What’s new in the other journals?
These snippets are extracts from a monthly service called the Journal Article Summary Service. It is a service that summarises all that is new in obstetrics and gynaecology over the preceding month. If you would like to know the details of how to subscribe, please email the editor Athol Kent at firstname.lastname@example.org or visit the website http://www.jassonline.com.
Although nausea and vomiting occur in most pregnancies, in only about 1% are symptoms severe enough to be labelled as hyperemesis gravidarum. The condition can lead to dehydration with metabolic disturbances including ketosis and a range of deficiencies can result if it is inadequately treated. Fetal compromise in the form of low birthweight and preterm delivery are commoner in hyperemesis sufferers than in the general population.
The cause is unclear despite its correlation with human chorionic gonadotrophin levels, and psychological research based on recurrence in subsequent pregnancies has not proved conclusive. The possibility of a genetic influence is supported by statistics showing that once a woman has one pregnancy with hyperemesis she is 20 times more likely to be a ‘serial sufferer’ than a woman who did not have a pregnancy with excess symptoms. Now firmer evidence is reported linking mothers and daughters through a Norwegian birth registry survey (Vikanes et al. BMJ 2010;340:c2050).
The researchers found that women whose mothers had hyperemesis had a three-fold increased risk of developing the condition themselves. If the woman’s partner had a mother with a history of hyperemesis this did not raise the woman’s risk, suggesting that fetal genes are not influential. It is concluded that the predisposition to the condition is genetically influenced through the mother and is not fetally determined.
For real inroads to be made into global maternal mortality rates, the situations and settings where most women die need to be addressed. Ninety-nine percent of deaths occur in countries with poor resources and the leading cause is postpartum haemorrhage, which accounts for 125 000 deaths per annum.
In a well-resourced setting women seldom die from postpartum haemorrhage so prevention with uterotonic agents and treatment with intravenous fluids and medical interventions do work. Where most of the deaths occur, intravenous fluids and skilled attendants are not available, nor are the best uterotonic agents. What should be considered is the wider distribution of misoprostol, which works nearly as well as intramuscular oxytocin despite having more side effects.
Misoprostol could be made available to communities and individual pregnant women where it is anticipated that there will be delivery at home in countries where medical services are largely unobtainable. This would save lives but ethically it is difficult for opinion leaders such as the World Health Organization (WHO), to recommend the use of one drug (misoprostol) where evidence exists of a superior option (oxytocin).
This is where evidence-based medicine and pragmatism meet head-on. Being pragmatic means advocating action that is dictated more by practical consequence than by theory.
Collecting further evidence for the use of misoprostol versus placebo in randomised trials for the primary prevention of postpartum haemorrhage would be unethical because we know it is a powerful uterotonic so other evidence will need to be relied upon (Prate et al. Health Policy 2009;89:131–48 and Sloan et al. BJOG 2010;117:788–800).
Potts et al. (Lancet 2010;375:1762–3) suggest that WHO and the International Federation for Obstetrics and Gynecology initiate a worldwide debate on the value of supplying misoprostol where alternative uterotonic agents are not readily available.
Academics provide data about the best uterotonics from properly conducted randomised studies but the results of these trials only apply where similar background situations exist. Where the best uterotonic agents are not available the findings of such studies do not apply. Surely this is where pragmatism should trump theory?
Maternal vitamin A
Adequate maternal levels of vitamin A are essential in early pregnancy for normal lung development in the fetus. Vitamin A regulates growth through cell proliferation and differentiation and children born to mothers in areas of deficiency may suffer from suboptimal alveolar development.
In the 1990s mothers in Nepal were given vitamin A, beta-carotene or placebo as part of a trial on the effects of supplementation on pregnancy outcomes and then 10 years later their children had their pulmonary function studied (Checkley et al. N Engl J Med 2010;362:1784–94). Lung function results were improved in those children who had received as newborns (and whose mothers had received) vitamin A compared with those given beta-carotene or placebo as measured by their forced expiratory volume. Populations experiencing chronic vitamin A deprivation should be provided with supplementation antenatally as well as subsequently through the child’s school years for optimal lung development.
On the other side of the coin, vitamin A supplementation has been shown not to reduce maternal mortality in Ghana (Kirkwood et al. Lancet 2010;375:640–9). Although Ghana has one of the highest maternal mortality rates in the world, the people of Ghana seldom suffer from night blindness, which is a manifestation of vitamin A deficiency, so it may be that supplementation did not benefit the women in a clinically discernible manner.
Supplementation is not going to be the magic bullet that will allow deprived nations to achieve their Millennium Development Goal of a 75% reduction in maternal mortality ratios by 2015. Progress toward the goals is described by Hogan et al. (Lancet 2010;375:1609–23) and their report deserves to be read by all who are concerned about women’s health globally.
Multiple sclerosis and vitamin D
It is possible that there is a link between low vitamin D levels in the mother and multiple sclerosis in her offspring. Vitamin D is generated by ultraviolet radiation so if the association is true, then a woman with less exposure to sunlight during the first trimester may be at risk of her child developing the disorder compared with women whose early pregnancies occur in sunnier months.
Such data exist for the northern hemisphere and now research from Australia finds evidence that supports similar trends (Staples et al. BMJ 2010;340:C1640). Month of birth and, by regression, first trimester sun exposure did correlate with the prevalence of multiple sclerosis in a linear fashion. The work does take ambient sunlight as a proxy for vitamin D status and did not allow for individual behaviour or supplemental intake but the findings do bolster the hypothesis of a causative association.
Bisphosphonates and fractures
Osteoporosis is frequently treated with bisphosphonates, which preserve bone mineral density by decreasing osteoclastic activity. This reduces the risk of fractures both during treatment and for some years thereafter, making these an important modality of fracture prevention in millions of women and men. Among the fractures that are reduced are hip and femoral neck breaks, which typically occur supratrochanterically and can cause death or morbidity as well as having devastating effects on independence and quality of life.
Bisphosphonates have a good safety record but reports have been appearing of atypical femoral shaft fractures attributable to their use. Although such fractures comprise <5% of all hip or femur fractures there have been concerns about ongoing bisphosphonate presription. Black et al. (N Eng J Med 2010;362:1761–7) with an accompanying editorial by Shane (N Engl J Med 2010;362:1825–7) researched all hip and femur fractures in people participating in randomised trials of bisphosphonates and found atypical fractures to be very rare, even in women treated for many years, so these agents should continue to be prescribed to reduce femoral neck, intertrochanteric and many other fractures in osteoporotic women and men.
Pregnancy health after bariatric surgery
Obesity is a risk factor for all forms of hypertension in pregnancy so bariatric surgery may be of benefit to overweight women who subsequently conceive. Extreme obesity with operative intervention, mainly in the form of gastric bypass, is becoming increasingly common in the USA.
A retrospective study by Bennett et al. (BMJ 2010;340:C1662) showed that weight loss after surgery resulted in lower rates of pre-eclampsia, chronic hypertension and gestational hypertension compared with a similar cohort of women delivering before surgery. The results were valid even after confounding variables such as age, diabetes and multiple pregnancies were taken into account so this means of weight loss may be increasingly attractive to obesity sufferers who seek a potentially healthier pregnancy.
Expectant and new fathers are at risk from depression. About one in ten experience antenatal or postpartum mood disruptions with the most frequent time for the appearance of ‘the blues’ being 3–6 months after delivery.
Given the personal, family and child developmental trauma associated with maternal depression, it would be surprising if the paternal effects were different. Paulson and Bazemore (JAMA 2010;303:1961–9) found a moderate correlation with maternal mental ill-health. Early interventions yield good results so perhaps the mother’s postnatal visit should include the father or at least an enquiry as to how he is coping?
Bowel cancer is the second most common cause of death from malignancies after bronchial carcinomas in developed countries. As gynaecologists we advise on routine screening, so should we discuss colorectal cancer detection with the women we see?
The answer is yes, according to the clear-cut results of a UK study that looked at screening for bowel cancer in asymptomatic women and men undergoing a 5-minute sigmoidoscopy examination. A national survey screening 55- to 65-year-olds showed that examining the lower part of the bowel by flexible sigmoidoscopy reduced the incidence of bowel cancer by one-third (Atken et al. Lancet 2010;375:1624–33).
The randomised trial took place over 16 years across the nation and the procedure was carried out by doctors or specially trained nurses in outpatient clinics. All small polyps were removed during the procedure and large or suspicious lesions were referred for colonoscopy. Mortality from bowel cancer was reduced by 43% in the intervention group and one life would be saved for every 400 screenings, which is far more effective than mammography or cervical cancer testing. If holistic medicine is your aim it may be time to add sigmoidoscopy screening to the advice given to your mature patients.
Mobile phones and brain tumours
There have been concerns that mobile phone use could be linked to brain tumours. Mobile phones are connected to cellular networks (hence the alternative name: cell phones) and do emit radiation, albeit in minimal doses, but links to gliomas or meningiomas have some theoretical basis although this has never been proven experimentally. Now a case–control study by Cardis et al. (Int J Epidemiol doi: 10.1093/ije/dyq079) has found no increase in risk comparing the time spent using a mobile phone by people developing these tumours and matched controls.
It is the largest study to date but it was retrospective and the subjects averaged only a few hours per month ‘on the air’, considerably less than those clocked up by today’s enthusiasts. So while there is no direct proof of harm the researchers remain cautious, citing heavy use and younger users as factors yet to be taken into account when talking about mobile phone safety.