Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 99
Filtrar
1.
Hum Reprod ; 37(12): 2831-2844, 2022 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-36166695

RESUMEN

STUDY QUESTION: Does mental health and behaviour differ between those conceived with and those conceived without ART? SUMMARY ANSWER: Our study observed less externalizing behaviour (delinquent/aggressive), and more parent-reported internalizing behaviour, as well as more (clinical) depression at age 14 years, in adolescents conceived after ART compared to their non-ART counterparts. WHAT IS KNOWN ALREADY: Health outcomes of ART-conceived offspring may differ from those conceived without ART, and previous studies have reported differences in behaviour and mental health, particularly in childhood. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study, investigating the long-term health of offspring conceived after ART (aged 14, 17 and 20 years), in the two operational fertility clinics in Western Australia 1991-2001 (n = 303). Their long-term health outcomes were compared to those of offspring conceived without ART from the Raine Study Generation 2 (Gen2) born 1989-1991 (n = 2868). Both cohorts are representative of the local adolescent population. PARTICIPANTS/MATERIALS, SETTING, METHODS: Mental health parameters and behaviour were assessed at ages 14 and 17 years, through the parent completed 'Child Behaviour Checklist' (CBCL; ART versus non-ART: age 14 years: N = 150 versus N = 1781, age 17 years: N = 160 versus N = 1351), and the adolescent completed equivalent 'Youth Self-Report' (YSR; age 14 years: by N = 151 versus N = 1557, age 17 years: N = 161 and N = 1232). Both tools generate a T-score (standardized for age and sex) for internalizing (withdrawn, somatic complaints, anxious/depressed), externalizing (delinquent/aggressive behaviour) and total behaviour. Adolescents also completed the 'Beck Depression Inventory for Youth' (BDI-Y; age 14 years: N = 151 versus N = 1563, age 17 years: N = 161 versus N = 1219). Higher scores indicate poorer mental health and behaviour on all the above tools. Parent-reported doctor-diagnosed conditions (anxiety, behavioural problems, attention problems and depression) were also univariately compared between the cohorts. In addition, univariate comparisons were conducted between the GUHS adolescents and Gen2 adolescents born to subfertile parents (time to pregnancy >12 months), as well as between offspring born to subfertile versus fertile parents within the Gen2 cohort. A subgroup analysis excluding offspring born preterm (<37 weeks' gestation) or at low birthweight (<2500 g) was also performed. Generalized estimating equations that account for correlated familial data were adjusted for the following covariates: non-singleton, primiparity, primary caregiver smoking, family financial problems, socio-economic status and both maternal and paternal ages at conception. MAIN RESULTS AND THE ROLE OF CHANCE: At both 14 and 17 years of age, ART versus non-ART-conceived adolescents reported lower mean T-scores for externalizing problems (age 14 years: 49 versus 51, P = 0.045, age 17 years: 49 versus 52, P < 0.001). A similar effect was reported by parents, although not significant (age 14 years: P = 0.293, age 17 years: P = 0.148). Fewer ART-conceived adolescents reported a T-score above the clinical cut-off for externalizing behaviour (≥60; age 14 years: 7.3% versus 16.3%, P = 0.003, age 17 years: 8.1% versus 19.7%, P < 0.001). At both ages, no differences in internalizing behaviour were reported by adolescents (age 14 years: P = 0.218, age 17 years: P = 0.717); however, higher mean scores were reported by parents of the ART-conceived adolescents than by parents of the non-ART conceived adolescents (age 14 years: 51 versus 48, P = 0.027, age 17 years: 50 versus 46, P < 0.001). No differences in internalizing behaviour above the clinical cut-off (T-score ≥ 60) were observed. At age 17 years, parents who conceived through ART reported higher total behaviour scores than those parents who conceived without ART (48 versus 45, P = 0.002). At age 14 years, ART versus non-ART-conceived adolescents reported significantly higher mean scores on the BDI-Y (9 versus 6, P = 0.005); a higher percentage of adolescents with a score indicating clinical depression (≥17; 12.6% versus 8.5%, aOR 2.37 (1.18-4.77), P = 0.016), as well as more moderate/severe depression (≥21; 9.3% versus 4.0%, P = 0.009). At age 17 years, no differences were reported on the BDI-Y. There was also a higher percentage of parent-reported doctor-diagnosed anxiety in the ART cohort (age 14 years: 8.6% versus 3.5%, P = 0.002, at age 17 years: 12.0% versus 4.5%, P < 0.001). Removing adolescents born preterm or at low birthweight did not alter the above results. Comparing outcomes between GUHS adolescents and Gen2 adolescents born to subfertile parents, as well as between those born to subfertile versus fertile parents within Gen2, did not alter results for CBCL and YSR outcomes. Those born to subfertile parents showed higher rates of clinical depression than those born to fertile parents at age 14 years (13.7% versus 6.9%, P = 0.035). LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study is the time difference between the GUHS and Gen2 assessments. Even though we have adjusted for covariates, additional socio-economic and lifestyle factors affecting behaviour and mental well-being could have changed. We were unable to differentiate between different types of ART (e.g. IVF versus ICSI), owing to the low number of ICSI cycles at the time of study. Fertility sub-analyses need to be replicated in larger cohorts to increase power, potentially using siblingship designs. Lastly, selection bias may be present. WIDER IMPLICATIONS OF THE FINDINGS: The reported lower prevalence of externalizing behaviour (delinquent/aggressive), and higher prevalence of internalizing behaviour, as well as more (clinical) depression at age 14 years, in ART versus non-ART-conceived adolescents, is in line with some previous studies, mostly conducted in childhood. It is reassuring that differences in the rates of depression were not observed at age 17 years, however, these findings require replication. As the use of ART is common, and mental health disorders are increasing, knowledge about a potential association is important for parents and healthcare providers alike. STUDY FUNDING/COMPETING INTEREST(S): This project was funded by an NHMRC Grant (Hart et al., ID 1042269). R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Problema de Conducta , Inyecciones de Esperma Intracitoplasmáticas , Niño , Masculino , Embarazo , Recién Nacido , Femenino , Adolescente , Humanos , Estudios Prospectivos , Salud Mental , Peso al Nacer , Fertilización In Vitro
2.
Hum Reprod ; 37(7): 1572-1580, 2022 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-35526152

RESUMEN

STUDY QUESTION: Are there differences in thyroid function between adolescents and young adults conceived with and without ART? SUMMARY ANSWER: This study demonstrated no evidence of clinically relevant differences in thyroid function between adolescents and young adults conceived with and without ART. WHAT IS KNOWN ALREADY: Studies to date have reported an increase in subclinical hypothyroidism in offspring conceived after ART. It has been suggested that the increase in maternal estrogen (E2) after fresh embryo transfers could affect thyroid function of the offspring. Suboptimal thyroid function at a young age can cause irreversible damage to the central nervous system, which makes early detection and correct treatment essential. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study, which aimed to recruit all adolescents born after conception with ART between 1991 and 2001 in the study area. The included participants (n = 303, aged 13-20 years) completed various health assessments. Depending on the age at enrolment, participants completed thyroid assessments at the 14- or 20-year follow-up. The outcomes of these replicated thyroid assessments were compared to those of participants conceived without ART from the Raine Study Generation 2 (Gen2). The Gen2 participants (n = 2868) were born between 1989 and 1992 and have been recognized to be representative of the local population. PARTICIPANTS/MATERIALS, SETTING, METHODS: Thyroid function assessments were compared between n = 134 GUHS and n = 1359 Gen2 adolescents at age 14 years and between n = 47 GUHS and n = 914 Gen2 young adults at age 20 years. The following mean thyroid hormone concentrations were compared between the cohorts: thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) and thyroid peroxidase antibodies (TPOAb). The prevalence of the following thyroid hormone profiles, based on individual thyroid hormone concentrations, was compared: euthyroidism, subclinical and overt hypo- and hyperthyroidism and thyroid autoimmunity. Outcomes were compared between the cohorts, and univariately between fresh embryo transfers (ET) and frozen ET (FET) within the GUHS. The correlation between maternal peak E2 concentrations (pE2) and fT4 was assessed within the GUHS. MAIN RESULTS AND THE ROLE OF CHANCE: All mean thyroid function outcomes fell within the normal range. At both ages, we report no differences in TSH concentrations. At age 14 years, lower fT3 concentrations (4.80 versus 5.35 pmol/L, P < 0.001) and higher fT4 concentrations (12.76 versus 12.19 pmol/L, P < 0.001) were detected in the GUHS adolescents compared to Gen2 adolescents. At age 20 years, higher fT3 and fT4 concentrations were reported in GUHS adolescents (4.91 versus 4.63 pmol/L, P = 0.012; 13.43 versus 12.45 pmol/L, P < 0.001, respectively) compared to Gen2 participants. No differences in the prevalence of subclinical and overt hypo- and hyperthyroidism or thyroid autoimmunity were demonstrated between the cohorts at age 14 and 20 years. Thyroid function did not differ between ET and FET, and no correlation between pE2 and fT4 was reported. LIMITATIONS, REASONS FOR CAUTION: The observational nature of the study limits the ability to prove causation. Furthermore, the comparison of ET and FET offspring at age 20 years may be lacking power. We were unable to differentiate between different types of ART (e.g. IVF versus ICSI) owing to the low number of ICSI cycles at the time of study. As ART laboratory and clinic data were collected contemporaneously with the time of treatment, no other data pertaining to the ART cycles were sought retrospectively; hence, some factors could not be accounted for. WIDER IMPLICATIONS OF THE FINDINGS: This study does not support previous findings of clinically relevant differences in thyroid function when comparing a cohort of adolescents conceived after ART to counterparts conceived without ART. The minor differences detected in fT3 and fT4 were considered not biologically relevant. Although these findings appear reassuring, they warrant reinvestigation in adulthood. STUDY FUNDING/COMPETING INTERESTS: This project was funded by an NHMRC Grant (Hart et al., ID 1042269). R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director and a shareholder of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Hipertiroidismo , Tirotropina , Adolescente , Fertilización In Vitro , Humanos , Masculino , Estudios Prospectivos , Estudios Retrospectivos , Adulto Joven
3.
Hum Reprod ; 37(8): 1880-1895, 2022 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-35640037

RESUMEN

STUDY QUESTION: Is the cardiometabolic health of adolescents conceived through ART worse than that of their counterparts conceived without ART? SUMMARY ANSWER: The majority of cardiometabolic and vascular health parameters of adolescents conceived through ART are similar or more favourable, than those of their counterparts of similar age and conceived without ART. WHAT IS KNOWN ALREADY: It has been proposed that the cardiometabolic health of offspring conceived with ART may be unfavourable compared to that of their counterparts conceived without ART. The literature pertaining to cardiometabolic health of offspring conceived after ART is contradictory, but generally suggests unfavourable cardiometabolic health parameters, such as an increase in blood pressure (BP), vascular dysfunction and adiposity, as well as unfavourable glucose and lipid profiles. With over 8 million children and adults born through ART worldwide, it is important to investigate whether these early signs of adverse cardiometabolic differences persist into adolescence and beyond. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study that recruited 303 adolescents and young adults conceived after ART (aged 13-21 years) and born between 1991 and 2001 in Western Australia. Their health parameters, including cardiometabolic factors, were assessed and compared with counterparts from the Raine Study Generation 2 (Gen2). The 2868 Gen2 participants were born 1989-1992 and are representative of the Western Australian adolescent population. At ∼17 years of age (2013-2017), 163 GUHS participants replicated assessments previously completed by Gen2 at a similar age. PARTICIPANTS/MATERIALS, SETTING, METHODS: Cardiometabolic parameters were compared between a total of 163 GUHS and 1457 Gen2 adolescents. Separate male (GUHS n = 81, Gen2 n = 735) and female (GUHS n = 82, Gen2 n = 722) analyses were conducted. Assessments consisted of a detailed questionnaire including health, lifestyle and demographic parameters, anthropometric assessments (height, weight, BMI, waist circumference and skinfold thickness), fasting serum biochemistry, arterial stiffness and BP (assessed using applanation tonometry). Abdominal ultrasonography was used to assess the presence and severity of hepatic steatosis, and thickness of abdominal fat compartments. Non-alcoholic fatty liver disease (NAFLD) was diagnosed if there was sonographic fatty liver in the absence of significant alcohol consumption. Chi2, Fisher's exact and Mann-Whitney U tests, performed in SPSS V25, examined cohort differences and generalized estimating equations adjusted for the following covariates: singleton vs non-singleton pregnancy, birthweight (z-score), gestational age, BMI, smoking, alcohol consumption in the past 6 months and parent cardiovascular status. Arterial stiffness measures and waist circumference were additionally adjusted for height, and female analyses were additionally adjusted for use of oral contraceptives in the preceding 6 months. MAIN RESULTS AND THE ROLE OF CHANCE: In adjusted analyses, GUHS females had a lower BMI (22.1 vs 23.3 kg/m2, P = 0.014), and thinner skinfolds (triceps, subscapular, mid-abdominal; 16.9 vs 18.7 mm, P = 0.021, 13.4 vs 15.0 mm, P = 0.027, 19.7 vs 23.2 mm, P < 0.001, respectively), whereas males were not significantly different. Waist circumference was lower in GUHS adolescents (males: 78.1 vs 81.3 cm, P = 0.008, females: 76.7 vs 83.3 cm, P = 0.007). There were no significant differences between the two groups in glucose, insulin, homeostatic model assessment for insulin resistance, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol (TC), alanine aminotransferase and high-sensitivity C-reactive protein in both sexes. In females, serum triglycerides were lower in GUHS adolescents (1.0 vs 1.2 mmol/l, P = 0.029). GUHS males had higher serum HDL-C (1.1 vs 1.0 mmol/l, P = 0.004) and a lower TC/HDL-C ratio (3.2 vs 3.6, P = 0.036). There were no significant differences in the prevalence of NAFLD or steatosis severity scores between the cohorts in males and females. GUHS females had less subcutaneous adipose tissue (9.4 vs 17.9 mm, P < 0.001), whereas GUHS males had greater visceral adipose thickness (44.7 vs 36.3 mm, P < 0.001). There was no significant difference in pre-peritoneal adipose thickness. Pulse wave velocity was lower in GUHS males (5.8 vs 6.3 m/s, P < 0.001) and heart rate corrected augmentation index was lower in GUHS females (-8.4 vs -2.7%, P = 0.048). There were no significant differences in BP or heart rate in males or females between the two groups. LIMITATIONS, REASONS FOR CAUTION: Despite the substantial study size and the unique study design of the ART cohort, we were unable to differentiate between different types of ART, due to the low number of ICSI cycles (e.g. IVF vs ICSI), draw definite conclusions, or relate the outcomes to the cause of infertility. Considering the differences in time points when both cohorts were studied, external factors could have changed, which could not be accounted for. Given the observational nature of this study, causation cannot be proven. WIDER IMPLICATIONS OF THE FINDINGS: Contrary to our hypothesis and previous findings focussing mainly on childhood, this study reports mostly similar or favourable cardiometabolic markers in adolescents conceived with ART compared to those conceived without ART. The greater visceral adipose thickness, particularly present in males, requires further investigation. While these findings are generally reassuring, future well-designed and appropriately powered studies are required to definitively address the issue of cardiometabolic health in ART adults. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by NHMRC project grant number 1042269 and R.J.H. received education grant funding support from Ferring Pharmaceuticals. R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Enfermedades Cardiovasculares , Enfermedad del Hígado Graso no Alcohólico , Adolescente , Australia , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Niño , Estudios de Cohortes , Femenino , Fertilización In Vitro/métodos , Glucosa , Humanos , Masculino , Embarazo , Estudios Prospectivos , Análisis de la Onda del Pulso , Adulto Joven
4.
Hum Reprod ; 36(7): 2035-2049, 2021 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-33890633

RESUMEN

STUDY QUESTION: Do the epigenome-wide DNA methylation profiles of adolescents born from ART differ from the epigenome of naturally conceived counterparts? SUMMARY ANSWER: No significant differences in the DNA methylation profiles of adolescents born from ART [IVF or ICSI] were observed when compared to their naturally conceived, similar aged counterparts. WHAT IS KNOWN ALREADY: Short-term and longer-term studies have investigated the general health outcomes of children born from IVF treatment, albeit without common agreement as to the cause and underlying mechanisms of these adverse health findings. Growing evidence suggests that the reported adverse health outcomes in IVF-born offspring might have underlying epigenetic mechanisms. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective study that recruited 303 adolescents and young adults, conceived through ART, to compare various long-term health outcomes and DNA methylation profiles with similar aged counterparts from Generation 2 from the Raine Study. GUHS assessments were conducted between 2013 and 2017. The effect of ART on DNA methylation levels of 231 adolescents mean age 15.96 ± 1.59 years (52.8% male) was compared to 1188 naturally conceived counterparts, 17.25 ± 0.58 years (50.9% male) from the Raine Study. PARTICIPANTS/MATERIALS, SETTING, METHODS: DNA methylation profiles from a subset of 231 adolescents (13-19.9 years) from the GUHS, generated using the Infinium Methylation Epic Bead Chip (EPIC) array were compared to 1188 profiles from the Raine Study previously measured using the Illumina 450K array. We conducted epigenome-wide association approach (EWAS) and tested for an association between the cohorts applying Firth's bias reduced logistic regression against the outcome of ART versus naturally conceived offspring. Additionally, within the GUHS cohort, we investigated differences in methylation status in fresh versus frozen embryo transfers, cause of infertility as well as IVF versus ICSI conceived offspring. Following the EWAS analysis we investigated nominally significant probes using Gene Set Enrichment Analysis (GSEA) to identify enriched biological pathways. Finally, within GUHS we compared four estimates (Horvath, Hanuum, PhenoAge [Levine], and skin Horvath) of epigenetic age and their correlation with chronological age. MAIN RESULTS AND THE ROLE OF CHANCE: Between the two cohorts, we did not identify any DNA methylation probes that reached a Bonferroni corrected P-value < 1.24E-0.7. When comparing IVF versus ICSI conceived adolescents within the GUHS cohort, after adjustment for participant age, sex, maternal smoking, multiple births, and batch effect, three methylation probes (cg15016734, cg26744878 and cg20233073) reached a Bonferroni correction of 6.31E-08. After correcting for cell count heterogeneity, two of the aforementioned probes remained significant and an additional two probes (cg 0331628 and cg 20235051) were identified. A general trend towards hypomethylation in the ICSI offspring was observed. All four measures of epigenetic age were highly correlated with chronological age and showed no evidence of accelerated epigenetic aging within their whole blood. LIMITATIONS, REASONS FOR CAUTION: The small sample size coupled with the use of whole blood, where epigenetic differences may occur in other tissue. This was corrected by the utilized statistical method that accounts for imbalanced sample size between groups and adjusting for cell count heterogeneity. Only a small portion of the methylome was analysed and rare individual differences may be missed. WIDER IMPLICATIONS OF THE FINDINGS: Our findings provide further reassurance that the effects of the ART manipulations occurring during early embryogenesis, existing in the neonatal period are indeed of a transient nature and do not persist into adolescence. However, we have not excluded that alternative epigenetic mechanisms may be at play. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by NHMRC project Grant no. 1042269 and R.J.H. received funding support from Ferring Pharmaceuticals Pty Ltd. R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from Merck Sharp & Dohme Corp.- Australia, Merck-Serono Australia Pty Ltd and Ferring Pharmaceuticals Pty Ltd. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director of PIVET Medical Centre, Perth, Western Australia. The remaining authors have no conflicts of interest.


Asunto(s)
Metilación de ADN , Técnicas Reproductivas Asistidas , Adolescente , Anciano , Australia , Niño , Femenino , Fertilización In Vitro , Humanos , Recién Nacido , Masculino , Embarazo , Estudios Prospectivos , Técnicas Reproductivas Asistidas/efectos adversos , Australia Occidental , Adulto Joven
5.
Reproduction ; 149(2): 147-54, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25376626

RESUMEN

Declining female fecundity at later age and the increasing tendency for women to delay childbirth have lead to a drastic rise in the number of women seeking assisted reproductive technology. Many women fail to respond adequately to standard ovarian stimulation regimens, raising a significant therapeutic challenge. Recently, we have demonstrated that the administration of GH, as an adjunct to ovarian stimulation, has improved the clinical outcomes by enhancing the oocyte quality. However, the mechanism(s) by which GH facilitated this improvement is yet to be understood. This study aimed to determine these potential mechanism(s) through the use of immunofluorescent localisation of GH receptors (GHRs) on the human oocyte and unbiased computer-based quantification to assess and compare oocyte quality between women of varying ages, with or without GH treatment. This study demonstrates for the first time, the presence of GHRs on the human oocyte. The oocytes retrieved from older women showed significant decrease in the expression of GHRs and amount of functional mitochondria when compared with those from younger patients. More interestingly, when older patients were treated with GH, a significant increase in functional mitochondria was observed in their oocytes. We conclude that GH exerts a direct mode of action, enabling the improvement of oocyte quality observed in our previous study, via the upregulation of its own receptors and enhancement of mitochondrial activity. This result, together with recent observations, provides scientific evidence in support of the use of GH supplementation for the clinical management of poor ovarian response.


Asunto(s)
Hormona de Crecimiento Humana/administración & dosificación , Inducción de la Ovulación/métodos , Adulto , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Persona de Mediana Edad , Mitocondrias/ultraestructura , Oocitos/química , Oocitos/fisiología , Oocitos/ultraestructura , Embarazo , Receptores de Somatotropina/análisis , Inyecciones de Esperma Intracitoplasmáticas/métodos
6.
Reprod Fertil Dev ; 25(6): 918-26, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22967503

RESUMEN

Oocyte vitrification is a clinical practice that allows preservation of fertility potential in women. Vitrification involves quick cooling using high concentrations of cryoprotectants to minimise freezing injuries. However, high concentrations of cryoprotectants have detrimental effects on oocyte quality and eventually the offspring. In addition, current assessment of oocyte quality after vitrification is commonly based only on the morphological appearance of the oocyte, raising concerns regarding its efficiency. Using both morphological and functional assessments, the present study investigated whether combinations of cryoprotectants at lower individual concentrations result in better cryosurvival rates than single cryoprotectants at higher concentrations. Surplus oocytes from IVF patients were vitrified within 24h after retrieval using the Cryotop method with several cryoprotectants, either individually or in combination. The morphological and functional quality of the vitrified oocytes was investigated using light microscopy and computer-based quantification of mitochondrial integrity, respectively. Oocyte quality was significantly higher using a combination of cryoprotectants than vitrification with individual cryoprotectants. In addition, the quality of vitrified oocyte varied depending on the cryoprotectants and type of combination used. The results of the present study indicate that observations based purely on the morphological appearance of the oocyte to assess the cryosurvival rate are insufficient and sometimes misleading. The outcome will have a significant implication in the area of human oocyte cryopreservation as an important approach for fertility preservation.


Asunto(s)
Criopreservación , Crioprotectores/farmacología , Mitocondrias/efectos de los fármacos , Oocitos/efectos de los fármacos , Adulto , Supervivencia Celular/efectos de los fármacos , Crioprotectores/efectos adversos , Dimetilsulfóxido/efectos adversos , Dimetilsulfóxido/farmacología , Complejo IV de Transporte de Electrones/metabolismo , Glicol de Etileno/efectos adversos , Glicol de Etileno/farmacología , Femenino , Fertilización In Vitro , Humanos , Infertilidad Femenina/metabolismo , Infertilidad Femenina/patología , Infertilidad Femenina/terapia , Infertilidad Masculina , Masculino , Mitocondrias/metabolismo , Mitocondrias/patología , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/metabolismo , Membranas Mitocondriales/patología , Oocitos/citología , Oocitos/metabolismo , Oocitos/patología , Concentración Osmolar , Glicoles de Propileno/efectos adversos , Glicoles de Propileno/farmacología , Transporte de Proteínas/efectos de los fármacos , Tubulina (Proteína)/metabolismo , Vitrificación , Adulto Joven
7.
J Assist Reprod Genet ; 19(2): 67-71, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11958507

RESUMEN

PURPOSE: (i) To determine the prevalence of micronuclei in the cytoplasm of embryos generated from in vitro matured oocytes. (ii) Assess whether micronuclei presence are the result of chromosome fragmentation or the loss of whole chromosomes. METHODS: In vitro fertilization was performed on mature oocytes generated from superovulated mice (control) and in vitro matured mouse oocytes. Fertilized oocytes were cultured to the two-cell stage and fixed to slides. Micronuclei assessment was performed after staining with Giemsa. Centromere assessment was made using immunofluorescent staining (CREST) of the centromeric kinetochores. RESULTS: Micronuclei were observed in 2% (4/197) of control two-cell embryos and 36.2% (46/127) of two-cell embryos generated from in vitro matured oocytes (P < 0.02). Centromeres were not detected in micronuclei from either group. CONCLUSIONS: A significant increase in micronuclei was observed in embryos generated from in vitro matured oocytes. The lack of accompanyingcentromeres would suggest the micronuclei are the result of chromosome fragmentation.


Asunto(s)
Rotura Cromosómica , Embrión de Mamíferos/fisiología , Fertilización In Vitro , Micronúcleos con Defecto Cromosómico , Oocitos/fisiología , Animales , Centrómero/genética , Análisis Citogenético , Femenino , Masculino , Ratones , Ratones Endogámicos
8.
Hum Reprod ; 13(11): 3094-8, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9853863

RESUMEN

A man with globozoospermia was treated in our in-vitro fertilization-intracytoplasmic sperm injection (ICSI) programme. In the treatment cycle, 24 oocytes were collected from his wife. All the oocytes were at metaphase II stage. The semen sample produced on the day had a normal sperm count, good motility, but with 100% globozoospermia. All oocytes were injected with randomly selected spermatozoa and of these, two oocytes showed two pronuclei and another contained a single pronucleus. The remainder were unfertilized. The normally fertilized oocytes (two pronuclear) cleaved to the four-cell stage and were transferred to the patient. At 48 h after ICSI, the 21 unfertilized oocytes were processed for cytogenetic analysis. All oocytes contained a haploid chromosome set. The only abnormality seen was a chromosome fragment in one metaphase. Eighteen oocytes contained decondensed sperm nuclei and of these, 14 nuclei were beginning to show signs of premature chromatin condensation (PCC) and the other four showed strong signs of PCC. Thus it appears that in some forms of globozoospermia, arrest of nuclear decondensation and/or PCC are another cause of fertilization failure. The most likely cause for this is the absence or down-regulation of spermatozoa associated activating factor in round-headed spermatozoa.


Asunto(s)
Aberraciones Cromosómicas , Fertilización In Vitro/métodos , Infertilidad Masculina/terapia , Microinyecciones , Oocitos/ultraestructura , Espermatozoides/anomalías , Adulto , Núcleo Celular/patología , Cromatina/patología , Femenino , Humanos , Infertilidad Masculina/etiología , Infertilidad Masculina/patología , Masculino , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/ultraestructura
9.
Hum Reprod ; 13(6): 1506-13, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9688383

RESUMEN

Female cigarette smoking has been implicated as having a detrimental effect on in-vitro fertilization (IVF) outcomes mediated through: (i) a diminished ovarian reserve (DOR), and (ii) an elevated pregnancy loss. Research is sparse regarding the effect of male smoking. The objective of this retrospective cohort study was to investigate the effect of male and female smoking on: (i) the collective quality of embryos selected for uterine transfer, and (ii) the likelihood of achieving an ongoing pregnancy at 12 weeks. A total of 498 consecutive IVF treatment cycles were analysed. Female smokers were significantly younger (P < 0.05) and achieved a better modified cumulative embryo score (mCES) (P < 0.05) than female non-smokers. Female age correlated inversely with the number of oocytes collected (r = -0.42, P < 0.01) and the number of oocytes in turn was important in terms of predicting mCES. The decreasing number of oocytes aspirated with increasing age was of a significantly stronger magnitude for female smokers than for female non-smokers (P < 0.05). Multiple logistic regression was used to determine whether smoking affected the likelihood of achieving a 12-week pregnancy. The mCES, tubal infertility and male smoking were found to be significant. Male smoking interacted with male age (P = 0.0164), indicating for male smokers a decrease of 2.4% in the likelihood of achieving a 12-week pregnancy with every 1-year increase in age. This is the first study to show that male smoking has a deleterious effect on pregnancy outcome among IVF patients. Our study supports the increased risk of DOR but fails to support the elevated incidence of pregnancy loss among female smokers. A reduced pregnancy rate was associated with male smoking possibly through pre-zygotic genetic damage. The growing realization of a paternal component of reproductive impairment suggests that studying the male is necessary.


Asunto(s)
Fertilización In Vitro , Resultado del Embarazo , Fumar/efectos adversos , Estudios de Cohortes , Embrión de Mamíferos/fisiología , Padre , Femenino , Humanos , Masculino , Embarazo , Estudios Retrospectivos , Factores de Riesgo
10.
Hum Reprod ; 12(7): 1550-3, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9262294

RESUMEN

Mouse oocytes and embryos were obtained following ovulation induction of (C57B16 x CBA) F1 animals. Zonae pellucidae were exposed to alpha-chymotrypsin in phosphate-buffered medium (PB1) supplemented with 3 mg/ml bovine serum albumin upon a heated stage (37 degrees C) and were observed constantly through an inverted microscope. The endpoint of the bioassay was the limits of the zona no longer being seen clearly at x 200 magnification, and the time taken for each zona to dissolve was recorded. A dose-dependent response in dissolution time was clearly seen, with 1% alpha-chymotrypsin being chosen as the routine working solution. Cryopreservation of 2-cell mouse embryos using propanediol did not cause zona hardening but induced a small and significant softening, as gauged by the time taken for zona dissolution (2181 +/- 167 versus 1864 +/- 82 s). Zona hardening was not suspected to occur after the freezing of human embryos as there was no difference in implantation rates per embryo for in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles between fresh [IVF: 63/644 (9.7%); ICSI: 51/330 (15.5%)] and frozen embryos [IVF: 36/458 (7.9%); ICSI: 18/112 (16.1%)]. Conversely, significant hardening of the zonae of mature oocytes was seen following cryopreservation (747 +/- 393 s) compared with freshly ovulated oocytes (151 +/- 68 s). It is concluded that (i) the freezing of murine oocytes with propanediol results in zona hardening, implying a possible benefit of ICSI after the cryopreservation of human oocytes, and (ii) the cryopreservation of embryos is not associated with zona hardening or reduced implantation, making microdissection of the zona in such cases generally unwarranted.


Asunto(s)
Criopreservación , Embrión de Mamíferos/fisiología , Fertilización In Vitro , Oocitos/fisiología , Zona Pelúcida/fisiología , Animales , Tampones (Química) , Quimotripsina/farmacología , Implantación del Embrión , Femenino , Fertilización In Vitro/métodos , Calor , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Microinyecciones , Inducción de la Ovulación , Fosfatos , Embarazo , Glicoles de Propileno , Albúmina Sérica Bovina , Zona Pelúcida/efectos de los fármacos
11.
Hum Reprod ; 12(5): 1056-8, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9194665

RESUMEN

This case report describes the birth of a baby following the transfer of cryopreserved embryos generated from intracytoplasmic sperm injection (ICSI) carried out on the second day after oocyte pick-up of in-vitro-matured metaphase I and germinal vesicle stage oocytes. The couple had a history of three failed intrauterine insemination attempts and reduced fertilization rates in two previous in-vitro fertilization (IVF) cycles. In the IVF-ICSI treatment cycle, 6/11 mature oocytes became fertilized following ICSI on the first day. However, the patient failed to conceive following the transfer of three embryos. Five oocytes were immature (two at metaphase I stage and three with a germinal vesicle) and these were cultured overnight. All had extruded a polar body by the following day and ICSI was therefore performed; four oocytes became fertilized, and were cryopreserved at the pronulear stage in propanediol. In the next treatment cycle, transfer of frozen embryos was planned. The pronuclear zygotes were thawed and cultured for 24 h prior to the transfer of two embryos in a cycle stimulated with low doses of follicle stimulating hormone. This resulted in a pregnancy and the delivery of a healthy baby boy. In-vitro maturation of metaphase I and germinal vesicle oocytes which are routinely collected in IVF-ICSI cycles, followed by second day ICSI fertilization, may provide a valuable source of embryos for infertile couples.


Asunto(s)
Transferencia de Embrión/métodos , Fertilización In Vitro , Infertilidad Femenina/terapia , Oocitos/fisiología , Resultado del Embarazo , Adulto , Criopreservación , Femenino , Congelación , Humanos , Masculino , Microinyecciones , Embarazo , Espermatozoides
12.
Hum Reprod ; 12(12): 2784-91, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9455853

RESUMEN

In the present study we have assessed the cytogenetic abnormalities of unfertilized oocytes from in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) programmes during a one year period (July 1995 to July 1996) with the cytogenetic analysis being carried out in a double-blind manner. A total of 88 unfertilized ICSI and 85 unfertilized IVF oocytes were used for the study and of these 51 and 62 oocytes, in each respective group, were suitable for analysis. The haploidy, diploidy and aneuploidy rates between ICSI (62.7, 7.8 and 5.9%) and IVF (61.3, 9.7 and 14.5%) groups were similar. A significant inter-patient variation in the incidence of hypohaploidy was observed within the IVF group. Chromosomal fragmentation or breakage was observed at a similar rate in both groups of unfertilized oocytes (23.5 and 14.5% for ICSI and IVF respectively). A significantly higher proportion of ICSI oocytes contained sperm nuclei (27/51, 52.9%) than did IVF oocytes (20/62, 32.3%, P < 0.01). The distribution and state of sperm head chromatin in relation to oocyte chromosomal complement was studied in both groups. ICSI oocytes contained decondensed or swollen sperm nuclei in association with haploid oocyte chromosomes (12/27, 44.4%) or condensed sperm heads in oocytes showing no chromosomal complements (7/27, 25.9%). In IVF oocytes sperm heads were either arrested in the condensed state (5/20, 25%), metaphase stage (3/20, 15%) or had undergone premature chromosome condensation (PCC; 6/20, 30%) in association with haploid oocyte chromosomes. The incidence of PCC was similar in the two groups. A marked variation in the incidence of total chromosomal abnormality was observed between patients within both ICSI (0-75%) and IVF (0-71%) groups indicating a possible similarity in oocyte quality between the majority of male factor and tubal infertility patients. The type of sperm used in the two fertilization procedures showed an increased incidence of chromosomal breakage with ICSI-MESA (microepididymal sperm aspiration) spermatozoa (4/6, 67%) compared to the ICSI-ejaculated (6/35, 17.1%; P < 0.05), ICSI-testicular biopsy (2/10, 20%) and IVF-normospermic (9/62, 14.5%; P < 0.01) spermatozoa. Chromosomal fragmentation may be associated with the degree of difficulty experienced at sperm injection, especially with sperm retrieved from the reproductive tract. Thus chromosomal fragmentation in ICSI may need further investigation using a larger sample size in order to assess the possible causative factors.


Asunto(s)
Aberraciones Cromosómicas , Fertilización In Vitro , Microinyecciones , Oocitos/ultraestructura , Aneuploidia , Núcleo Celular , Cromosomas/ultraestructura , Fragmentación del ADN , Diploidia , Método Doble Ciego , Femenino , Fertilización In Vitro/métodos , Haploidia , Humanos , Infertilidad Femenina , Infertilidad Masculina/genética , Masculino , Embarazo , Espermatozoides/ultraestructura
13.
Hum Reprod ; 11(11): 2474-6, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8981137

RESUMEN

The present report describes the motility changes in vitro (percentage motile and progressively motile) of freshly collected testicular and epididymal spermatozoa and following freeze/thaw of the same spermatozoa from a man with obstructive azoospermia. Washed spermatozoa were cultured in micro droplets under paraffin oil or in test tubes using HEPES-buffered or bicarbonate-buffered medium containing 10% human serum. In fresh testicular sperm cultures 60-65% of the sperm cells became motile within 2 days of culture; the motility was maintained for a further 4-5 days before a decline was observed. The progressive motility improved markedly on the third day of culture and it peaked around day 5. Only a small number of frozen/thawed testicular spermatozoa became motile during in-vitro culture (15-20%) and the motility was maintained for only 2-3 days before it declined. Furthermore, only 10-12% of the spermatozoa showed progressive motility. Spermatozoa recovered from micro-epididymal sperm aspiration (MESA) showed a gradual decrease in progressive motility and in 5 days all sperm cells were found to be immotile in both freshly collected and frozen/thawed spermatozoa. All culture systems supported sperm motility. It is clear that testicular spermatozoa, particularly from men with obstructive azoospermia, can be collected and maintained in vitro for up to 1 week before the oocyte retrieval but when frozen testicular or epididymal spermatozoa are used it is more reliable to thaw these spermatozoa on the day of intracytoplasmic sperm injection.


Asunto(s)
Criopreservación , Epidídimo/citología , Fertilización In Vitro/métodos , Microinyecciones , Motilidad Espermática , Testículo/citología , Adulto , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vasectomía
14.
Eur J Obstet Gynecol Reprod Biol ; 66(2): 197-9, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8735748

RESUMEN

We report trophoblast antigen (pregnancy-associated plasma protein-A, PAPP-A; free beta-human chorionic gonadotrophin, F beta hCG) expression in a trimosy 22 pregnancy. Maternal concentrations of these antigens were depressed prior to detection of abnormalities by ultrasonography. Immunohistochemical findings were consistent with depressed marker expression.


Asunto(s)
Gonadotropina Coriónica Humana de Subunidad beta/análisis , Cromosomas Humanos Par 22 , Placenta/inmunología , Proteína Plasmática A Asociada al Embarazo/análisis , Trisomía , Gonadotropina Coriónica Humana de Subunidad beta/sangre , Femenino , Humanos , Embarazo , Primer Trimestre del Embarazo
17.
Hum Reprod ; 10 Suppl 1: 67-71, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8592043

RESUMEN

Pentoxifylline was first used within an in-vitro fertilization (IVF) programme before the advent of alternative treatment strategies such as oocyte micromanipulation. Over the years, it has continued to be useful in aiding fertilization in selected IVF cases, with a beneficial effect also being seen in certain cases treated by intrauterine insemination. In both instances, the acrosome reaction to ionophore challenge test appears to have been invaluable in identifying suitable patients. The stimulation of spermatozoa by pentoxifylline should remain a therapeutic option in the treatment of couples with a male factor present. As an adjunct to IVF, it has the advantage of being simpler and less costly to perform compared with micromanipulation. However, its use should be restricted to selected cases, and the merits over and above those of invasive procedures such as intracytoplasmic sperm injection should be discussed with the individual patients. The pretreatment of spermatozoa prior to intrauterine insemination in selected cases gives an alternative therapeutic strategy to those patients not wishing or unable to undertake IVF.


Asunto(s)
Fertilización In Vitro , Infertilidad Masculina/terapia , Pentoxifilina/uso terapéutico , Fertilización/efectos de los fármacos , Fertilización In Vitro/tendencias , Humanos , Inseminación Artificial , Masculino , Espermatozoides/efectos de los fármacos
18.
J Assist Reprod Genet ; 12(5): 312-8, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-8520194

RESUMEN

PURPOSE: Our purpose was to evaluate the efficacy of direct insemination (IVF), micromanipulation by partial zona dissection (PZD), and subzonal sperm insemination (SUZI) using sperm-treated with pentoxifylline (PF) +/- 2-deoxyadenosine (2DA). RESULTS: The overall fertilization rate achieved was similar for all three fertilization techniques (33.1, 30.2, and 26.9% for IVF, SUZI, and PZD, respectively). Patients who had reduced fertilization in previous IVF attempts showed improved fertilization with sperm stimulants, either PF alone or PF in combination with 2DA in standard IVF. In certain cases, SUZI or PZD gave significantly improved fertilization rates in comparison to IVF. CONCLUSION: Selective use of sperm stimulants in IVF can achieve fertilization for the majority of male-factor cases. However, PZD and SUZI techniques are useful, especially when sperm stimulants fail to achieve fertilization or achieve poor fertilization in direct insemination.


Asunto(s)
Desoxiadenosinas/farmacología , Fertilización In Vitro/métodos , Infertilidad Masculina , Inseminación Artificial/métodos , Pentoxifilina/farmacología , Inhibidores de Fosfodiesterasa/farmacología , Índice de Embarazo , Espermatozoides/efectos de los fármacos , Zona Pelúcida/fisiología , Femenino , Humanos , Masculino , Embarazo , Semen/fisiología , Motilidad Espermática/efectos de los fármacos , Motilidad Espermática/fisiología , Espermatozoides/fisiología
19.
Hum Reprod ; 9(9): 1710-6, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7836523

RESUMEN

Microsurgical epididymal sperm aspiration (MESA) and in-vitro fertilization (IVF) were found to offer limited opportunity for fatherhood to 45 men with obstructive azoospermia, due principally to poor embryo implantation. Adequate sperm preparations were obtained in 46/50 treatment cycles (92%), with the best motility found in the caput epididymis in 89% of cases. The mean fertilization rate was 11.2% and fertilization occurred in 23 cycles (50%), with embryo transfer arising from 12/26 men with vas aplasia (CAV), 4/9 with genital tract obstruction (EV) and 7/11 with irreversible vasectomy (VV). The overall implantation rate was low, 8.7% per embryo transfer (11.7% per 2-3 embryo transfers) and was not improved by Fallopian transfer. There were two pregnancies (4% per cycle), both in the EV group where embryo formation and implantation (2/4, 50% per cycle) were optimum even though sperm preparations were paradoxically inferior to the CAV and VV groups. The spermatozoa retrieved in the two successful EV cycles were appreciably blood contaminated. Analysis of the 21 failed embryo transfers showed delayed fertilization in 10 cycles, cystic fibrosis (CF) mutation or familial disease in 7/12 CAV men and the VV men were older (P < 0.001). A pregnancy which miscarried arose from a case of Young's syndrome, a carrier of CF mutation DF508. Male factors could thus be implicated in the high embryo wastage of MESA cycles and might also be influencing implantation in other IVF procedures. Where feasible, male reconstructive surgery is preferable unless fertilization can be improved, possibly by speedier retrieval techniques or by permitting sperm capacitation in vitro, but probably more effectively by micro-assisted insemination.


Asunto(s)
Epidídimo/patología , Fertilización In Vitro/métodos , Oligospermia/terapia , Adulto , Constricción Patológica , Fibrosis Quística/genética , Transferencia de Embrión , Epidídimo/cirugía , Femenino , Humanos , Masculino , Microcirugia , Mutación , Oligospermia/etiología , Oligospermia/patología , Embarazo , Espermatozoides , Succión , Conducto Deferente/anomalías , Vasectomía/efectos adversos
20.
Fertil Steril ; 61(5): 902-10, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8174729

RESUMEN

OBJECTIVE: To assess the utility of the acrosome reaction (AR) to ionophore challenge test in determining the sperm treatment protocols for patients undergoing assisted reproduction. DESIGN, SETTING, PATIENTS: One hundred twenty-one couples undergoing an IVF-ET or GIFT procedure from January to July 1992 were included in this prospective study. All cases had a preliminary semen analysis within the previous 3 months and an AR to ionophore challenge test was carried out unless an acceptable fertilization rate occurred on previous IVF. For those patients whose AR to ionophore challenge score was below the accepted fertile range of > or = 10%, a second AR to ionophore challenge test was performed after exposure of sperm to the stimulant pentoxifylline. Couples then were managed by assisted reproduction with randomized allocation of oocytes for fertilization with a standard sperm preparation or with added sperm stimulants, either 3.6 mM pentoxifylline alone or combined with 3.0 mM 2-deoxyadenosine. The study was double-blind with neither the patients nor the embryologist knowing the AR to ionophore challenge result at the time of the IVF procedure. MAIN OUTCOME MEASURES: Data from the preliminary semen analyses and AR to ionophore challenge scores were correlated with the fertilization rates achieved using control and treated sperm preparations. The rates of total fertilization failure and the numbers of clinical pregnancies occurring in each subgroup were also recorded. RESULTS: All AR to ionophore challenge groups showed normal sperm counts except the groups with poor AR to ionophore challenge, which demonstrated reduced sperm counts. The group with normal AR to ionophore challenge scores or previous normal fertilization showed satisfactory fertilization rates with either control or treated sperm, although some individual cases showed reduced fertilization with treated sperm. The fertilization rate for the group with low AR to ionophore challenge scores improved significantly with pentoxifylline, and the benefit was greatest when this had been predicted from the AR to ionophore challenge studies. Cases with persisting poor AR to ionophore challenge despite pentoxifylline showed no significant improvement in fertilization rates with sperm exposed to either sperm stimulant regimens. Poor AR to ionophore challenge scores were also predictive of total fertilization failure, but this problem was reduced by sperm stimulation. The AR to ionophore challenge score at 10% cutoff level showed optimal levels of sensitivity (82.1%), highest negative predictive value (82.1%), and lowest false negative rate (17.9%). CONCLUSIONS: The AR to ionophore challenge test is useful in the assessment and management of the male factor in assisted reproduction. It can be used to identify the majority of cases who will benefit from the use of sperm stimulants.


Asunto(s)
Acrosoma/fisiología , Calcimicina/farmacología , Fertilización In Vitro/métodos , Reproducción/fisiología , Permeabilidad de la Membrana Celular/fisiología , Desoxiadenosinas/farmacología , Método Doble Ciego , Femenino , Fertilidad/fisiología , Fertilización/fisiología , Transferencia Intrafalopiana del Gameto , Humanos , Infertilidad Masculina/terapia , Masculino , Pentoxifilina/farmacología , Estudios Prospectivos , Espermatozoides/citología , Espermatozoides/fisiología , Espermatozoides/ultraestructura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...