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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormal embryo development represents the major cause of implantation failures and accounts for the low rate of human infertility in vivo or in vitro. Chromosome abnormalities are widely involved in this process. Indeed, 28.4% of oocytes carry a chromosome aberration, i.e. 25.6% aneuploidy and 2.8% structural anomalies. Fertilisation abnormalities (possibly increased by in vitro procedures) were recorded: 7 to 28% of oocytes from fertilisation failure showed a sperm premature chromosome condensation probably resulting from ooplasmic immaturity. Moreover, 1.6% and 3.8% of inseminated oocytes had either a single or 3 pronuclei demonstrating parthenogenesis or triploidy, respectively. In vitro developmental capacities of embryos depends on the degree of ploidy. Parthenogenetic embryos display a fairly normal development until implantation. Triploid zygotes show an original way of division: half of them divide first into 3 cells and then into 6 cells (via a tripolar spindle) whereas diploid zygotes divide into 2 and then 4 cells. As a consequence of either meiotic or mitotic non disjunctions or fertilisation anomalies, 25 to 71% preimplantation embryos carry a chromosome disorder. As an outgrowth of in vitro fertilisation and embryo transfer, detection of genetic and metabolic defects prior to implantation might be possible in the future. So far, 6 girls have been born in couples at risk of transmitting X-linked disease. This technic will increase the efficiency of IVF and avoid the trauma of repeated abortions.
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PMID:Cytogenetic analysis of oocytes and embryos. 130 24

Traditionally infertility has been viewed as a medical condition and has been managed within the medical model of diagnosis, treatment, and cure. The prevalence of infertility has been medically explained by women's sexual promiscuity, pursuit of professional career advancement, and psychological immaturity. Although authors have recently recognized an equitable proportion of infertility problems attributable to male factors, the vast majority of infertility testing and treatment procedures remain directed toward women. Reproductive technologies and their potential for perpetual treatment create a scenario of vulnerability for the infertile woman, which demands the attention of care providers who advocate feminist values of health. In this article, we present a historical overview of infertility and offer a feminist perspective for providing physical and emotional health care to infertile women. Strategies for integrating feminist perspectives of health into infertility programs are discussed.
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PMID:Walking the line between feminism and infertility: implications for nursing, medicine, and patient care. 188 43

Kallmann's syndrome is a genetic disorder that includes pituitary gonadotropin deficiency associated with sexual immaturity and infertility. A successful treatment program resulted in normalization of sexual development, spermatogenesis, and conception.
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PMID:Kallmann's syndrome: reproductive success. 239 36

Cryptorchidism is associated with impaired spermatogenesis and, at times, sterility. Early orchiopexy has been advocated as a possible means to prevent spermatogenic impairment and infertility in patients with cryptorchidism. This retrospective study is derived from data obtained from 74 cases that were observed during a period of approximately 10 years at our hospital. Particular attention was devoted to epididymal and vas deferens histological status. Of the 47 epididymides and vas deferens examined only 2 epididymides and 2 vas deferens showed histological maturity. The remainder showed varying degrees of immaturity that additionally correlated, when testicular tissue was available, with the presence of unfavorable testicular histological findings. Cryptorchidism is associated with changes in the gonads and spermatic duct system.
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PMID:Epididymal and vas deferens immaturity in cryptorchidism. 290 59

Cycling adult female hamsters can be induced to mate and ovulate 24 h early by the injection of 20 IU human chorionic gonadotropin (hCG) at 1500 h on Day 3 (day before proestrus), but pregnancy is not established. Although there is evidence of decreased sperm transport in precociously ovulated females, this does not appear to be the primary cause of infertility. Reduced size and vascularity of corpora lutea (CL) in treated females suggests incomplete or failed CL activation. Control and hCG-treated females were killed by exsanguination under ether anesthesia at intervals for the first 5 days after mating. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, estradiol, and progesterone were measured by radioimmunoassay. Luteinizing hormone in treated animals was very high at 2200 h on Day 1 after mating (31 h after the hCG injection), due to endogenous release, and dropped below control levels thereafter. Follicle-stimulating hormone, by contrast, was significantly lower than controls at 2200 h on Day 1 and remained low until 2200 h on Day 3 after mating. Prolactin in treated animals was not different from that in controls, except for 1000 h on Day 4, when it showed a significant dip. Estradiol in treated animals was significantly higher than in controls at 2200 h on Day 1 (when LH was also high and FSH was low), and remained high at 1000 h and 2200 h on Day 2, dropping thereafter to control levels. Progesterone was initially at control levels but had dropped significantly by 1000 h on Day 2 and remained low for the next 24 h. These results suggest that pregnancy failure is due to inadequate activation of corpora lutea. This may be due to: 1) immaturity of follicles at the time of ovulation; 2) inappropriate timing of preovulatory events; 3) the luteolytic effects of high levels of LH or estradiol or both; 4) the low level of FSH in the early stages of corpus luteum development; or 5) a combination of the above. Abnormalities of prolactin secretion were not investigated in detail but cannot be ruled out at this time.
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PMID:Multiple causes of pregnancy failure in hamsters precociously ovulated by human chorionic gonadotropin. 393 83

There is a strong association between cigarette smoking and reduced fecundity, reduced fertility, and early mean age of menopause, suggesting that smoking may impair oocyte function and viability. We analysed the effect of smoking on meiotic maturation of oocytes. A total of 156 women undergoing in-vitro fertilization therapy, classified as non-smokers (n = 102), passive smokers (n = 21), light smokers (< 15 cigarettes/day; n = 19), and heavy smokers (> or = 15 cigarettes/day, n = 14), participated in this study. Tubal factor infertility was more frequent in smokers, in agreement with the literature, and showed a significant dose effect (P = 0.008). Smokers had decreased numbers of retrieved oocytes compared with non-smokers, suggesting reduced fertility. Cytogenetic data from 286 oocytes apparently unfertilized showed similar proportions of haploid (normal) and aneuploid chromosome complements among groups. In contrast, oocytes with diploid complements were more frequent among smokers. Regression of individual proportions of diploid oocytes on number of cigarettes smoked per day was very significant (P = 0.0003). The increased frequency of oocyte diploidy in smokers, probably resulting from prevention of first polar body extrusion, indicates meiotic immaturity. Also, triploid zygotes occurred more frequently in smokers (P = 0.03), suggesting preferential digynic fertilization. Our study shows that external factors, like cigarette smoking, may be hazardous to the viability and function of developing oocytes and their resulting embryos.
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PMID:Cigarette smoking may affect meiotic maturation of human oocytes. 882 47

The present study was designed to compare the cycle characteristics of in-vitro fertilization (IVF) and the chromosomal normality of oocytes in patients with polycystic ovarian syndrome (PCOS) with those of patients with tubal factor infertility. In all, 28 cycles of 24 PCOS patients and 55 cycles of 31 patients with tubal factor infertility (control) were investigated. Although a significantly greater number of oocytes were retrieved from PCOS patients (mean +/- SD: 15.6 +/- 6.4 versus 9.0 +/- 4.0, PCOS versus control group, P < 0.05), the percentage of fertilized oocytes was significantly lower in the PCOS group compared with controls (40.1 versus 73.8%, P < 0.01). The pregnancy rate per embryo transfer did not differ between the two groups. Cytogenetic analysis was performed on 74 oocytes from PCOS patients and 73 oocytes from control patients. In the PCOS group, 10 of the 74 oocytes (13.5%) demonstrated aneuploidy, four (5.4%) oocytes were diploid and six (8.1%) oocytes were metaphase II with a prematurely condensed sperm chromosome (PCC). In the tubal infertility group, nine of the 73 (12.3%) oocytes showed aneuploidy, four (5.5%) oocytes were diploid and five (6.8%) oocytes were found to have PCC. There was no significant difference in the aneuploidy, diploidy and PCC rates between the two groups. These results suggest that the reduced fertilization observed in PCOS is not attributable to chromosomal aberrations or immaturity of oocytes recruited from patients with PCOS.
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PMID:The chromosomal normality of unfertilized oocytes from patients with polycystic ovarian syndrome. 913 Jul 43

Since the beginning of in vitro fertilization (IVF), basic research has enlightened the field of human reproduction, especially in genetics. Indeed, the contribution of chromosomal anomalies to oocyte disorders and impaired developmental capacities of the embryos is now well known. Among oocytes that failed to fertilize after in vitro insemination, 26.5% were found to be abnormal comprising 13.3% hypohaploidy, 8.1% hyperhaploidy, 1.6% structural anomalies and 3.5% diploidy. The total incidence of abnormalities seems to be correlated to the female status, and was found to be higher in oocytes from women with tubal or unexplained infertility than in those from women whose husband was infertile as a sole cause of couple infertility. Although few oocytes recovered during a natural cycle were studied, gonadotropins widely used to stimulate follicle growth and ovulation do not increase the risk of anomalies. The effect of maternal age on fetal aneuploidy, well documented at birth, has not yet be found unambiguously to be a consequence of an increased rate of aneuploid oocytes. Intra- and extrafollicular influences (perifollicular microvasculature, oxygenation, the presence of residues from cigarette smoke) are able to disturb maturation leading to immaturity and aneuploidy. To conclude, oocyte meiosis is very sensitive to endogenous or exogenous factors, which could lead to chromosomally abnormal oocytes and as a consequence, to abnormal zygotes.
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PMID:The human oocyte. Genetic aspects. 925 59

The use of epididymal spermatozoa in assisted reproduction (ART) permits fertility in men with surgically irremediable obstructive azoospermia. When used for conventional IVF (sperm-oocyte co-culture), epididymal spermatozoa show reduced fertilization and pregnancy rates (compared with ejaculated spermatozoa from men with a range of spermatogenic disorders) as evidence of their functional immaturity. However, when used with intracytoplasmic sperm injection (ICSI) either fresh or frozen-thawed epididymal spermatozoa produce ART success rates similar to those of ejaculated spermatozoa. The clinical place of epididymal sperm retrieval for ICSI has come under review as a result of data showing similarly good outcomes with testicular spermatozoa obtained by needle aspiration. In Australia ICSI using epididymal or testicular spermatozoa is an increasingly favoured option for vasectomy-related infertility and in other types of obstructive azoospermia for a number of reasons including better pregnancy outcomes, the less invasive nature of the procedures and less expense involved; however, this cost-benefit analysis will vary in other health systems.
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PMID:The use of epididymal spermatozoa in assisted reproduction. 1064 87

Since the beginning of in vitro fertilization (IVF), basic research has provided insight in the field of human reproduction, especially in genetics. Indeed, the contribution of chromosomal abnormalities to oocyte disorders and impaired embryonic development is now well known. Of oocytes that fail to fertilize after in vitro insemination, 26.5% have been found to be abnormal, with 13.3% showing hypohaploidy, 8.1% hyperhaploidy, 1.6% structural abnormalities and 3.5% diploidy. The total incidence of abnormalities seems to be correlated with the fertility status of the woman. It is higher in oocytes from women with tubal or unexplained infertility than in those from women whose husband's infertility is the sole cause of infertility in the couple. Although few oocytes recovered during natural cycles have been studied, gonadotropins, which are widely used to stimulate follicle growth and ovulation, do not increase the risk of abnormalities. The effect of maternal age on fetal aneuploidy, well documented at birth, has not been unambiguously shown to result from an increase in the frequency of aneuploid oocytes. Intra- and extra-follicular influences (perifollicular microvasculature, oxygenation, and the presence of residues from cigarette smoke) may disturb maturation, leading to immaturity and aneuploidy. Thus, oocyte meiosis is very sensitive to endogenous and exogenous factors that could result in oocytes with chromosomal abnormalities and therefore, abnormal zygotes.
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PMID:Chromosomal abnormalities in oocytes. 1157 35


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