Preimplantation genetic diagnosis: patients' experiences and attitudes

BACKGROUND: This study aims to report the experiences and attitudes of patients who have undergone preimplantation genetic diagnosis (PGD). The extent to which this technique is acceptable to the individuals for whom it is intended is relatively unexplored, and remains a crucial issue that may ultimately determine the value of PGD as an alternative to prenatal diagnosis in high-risk couples. METHODS: An information sheet and questionnaire was distributed to 67 couples who had been treated at the Hammersmith Hospital, London and the Dexeus Institute, Barcelona. RESULTS: One-third of patients had an affected child, over half had previous experience of conventional prenatal diagnosis and over one-third had had terminations of pregnancy because of a genetic risk. Patients perceive the main advantage of PGD to be that only unaffected embryos are transferred to the uterus and thus therapeutic termination of pregnancy can be avoided; the main disadvantage is the low success rate. A total of 41% of patients found the treatment cycle extremely stressful, and, of the 20 patients who had experienced both prenatal diagnosis and PGD, 40% of patients found PGD less stressful, although 35% experienced more stress. Of those couples who contemplated a further pregnancy 76% would choose PGD, 16% would opt for prenatal diagnosis, and 8% no tests at all. CONCLUSIONS: The experience of prenatal diagnosis and termination of pregnancy can be an unwelcome memory and this leads to a demand for an alternative approach. Our data suggest that PGD is acceptable to patients and is a valuable alternative to prenatal diagnosis.     

Ethical considerations on preimplantation genetic diagnosis for HLA typing to match a future child as a donor of haematopoietic stem cells to a sibling

Recently, several requests were made by couples with an affected child who wanted preimplantation genetic diagnosis (PGD) to select embryos in the hope of conceiving an HLA identical donor sibling. This article considers the ethical arguments for and against the application of PGD for this goal. Only embryos HLA matched with an existing sibling in need of a compatible donor of haematopoietic stem cells would be transferred. The main arguments are the instrumentalization of the child, the best-interests standard, the postnatal test for acceptability and the experience of the donor child. It is argued that conceiving a child to save a child is a morally defensible decision on the condition that the operation that will be performed on the future child is acceptable to perform on an existing child. The instrumentalization of the donor child does not demonstrate disrespect for its autonomy or its intrinsic worth.     

Potential dangers in the customary methods of conducting meta-analyses. Recombinant versus urinary follicle stimulating hormone.

The customary method of combining success rates in meta-analyses may often result in serious biases, leading to erroneous inferences. This arises because of an inadmissible pooling of frequencies from heterogeneous sources. The fundamental statistical principle, that the magnitude of an 'effect' should always be tested against the variation in that effect over the sample, may not therefore be satisfied. A simple, but rigorous, alternative method is described.     

Sharing information with donor insemination offspring. A child-conception versus a family-building approach

This paper suggests an innovative approach to the sharing of information between parents and their donor-conceived offspring. The 'family-building' approach is offered in the hope that it will stimulate discussion and development. Traditionally, the emphasis has been on telling the child about his/her donor conception. This has the potential to unintentionally separate the child from the parents. The family-building approach presents donor conception as an issue concerning all members of the family, thus encouraging the child to see him/herself as an integral part of this family's history. Within this approach, the semen provider is acknowledged for his contribution and for having an ongoing significance in the family. It is important, however, to clearly differentiate between him as the genitor and the child's father as the loving and nurturing male in the family. Implications for professionals include the need to acknowledge that donor insemination does not only enable a woman to become pregnant but that it creates a family with a past, present and future. Therefore it will be helpful to provide information about and explore attitudes towards this type of family-building before couples start treatment.     

Why does hydrosalpinx reduce fertility? The importance of hydrosalpinx fluid

The debate on hydrosalpinx and impaired IVF outcome has mainly focused on the best treatment before IVF and on functional surgery as an alternative treatment. We would like to initiate a debate on the possible reasons why the outcome is impaired. We know that salpingectomy is effective in terms of improved birth rates after IVF, but we do not know exactly why. The main focus is on embryotoxic properties of the hydrosalpinx fluid, which include micro-organisms, endotoxins, cytokines, oxidative stress and lack of nutrients. The endometrial receptivity may be reduced as an effect of disturbed expression of the cytokine cascade, which is essential for implantation. The presence of excessive fluid in the uterine cavity may also be a mechanical hindrance to implantation. We believe that the hydrosalpinx fluid is of crucial importance, but the actual mechanism of action needs to be clarified.     

Ovary and ovulation: A model conforming the decline in follicle numbers to the age of menopause in women

The store of primordial follicles in the ovary is fixed beforebirth and dwindles with age until it is unable to provide enoughGraafian stages to sustain menstrual cyclicity. According toa simple bi-exponential model of ageing, the rate of follicledisappearance increases at age 37.5 years (or when 25 000 folliclesremain) so that the numbers fall to approximately 1000 at 51years, the median age of menopause in the population. This studyattempts to produce a biologically more realistic model of fofficledisappearance and harmonizes follicle dynamics with the distributionof menopausal ages from an American survey. The step-changein the rate of fofficle attrition was replaced by a model whichassumed that this rate changes more gradually with the sizeof the follicle store. This produced a distribution of predictedmenopausal ages (based on an assumed threshold of 1000 follicles)which was closer to observed data. The fit further improvedwhen the model was modified by having a threshold that variedacross the population. Using such a stochastic threshold modelfor menopause, the number of fertile years remaining could beforecast with an acceptable margin of uncertainty if it everbecomes possible to estimate the size of the follicle storein vivo.     

Semen production in adolescent cancer patients

BACKGROUND: The influence of an accompanying person (parent, guardian or nurse) on the ability of an adolescent (post-pubescent, <20 years of age) to produce a semen sample for cryopreservation, is undetermined, as is the potential for use of urine samples to retrieve sperm in those adolescents that are unable to produce a semen sample. METHODS: The records from 1991-2000 inclusive were reviewed to derive those adolescent patients who were unable to produce semen for cryopreservation prior to undergoing treatment for a malignant condition. RESULTS: During the study period 238 adolescents attended our unit of whom 205 (86.1%) banked semen ('producers'). The remaining 33 adolescents (13.9%) were initially unable to produce a sample ('non-producers'), four of these provided a urine specimen for analysis (12.1%) and of these one had sufficient sperm for cryopreservation. Of the 'accompanied' patients 29.7% (19/64) were non-producers while in the 'unaccompanied' patients only 8.0% (14/174) were non-producers (chi(2) = 16.58, P < 0.001). The relative risk (RR) of not producing a semen sample for the accompanied group of patients was greater than that for the unaccompanied group (RR = 3.689, 95% confidence interval: 2.0-6.9). One patient returning alone successfully provided a semen sample for storage. CONCLUSION: Units should consider the effect of the presence of an accompanying person when an adolescent is unable to produce a semen sample and should consider requesting urine to retrieve sperm.     

Differential distribution of aneuploidy in human gametes according to their sex.

The cytogenetic study of human gametes is a new and important source of information because most chromosomal abnormalities originate from meiotic disorders. The frequency and type of abnormalities were analysed in both spermatozoa and mature oocytes. A total of 13,975 human sperm chromosome complements and 1897 oocyte chromosome complements were analysed. In the present study, pooled cytogenetic data on human gametes have been examined to determine and compare the distribution of non-disjunctions in male and female gametes. Human spermatozoa are characterized by a significant excess of hypohaploidy and an equal distribution of aneuploidies among all chromosome groups, whereas mature oocytes display an equal ratio of hypohaploidy to hyperhaploidy and a high variability in the distribution of non-disjunction: in particular, there is a significant over-representation of aneuploidies in both D and G chromosome groups. This indicates that non-disjunction is not a random event in female meiosis and, consequently, that there are differences in the meiotic process between the sexes. Meiotic and environmental factors which could explain the non-random malsegregation of chromosomes in female meiosis are discussed. The role of maternal age as a cause of aneuploidy is questioned.     

Polycystic ovary syndrome in adolescence--a therapeutic conundrum

The polycystic ovary syndrome (PCOS) often presents in adolescence with menstrual disorders, acne and hirsutism. The early diagnostic signs are sometimes dismissed as 'normal' changes of adolescence, and the opportunity to save the teenager from the stigmata of the syndrome is missed. The finding that the metabolic syndrome is a possible long-term sequela of PCOS now presents a challenge to make an early diagnosis, educate patients regarding the importance of weight control and exercise, and treat accordingly both symptomatically and prophylactically. The use of long-term insulin sensitizers, particularly metformin, for these purposes in adolescents is now the subject of an inter-disciplinary debate. Good, hard supportive data are not yet forthcoming but, as in the adult, the establishment of metformin treatment for the hyperinsulinaemic adolescent with PCOS may precede the evidence.     

Analysis of CGG variation through 642 meioses in Fragile X families

Fragile X syndrome is the commonest familial form of inherited mental retardation. The molecular defect is an expansion of the CGG trinucleotide repeats in the 5' untranslated region of the FMR1 gene that is inherited in an unstable fashion in fragile X families. In an attempt to provide more information about the CGG tract intergenerational variation, we have evaluated 642 transmissions in 175 Fragile X families. PCR and Southern blot (StB12.3) was used to analyse the CGG number. Among premutated alleles, 90.2% showed expansion, two-thirds to a full mutation while the rest remained in the premutation range, 5.5% of alleles did not vary and finally 4.3% of them reduced in size. Premutated females showed an increased risk of expansion to the full mutation depending on the CGG tract. The estimated risk for 80 triplets is more than seven times that of a woman carrying 59 CGG, the risk being 100% for alleles of >100 repeats. Fifty-nine repeats was the smallest allele that expanded to full mutation. Contractions were detected more frequently in males than in females, being statistically significant. This study contributes to the literature by increasing the data available regarding transmissions in Fragile X families and it allows us to perform more precise genetic counselling for women with the CGG repeat in the premutation range.     

The ICMART glossary on ART terminology

The International Committee Monitoring Assisted Reproductive Technologies (ICMART) is an independent, international non-profit organization that has taken a leading role in the development, collection and dissemination of worldwide data on ART. Information on availability, efficacy and safety is provided to health professionals, health authorities and the public. The glossary facilitates dissemination of ART data through a set of agreed definitions as seen in the most recent World Report on ART. It provides a conceptual framework for further international terminology and data development of ART.     

Sex hormones and cardiovascular risk.

Inspection of the age-incidence curve of ischaemic heart disease in both sexes shows an increase in slope for women around the menopause, approaching that of men at older ages. Although the increase is likely to be related to the menopause, epidemiological evidence is not defined. Likewise, there is some suggestion that reproductive factors may be related to the subsequent risk of cardiovascular diseases, since a few studies found an elevated risk in women with an earlier first birth. In terms of prevention and public health considerations, treatments via exogenous hormones are, however, much more important. A systematic overview of the available epidemiological evidence indicates that oestrogen replacement treatment is protective against ischaemic heart disease. The overall relative risks based on 18 studies and greater than 3300 cases was 0.81, with a narrow 95% confidence interval (0.76-0.85), thus suggesting a protective effect of 15-25%. This protection has a plausible biological interpretation in terms of increased high density lipoprotein (HDL) levels. The serum lipoprotein pattern can be unfavourably influenced by progestin supplementation. With reference to oral contraceptives, the relative risk for cardiovascular mortality was increased about twofold in current users. There appears now to be convincing evidence that the elevated risk is restricted to current users.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endometriosis and unexplained recurrent spontaneous abortion: pathological states resulting from aberrant modulation of natural killer cell function?

The observation that natural killer (NK) cell activity is abnormally low in endometriosis patients and abnormally high in women with otherwise unexplained recurrent spontaneous abortion represents, at present, an intriguing curiosity. There is evidence suggesting that these conditions are associated with an opposite regulation of NK cell behaviour. This review discusses these observations and potential relationships.     

The Mesothelium, Teflon or Velcro? Mesothelium in endometriosis pathogenesis

Sampson's transplantation theory for the pathogenesis of peritoneal endometriosis is widely accepted. The events that take place, however, on the cellular and subcellular level during the transition of endometrial tissue in the abdominal cavity into peritoneal endometriosis remain controversial. The mesothelium plays a central role in the debate on this subject.The interaction between endometrium and peritoneum has been studied in an in-vitro model using amnion, peritoneum and mesothelial cells in culture on the one hand and cyclic and menstrual endometrium on the other hand. The results of these studies indicate that (i) an intact mesothelial lining prevents adhesion of shed endometrial tissue, (ii) shed endometrial tissue adheres to the peritoneal extracellular matrix and (iii) menstrual effluent creates its own adhesion sites by damaging the mesothelial lining thus exposing the extracellular matrix. Therefore we conclude that the mesothelium has the properties of Teflon, while the extracellular matrix resembles Velcro.     

Isolation of human cationic antimicrobial protein-18 from seminal plasma and its association with prostasomes

BACKGROUND: Cathelicidins are a group of antibiotic peptides with broad antimicrobial activity. They are considered to be an essential part of the innate immune system. The only known human cathelicidin is the human cationic antimicrobial protein (hCAP-18), from which the antimicrobial peptide LL-37 is released. METHODS AND RESULTS: In the present study, we purified hCAP-18 from seminal plasma and confirmed its identity by N-terminal amino acid sequencing. Gel filtration of seminal plasma showed the presence of hCAP-18 in both a low and a high molecular weight peak. Fractions corresponding to the high molecular form of hCAP-18 also contained dipeptidyl peptidase IV (CD26), a prostasome marker. This finding suggested that hCAP-18 found in fractions corresponding to high molecular weight molecules, is prostasome-associated. Flow cytometry confirmed the association of hCAP-18 with prostasomes and indicated that the molecule is surface bound. Western blot showed the presence of intact hCAP-18 in sperm, prostasomes and ultracentrifuged seminal plasma. CONCLUSIONS: These findings suggest that hCAP-18 may have an important role in antimicrobial defence during human reproduction. The binding of hCAP-18 to prostasomes indicates that protasomes can serve as a reservoir of this precursor of the antibiotic peptide LL-37.     

Is chromosome analysis mandatory in the initial investigation of normovulatory women seeking infertility treatment?

BACKGROUND: There is no agreement about the frequency of chromosomal abnormalities (CAs) in the female partner of an infertile couple and therefore there is no evidence base for determining whether karyotype analysis is mandatory before the initiation of infertility treatment. The aim of this prospective study was to estimate the prevalence of karyotype abnormalities in normovulatory women attending an infertility clinic and compare it to that known to be present in the newborn female population. METHODS: Cytogenetic testing was performed in 1206 women with normal ovulatory cycle seeking infertility treatment. At least 15 GTG-banded metaphases were analysed in each case. In the case of a structural abnormality, fluorescent in situ hybridization (FISH) analysis and high resolution banding (HRB) were performed on a new blood sample to elucidate the aberration. When mosaicism was suspected, the number of analysed metaphases was increased to a total of 115 and an additional analysis of 200 metaphases was done on a second blood sample. RESULTS: A chromosomal abnormality was demonstrated in 0.58% (95% CI: 0.28-1.19) of cases which did not differ significantly from that reported in female newborns (0.79%; 95% CI: 0.68-0.94). Balanced reciprocal translocation was observed in 0.4% of patients (n = 5), paracentric inversion of chromosome X in 0.08% (n = 1) and gonosomal mosaicism in 0.08% (n = 1). However, chromosomal aberrations were less common among females with primary infertility compared to those with secondary infertility (0.25 versus 1.25%, P = 0.04). CONCLUSIONS: The present study suggests that routine cytogenetic analysis cannot be advocated in normovulatory infertile women. Nevertheless, the relatively higher frequency of abnormal karyotypes in women with secondary infertility indicates that this subgroup of patients might benefit from a routine karyotype analysis.     

Is adenomyosis an immune disease?

Adenomyosis is characterized as ectopic endometrial tissueswithin the myometrium in the uterus. The only difference betweenadenomyosis and endometriosis is the site of endometriotic tissues:inside or outside of the uterus. It is well known that endometriosisis frequently associated with various autoimmune phenomena.This short review covers various aspects of the immune cascadefound in adenomyosis. In adenomyosis, a series of immune responsesis activated, including changes in both cellular and humoralimmunity, i.e. a strong expression of cell surface antigensor adhesion molecules, an increased number of macrophages orimmune cells, and deposition of immunoglobulins and complementcomponents. Furthermore, the disease exhibited high frequencyof autoantibodies in peripheral blood. Thus, an immunological'vicious circle' is formed in the endometrium in adenomyosis.Endometrial cells seem to be under immunological stress, protectingthemselves by exposing health shock proteins. It is concludedthat the endometrial environment in adenomyosis differs widelyfrom that in normal fertile women. These abnormal immune responsesmight be involved in poor reproductive performance in adenomyosis.     

The importance of fibroblasts in remodelling of the human uterine cervix during pregnancy and parturition

It is well established that fibroblasts play a crucial role in pathophysiological extracellular matrix remodelling. The aim of this project is to elucidate their role in normal physiological remodelling. Specifically, the remodelling of the human cervix during pregnancy, resulting in an enabled passage of the child, is used as the model system. Fibroblast cultures were established from cervices of non-pregnant women, women after 36 weeks of pregnancy and women directly after partus. The cells were immunostained and quantified by western blots for differentiation markers. The cultures were screened for cytokine and metalloproteinase production and characterized by global proteome analysis. The cell cultures established from partal donors differ significantly from those from non-pregnant donors, which is in accordance with in vivo findings. A decrease in alpha-smooth actin and prolyl-4-hydroxylase and an increase in interleukin (IL)-6, IL-8 and matrix metalloproteinases (MMP)-1 and MMP-3 were observed in cultures from partal donors. 2D-gel electrophoresis followed by mass spectrometry showed that the expression of 59 proteins was changed significantly in cultures of partal donors. The regulated proteins are involved in protein kinase C signalling, Ca2+ binding, cytoskeletal organization, angiogenesis and degradation. Our data suggest that remodelling of the human cervix is orchestrated by fibroblasts, which are activated or recruited by the inflammatory processes occurring during the ripening cascade.     

How identical would cloned children be? An understanding essential to the ethical debate

The ban on human cloning in many countries worldwide is founded on an assumption that cloned children will be identical to each other and to their nuclear donor. This paper explores the scientific basis for this assumption, considering both the principles and practice of cloning in animals and comparing genetic and epigenetic variation in potential human clones with that in monozygotic twins.     

Cytokines and the hypothalamic--pituitary--ovarian--endometrial axis

Recently, the demarcating boundaries that allowed separationof the fields of reproductive biology, endocrinology, immunologyand neurobiology have faded. The missing link that now tiesthese disciplines together is the understanding that the languageby which cells communicate within these diverse systems is unanimous.This language is the network of products collectively calledcytokines. The effect of these factors spans from the hypothalamusto the endometrium and is undoubtedly involved in the maintenanceof the delicate balance within the hypothalamic—pituitary—gonadal—endometrialaxis. Orchestrated networks of these cytokines also seem tobe linked to the steroid hormone signals, an essential featurefor maintenance of normal menstrual cycles. Evidence in favourof these emerging concepts is discussed. Major emphasis is placedon interferons, interleukins, tumour necrosis factor, transforminggrowth factors and colony-stimulating factors.