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PubMedDate not supplied

Individual fertility rate: a new individual fertility measure for small populations.

Fertility measurement in small preindustrial societies is hampered by small numbers and the lack of some essential data. Most measures of fertility are collective and require large enough populations to permit grouped data analysis. Existing individual measures of fertility are often unsatisfactory. This paper presents a new measure of individual fertility, the Individual Fertility Rate (IFR), which is constructed by dividing parity by reproductive span in years and multiplying the product by 100. The result is a number which may be used as a dependent individual or cumulative variable to study the effects of health and socioeconomic factors on fertility.

Adult↗
PubMed1992

Improved fertilization rate in an in vitro fertilization program by egg yolk-treated sperm.

High fertilization and PRs have been achieved by using thawed donor sperm cryopreserved with medium containing EY. The aim of our study was to examine the possible effect of EY on the fertilizing capacity of fresh sperm in an IVF program. Preincubation of spermatozoa in EY for 2 hours at room temperature significantly improved fertilization (P less than 0.001) in couples who had low fertilization rates in previous cycles, whereas no effect was found concerning couples with high fertilization rates.

Egg Proteins↗
PubMed1993

Co-culture with granulosa cells does not increase the fertilization rate in couples with previous fertilization failures.

Ten couples included in our in-vitro fertilization programme, selected because of one of more previous total fertilization failures or a low fertilization rate (< 20%), were entered in an experimental protocol of egg insemination on autologous granulosa cells. Half the oocytes from each patient were randomly assigned to either a control or a co-culture group. We observed no difference in the fertilization rate between the control (16.2%) and co-culture groups (12.1%). Only two couples benefited from this technique since fertilization was obtained only in co-culture. The poor efficiency of this protocol led us to propose the use of sperm micro-injection if all classical attempts to improve fertilization were unsuccessful.

Cells, Cultured↗
PubMed1992

Pilot study with 120 mg Andriol treatment for couples with a low fertilization rate during in-vitro fertilization.

Treatment with 120 mg/day of Andriol (testosterone undecanoate; Organon, The Netherlands) was given to 11 men whose semen had either failed to fertilize, or had resulted in a less than 33% fertilization rate in a first in-vitro fertilization (IVF) trial. Repeat IVF at the end of a 3 month treatment period resulted in a highly significant increase in the number of oocytes fertilized from 4/95 (4.2%) before to 23/87 (26.4%, P less than 0.001) after Andriol treatment. One couple attained spontaneous conception during the second month of Andriol intake and three pregnancies occurred among the remaining 10 cases undergoing repeat IVF, for a total ongoing pregnancy rate of 36.4%. Sperm concentration but not motility increased in the native semen after Andriol intake, but there were no significant changes in sperm characteristics after preparation. The improvement in pregnancy rate contrasts favourably with the results obtained by repeat IVF of untreated historical controls. The result obtained in the present pilot study should encourage the performance of a larger, placebo-controlled investigation protocol.

Female↗
PubMed1994

Correlation between epididymal length and fertilization rate in men with congenital absence of the vas deferens.

OBJECTIVE: To investigate whether the variable length of the epididymides in men with congenital absence of the vas deferens might have a correlation with IVF and pregnancy rate results. DESIGN: Microsurgical retrieval of epididymal sperm from men with congenital absence of the vas deferens and their use for IVF. SETTING: Center for Reproductive Health, University of California, Irvine, California. PATIENTS: One hundred eight men with confirmed diagnosis of congenital absence of the vas deferens enrolled in the microsurgical epididymal sperm aspiration and IVF program. INTERVENTIONS: Measurement in centimeters of the epididymal length at the time of the sperm aspiration procedure. MAIN OUTCOME MEASURE: Rates of fertilization and pregnancy according to the epididymal length. RESULTS: Three groups were identified: group I (n = 29), epididymal length between 0.5 and 1.9 cm; group II (n = 66), length between 2.0 and 4.0 cm; and group III (n = 13), length in excess of 4.0 cm. Although the aspiration site was the proximal caput for each case, patients of group III had the highest fertilization and pregnancy rate (24% and 43%, respectively). Patients with the shortest epididymis (group I) had the worst IVF outcome (fertilization rate 7% and pregnancy rate 7%) whereas in group II the fertilization rate was 13% and the pregnancy rate was 18%. CONCLUSION: This study demonstrates that epididymal sperm from men with congenital absence of the vas deferens having a longer epididymis have a better IVF rate. A long epididymis can allow [1] the arrival of more frequent waves of fresh sperm whereas in a short epididymis the system is completely congested and occupied by old and senescent sperm, [2] less obstructive damages, and [3] a back flow of biochemical factors produced in the more distal segments that could ultimately enhance the fertilization capacity of proximal epididymal sperm.

Epididymis↗
PubMed1994

Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population.

OBJECTIVE: To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome. DESIGN: Retrospective analysis of all IVF cycles (January 1987 to December 1992). MAIN OUTCOME MEASURES: All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome. RESULTS: Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate. CONCLUSIONS: Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.

Adult↗
PubMed1999

Sperm treatment with extracellular ATP increases fertilization rates in in-vitro fertilization for male factor infertility.

Previous work from our laboratory has revealed that extracellular ATP is a rapid and potent activator of human sperm acrosome reaction and fertilizing ability. In the present study, we assessed the effects of in-vitro sperm incubation with ATP on fertilization and embryo development in couples undergoing in-vitro fertilization (IVF) for male factor infertility. Oocytes from 22 women undergoing ovulation induction were divided in two groups and inseminated in vitro either with selected spermatozoa from the corresponding partner suffering from male factor infertility pre-incubated with ATP (2.5 mM) for 1 h, or with spermatozoa incubated with 0.9% NaCl solution (control group). After insemination, fertilization was assessed by the presence of pronuclei and then by embryo cleavage. The fertilization rate in the group of oocytes inseminated with ATP-treated spermatozoa improved significantly with respect to the control group (65.7 versus 42.5%, P < 0.01). No significant differences were observed in embryo cleavage and embryo quality. Embryos from both treated and control groups were transferred together in 20 transfer procedures, and in two couples fertilization was not obtained. Nine pregnancies occurred: one biochemical, one miscarriage, and seven patients delivered 9 healthy babies. Two pregnancies were twin with an overall pregnancy rate of 40.9% per cycle and of 45% per transfer. In conclusion, the results of the present study demonstrate that, in humans, extracellular ATP induces a significant increase of sperm fertilizing potential, as these findings are a rationale for the use of ATP for in-vitro treatment of human spermatozoa during IVF.

Adenosine Triphosphate↗
PubMedDate not supplied

Nitrate loss in subsurface drainage as affected by nitrogen fertilizer rate.

The relationships between N fertilizer rate, yield, and NO3 leaching need to be quantified to develop soil and crop management practices that are economically and environmentally sustainable. From 1996 through 1999, we measured yield and NO3 loss from a subsurface drained field in central Iowa at three N fertilizer rates: a low (L) rate of 67 kg ha(-1) in 1996 and 57 kg ha(-1) in 1998, a medium (M) rate of 135 kg ha(-1) in 1996 and 114 kg ha(-1) in 1998, and a high (H) rate of 202 kg ha(-1) in 1996 and 172 kg ha(-1) in 1998. Corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] were grown in rotation with N fertilizer applied in the spring to corn only. For the L treatment, NO3 concentrations in the drainage water exceeded the 10 mg N L(-1) maximum contaminant level (MCL) established by the USEPA for drinking water only during the years that corn was grown. For the M and H treatments, NO3 concentrations exceeded the MCL in all years, regardless of crop grown. For all years, the NO3 mass loss in tile drainage water from the H treatment (48 kg N ha(-1)) was significantly greater than the mass losses from the M (35 kg N ha(-1)) and L (29 kg N ha(-1)) treatments, which were not significantly different. The economically optimum N fertilizer rate for corn was between 67 and 135 kg ha(-1) in 1996 and 114 and 172 kg ha(-1) in 1998, but the net N mass balance indicated that N was being mined from the soil at these N fertilizer levels and that the system would not be sustainable.

Agriculture↗
PubMed1988

[[Determinants of the decline in the total marital fertility rate in the early 1970s]].

The author examines "the relationship between the total marital fertility rate and the cohort marital fertility pattern in Japan since the late 1960s. We calculated parity-duration-year-specific marital fertility rates and conducted comparisons among them cohort by cohort and period by period. In addition, we carried out a decomposition of the change in total marital fertility rates into the tempo and quantum components on two different assumptions about future completed fertility. By calculating the first-birth, second-birth and third-birth timing indices, we could specify the effect due to a change of birth timing for each parity on the variation of the total marital fertility rate." It is found that "given that the drop in the total fertility rate in the early 1970s is largely attributable to a decrease in the total marital fertility rate, most of the drop in the total fertility rate in this period is also attributable to the change in second-birth timing over marriage cohorts since the middle 1960s and the temporal disturbance in second-birth timing in marriage cohorts of the early 1970s." (SUMMARY IN ENG)

Asia↗
PubMed2002

The general fertility rate in women with psychotic disorders.

OBJECTIVE: This study determined the general fertility rate and age-specific fertility rates for women with psychotic disorders. METHOD: This historical matched-cohort study of patient records from a primary care database (the General Practice Research Database) was carried out for women of childbearing age (15-44 years) with psychotic disorders. RESULTS: The women with psychotic disorders (N=7,936) had a lower overall general fertility rate than the normal comparison subjects (N=23,023), although fertility was only significantly lower in the women aged 25 and above. This lower fertility rate was less marked in women with affective psychoses. There was no evidence that treatment with neuroleptics influenced the fertility rate in women with non-affective psychoses. CONCLUSIONS: This study found markedly lower fertility rates in women with psychotic disorders than in matched normal comparison subjects, particularly in women with non-affective disorders. Knowledge of fertility rates in women with psychotic disorders is fundamental for clinicians and researchers, since it has implications for family planning services, prevention of obstetric complications, child-care support, and hypotheses about the etiology of these disorders.

Adolescent↗
PubMed2004

The impact of a reduced fertility rate on women's health.

HEALTH ISSUE: Total fertility rates (TFRs) have decreased worldwide. The Canadian fertility rate has gone from 3.90 per woman in 1960 to 1.49 in 2000. However, not many studies have examined the impact on women's health of reduced fertility rates, delayed fertility and more births to unmarried women. This paper presents information on the relation between family size and specific determinants of health. KEY FINDINGS: The rate of TFR decline varies considerably by geographic location and socio-demographic subgroup. Further, the associations between family size and selected determinants of health are different for women and men. For example a woman with one child is almost four times more likely to be "coupled" than a childless woman, and if she has two children she is significantly more likely to be "coupled" than if she had only one child. However, a man with one or more children is over six times more likely to be "coupled" than his childless counterpart, and this does not vary with family size. DATA GAPS AND RECOMMENDATIONS: There is a paucity of data on the impact of reduced fertility rates on women's health in general and on how women's roles affect their decision to have children. While it would be useful to examine longer-term health outcomes by parity and age of first birth, as well as socio-economic and role-related variables these longitudinal and detailed "role related" data are not available. Given the differing profiles of women and men with children, further health policies research is needed to support vulnerable women with children.

Journal Article↗
PubMed1998

Case report: high fertilization rate in conventional in-vitro fertilization utilizing spermatozoa from an oligozoospermic subject presenting microdeletions of the Y chromosome long arm.

A case is reported in which a high fertilization rate was achieved by conventional in-vitro fertilization (IVF), using spermatozoa from an oligozoospermic man carrying a microdeletion of the long arm of the Y chromosome. The patient presented with idiopathic infertility of 10 years duration; the fertility status of his wife was completely normal. After IVF, five out of eight oocytes retrieved showed normal fertilization and four showed normal embryo cleavage. Four embryos were transferred; however, pregnancy did not result. These results demonstrate that spermatozoa from oligozoospermic patients carrying a Yq microdeletion are fully competent in achieving capacitation, acrosome reaction and fertilizing ability during IVF. Therefore, although definitive conclusions cannot be made from a single case report, we suggest that Yq microdeletion analysis should be considered in oligozoospermic patients undergoing conventional IVF.

Adult↗
PubMed2000

Assessment of maximal fertilization rates with intracytoplasmic sperm injection.

PURPOSE: Maximal fertilization rates following ICSI were assessed using two essential steps: immobilization of sperm and aspiration of oocyte cytoplasm. METHODS: ICSI procedure was performed for couples (N = 42) in whom the male suffered severe infertility or failure of fertilization in previous IVF cycle using different oocyte cytoplasmic aspiration and sperm immobilization methods. Outcome in four patient groups was measured by oocyte damage, fertilization rate, and pregnancy rate. RESULTS: Maximal fertilization (90%) were achieved from the group which used immobilization of sperm by hard-touching the tail with a pipette and optimal aspiration of oocyte cytoplasm. CONCLUSIONS: The results suggest that if the immobilization of sperm and aspiration of oocyte cytoplasm are handled right during ICSI, this procedure can be expected to yield a 90% fertilization rate.

Female↗
PubMed2004

Successful fertilization and pregnancy after intracytoplasmic sperm injection and oocyte activation with calcium ionophore in a normozoospermic patient with extremely low fertilization rates in intracytoplasmic sperm injection cycles.

OBJECTIVE: To investigate the effect of calcium ionophore on the fertilization rate of a patient with normozoospermia who nonetheless exhibited a low fertilization rate in intracytoplasmic sperm injection (ICSI). DESIGN: Case report. SETTING: In vitro fertilization center. PATIENT(S): A male patient whose sperm, though diagnosed as normal by semen analysis, exhibited a severely low fertilization rate in ICSI cycles. INTERVENTION(S): Oocytes were activated by calcium ionophore after ICSI. MAIN OUTCOME MEASURE(S): Fertilization rate after oocyte activation; ultrastructure and protein expression of the patient's sperm. RESULT(S): The fertilization rate of oocytes activated with calcium ionophore (12 of 15, 80.0%) was higher than that of the nonactivated oocytes (4 of 16, 25.0%). Four embryos derived from the activated oocytes were transferred, resulting in a twin pregnancy. Further investigation revealed abnormalities in the patient's sperm: many nuclear vacuoles were observed and the expression of some proteins was absent. CONCLUSION(S): Oocyte activation with calcium ionophore was effective at increasing the fertilization rate of dysfunctional sperm characterized by ultrastructural and protein expression anomalies.

Adult↗
PubMed1993

Prediction of in vitro fertilization rates from semen variables.

OBJECTIVE: To assess the value of semen variables for predicting fertilization rates. DESIGN: Measures of the fresh semen and the motile sperm fraction used for insemination were related to the fertilization rate by multiple regression analysis. The regression model was then used to construct a two-dimensional clinical chart. SETTING: University-affiliated reproductive medicine unit. PATIENTS: The results of 294 IVF cycles were analyzed retrospectively. Selection criteria were: [1] first cycle of IVF; [2] tubal and/or male factor infertility; and [3] four or more oocytes inseminated. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The fertilization rate was related to measured variables of the fresh semen and the motile sperm fraction used for insemination. Fertilization rate was categorized as poor (< 35%) or acceptable (> or = 35%). RESULTS: Multiple regression analysis demonstrated a strong correlation between the fertilization rate and the combined indexes of percentage normal morphology and grade of motility in the fresh semen and percentage progressive motility in the motile sperm fraction. A two-dimensional chart that expressed these relationships was constructed. Its accuracy of prediction was 77% for poor fertilization and 95% for acceptable fertilization. CONCLUSIONS: The fertilization rate is strongly correlated with percentage normal sperm morphology in the fresh semen and the percentage progressive motility in the motile sperm fraction used for insemination. The clinical chart provides a simple but powerful tool for predicting fertilization outcome.

Confidence Intervals↗