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It is proven that folic acid supplementation reduces the incidence of neural tube defects. Whether adding folate to a woman’s diet periconceptually makes any difference to the incidence of cleft lip, with or without cleft palate, is unknown. To investigate such a connection, Wilcox et al. (BMJ 2007;334:464–7) looked at the diets of Norwegian women whose child was born with a facial cleft and compared them with diets of the controls. Folic acid supplementation in early pregnancy was associated with one-third decreased risk of cleft lip, whereas a diet rich in fruits, vegetables and other foods containing folate somewhat only reduced the risk. Not surprisingly, the lowest incidence was in women with folate-rich diets who took multivitamin supplements containing folate. With clear benefits in pregnancy, it is difficult to understand why folate fortification of wheat, cornflower and rice is not routine in all countries. It is practised in Brazil, Canada, Chile, Costa Rica, Jordan, South Africa and the USA but not in Europe and other developed countries (Bille et al., BMJ 2007;334:433–4). There is also theoretical advantage of adding folate to reduce homocysteine levels, which are in turn linked to lesser risk of cardiovascular disorders. The evidence is there for reduced birth defects, so what more is required? While on the subject of supplementation, giving multi-micronutrients to malnourished pregnant women seems to be a good idea. Gupta et al. (Arch Pediatr Adolesc Med 2007;161:58–64) showed that women with a mean body mass index of less than 18 kg/m2 had heavier and longer babies compared with those given iron and folate only. These were disadvantaged women in an urban setting in India so the results cannot be extrapolated to more privileged situations, but this research points to inadequate diets in the poor as a cause of growth restriction. Some women diagnosed with early breast cancer in one breast are later found to have cancer in the other breast also. Even careful clinical examination and mammography can fail to identify early lesions, so the question arises as to whether more extensive investigations, such as magnetic resonance imaging (MRI), should not be carried out routinely at the time of the initial diagnosis. Lehman et al. (NEJM 2007;356:1295–303) report on nearly 1000 women across the USA who had early cancer in one breast, with negative mammography and clinical examination in the other, and then had MRI of the ‘cancer-free’ breast. Within 1 year of the initial diagnosis, they found 3% of the women had or developed cancer in the contralateral breast. The sensitivity and specificity were not as high as ideally required in a screening test, but with a negative predictive value of 99%, women may well find it acceptable. The cancers found in the contralateral breast were all early and had not spread, so MRI evaluation should be considered if malignancy is found in one breast, even if routine investigations are apparently negative. The proportion of male babies born is known as the secondary sex ratio. There are various natural and unnatural ways this sex ratio can be affected. For instance, parental age or relative infertility may sway the balance, and these are natural forces, whereas environmental toxins or feticide of female fetuses to select a male child are extremely unnatural. Recent observations suggest that subfertility, as reflected by a delay in conceiving, may tip the sex ratio more in favour of male sex. Gathering such data obviously requires large numbers and information about the duration of delay when trying to conceive. Now Joffe et al. (BMJ 2007;334:524–6) provide evidence from four large European databases showing that the time-to-pregnancy interval has no bearing on the secondary sex ratio. No matter how short or long a couple takes to conceive, this time has no bearing on the sex of the child. It is interesting that although an equal chance of either sex is present at conception, more boys than girls are born. Somehow embryologically, boys are favoured, giving a secondary sex ratio of 51% which varies only slightly within narrow limits (Bonde, BMJ 2007;334:486–7). Thereafter, girls survive better, mature faster and live longer, which provides a natural demographic balance. Problems arise when humans interfere, as is happening in China, where 117 boys are born for every 100 girls, and in India, where for sociological reasons female feticide is practised which will lead to huge societal stresses. This is genetic and social engineering of the worst kind and is destined to haunt these cultures in ways that can only be imagined. Oral contraceptives (OCs) are known to decrease a woman’s risk of developing epithelial ovarian cancer. However, the dose of estrogens and progestins in OCs have come down in recent years, so it is unclear if the protection previously offered still holds. Lurie et al. (Obstet Gynecol 2007;109:597–607) conducted a case–control study on more than 700 women with epithelial ovarian cancer that took into account the woman’s OC history and matched them with controls who may or may not have used OCs. Their results were conclusive. OCs were effective in decreasing the risk of cancer, and the lowest formulations offered the strongest protection. The authors postulate that the antiovulatory mechanisms of OCs are the key factors in reducing malignancy rates and that women taking the lower dose pills are more likely to be compliant compared with high-dose users. Consistency of use rather than the hormonal dose probably explains the effect, and a reduction in ovarian cancers may well continue because of OC use. The Perspective piece by Ecker and Frigoletto (NEJM 2007;356:885–8) is refreshing. It gives the US view of their ever-climbing caesarean rate, which has now reached 30% and shows no signs of slowing. On the contrary, they believe it will continue to escalate and describe a realistic picture of a 21st century American woman’s view of reproduction. The modern US woman is fully and assertively emancipated in a consumer-oriented, highly competitive society. Demand is high for quality services, and there is a massive amount of information and communication exchange. The American woman is well informed and is able to access data electronically with a facility far greater than that for her European sister. They are different to a generation ago in that over the past 20 years obesity has doubled, their age at first delivery is 4 years older and the proportion of those older than 35 years is twice what it was. The number of multiple gestations has doubled, and preterm delivery rates are rising. During this century, vaginal breech deliveries have become obsolete, and operative vaginal deliveries have halved to 5%. Induction rates are at 20%, with elective timing of attempted vaginal delivery seemingly a legitimate way of managing an otherwise normal pregnancy. Vaginal deliveries after a previous caesarean section have dropped from 30% a decade ago to less than 10%. These are the practicalities but possibly more important is the perception of US obstetricians that they are providing care ‘amidst a malpractice crisis’. They face an average of three lawsuits against them during their careers, and the risk of being sued for failing to carry out a timely caesarean section is readily accepted as a reason to literally ‘cut their losses’ and resort to an abdominal delivery for lesser and lesser indications. This combined with a zero tolerance for less than optimal outcomes and statistics showing odds, however small, in favour of caesarean sections being in everyone’s short-term interest, the continuing rise in caesarean section rates in the USA seems inevitable. Women donate eggs for two reasons. First, for other women to conceive, and second, for research. Both are dogged by controversy on medical, societal and financial grounds. The USA and the UK are currently trying to create guidelines and legislation that will allow workers in assisted reproduction and laboratory research to operate without fear of prosecution. Infertile women undergoing in vitro fertilisation (IVF) are usually given some form of gonadotrophin-releasing hormone (GnRH) to stimulate multiple oocyte production. This hyperstimulation and harvesting result in more oocytes than can be used in fertilisation and embryo transfer in any given cycle, so there are spare oocytes for later use by the woman or for donation. Whether the stimulation should be with GnRH agonists or antagonists is one debate and another is whether one or two embryos should be transferred. What is not in question is that the demand for oocytes far exceeds supply. Women younger than 35 years have significantly higher IVF success rates than older women, precisely the group who are now more often seeking reproductive assistance. The result is that the donation or sale of oocytes has become a big issue. Clearly, the unauthorised harvesting of oocytes is illegal as an Israeli doctor has found to his cost (BMJ 2007;334:557), but what about consented donations to infertile women? The free donation of ‘extra ova’ from women to their infertile fellow patients seems straightforward enough, but already the problem of incentives has arisen. In private clinics, can these spare oocytes be bought or can the woman be given a discount for her treatment if she donates? This discount for donation occurs in the UK where 75% of all IVF procedures are funded by the patients themselves despite decrees that all infertile couples are entitled to four IVF cycles within the NHS (Ledger, Lancet 2007;369:717–18). Moving further along the continuum, is it acceptable for a woman who has no fertility problems to supply oocytes for payment? In the USA it is, where thousands of babies are born annually from oocytes acquired from women who receive an average of $5000 per harvest (Spar, NEJM 2007;356:1289–91). The UK has the Human Fertilisation and Embryology Authority which is the regulator of IVF treatment. It has now ruled that altruistic oocyte donation, in conjunction with fertility treatment or not, is acceptable. The report by Mayor (BMJ 2007;334:445) made no mention of discounts for donations in the private sector—also known as ‘egg sharing’—so compensation for cooperation remains a grey area. Other places such as Singapore, Israel and South Korea allow donations but without payment or personal benefit. The role of oocytes in research is more complex, despite the fact they may not be bought for study purposes. Research falls into two categories—infertility or stem cell research. The former is not as contentious, despite using human reproductive material, but the latter is highly controversial because of using somatic cell nuclear transfer to create lines of stem cells, from which the US administration has withheld federal funding. The arguments go that without payment, women will not donate oocytes for research, but attracted by pay, women could be tempted to ‘sell their eggs’ in a competitive market to their own potential detriment.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.