SEARCH · PubMed Health

Results for “Fertilization rate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

PubMed2001

Decreased fertilization rate and embryo quality after ICSI in oligozoospermic men with microdeletions in the azoospermia factor c region of the Y chromosome.

Microdeletions of the azoospermia factor (AZF) region of the Y chromosome occur in between 1 and 29% of oligozoospermic and azoospermic men, and most deletions are found in the AZFc region. These men can father children when intracytoplasmic sperm injection (ICSI) is used, but the success rate is unclear. Thus, the success rate of 19 ICSI treatments in eight couples with a microdeletion in the AZFc region of the Y chromosome was analysed retrospectively. These were compared with a control group of 239 ICSI treatments in 107 couples undergoing ICSI treatment with ejaculated spermatozoa. The fertilization rate was significantly lower in the group of Y-deleted men (55%; 95% CI: 41-69%) compared with controls (71%; 95% CI: 67-74%; P < 0.01). The embryo quality was also significantly poorer among Y-deleted men (P<0.001). Pregnancy, implantation and take-home baby rates were not significantly lower in the Y-deleted group. This study shows that ICSI in oligozoospermic men with microdeletions in the AZFc region of the Y chromosome leads to a lower fertilization rate and poorer embryo quality.

Adult↗

PubMed1983

Indochinese refugee fertility rates and pregnancy risk factors, Oregon.

Matching 471 Oregon birth certificates with official Indochinese arrival lists reveals a fertility rate of 126.7, 1.8 times the US rate of 68.5. Greater maternal and infant risk rates were noted, particularly for Hmong. Data indicate improvements in obtaining prenatal care and in reducing the number of low birth weight infants for refugees who have resided in the US three or more months: however, the improvements appear to be reversed after 12 months of US residency.

Adolescent↗

PubMed1982

Increased numbers of sperm in the oviducts and improved fertilization rates in rabbits after administration of phenylephrine or ergonovine near the time of insemination.

Phenylephrine, an alpha-adrenoceptor agonist, was administered im to does near the time of mating or insemination. The treatment increased sperm numbers in the oviducts by about 50-fold and in the uterus by about 10-fold at 2 or 2.5 h after insemination. Methoxamine, another alpha-adrenoceptor agonist that was given im, did not increase sperm numbers, although both phenylephrine' and methoxamine significantly increased the number and amplitude of uterine contractions when contractions were measured by strain gauge force transducers attached to the uterus of conscious does. Ergonovine, an ergot derivative given im, increased sperm numbers more than 10-fold in the oviducts and five to 10-fold in the uterus at 2 or 2.5 h after insemination. Ergonovine increased the frequency and amplitude of uterine contractions when given iv but not when given im. In tests with a range of doses of phenylephrine and ergonovine, 5 mg of phenylephrine and .6 mg of ergonovine appeared to be near optimal for maximizing the number of sperm in the uterus and oviducts at 2.5 h after insemination. Phenoxybenzamine, an alpha-adrenoceptor blocking agent, prevented the phenylephrine-induced increases in both uterine contractions and sperm numbers in the oviducts and uterus. Phenoxybenzamine also prevented the effect of ergonovine on sperm numbers. In does inseminated with low numbers of sperm (92,000; an inseminate selected to result in a low fertilization rate in control does), the administration of phenylephrine or ergonovine significantly increased ovum fertilization rates (16% for control does, 52 and 63%, respectively, for phenylephrine- and ergonovine-treated does).

Animals↗

PubMed1999

In-vitro matured metaphase-I oocytes have a lower fertilization rate but similar embryo quality as mature metaphase-II oocytes after intracytoplasmic sperm injection.

About 4% of all the oocytes denuded prior to intracytoplasmic sperm injection (ICSI) are in metaphase-I (MI). Frequently, these oocytes achieve meiosis after a few hours of in-vitro culture and are available for ICSI on the day of oocyte retrieval. In this retrospective study, the aim was to evaluate the fertilization rate and the developmental capacity of these in-vitro matured MI oocytes. After controlled ovarian stimulation using human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG) in 896 ICSI cycles, 1210 MI-to-MII-matured oocytes were injected approximately 4 h after in-vitro culture and 8803 MII oocytes were injected immediately, or later, after denudation. The fertilization rate of in-vitro matured oocytes was significantly lower than that of mature MII oocytes (52.7 and 70.8% respectively, P < 0.00l). Embryo quality was only slightly different as regards the numbers of good quality embryos: 47.4% good quality embryos were obtained in the in-vitro matured oocyte group, whereas 53.2% good quality embryos were obtained in the MII oocyte group (P < 0.05). The same proportions of excellent (5.7 and 7.0%, NS) and fair quality (17.6 and 15.3%, NS) embryos were obtained for in-vitro matured and mature oocytes respectively. Embryos derived from in-vitro matured oocytes were transferred only if they were of better quality or if there were not enough mature oocyte derived embryos available. Fifteen transfers involved only embryos derived from in-vitro matured oocytes: 11 single embryo transfers and four transfers of two embryos, resulting in one singleton pregnancy and the birth of a healthy baby. It may be concluded that in cycles with few MII oocytes it might be worthwhile to inject in-vitro matured MI oocytes in order to increase the number of embryos available for transfer.

Cell Differentiation↗

PubMed1995

Some analytical models to estimate maternal age at birth using age-specific fertility rates.

"A class of analytical models to study the distribution of maternal age at different births from the data on age-specific fertility rates has been presented. Deriving the distributions and means of maternal age at birth of any specific order, final parity and at next-to-last birth, we have extended the approach to estimate parity progression ratios and the ultimate parity distribution of women in the population.... We illustrate computations of various components of the model expressions with the current fertility experiences of the United States for 1970."

Age Factors↗

PubMed1987

Fertility rates in female patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Among 80 women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (40 with the simple virilizing form and 40 with the salt-losing form), 40 reported having an adequate introitus and being heterosexually active. In 15 of 25 patients with the simple virilizing form, 25 pregnancies resulted in 20 normal children, whereas only 1 of 15 women with the salt-losing form became pregnant; this pregnancy was electively terminated. Several factors seem to be responsible for the low fertility rates: noncompliance with therapy was probably high, as suggested by hirsutism and poor endocrine follow-up in 25 percent of patients; whereas 49 patients had regular menstrual periods, 14 had irregular periods, 10 had amenorrhea, 5 had undergone hysterectomy, and 2 had entered menopause; 87 percent of patients with salt loss and 50 percent of those with simple virilization (P less than 0.001) had remained single; the vaginal introitus was reported to be inadequate for intercourse by 35 percent of patients (53 percent of those with salt loss and 18 percent of those with simple virilization; P less than 0.002); and heterosexual activity was reported less frequently among patients with an inadequate introitus. The status of the introitus seemed to have a more important role in the sexual activity reported than did the degree of prenatal exposure to androgen (which was higher among patients with salt loss than among those with simple virilization). However, our data did not rule out an effect of androgen exposure on female fetuses. Our experience indicates that improved surgical correction of the external genitalia and better compliance with therapy will be necessary to improve fertility rates among women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Adolescent↗

PubMed1996

Effects of rooting medium and fertilizer rate on response of white clover to tropospheric ozone.

Two white clover (Trifolium repens L.) clones with varying sensitivity to O(3) are being developed as a system to indicate effects of ambient concentrations of tropospheric O(3) on plants. One clone (NC-S) is highly sensitive to O(3) and the other (NC-R) is highly resistant. The system relies on periodic measurement of foliar injury, foliar chlorophyll, and forage production of NC-S and NC-R grown in 15-liter pots throughout a summer season. Relative amounts of foliar injury and ratios (NC-S/NC-R) for chlorophyll and forage weight can be used to estimate biologically effective ambient O(3) concentrations. The effect of variation in rooting media formulation and fertilizer rate on response of NC-S and NC-R to ambient O(3) was determined in the present study. In the rooting medium experiment, clover was grown in three mixtures of sandy loam topsoil:course washed sand:Metro Mix 220 (ratios (by volume) of 2:1:1, 2:1:5, and 6:1:1). In the fertilizer experiment, clover was grown in the 2:1:1 medium at four fertilizer rates (soluble 5-11-26 (N-P-K) at 0.0, 0.5, 1.0, or 2.0 g per pot). Ozone caused more foliar injury, more chlorosis, and a greater decrease in forage production of NC-S than of NC-R in all studies. Rooting media treatments affected both clones similarly and occasional clone x media interactions were judged to be random. Forage production by NC-S, relative to that of NC-R, was generally greater in the 0.0 fertilizer treatment, but the forage ratios were similar at all other fertilizer treatments. The relative response of NC-S and NC-R to O(3) is fairly stable under cultural conditions that support normal plant growth.

Journal Article↗

PubMed1983

[Forecasting cohort fertility rates by using an exponential function].

"Population forecasts based on cross sectional data do not allow for the variations in cohort fertility. In this paper methods are developed to fit cohort fertility rates by an exponential function. Out of a number of selected functions the Weibull-function shows the best fit. For predicting cohort fertility pattern the parameter values can be derived from the forecasts of a small number of demographic statistics." (summary in ENG)

Birth Rate↗

PubMed1993

[Comparison of preparation techniques with reference to final spermatozoa concentration and survival and fertilization rate in vitro in normal and pathologic ejaculates].

Various methods are available in the preparation of normal and pathological ejaculates within the framework of available techniques of assisted reproduction. The authors examined the recovery rate, the long-term motility and the fertilization rate in vitro after both normal and pathological test results, of preparations, using one of the three most commonly used techniques. Centrifugation with its resulting swim up (Z) is a method still widely used because of the good sperm recovery rate it produces. However, in our tests, it achieved the lowest level capacity, compared with sperm separation by migration/sedimentation, with resultant swim up (M) and Percoll gradient centrifugation (P). The statistically highly significant fast decline of motility after preparation by Z, compared with the other two above mentioned techniques, in both normal and pathological ejaculates is a further indication, that Z has a negative influence upon the integrity of the spermatozoa. The results of research submitted here suggest the abandonment of Z in its standard form in favour of other techniques. After normal test results, both M and P might be used, but in the case of pathological ejaculate, P would be recommended.

Female↗

PubMed2001

Performing ICSI using an injection pipette with the smallest possible inner diameter and a long taper increases normal fertilization rate, decreases incidence of degeneration and tripronuclear zygotes, and enhances embryo development.

PURPOSE: To compare the efficacy of two types of injection pipette used for ICSI, one with a larger (5-7 microns) inner diameter and a shorter taper with that inner diameter, and another with the smallest (3-5 microns) possible inner diameter and a longer taper with that inner diameter. METHODS: Retrieved oocytes at metaphase II stage were injected using one of two types of injection pipette, in 33 and 94 cycles, respectively, in a total of 127 cycles in 108 patients. RESULTS: In comparison to the injection pipette with a larger (5-7 microns) inner diameter and a shorter taper with that inner diameter, the injection pipette with the smallest (3-5 microns) possible inner diameter and a longer taper with that inner diameter increased normal fertilization rate ((70 +/- 3.6)% vs. (86 +/- 2.2)%; P = .001; mean +/- SEM); decreased the incidence of degeneration ((14 +/- 2.4)% vs. (5 +/- 1.4)%; P = .001) and tripronuclear zygotes ((1.0 +/- 0.35)% vs. (0.1 +/- 0.21)%; P = .03); increased Day-2 diploid embryos ((69 +/- 3.7)% vs. (85 +/- 2.2)%; P = .001) and good-quality Day-2 diploid embryos ((67 +/- 4.0)% vs. (79 +/- 2.4)%; P = .03), all per injected oocyte; and increased the number of blastomeres per good-quality Day-2 diploid embryo ((3.0 +/- 0.21 vs. 3.8 +/- 0.12; P = .0003). CONCLUSIONS: Performing ICSI using an injection pipette with the smallest (3-5 microns) possible inner diameter and a longer taper with that inner diameter maximizes normal fertilization rate, minimizes the incidence of postinjection degeneration and tripronuclear zygotes, and enhances embryo development.

Adult↗

PubMed2002

Fertility rate evaluation by laparoscopic approach in the experimental animal.

PURPOSE OF INVESTIGATION: The aim of the present study was to evaluate the effect of laparoscopic insemination (LAP) and natural mating (NM) on fertility rate in experimental animal (Ovis Aries Comisana) during the month of June. METHODS: For the experiment, 97 ewes were used. Laparoscopic insemination was performed with the frozen semen of three different Romanov rams: Laparoscopic insemination I (n = 24); Laparoscopic insemination 2 (n = 26); and laparoscopic insemination 3 (n = 28), and natural mating was performed with two different Ovis Aries Comisana rams with proven fertility: Natural mating I (n = 10); Natural mating 2 (n = 9). Estrus was synchronized with fluorogestone acetate impregnated intravaginal sponges (40 mg, 14 days). Pregnant mare serum gonadotrophin (Folligon, Intervet International) at a dose of 400 UI was given intramuscularly at sponge removal. Artificial insemination was carried out 60 hours after the removal of the sponges in the laparoscopic insemination groups. RESULTS: The mean pregnancy rate at ecographic diagnosis performed at about 36 days from sponge removal for the laparoscopic insemination and natural mating groups were respectively, 62.8% and 78.9% with no significant difference. CONCLUSION: The mean fertility rates for the LAP and NM groups were 56.0 and 73.4, respectively, with no significant difference.

Animals↗

PubMed1975

Sperm concentration and fertilization rate in Bufo arenarum (Amphibia: Anura).

The influence of sperm concentration upon the fertilization rate of Bufo arenarum oocytes was determinated. The experimental results were analysed according to the theories of Rothschild and Swann, and Hultin and Hagström for Psammechinus miliaris. The experimental results agreed with the predictions of the latter theory. Since Bufo arenarum and Psammechinus miliaris oocytes differ in both size and disposition of jelly envelopes, the postulations of Hultin and Hagström's theory appear to have a general validity.

Animals↗

PubMed1993

Major causes of the regional difference in fertility rate: factor analysis of 72 counties and county-level cities in Anhui Province.

The author compares fertility rates among 72 counties and county-level cities in Anhui Province, China. "The many causes of fertility difference...may be categorized into two major groups: social, economic and cultural factors; and population control (mainly birth control) factors.... This paper uses modern statistical methods and techniques, proposes necessary hypotheses and, through factor analysis, transforms the myriad of indexes related to economy, culture and population control in the 72 counties and cities into two indices.... Following the factor analysis, the counties and cities are then categorized into groups and types according to the values of these two indices."

Asia↗

PubMed1987

[Don Daeng village in northeast Thailand: population (2). An estimate of migration by mortality and fertility rates].

"The population dynamics of Don Daeng, a rice-growing village in Northeast Thailand, was studied as part of an integrated village study program in 1981-1984. The mortality and fertility rates since the 1930s were determined from data obtained by interviewing 232 ever-married women who gave birth to 876 children, while those for the preceding periods were estimated from the village population in three separate years and by extrapolation of the trend since the 1930s, which was adjusted for the results of the national censuses....[Results indicate that] immigration dominated until the early 1940s, when paddy acreage could no longer be expanded, and since then emigration has taken place." (SUMMARY IN ENG)

Agriculture↗

PubMed2005

Effects of stocking and nitrogen fertilization rates on steers grazing dallisgrass-dominated pasture.

To compare the performance of steer calves managed under different stocking rates (SR; 3.7, 6.2, 8.6, and 11.1 steers/ha for 140 d; chi(I1)) and N fertilization rates (112, 224, and 336 kg of N/ha; chi(I2)) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 +/- 2.5 kg) were assigned randomly to one of 12 0.81-ha dallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: gammai = beta0 + beta1chi(I1) + beta2chi(I2) + beta(11)chi2(I1) + beta(12)chi2(I2) + beta(12)chi(i1)chi(i2) + epsilonI, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and returned 355.64 dollars. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112, 224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually.

Analysis of Variance↗

PubMed1991

Fertility rates in men with normal semen characteristics: spermatozoal testing by induction of the acrosome reaction and Wright-Giemsa staining for subtle abnormal forms.

Little is known about the fertility potential of semen from men who fulfill the accepted criteria of normal semen quality. We examined retrospectively the fertility rates of semen donors with normal semen quality. Donor performance was evaluated in women who had no known infertility factors or had only ovulatory dysfunction corrected by clomiphene. Cycles of therapeutic donor insemination were monitored for ovulation, and pregnancy outcome was followed up. Pregnancy resulted from therapeutic donor insemination with 21 donors and did not result in pregnancy with five (the range of the percentage of cycles in which pregnancy occurred was zero to 31). The comparison of donor semen analysis characteristics with pregnancy rates indicated that the total number of motile spermatozoa per ejaculate correlated with pregnancy rate (P = .04). Cox proportional hazard regression analysis showed that when the value for percentage of abnormal forms was combined with the total number of motile spermatozoa, a significant negative association was found between abnormal forms and conception (P = .04). Experiments comparing semen from high-fertility donors (top quartile of pregnancy rate) and low-fertility donors (lowest quartile) demonstrated a greater proportion of spermatozoa with inducible acrosome reactions in the high-fertility group (P less than .05). A Wright-Giemsa stain used to detect subtle abnormal forms in spermatozoa did not discriminate between the groups. These data suggest that differences in fertility potential exist among donors, even though all may exceed the accepted criteria for normal semen quality. Differences in the ability of spermatozoa to capacitate or undergo the acrosome reaction may be a mechanism for diminished fertility in donors with normal semen characteristics.

Acrosome↗

PubMed2001

Nitrogen fertilizer rate and crop management effects on nitrate leaching from an agricultural field in central Pennsylvania.

Eighteen pan lysimeters were installed at a depth of 1.2 m in a Hagerstown silt loam soil in a corn field in central Pennsylvania in 1988. In 1995, wick lysimeters were also installed at 1.2 m depth in the same access pits. Treatments have included N fertilizer rates, use of manure, crop rotation (continuous corn, corn-soybean, alfalfa-corn), and tillage (chisel plow-disk, no-till). The leachate data were used to evaluate a number of nitrate leaching models. Some of the highlights of the 11 years of results include the following: 1) growing corn without organic N inputs at the economic optimum N rate (EON) resulted in NO3--N concentrations of 15 to 20 mg l(-1) in leachate; 2) use of manure or previous alfalfa crop as partial source of N also resulted in 15 to 20 mg l(-1) of NO3--N in leachate below corn at EON; 3) NO3--N concentration in leachate below alfalfa was approximately 4 mg l(-1); 4) NO3--N concentration in leachate below soybeans following corn was influenced by fertilizer N rate applied to corn; 5) the mass of NO3--N leached below corn at the EON rate averaged 90 kg N ha(-1) (approx. 40% of fertilizer N applied at EON); 6) wick lysimeters collected approximately 100% of leachate vs. 40-50% collected by pan lysimeters. Coefficients of variation of the collected leachate volumes for both lysimeter types were similar; 7) tillage did not markedly affect nitrate leaching losses; 8) tested leaching models could accurately predict leachate volumes and could be calibrated to match nitrate leaching losses in calibration years, but only one model (SOILN) accurately predicted nitrate leaching losses in the majority of validation treatment years. Apparent problems with tested models: there was difficulty estimating sizes of organic N pools and their transformation rates, and the models either did not include a macropore flow component or did not handle macropore flow well.

Agriculture↗

PubMed1990

Celibacy and fertility rates in patients with major affective disorders: the relevance of delusional symptoms and suicidal behaviour.

The celibacy and fertility rates of 186 patients with major affective disorders were analysed as a function of the presence or absence of histories of mood congruent delusions or suicidal behaviour in the depressive phases of the disease. Both delusional and suicidal histories were irrelevant to celibacy rates. On the contrary, delusional depressives had a reduced incidence of cases with 2 or more children and suicide attempters had both a lower frequency of high-fertility cases and a smaller mean number of children than nonattempters. The differences were apparently not attributable to the length of the fertile period of life spent in illness.

Adult↗