RESUMO
STUDY QUESTION: How do families with children conceived using donor sperm operate as the children grow up? SUMMARY ANSWER: Families with children aged 5-13 years conceived through anonymous donor sperm function well, when compared with other family types with children of the same developmental stage. WHAT IS KNOWN ALREADY: Previous studies on family relationships after donor sperm conception have been reassuring. However, these studies have suffered from methodological limitations due to small sample sizes, respondent biases and absence of appropriate controls. STUDY DESIGN, SIZE, DURATION: This study was an observational study comparing 79 'donor insemination' (DI) families with 987 'couple' families, 364 'single mother' and 112 'step-father' families as part of the Australian Institute of Family Studies Children and Family Life (CFL) study. CFL involved the collection of data on family functioning and child wellbeing from all resident parents through a Family and Child Questionnaire for the 'primary' parent (FACQ-P1) and a Family Relationship Questionnaire (FRQ-P2) for the 'other' parent. PARTICIPANTS/MATERIALS, SETTING, METHODS: All questionnaires were coded with the identity known only to the researchers. The outcomes studied included parent psychological adjustment, family functioning, couple relationship, parenting and parent-child relationship. Family types were compared, separately for mothers' and fathers' reports. The results presented are the estimated means for each family type based on the final model for each outcome: post hoc comparisons between family types are reported with 95% confidence limits. MAIN RESULTS AND THE ROLE OF CHANCE: With all of the outcomes considered, there was not one result where the DI families showed poorer functioning on average than the comparison groups. LIMITATIONS, REASON FOR CAUTION: The final sample size of DI families is 79 with an excellent response rate of nearly 80%. However, there remains some scope for response bias. WIDER IMPLICATIONS OF THE FINDINGS: This study further reassures us that families conceived with anonymous donor sperm do not function any differently from other family types.
Assuntos
Família/psicologia , Inseminação Artificial Heteróloga/psicologia , Relações Pais-Filho , Adolescente , Adulto , Criança , Pré-Escolar , Características da Família , Feminino , Humanos , MasculinoRESUMO
Cardiac ejection of blood into the aorta generates a reaction force on the body that can be measured externally via the ballistocardiogram (BCG). In this study, a commercial bathroom scale was modified to measure the BCGs of nine healthy subjects recovering from treadmill exercise. During the recovery, Doppler echocardiogram signals were obtained simultaneously from the left ventricular outflow tract of the heart. The percentage changes in root-mean-square (RMS) power of the BCG were strongly correlated with the percentage changes in cardiac output measured by Doppler echocardiography (R(2) = 0.85, n = 275 data points). The correlation coefficients for individually analyzed data ranged from 0.79 to 0.96. Using Bland-Altman methods for assessing agreement, the mean bias was found to be -0.5% (+/-24%) in estimating the percentage changes in cardiac output. In contrast to other non-invasive methods for trending cardiac output, the unobtrusive procedure presented here uses inexpensive equipment and could be performed without the aid of a medical professional.
Assuntos
Balistocardiografia/instrumentação , Balistocardiografia/métodos , Débito Cardíaco/fisiologia , Exercício Físico/fisiologia , Adulto , Balistocardiografia/normas , Ecocardiografia Doppler , Eletrônica , Desenho de Equipamento , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Reprodutibilidade dos Testes , Pesos e Medidas , Adulto JovemRESUMO
The ballistocardiogram (BCG) measures the reaction of the body to cardiac ejection forces, and is an effective, non-invasive means of evaluating cardiovascular function. A simple, robust method is presented for acquiring high-quality, repeatable BCG signals from a modified, commercially available scale. The measured BCG waveforms for all subjects qualitatively matched values in the existing literature and physiologic expectations in terms of timing and IJ amplitude. Additionally, the BCG IJ amplitude was shown to be correlated with diastolic filling time for a subject with premature atrial contractions, demonstrating the sensitivity of the apparatus to beat-by-beat hemodynamic changes. The signal-to-noise ratio (SNR) of the BCG was estimated using two methods, and the average SNR over all subjects was greater than 12 for both estimates. The BCG measurement was shown to be repeatable over 50 recordings taken from the same subject over a three week period. This approach could allow patients at home to monitor trends in cardiovascular health.
Assuntos
Balistocardiografia/instrumentação , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Monitorização Fisiológica/instrumentação , Adulto , Artefatos , Balistocardiografia/normas , Eletrocardiografia , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Monitorização Fisiológica/normas , Pacientes Ambulatoriais , Reprodutibilidade dos Testes , Manobra de Valsalva , Pesos e MedidasRESUMO
Polymorphisms of the ABCB1 (MDR1) and ABCG2 (BCRP) genes were reported to alter the expression and function of these drug transporters. Both proteins are present at the main pharmacokinetic barriers including the blood-brain barrier. Data from 291 children with acute lymphoblastic leukaemia were analysed in this retrospective study. ABCB1 3435T>C, 2677G>T/A, 1236C>T and ABCG2 421C>A, 34G>A genotypes were determined. Encephalopathy episodes were more frequent among those with ABCB1 3435TT genotype than in the 3435CC/CT group (odds ratio (OR) 3.5; P=0.03). Patients with the ABCG2 421A allele tended to have more complications than wild type homozygotes (OR=2.0; P=0.25). The rate of the adverse effect was similar in those harbouring no or only one of the predisposing genotypes, that is, either ABCB1 3435TT or ABCG2 421AA/AC. However, significantly more children suffered encephalopathy in the group with both predisposing genotypes (OR=12.3; P=0.005). In conclusion, these variations exert synergistic effect in predisposing patients to toxic neurological complications of chemotherapy.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/genética , Antineoplásicos/efeitos adversos , Epistasia Genética , Proteínas de Neoplasias/genética , Síndromes Neurotóxicas/etiologia , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Alelos , Pré-Escolar , Estudos de Coortes , Feminino , Frequência do Gene , Humanos , Masculino , Síndromes Neurotóxicas/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , PrevalênciaRESUMO
Multi-microelectrode silicon devices were developed for extracellular recording from multiple axons in regenerated eighth cranial nerves of American bullfrogs. Each includes a photolithographically defined array of holes and adjacent metal microelectrodes. A device is implanted within a transected eighth nerve; regenerating fibers grow through the holes en route to the brainstem. Multiple spike trains were recorded from two animals at up to 21 weeks after implantation. Single units were tracked for over 8 h. Some responded to sound with tuning typical of fibers innervating the amphibian and basilar papillae. Units of vestibular origin also were recorded. Action potentials were 30-140 microV P-P amid noise of 5 10 microV RMS, an adequate signal-to-noise ratio for spike detection and sorting. Histology confirmed that bundles of myelinated fibers grew through holes near electrodes that recorded activity. The implantation success rate was low, due to surgical morbidity, device extrusion, and lack of nerve regeneration through some devices. Future designs will address these issues and incorporate transistor amplifiers on devices to increase signal-to-noise ratios. The potential of implanted silicon devices to simultaneously record from many axons offers an opportunity for multicellular studies of auditor, vestibular and seismic signal processing in the vertebrate inner ear.
Assuntos
Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Microeletrodos , Silício , Nervo Vestibulococlear/fisiologia , Estimulação Acústica , Potenciais de Ação/fisiologia , Animais , Histocitoquímica , Masculino , Fibras Nervosas/fisiologia , Regeneração Nervosa/fisiologia , Rana catesbeiana , Nervo Vestibulococlear/cirurgiaRESUMO
A planar 6 x 6 array of iridium electrodes with four reference electrodes has been developed for use with neural tissue preparations. Precise knowledge of the relative locations of the array elements allows for spatial neurophysiological analyses. The 10 microns diameter platinized iridium electrodes on a 100 microns pitch have been used to stimulate acutely prepared slices of spinal cord from free-ranging rodents. An intracellular recording from a single neuron in the substantia gelatinosa (SG) using the whole-cell, tight-seal technique allowed low noise, high resolution studies of excitatory or inhibitory electrical responses of a given neuron to inputs from the primary afferent fibers or from stimulation by individual electrodes of the array. The resulting maps of responses provide an indication of the interconnectivity of neural processes. The pattern emerging is that of limited interconnectivity in the SG from areas surrounding a recorded neuron but with strong excitatory or inhibitory effects from those oriented in a longitudinal (rostral-caudal) direction relative to the neuron. The observations to date suggest the neurons of the SG are arranged in sets of independent networks, possibly related to sensory modality and input from particular body regions.
Assuntos
Microeletrodos , Rede Nervosa , Medula Espinal/fisiologia , Animais , Cricetinae , Estimulação Elétrica , Técnicas In Vitro , Gravação em VídeoRESUMO
The ability to apply and control the force and force velocity of mechanical stimulation is essential for the study of mechanoelectric transduction and adaptation processes. Silicon micromachining technology was used to produce miniature (20-70 microns wide) mechanical microprobes. Passive polysilicon, piezoresistive, force sensing elements were deposited onto the boron-doped epitaxial silicon and the individual devices were chemically etched from the bulk wafer. These microprobes display a linear force versus output voltage relationship. Stimulation forces up to 2 mN can be generated with a measurement resolution of 1.5 microN. The probes were mounted onto circuit board holders and their output sent to a proportional-integral controller which drives an electromagnetic actuator. By using this force-feedback control circuit coupled to a PC it is possible to define any stimulus wave form pattern and independently control and measure the actual stimulus force and velocity. A computer controlled 3-axis stepper motor (0.025 micron step capability) manipulator is used to position the silicon microprobe-actuator assembly relative to the mechanoreceptive field. Sensor feedback control coupled to the 3-axis stepper motor manipulator allows automatic touchdown control and/or preloading of the probe prior to stimulation. Three-dimensional topographic manipulator feedback position control allows automated receptive field mapping.
Assuntos
Biorretroalimentação Psicológica/instrumentação , Micromanipulação/instrumentação , Tecido Nervoso/fisiologia , Estimulação Física/instrumentação , Potenciais de Ação/fisiologia , Animais , Córnea/inervação , Córnea/fisiologia , Eletrofisiologia , Potenciais Evocados/fisiologia , Espaço Extracelular/fisiologia , Técnicas In Vitro , Mecanorreceptores/fisiologia , Coelhos , SilícioRESUMO
The use of cell-based biosensors outside of the laboratory has been limited due to many issues including preparation of the sample, maintenance of the biological environment, and integration of the electronics for data collection and analysis. This paper describes a system that addresses several of these issues with the development of an integrated silicon-polydimethylsiloxane cell-cartridge. The cell-cartridge contains a CMOS silicon chip that incorporates a digital interface, temperature control system, microelectrode electrophysiology sensors, and analog signal buffering. Additionally, the cell-cartridge supports two separate cell populations in two 10 microl sealed chambers that have independent fluidic channels for sample injection. A portable, microcontroller-based electronics system capable of monitoring the action potential (AP) activity within the cell-cartridges was also developed. The AP activities of cardiomyocyte syncytia in the two chambers differentially responded to the flow of a control medium versus the flow of a biochemical agent. The cell-cartridges and portable electronics system were used to successfully record AP activity from cardiomyocytes outside of the laboratory under realistic application conditions.
Assuntos
Técnicas Biossensoriais/instrumentação , Potenciais de Ação , Animais , Linhagem Celular , Desenho de Equipamento , Camundongos , Miocárdio/citologia , Miocárdio/metabolismoRESUMO
There are several groups of researchers developing cell-based biosensors for chemical and biological warfare agents based on electrophysiologic monitoring of cells. In order to transition such sensors from the laboratory to the field, a general-purpose hardware and software platform is required. This paper describes the design, implementation, and field-testing of such a system, consisting of cell-transport and data acquisition instruments. The cell-transport module is a self-contained, battery-powered instrument that allows various types of cell-based modules to be maintained at a preset temperature and ambient CO(2) level while in transit or in the field. The data acquisition module provides 32 channels of action potential amplification, filtering, and real-time data streaming to a laptop computer. At present, detailed analysis of the data acquired is carried out off-line, but sufficient computing power is available in the data acquisition module to enable the most useful algorithms to eventually be run real-time in the field. Both modules have sufficient internal power to permit realistic field-testing, such as the example presented in this paper.
Assuntos
Técnicas Biossensoriais/instrumentação , Potenciais de Ação , Algoritmos , Animais , Técnicas Biossensoriais/estatística & dados numéricos , Linhagem Celular , Desenho de Equipamento , Camundongos , Miocárdio/citologia , Miocárdio/metabolismo , SoftwareRESUMO
Cell-based biosensors (CBBs) utilize whole cells to detect biologically active agents. Although CBBs have shown success in detecting the presence of biological agents, efforts to classify the type of agent based on functional activity have proven difficult because multiple biochemical pathways can lead to the same cellular response. However, a new approach using a genetically-engineered cell-based biosensor (GECBB) described in this paper translates this cross-talk noise into common-mode noise that can be rejected. The GECBB operates by assaying for an agent's ability to differentially activate two populations of cells, wild-type (WT) cells and cells genetically engineered to lack a specific receptor, knockout (KO) cells. Any biological agent that targets the knocked out receptor will evoke a response in the WT but not in the KO. Thus, the GECBB is exquisitely sensitive to agents that effect the engineered pathway. This approach provides the benefits of an assay for specific functional activity while simplifying signal analysis. The GECBB implemented was designed to be sensitive to agents that activate the beta 1-adrenergic receptor (beta 1-AR). This was achieved by using mouse cardiomyocytes in which the beta 1-AR had been knocked out. The cellular signal used in the GECBB was the spontaneous beat rate of the two cardiomyocyte syncitia as measured with microelectrode arrays. The GECBB was able to detect the beta-AR agonist isoproterenol (ISO) at a concentration of 10 microM (P<0.005).
Assuntos
Técnicas Biossensoriais/instrumentação , Agonistas Adrenérgicos beta/análise , Animais , Células Cultivadas , Desenho de Equipamento , Engenharia Genética , Isoproterenol/análise , Camundongos , Camundongos Knockout , Miocárdio/citologia , Miocárdio/metabolismo , Receptores Adrenérgicos beta 1/genética , Receptores Adrenérgicos beta 1/metabolismo , TransdutoresRESUMO
An extracellular recording system incorporating an electrode array and an amplifier/stimulator CMOS chip is described and characterized. Important features of this custom VLSI chip include 16 instrumentation amplifiers with a gain of 50 and the incorporation of a cross-point array allowing designation of an extracellular microelectrode as either a stimulator or sensor. The planar array consisted of 32 microelectrodes, 14 microns in diameter, and four larger reference electrodes. Microelectrodes, interconnecting traces, and bond pads were patterned with a 500-nm layer of gold. The interconnecting traces were passivated with a 1-micron thick layer of silicon nitride to provide chemical and electrical insulation and microelectrode impedance was lowered utilizing electrode position of platinum black. The amplifier exhibited a nearly flat frequency response with high pass and low pass corner frequencies of 0.7 Hz and 50 kHz, respectively. The input referred noise over the 50 kHz bandwidth was 12-16 microVRMS, well below the magnitude of previously reported extracellular potentials. Crosstalk between neighboring channels resulted in an output signal below the amplifier noise level, even for relatively large extracellular potentials. Using this system, extracellular recording were demonstrated yielding typical peak-to-peak biopotentials of magnitude 0.9-2.1 mV and 100-400 microV for chick cardiac myocytes and rat spinal cord neurons, respectively. The key components of this extracellular recording system can be manufactured using industry standard thin film photolithographic techniques.
Assuntos
Amplificadores Eletrônicos , Eletrônica Médica/instrumentação , Microeletrodos , Animais , Embrião de Galinha , Eletrofisiologia , Estudos de Avaliação como Assunto , Potenciais da Membrana , Miocárdio/citologia , Miocárdio/metabolismo , Neurônios/metabolismo , Ratos , Transdução de Sinais , Medula Espinal/citologia , Medula Espinal/metabolismoRESUMO
One of the major complications after high-dose methotrexate (HDMTX) infusions is renal damage. We investigated the occurrence of proteinuria after HDMTX administration in children with pediatric malignancies (acute lymphoid leukaemia, osteosarcoma Burkitt's lymphoma). In the period 1989-1990 we gave 52 HDMTX courses to 24 children. During this period, prehydration and extra urinary alkalisation were performed only if the urinary specific gravity was over 1010 or if the urinary pH fell below 7. Using this schedule the mean values obtained for protein extraction were: before the therapy, 0.12 +/- 0.03 g/m2; on day 1 after MTX treatment, 0.38 +/- 0.06 g/m2; and on day 2 after the MTX infusion, 0.39 +/- 0.11 g/m2 (P < 0.01). A significant increase in proteinuria (> 0.2 g/m2 post- vs pretreatment) was detectable in 54% of the patients. In the period 1991-1992 we modified the hydration-alkalisation schedule to include i.v. prehydration for 18-24 h at 3 l/m2/day with a 0.45% NaCl-5% glucose solution along with sodium bicarbonate and posthydration for 72 h with the same solution. On this protocol the mean values determined for the urinary protein content were all in the normal range (pretreatment, 0.03 g/m2/day; day 1, 0.05 g/m2/day; and day 2, 0.08 g/m2/day). These findings were significantly different from the previous results (P < 0.05).
Assuntos
Metotrexato/efeitos adversos , Neoplasias/tratamento farmacológico , Proteinúria/induzido quimicamente , Adolescente , Neoplasias Ósseas/tratamento farmacológico , Linfoma de Burkitt/tratamento farmacológico , Criança , Feminino , Hidratação , Taxa de Filtração Glomerular/efeitos dos fármacos , Glucose/administração & dosagem , Humanos , Masculino , Metotrexato/administração & dosagem , Metotrexato/uso terapêutico , Osteossarcoma/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Proteinúria/prevenção & controle , Bicarbonato de Sódio/administração & dosagemRESUMO
To our knowledge, this is the first case report of three pregnancies resulting from the one batch of embryos. As the survival rate for cryopreserved embryos increases, there will be more families that will be able to be completed after just one cycle of hyperstimulation and oocyte collection, thereby making IVF-ET more cost-effective.
Assuntos
Fertilização in vitro , Trigêmeos , Transferência Embrionária , Feminino , Humanos , Infertilidade Masculina , Inseminação Artificial Heteróloga , Inseminação Artificial Homóloga , Masculino , GravidezRESUMO
OBJECTIVE: To describe the experience of changing from the use of the 10-mm standard laparoscope to the use of the 2-mm microlaparoscope (MicroLap, Imagyn Medical Inc., Laguna Niguel, CA) and to compare the amount of postoperative pain and requirement for analgesics after each technique. DESIGN: Prospective study. SETTING: Day surgery unit in an academic reproductive medicine unit. PATIENT(S): One hundred thirty-five women undergoing diagnostic microlaparoscopy. INTERVENTION(S): Diagnostic laparoscopy with a 2-mm instrument. Recording of postoperative pain on an analog scale. MAIN OUTCOME MEASURE(S): Ability to complete the procedure satisfactorily with the microlaparoscope, pain scores, and use of analgesics. RESULT(S): All diagnostic procedures were performed satisfactorily with the use of the MicroLap. Patients who underwent MicroLap procedures had significantly less abdominal pain postoperatively, but there was no difference in shoulder tip (gas-related) pain. Less analgesia was required after the microlaparoscopy. CONCLUSION(S): In most situations, the microlaparoscope is the instrument of choice for initial diagnostic laparoscopy. The 10-mm laparoscope should be used only as a secondary instrument after microlaparoscopy, if indicated.
Assuntos
Analgésicos Opioides/administração & dosagem , Endoscópios , Fentanila/administração & dosagem , Laparoscopia/métodos , Dor Pós-Operatória/diagnóstico , Dor Abdominal/diagnóstico , Relação Dose-Resposta a Droga , Feminino , Humanos , Micromanipulação , Valor Preditivo dos Testes , Estudos Prospectivos , Dor de Ombro/diagnósticoRESUMO
One hundred and forty-seven healthy men were investigated to determine whether there was an association between chromosomal variants and decreased fertility. Modern chromosome banding techniques detected normal variant karyotypes in 22 (15%) of these men. The fertility parameters of the 125 men with 46,XY karyotype were compared with those of the 22 men in the variant group. Analysis of the results showed that the two groups were not biologically different with respect to semen analysis and reproductive hormone levels.
Assuntos
Infertilidade Masculina/genética , Bandeamento Cromossômico , Hormônio Foliculoestimulante/sangue , Variação Genética , Humanos , Cariotipagem , Hormônio Luteinizante/sangue , Masculino , Prolactina/sangue , Sêmen/análise , Cromossomos Sexuais , Testosterona/sangueRESUMO
OBJECTIVE: To review 20 years of experience with sperm storage before vasectomy or before chemotherapy and/or radiation therapy (medical storage), and to evaluate its usefulness. DESIGN: Retrospective data analysis. SETTING: University-affiliated reproductive medicine clinic. PATIENT(S): Two hundred fifty-six men who underwent vasectomy and 258 men who underwent chemotherapy and/or radiation therapy. INTERVENTION(S): Review of patient clinical notes. MAIN OUTCOME MEASURE(S): The subsequent use of cryostored sperm and the number of pregnancies that resulted. RESULT(S): Only 4 of the 256 men who underwent vasectomy returned for treatment, and three pregnancies were achieved. Eighteen of the 258 men who underwent chemotherapy and/or radiation therapy returned for treatment, and six pregnancies were achieved. CONCLUSION(S): Only a small proportion of men (2%) returned to use their cryostored specimens after vasectomy, and pregnancy was achieved in most cases. Seven percent of men returned to use their specimens after chemotherapy and/or radiation therapy, and pregnancy was achieved in only one third of cases.
Assuntos
Criopreservação , Preservação do Sêmen/estatística & dados numéricos , Bancos de Esperma , Adolescente , Adulto , Tratamento Farmacológico , Feminino , Fertilização in vitro/estatística & dados numéricos , Humanos , Inseminação Artificial/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Radioterapia , Estudos Retrospectivos , VasectomiaRESUMO
Forty consecutive women were treated with human pituitary gonadotropin to induce ovulation. Thirty-seven patients (93%) ovulated and thirty (75%) conceived on at least one occasion. The cumulative conception rate for the series equaled that of the general population. Women with a past history of anorexia nervosa had the shortest average time to pregnancy. Of patients who did not conceive, four represented failures of patient selection in that they withdrew from treatment for a variety of psychiatric and social reasons, and six represented failures of treatment, not becoming pregnant despite the induction of ovulation. It is concluded that realistic goals for a contemporary human gonadotropin program include induction of ovulation in all patients and a cumulative conception rate equal to that of the general community.
Assuntos
Fertilidade/efeitos dos fármacos , Gonadotropinas Hipofisárias/farmacologia , Indução da Ovulação , Anovulação/tratamento farmacológico , Anovulação/etiologia , Feminino , Gonadotropinas Hipofisárias/efeitos adversos , Gonadotropinas Hipofisárias/uso terapêutico , Humanos , Infertilidade Feminina/tratamento farmacológico , Ovário/efeitos dos fármacos , Ovulação/efeitos dos fármacos , Gravidez , Receptores de Superfície Celular/efeitos dos fármacos , Receptores do LHRESUMO
Whereas the dose of hMG is significantly correlated with both BMI and BW, commencing the more obese patient on higher hMG doses is not justified in view of the cancellation of cycles from over-responsiveness in the more obese patients started on higher hMG dosage regimens. If the more obese patient is slow to respond, however, a greater degree of clinical freedom may be exercised to increase the dose. The ultimate outcome of the cycle is not related to BMI, BW, or the dose of hMG used.
Assuntos
Envelhecimento , Índice de Massa Corporal , Peso Corporal , Menotropinas/administração & dosagem , Indução da Ovulação , Síndrome do Ovário Policístico/fisiopatologia , Feminino , Humanos , Menotropinas/uso terapêutico , GravidezRESUMO
OBJECTIVE: To determine the validity of the criteria currently used to select fertile sperm donors. DESIGN: Retrospective study of the outcome of donor insemination treatment cycles over a 15-year period. SETTING: The Reproductive Medicine Clinic of Prince Henry's Institute of Medical Research (formerly Medical Research Centre, Prince Henry's Hospital, South Melbourne, Victoria, Australia). PATIENTS: Couples (1,299) presented with severe male factor infertility (azoospermia or severe oligozoospermia) and were treated by donor insemination (10,796 treatment cycles) using cryopreserved semen from 292 normal healthy men aged between 18 and 46 years as sperm donors. MAIN OUTCOME MEASURES: Semen characteristics, including volume, count, motility, motility index, normal morphology, live cells, and post-thaw motility, were analyzed by logistic regression analysis to determine which groups of factors were related independently and significantly to pregnancy rates. RESULTS: The pregnancy rate for donor insemination was 8.9% per cycle. By logistic regression count, normal morphology, post-thaw motility (%), and post-thaw motility index together explained 28% of the variance of the pregnancy rates. Other factors, including prethaw motility characteristics (percent motility and motility index), donor age, weight, LH, FSH, and T levels, were not significant. CONCLUSIONS: The standard parameters of sperm count, morphology, and post-thaw motility are the most important factors for the selection of highly fertile donors. As most of the variability in the pregnancy rates resulted from other undetermined factors related both to the donor and the recipient, it is suggested that the pragmatic approach of discarding donors after a reasonable number of treatment failures (20 to 50) should continue.