity, but this remains an hypothesis. It will be important to determine the aetiology of these phenomena so that logical preventive strategies can be developed.