RESUMEN
PURPOSE: Depressive symptoms often occur among women of reproductive age. In this article we perform an analysis of existing studies to examine a possible correlation between depression and the use of hormone-based contraceptives. METHODS: The computerized databases MEDLINE/PubMed were searched for studies examining the relation between depressive disorders and hormonal contraception of the years 1976-2010. RESULTS: Data on this topic are limited. At least two confounding variables influence the analysis of the available data and make it difficult to draw firm conclusions: the inconsistent use of the term "depression" and the large number of combined contraceptives which vary in their composition. The association between the use of oral contraceptives and depression is not clear. We found that depression is not a common side effect of hormone-based contraceptives. CONCLUSION: Individual, patient-based decisions with consideration of the individual history and predispositions are recommended when starting oral contraceptives. If depressive symptoms or mood changes occur, decisions regarding discontinuation or medication change need to be made on an individual basis.
Asunto(s)
Anticonceptivos Hormonales Orales/efectos adversos , Trastorno Depresivo/inducido químicamente , Afecto/efectos de los fármacos , Femenino , HumanosRESUMEN
We report a European wide assessment of the economic burden of gastrointestinal nematodes, Fasciola hepatica (common liver fluke) and Dictyocaulus viviparus (bovine lungworm) infections to the ruminant livestock industry. The economic impact of these parasitic helminth infections was estimated by a deterministic spreadsheet model as a function of the proportion of the ruminant population exposed to grazing, the infection frequency and intensity, the effect of the infection on animal productivity and mortality and anthelmintic treatment costs. In addition, we estimated the costs of anthelmintic resistant nematode infections and collected information on public research budgets addressing helminth infections in ruminant livestock. The epidemiologic and economic input data were collected from international databases and via expert opinion of the Working Group members of the European Co-operation in Science and Technology (COST) action COMbatting Anthelmintic Resistance in ruminants (COMBAR). In order to reflect the effects of uncertainty in the input data, low and high cost estimates were obtained by varying uncertain input data arbitrarily in both directions by 20 %. The combined annual cost [low estimate-high estimate] of the three helminth infections in 18 participating countries was estimated at 1.8 billion [ 1.0-2.7 billion]. Eighty-one percent of this cost was due to lost production and 19 % was attributed to treatment costs. The cost of gastrointestinal nematode infections with resistance against macrocyclic lactones was estimated to be 38 million [ 11-87 million] annually. The annual estimated costs of helminth infections per sector were 941 million [ 488 - 1442 million] in dairy cattle, 423 million [ 205-663 million] in beef cattle, 151million [ 90-213 million] in dairy sheep, 206 million [ 132-248 million] in meat sheep and 86 million [ 67-107 million] in dairy goats. Important data gaps were present in all phases of the calculations which lead to large uncertainties around the estimates. Accessibility of more granular animal population datasets at EU level, deeper knowledge of the effects of infection on production, levels of infection and livestock grazing exposure across Europe would make the largest contribution to improved burden assessments. The known current public investment in research on helminth control was 0.15 % of the estimated annual costs for the considered parasitic diseases. Our data suggest that the costs of enzootic helminth infections which usually occur at high prevalence annually in ruminants, are similar or higher than reported costs of epizootic diseases. Our data can support decision making in research and policy to mitigate the negative impacts of helminth infections and anthelmintic resistance in Europe, and provide a baseline against which to measure future changes.
Asunto(s)
Enfermedades de los Bovinos/economía , Costo de Enfermedad , Infecciones por Dictyocaulus/economía , Fascioliasis/veterinaria , Enfermedades de las Cabras/economía , Enfermedades de las Ovejas/economía , Animales , Bovinos , Dictyocaulus/fisiología , Europa (Continente) , Fasciola hepatica/fisiología , Fascioliasis/economía , Cabras , Ovinos , Oveja DomésticaRESUMEN
Due to welfare concerns and legal restrictions in certain countries, alternatives to wire net floors must be developed in rabbit husbandries. Also, there is a difference in regulations in Europe for laboratory rabbits vs. rabbits bred and kept for meat production. While there are regulations concerning floor design of enclosures for rabbits bred for meat production in many European countries, the European Directive 2010/63 lacks regulations for rabbits used for scientific purposes. This study compares two floors, which meet the Austrian legal requirements for growing rabbits intended for consumption as well as the requirements for laboratory rabbits. The dual use of rabbits bred for meat production and applicable for scientific purposes would avoid the problem of surplus animals of specialized producers for laboratory rabbits. A noryl floor with 12â¯mm circular holes was compared to a 10â¯mm slatted plastic floor. Parameters were soiling of cages and animals, parasitic burden, clinical health, and losses using objective scoring. Soiling of cages and animals and coccidial oocytes were significantly higher on the floors with circular holes. Obvious signs of disease showed a non-significant trend to be more frequent in the group with circular holes. This was linked with significantly higher losses. In conclusion, our study clearly shows that the floor with circular hole design cannot be endorsed, although it meets legal requirements. The slatted floor type can be cautiously recommended; however, to assure animal welfare in laboratory rabbits, legal authorities in Europe should take on the responsibility of regulating floor design in this sector.
Asunto(s)
Crianza de Animales Domésticos , Bienestar del Animal , Pisos y Cubiertas de Piso , Vivienda para Animales , Conejos/fisiología , Animales , Animales de Laboratorio/fisiología , Coccidiosis/parasitología , Coccidiosis/veterinaria , Heces/parasitología , Pisos y Cubiertas de Piso/clasificación , Pisos y Cubiertas de Piso/legislación & jurisprudencia , Vivienda para Animales/legislación & jurisprudencia , Conejos/parasitologíaRESUMEN
Onchocerca lupi is an emerging zoonotic parasite infecting the ocular connective tissue of dogs, cats and humans. The only known case of canine ocular onchocerciasis in Germany was documented in 2002 in a shelter dog. However, the species of Onchocerca causing the infection could not be identified. Here, we report a case of the ocular infection with O. lupi in a dog, confirmed by PCR and sequencing of the cox1 gene. Further investigations are required to assess the risk factors for transmission and spread of the parasite in Germany.
Asunto(s)
Enfermedades de los Perros/parasitología , Infecciones Parasitarias del Ojo/veterinaria , Onchocerca/aislamiento & purificación , Oncocercosis Ocular/veterinaria , Animales , Gatos , Perros , Infecciones Parasitarias del Ojo/parasitología , Femenino , Alemania , Humanos , Oncocercosis Ocular/parasitología , Reacción en Cadena de la Polimerasa , Factores de Riesgo , SerogrupoRESUMEN
Endometrial cancer (EC) is the most frequent malignant tumor of the female genital tract. Increasing evidence suggests that at least two different types of EC exist. Type I is associated with an endocrine milieu of estrogen predominance. These tumors are of endometrioid histology and develop from endometrial hyperplasia. They have a good prognosis and are sensitive to endocrine manipulation. Type II EC is not associated with a history of unopposed estrogens and develops from the atrophic endometrium of elderly women. They are of serous histology, have a poor prognosis, and do not react to endocrine manipulation. Both types of EC probably differ markedly with regard to the molecular mechanisms of malignant transformation. This article reviews reproductive and lifestyle factors modifying the risk of developing type I EC, including the use of hormonal contraceptives, hormone replacement therapy and tamoxifen. The roles of established and novel therapies for precancerous lesions and for invasive EC in the adjuvant and palliative settings are discussed.
Asunto(s)
Neoplasias Endometriales/metabolismo , Estrógenos/metabolismo , Neoplasias Hormono-Dependientes/metabolismo , Anticonceptivos Hormonales Orales/metabolismo , Neoplasias Endometriales/etiología , Antagonistas de Estrógenos/metabolismo , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Factores de Riesgo , Tamoxifeno/metabolismoRESUMEN
The pulsatile release pattern of LH during the entire menstrual cycle is well defined; however, the response of corpora lutea to these LH pulses in patients suffering from corpus luteum insufficiencies (CLI) is largely unknown. Patients suffering from CLI were selected from infertile patients on the basis of low progesterone (P < 25 nmol/L) in a blood sample withdrawn during a monitoring cycle. During the next cycle, nine blood samples were collected during the follicular and luteal phase and follicular development was assessed by vaginal sonography. Of 109 patients who had a CLI in the monitoring cycle, 55 had a CLI again, and 38 women agreed to undergo assessment of pulsatile hormone secretion. These women again had P < 25 nmol/L at days 6 and 7 of the luteal phase and blood samples were withdrawn through antecubital vein catheters from 0900-1700 h at 10-min intervals on days 7, 8, or 9 following ovulation. From 38 patients with such defined CLI, 16 (42%) had no LH episode and significantly lower basal LH levels in comparison with 14 control subjects. Thirteen (34%) of the patients had normal appearing LH episodes despite too low P and E2 concentrations, but their CL did not react to the LH episodes. The remaining 9 patients (24%) had normal LH episodes; their CL reacted to these episodes, but their basal P levels were too low. In all blood samples LH was not only determined using an immunoassay but also by the mouse Leydig cell testosterone production bioassay. It could be established that no CLI exists, which is due to the release of bioinactive LH. It is anticipated that the differentiation of three different types of CLI, one of hypothalamic and two of ovarian origin, may allow the development of differential diagnostic and therapeutic tools in the future.
Asunto(s)
Cuerpo Lúteo/metabolismo , Hormona Luteinizante/metabolismo , Enfermedades del Ovario/fisiopatología , Adulto , Animales , Bioensayo , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Infertilidad Femenina/etiología , Infertilidad Femenina/fisiopatología , Células Intersticiales del Testículo/efectos de los fármacos , Células Intersticiales del Testículo/metabolismo , Hormona Luteinizante/sangre , Hormona Luteinizante/farmacología , Masculino , Ratones , Enfermedades del Ovario/complicaciones , Periodicidad , Progesterona/sangre , Prolactina/sangre , Testosterona/biosíntesisRESUMEN
Bioassays and immunoassays of protein hormones often read different parts of the molecule and give conflicting results. Therefore, we studied the LH bioactivity (bLH; mouse Leydig cell testosterone production assay) and immunoreactive LH (irLH) using five immunoassays [one conventional polyclonal RIA and four immunometric sandwich assays using monoclonal antibodies (mAB)] in five women suffering from polycystic ovarian disease (PCOD). Blood samples were taken from these patients at 10-min intervals for 24 h. Data were analyzed by the PC Pulsar pulse detection program. As described by others, bLH is increased in PCOD patients, and LH pulse frequency is largely accelerated (18-28 pulses/24 h). Almost every LH pulse was detected by the polyclonal RIA, whereas all mAB immunoassays detected significantly fewer pulses than the bioassay or the RIA. Occasionally, irLH pulses were detected by some assay systems when bLH activity did not increase, and there was a great difference in the temporal occurrence of bLH and irLH pulses. It is concluded that the type of immunoassay used for the detection of LH levels is also of importance for the number of detected LH pulses. Furthermore, each mAB immunoassay appears to detect different epitopes on the LH molecule, such that different conformational and/or glycosilated states are identified. Often, irLH pulses occur with no concurrent bLH pulses, which may indicate that the pituitary in PCOD patients releases pulses of biologically inactive LH in response to hypothalamic GnRH release. Hence, the pituitary gonadotrophs must be in some degree of synchrony in producing such biologically inactive material.
Asunto(s)
Hormona Luteinizante/sangre , Síndrome del Ovario Poliquístico/sangre , Bioensayo , Femenino , Hormona Liberadora de Gonadotropina/metabolismo , Humanos , Inmunoensayo , Hormona Luteinizante/inmunologíaRESUMEN
In 54 healthy women luteal function was assessed by sequential withdrawals of blood samples at 10-min intervals for 8-10 h. Subgroups of the women were studied during the early and late ovulatory period and during the early, mid- and late luteal phase. Bio- and immunoreactive luteinizing hormone (LH), prolactin, testosterone, estradiol and progesterone levels were determined in each sample. While the bio- and immunoreactivity of LH pulses correlated fairly well, a number of bio- or immunoreactive LH pulses were observed that were not detected by the respective other method. Responsivity of the corpus luteum to LH episodes developed during the second half of the luteal phase and was most marked in cases where LH episodes were accompanied by prolactin episodes. In the absence of prolactin episodes. LH episodes did not stimulate progesterone or estradiol secretion. The highest incidence of coincident LH and prolactin pulses was observed during the mid- and late luteal phase. Serum testosterone levels showed also some fluctuations but these were independent of immuno- or bioactive LH episodes and therefore most likely not of luteal origin. Prior to menstruation LH episodes were not any more stimulatory to progesterone secretion, indicating that it is not the withdrawal of LH but, rather, another possibly intraovarian mechanism that results in luteolysis. In a number of women, increased estradiol and progesterone secretion was strictly related to the prior occurrence of LH and prolactin pulses. In other subjects, both gonadal steroids fluctuated largely with no discernible correlation to LH fluctuations. This may indicate that in these subjects the corpora lutea have some degree of autonomous regulation.
Asunto(s)
Cuerpo Lúteo/fisiología , Fase Luteínica/fisiología , Hormona Luteinizante/fisiología , Prolactina/fisiología , Adolescente , Adulto , Estradiol/sangre , Femenino , Humanos , Hormona Luteinizante/sangre , Ovulación/fisiología , Progesterona/sangre , Prolactina/sangre , Testosterona/sangre , Factores de TiempoRESUMEN
OBJECTIVE: To report the initiation of a pregnancy that was achieved by intracytoplasmic sperm injection (ICSI) with sperm from a patient with Klinefelter's syndrome. DESIGN: Case report. SETTING: University women's hospital IVF center. PATIENT(S): A couple with primary infertility and nonmosaic 47,XXY karyotype of the male partner. INTERVENTION(S): Intracytoplasmic sperm injection after ovarian stimulation and transvaginal ultrasound-guided oocyte pick-up with sperm from a hypergonadotropic man with a nonmosaic 47,XXY karyotype. MAIN OUTCOME MEASURE(S): Clinical pregnancy. RESULT(S): Despite a 47,XXY karyotype in all 50 analyzed lymphocyte metaphases, the sperm of the patient led to a clinical pregnancy with the first attempt of ICSI and intrauterine transfer of three embryos. The pregnancy stopped developing in the ninth week. Cytogenetic investigation of the abortion material revealed a numerical normal 46,XXY karyotype. CONCLUSION(S): Sperm from a patient with hypergonadotropic nonmosaic Klinefelter's syndrome, when used for ICSI, can lead to a pregnancy.
Asunto(s)
Citoplasma , Síndrome de Klinefelter/genética , Micromanipulación , Espermatozoides , Aborto Inducido , Adulto , Femenino , Humanos , Cariotipificación , Masculino , Microinyecciones , EmbarazoRESUMEN
OBJECTIVE: To examine the possible association between factor XII (FXII) deficiency and an elevated number of abortions. DESIGN: Factor XII activity, FXII antigen concentration, other blood clotting parameters, and phospholipid antibodies were examined in venous blood from 43 women with repeated (3 to 7) abortions before the 28th week of gestation but without gynecological and chromosomal abnormalities. The data were compared with those obtained from 49 age-matched women without fetal loss. RESULTS: Eight cases with moderately reduced FXII activity (35% to 68% of normal) could be identified in the abortion group, whereas among controls no abnormalities in FXII activity and antigen concentration were found. The relative occurrence of reduced FXII level was higher among patients with more than three abortions as compared with those with three abortions. CONCLUSION: Repeated abortions may be associated with reduced level of FXII activity of unknown origin.
Asunto(s)
Aborto Habitual/complicaciones , Deficiencia del Factor XII/complicaciones , Aborto Habitual/sangre , Aborto Habitual/clasificación , Adulto , Factor XII/análisis , Femenino , Humanos , Embarazo , Valores de ReferenciaRESUMEN
During the second half of the luteal phase, the human corpus luteum becomes responsive to regular luteinizing hormone (LH) pulses. These LH pulses stimulate progesterone secretion tonically, and during this tonic stimulation, additional LH-independent progesterone pulses occur, which are particularly pronounced in women with human chorionic gonadotropin-stimulated luteal function. No progesterone pulses are seen in women suffering from corpus luteum deficiency due to absent LH pulses. The corpus luteum thus has a progesterone pulse generator turned on by gonadotropins but functioning for several hours without further gonadotropic support. This pulse generator appears to be regulated by intraluteal auto-/paracrine mechanisms, which we have investigated in a porcine model using molecular, cellular, and in vivo tools. Luteal oxytocin and progesterone release occurs in tightly coupled pulses. In vivo, oxytocin and prostaglandin F2 alpha(PGF2 alpha) stimulate estradiol and progesterone release and estradiol itself further stimulates progesterone release. Analysis of the different luteal cell compartments (large luteal cells, small luteal cells, fibroblasts) suggests an intraluteal circuit that involves paracrine effects of estradiol, oxytocin, and PGF2 alpha. At the time of luteolysis, the luteotropic effects of estradiol are inhibited by tumor necrosis factor derived from invading macrophages and the intraluteal circuit is thereby disrupted, leading to luteolysis.
Asunto(s)
Cuerpo Lúteo/metabolismo , Estradiol/biosíntesis , Hormona Luteinizante/fisiología , Progesterona/biosíntesis , Cuerpo Lúteo/fisiología , Dinoprost/fisiología , Estradiol/fisiología , Femenino , Humanos , Progesterona/fisiologíaRESUMEN
Twenty patients, aged 30-60 yr, who had undergone bilateral ovariectomy, were treated orally with 5 mg medrogestone (6,17-dimethylpregna-4,6-diene-3,20-dione) and 1.25 mg conjugated oestrogens per day, according to a constant dosage pattern during the cycle (22 + 6 days). The lipids and lipoproteins were determined twice before the start of therapy and 3, 6 and 12 mth thereafter. The lipids were quantified enzymatically and the lipoproteins by quantitative lipoprotein electrophoresis. Whilst cholesterol and triglyceride concentrations showed no detectable change, a slight but significant increase was seen in the high-density alphalipoprotein (HDL) cholesterol concentrations. The low-density beta-lipoprotein (LDL) cholesterol level showed a moderate fall. There was a resultant reduction in the beta/alpha-lipoprotein ratio. Accordingly, the apoprotein A1 concentrations were found to be elevated, while apoprotein B tended to fall to lower levels during therapy. When these changes are measured by the lipid metabolism risk criterion for the occurrence of coronary heart disease applicable to post-menopausal patients, the effects of the above-mentioned combination may be regarded as entirely favourable.
Asunto(s)
Estrógenos Conjugados (USP)/administración & dosificación , Lípidos/sangre , Lipoproteínas/sangre , Medrogestona/administración & dosificación , Pregnadienos/administración & dosificación , Adulto , Enfermedad Coronaria/etiología , Quimioterapia Combinada , Estrógenos Conjugados (USP)/efectos adversos , Femenino , Humanos , Medrogestona/efectos adversos , Persona de Mediana Edad , Ovariectomía , RiesgoRESUMEN
Any definition of involuntary childlessness has to consider the difference between sterility and subfertility. As the latter affects about 20-30% of all couples at least once in their lives, general practitioners (GPs) may be the first to be confronted with this problem. This review presents the most relevant diagnostic and therapeutic options in cases of female or male infertility, and discusses the new assisted reproductive technologies (such as insemination, in vitro fertilization, gamete transfer and intracytoplasmatic sperm injection) so that GPs may adequately inform their patients about these procedures and their risks and outcomes. Although controversial, involuntary childlessness and its clinical treatment seem to have a strong psychological impact on a couple's social, emotional and sexual life. Being available for discussion with childless couples and offering ongoing support may be the most important role for the GP in this context.
Asunto(s)
Infertilidad/terapia , Medicina Reproductiva , Medicina Familiar y Comunitaria , Femenino , Humanos , Infertilidad/psicología , MasculinoRESUMEN
Selecting the gender of offspring has given rise to various and sometimes amusing stories. But regardless of which prefertilisation technique is used to influence the sex ratio of offspring it must fulfill certain criteria. First of all it must achieve a complete separation of the X and Y bearing sperm in sufficient quantities. Secondly sperm must be viable after separation and capable of fertilising. Sex preselection methods can be divided into two general groups which either separate spermatozoa on the basis of subtle physical or kinetic features or those which rely on distinctive nuclear characteristics unique either to X or Y chromosome bearing sperm. These, in turn, can be divided into in vivo methods designed to produce optimal conditions for fertilisation by either the X or Y bearing sperm, or in vitro sperm separation methods designed to separate X or Y bearing sperm. According to all published data, the different separation techniques have been shown not to be very effective. Only sex selection of spermatozoa by chromatin differences (cell sorting by flow cytometry) has demonstrated a significant enrichment of the X bearing sperm.
Asunto(s)
Preselección del Sexo/métodos , Cromosomas Humanos X , Cromosomas Humanos Y , Humanos , Técnicas Reproductivas Asistidas , Razón de MasculinidadAsunto(s)
Retardo del Crecimiento Fetal/inmunología , Preeclampsia/inmunología , Complejo Antígeno-Anticuerpo/inmunología , Reacciones Antígeno-Anticuerpo , Femenino , Feto/inmunología , Enfermedad Injerto contra Huésped/inmunología , Antígenos HLA/inmunología , Antígenos HLA-DR/genética , Humanos , Inmunidad Celular , Isoantígenos/inmunología , Placenta/irrigación sanguínea , EmbarazoRESUMEN
By the development of microelectronic it is nowadays possible to manage even large amounts of data by personal computers (PC). Quality control and a prescribed operationstatistics compels to use a computer. In most cases, however, the employment of a computer fails because of the lack of adequate soft-ware. As a basis of such a use the relational data bank system dBASE-III offers it's services. The introduced system OPSTAT serves to fill in and to control the operation manual and makes it possible to register and to analyse all operations, diagnoses, complications and special risk factors.
Asunto(s)
Documentación/métodos , Enfermedades de los Genitales Femeninos/cirugía , Sistemas de Información , Microcomputadores , Programas Informáticos , Femenino , Hospitales Universitarios , Humanos , Garantía de la Calidad de Atención de SaludRESUMEN
It is now commonly assumed that a normal, successful pregnancy requires the specific recognition of the trophoblast by the immune system of the mother, resulting in production of protective or blocking factors (BF). In habitually aborting women, this recognition and/or BF production does not seem to occur. Immunisation of patients with leukocytes from the partner or from donors is postulated to induce these BF and to prevent fetal loss. After the exclusion of nonimmunological causes, 31 patients with at least three previous abortions and no pregnancies lasting longer than 16 weeks, were immunised with leukocytes from their partners. Eight women were already pregnant when treated, 15 became subsequently pregnant. Seventeen (= 74%) had uncomplicated pregnancies, six suffered again from early pregnancy loss. All 15 children, born so far had average birth weights and developed normally. The EAI-test (Power 1983) was of prognostic value: an increase of more than 50% in rosette inhibition activity in the serum of treated patients, correlated well with the successful outcome of their pregnancies; whereby the lack of this increase was associated with another early pregnancy loss. We could not confirm the reported of higher HLA-identity of couples with habitually aborting women, compared to fertile couples. HLA-typing (A, B, C, DR, and DQ) showed a higher proportion of identical allo-types in a group of 33 fertile couples than in a group of 44 couples with habitual abortions. This finding was significant (p less than 0.05).
Asunto(s)
Aborto Habitual/prevención & control , Inmunoterapia Adoptiva/métodos , Aborto Habitual/inmunología , Adulto , Sitios de Unión de Anticuerpos/inmunología , Femenino , Antígenos HLA/inmunología , Humanos , Recién Nacido , Transfusión de Linfocitos , Linfocitos/inmunología , Embarazo , Formación de Roseta , Trofoblastos/inmunologíaRESUMEN
The lymph nodes of the parotid gland get their tributary lymph vessels from the skin of the face, the scalp and the anterior face of the concha. Therefore malignant skin tumours--the majority of them are melanomas and squamous cell carcinomas--may lead to parotid metastases. In comparison to these regional metastases, parotid metastases of distant tumors are extremely rare. The paper describes for the first time a parotid metastases of an uterus sarcoma.
Asunto(s)
Neoplasias de la Parótida/secundario , Anciano , Carcinoma de Células Escamosas/secundario , Femenino , Neoplasias de Cabeza y Cuello/diagnóstico , Humanos , Leiomiosarcoma/diagnóstico , Leiomiosarcoma/secundario , Metástasis Linfática , Melanoma/secundario , Neoplasias de la Parótida/diagnóstico , Neoplasias Cutáneas/diagnóstico , Neoplasias Uterinas/diagnósticoRESUMEN
From an immunological point of view the product of pregnancy may be regarded as a haplo-different allotransplant. A system possibly closely linked to the HLA-region is postulated to lead to the immunological recognition of the fetus by the mother and, paradoxically, to a take of the "transplant". The postulated system apparently codes for antigens present on both trophoblast and adult lymphocytes (TLX = trophoblast-lymphocyte-crossreacting). The prevention of rejection is thought to be effected by blocking factors (BF) present in the serum or plasma of the mother. There may be different kinds of BF: a specific BF (detectable only in an autologous assay system), appearing late in pregnancy, which inhibits several lymphocyte-dependent reactions (e.g. production of MIF, MLC). This BF has been identified as an IgG-class antibody. a nonspecific BF, appearing early in pregnancy which inhibits the MLC in vitro. c) may be a third BF, also specific, which is found only in plasma but not in serum. All described BF-activities were absent in women with habitual abortions. HLA-identity or partial identity could imply TLX-identity. The consequence of such an identity could be: non-detection of the trophoblast by the immune system of the mother, no production of BF, abortion. However several investigators could not find any HLA-identity of the partners with habitual abortions. A protective effect on the fetus has been seen when pregnant women were immunised with adult leukocytes, using either buffycoats from various HLA-different but bloodgroup-compatible donors or isolated leukocytes from the spouse.(ABSTRACT TRUNCATED AT 250 WORDS)