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PubMed2001

The use of in vitro fertilization techniques to investigate the fertilizing ability of bovine sperm with proximal cytoplasmic droplets.

The objective of this experiment was to determine the effect of proximal droplets on sperm-oocyte binding, zona penetration, fertilization, and the developmental competence of oocytes fertilized by sperm with proximal droplets (PD) in an in vitro fertilization (IVF) and culture system. Frozen semen from three bulls (PD1, PD2 and PD3) with varying proportions of normal appearing sperm with proximal droplets and semen from a normal control bull (C) were used in this experiment. The mean number of sperm bound to the zona pellucida (26.8 +/- 2.0, n=100; 15.2 +/- 1.1, n=100; 16.2 +/- 1.0, n=100) for bulls PD1, PD2, and PD3, respectively, were significantly lower (P<0.05) than that of the control bull C (47.4+/- 1.9; n=114). No spermatozoa with PD were found bound to the zona pellucida and this finding was consistent among the three bulls. The percentage penetration of zonae for the bulls PD1, PD2 and PD3 (74%, 74/100; 71%, 71/100 and 69%, 69/100, respectively) were not different than that of bull C (72%, 179/245). Similarly, the mean number of sperm penetrating the zona pellucida (1.43+/- 1.2, 1.24 +/- 1.1 and 1.20 +/- 1.1, for bulls PD1, PD2 and PD3, respectively) were not different than that of bull C (1.45 +/- 1.1). However, fertilization rates (8.8%, 8/90; 16.8%, 16/95; and 10.6%, 11/103, for bulls PD1, PD2 and PD3, respectively) were lower (P<0.001) than that of bull C (68.7%; 77/112). Similarly, cleavage rates (5%, 10/200; 8%, 8/100 and 14%, 15/111) for the bulls PD1, PD2 and PD3, respectively, were lower than that of the control bull, C (60.7%; 79/130). Cleaved zygotes resulting from the fertilization of oocytes by apparently normal sperm from bulls with PD did not develop beyond cleavage, whereas, 43.8% (57/130) morulae and 20% (26/130) blastocysts were produced by oocytes fertilized by sperm from bull C. In summary, normal appearing sperm with PD did not bind to the zona pellucida. Apparently normal sperm with out proximal droplets co-existing in the semen along with sperm containing PD were also functionally deficient, resulting in reduced zonae binding and zygotes resulting from insemination with semen with a high percentage of PD did not develop beyond cleavage.

Animals↗
PubMedDate not supplied

Fertility maintenance and 5-fluorouracil timing within the mammalian fertility cycle.

The mammalian fertility cycle is responsible for tight coordination of molecular, biochemical and cellular events. We have investigated whether timing of 5-fluorouracil (5-FU) chemotherapy within this cycle affects its reproductive toxicology. When this very short half-life, largely S-phase active cytotoxic antimetabolite is administered during the estrous phase (immediate postovulatory) of the fertility cycle, female mice suffer greater subsequent loss of fertility (decreased successful pregnancy rate) than those mice receiving 5-FU during the metestrous, diestrous, or proestrous stages. Pups subsequently born to mothers given 5-FU during the estrous and metestrous stages are of lower weight compared with those born to mothers treated with 5-FU during diestrus or proestrus. Acute lethality is similarly affected by the fertility cycle timing of 5-FU administration. Treatment during estrus is associated with the greatest overall lethal toxicity. This finding indicates that the 5-FU susceptibility of nonreproductive tissues, the integrity of which is essential for survival, may also be coordinated by the mammalian fertility cycle. It is concluded that optimizing the fertility cycle timing of 5-FU (e.g., during the periovulatory, proestrous stage) diminishes the frequency and severity of long-term reproductive damage.

Animals↗
PubMed1998

Fertility decline in Scotland, England and Wales, and Ireland: comparisons from the 1911 census of fertility.

Data on family size by year of marriage, age at marriage, and duration of marriage, from the 1911 Fertility Census, are compared between Scotland, England and Wales, Irish county boroughs, and the rest of Ireland. While means show significant inter-country differences, from the 1880s marked similarities are found across all the countries in the pattern of fertility decline, strongly suggesting significant fertility limitation in rural Ireland well before 1911. Noting the implications for the use of rural Ireland as a natural fertility population, the data are instead compared with the Coale-Trussell and Hinde-Woods schedules. The former provides more plausible results, which imply strong period rather than cohort effects in the fertility decline. Except in rural Ireland, little evidence is found for significant fertility limitation early in marriage among younger marrying couples, but many older marrying couples appear to have stopped childbearing at very low parities from an early date.

Censuses↗
PubMed2006

From low to high fertility in Sulawesi (Indonesia) during the colonial period: explaining the 'first fertility transition'.

This paper examines the past transition from low to high fertility which, in Indonesia as elsewhere, preceded the return to lower birth rates. Data from two parts of the island of Sulawesi where fertility rose during the colonial period are used to explain both why it rose, and why it was originally low. Economic conditions, it is argued, were the most important factors, affecting fertility via the supply of income and the demand for labour. Two schematic models of the 'first fertility transition' are proposed. In areas with low population densities and area-extensive forms of agriculture responsive to commercial stimuli, birth rates rose as the growth of commerce raised levels of prosperity, facilitated marriage, and undermined institutions such as debt-slavery which had previously acted to restrict marital fertility. In densely populated areas with labour-intensive agriculture and heavy state taxation in labour, fertility rose in response to demands for women's (and possibly child) labour that did not necessarily lead to gains in income.

Amenorrhea↗
PubMed1997

Effects of follicular fluid supplementation of in-vitro maturation medium on the fertilization and development of equine oocytes after in-vitro fertilization or intracytoplasmic sperm injection.

The aim of this study was to compare the effect of the addition of follicular fluid (FF) collected from preovulatory follicles with that of oestrous mare serum (EMS) (acting as the control) to TCM-199 medium on the in-vitro maturation, fertilization and development of equine cumulus-enclosed oocytes. Oocytes (<30 mm in diameter) were obtained from the ovaries of slaughtered mares. After in-vitro maturation in the presence of the two supplements, their fertilization, cleavage and developmental potential were compared after conventional in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) using frozen-thawed spermatozoa. Follicular fluid did not increase the maturation of oocytes to metaphase II stage compared to control. After IVF, there was no difference in fertilization rates between FF-supplemented oocytes and controls (7/87, 8.4% of oocytes showing two pronuclei with FF versus 7/116, 6% with EMS; not significant). However, after ICSI, FF-supplemented oocytes showed significantly increased normal fertilization (32/85, 37.6% of two-pronuclear oocytes) and developmental potential (15/31, 48% cleavage) compared to the control oocytes (7/47, 14.9%, P < 0.01; and 2/48, 4%, P < 0.01, respectively). Overall, ICSI resulted in increased fertilization rates compared to IVF, regardless of the presence or absence of FF (39/132, 29.5% with ICSI versus 14/203, 6.9%). These results suggest that follicular fluid supplementation may improve the maturity of equine cumulus-enclosed oocytes sufficiently for the successful use of ICSI, but not sufficiently for normal sperm-egg interaction occurring during IVF.

Animals↗
PubMed1999

Effect of in-utero diethylstilboestrol exposure on human oocyte quality and fertilization in a programme of in-vitro fertilization.

Genital tract abnormalities and adverse pregnancy outcome are well known in women exposed in utero to diethylstilboestrol (DES). Data about adverse reproductive performance in women exposed to DES have been published, including controversial reports of menstrual dysfunction, poor responses after ovarian stimulation, oocyte maturation and fertilization abnormalities. We compared oocyte quality, in-vitro fertilization results and embryo quality for women exposed in utero to DES with a control group. Between 1989 and 1996, 56 DES-exposed women who had 125 in-vitro fertilization (IVF) attempts were retrospectively compared to a control group of 45 women with tubal disease, who underwent 73 IVF attempts. Couples suffering from male infertility were excluded. The parameters compared were oocyte quality (maturation abnormalities, immature oocyte, mature oocyte), fertilization and cleavage rate (per treated and metaphase II oocytes), and embryo quality (number and grade). We found no significant difference in oocyte maturational status, fertilization rates, cleavage rates, embryo quality and development between DES-exposed subjects and control subjects. These results suggest that in-utero exposure to DES has no significant influence on oocyte quality and fertilization ability as judged during IVF attempts.

Adult↗
PubMed1988

In-vitro fertilization with husband and donor sperm in patients with previous fertilization failures using husband sperm.

When previous attempts at in-vitro fertilization using semen from the husband failed, a subsequent IVF attempt was performed using husband and donor sperm in order to compare fertilization and embryo formation after insemination with husband and donor sperm of the same oocyte population. Significantly more eggs were fertilized in patients suffering from andrological and idiopathic infertility when donor sperm were used. No differences were seen in patients with tubal infertility. In the andrological group, the embryos fertilized by the husband showed significantly more fragmentation. No pregnancies were established when husband-fertilized oocytes (embryos) were replaced in the andrological and idiopathic infertility group. This study suggested that an IVF trial using husband and donor sperm might be indicated in couples suffering from andrological or idiopathic infertility in whom no fertilization occurred in a previous cycle using sperm from the husband.

Adult↗
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↗
PubMed1994

The influence of subzonal microinsemination of oocytes failing to fertilize in scheduled routine in-vitro fertilization cycles.

The subzonal microinsemination (SUZI) of oocytes failing to fertilize following routine in-vitro fertilization (IVF) insemination was studied in comparison to routine reinsemination. The data presented indicate that fertilization rate was significantly better with SUZI (23.4%) than with reinsemination (8.3%). The percentage of cleaved replaceable embryos generated was also significantly higher following SUZI than with reinsemination (96.6% versus 66.7% respectively). SUZI led to a significantly higher increase in the percentage of additional number of fertilized oocytes (100%), fertilization cycles (185%), embryos replaced (108%) and embryo replacement cycle over that generated by initial insemination. These were in comparison to 26, 14.3, 11.6 and 15%, respectively, as a result of reinsemination. No pregnancy occurred following replacement of embryos generated from reinsemination. Six pregnancies resulted from replacement of embryos following SUZI. We suggest therefore that SUZI should be the preferred option of practice when oocytes have failed to fertilize following initial insemination for routine IVF.

Embryo Transfer↗
PubMed1994

An indiscriminate use of pentoxifylline does not improve in-vitro fertilization in poor fertilizers.

In order to enhance fertilization in vitro, pentoxifylline (PTX) was used in couples showing low fertilization rates in previous in-vitro fertilization (IVF) attempts for the treatment of male-factor infertility. Sibling oocytes were inseminated at random with spermatozoa prepared with or without PTX. After selection by Percoll gradient, sperm samples were divided into two equal aliquots. One aliquot was incubated in Earle's medium containing approximately 3.6 mM PTX (treatment group), the other aliquot was incubated with PTX-free Earle's medium (control group). After 30 min, both suspensions were washed twice. Sperm parameters after preparation did not differ between treatment and control samples, and nor did the mean fertilization rates, which were 49.3 and 42.6% respectively. Cleavage characteristics and morphological quality of the embryos were not significantly different between the treatment and control groups. The results of this study demonstrate that indiscriminate use of PTX in an IVF programme increases neither fertilization rate nor embryo transfer rate in poor fertilizers. More prospective research is needed to evaluate the role of PTX in IVF in couples selected according to the effect of the compound on sperm function, e.g. hyperactivation and acrosome reaction.

Adult↗
PubMed1984

Estimation of fertility and fecundity in women receiving artificial insemination by donor semen and in normal fertile women.

The pregnancy rates after artificial insemination by donor semen (AID) have been compared with pregnancy rates in normal fertile women to assess the efficiency of AID. To do this, the curve y = a(1-(1-b)x) was fitted to life-tabled cumulative pregnancy rates. The equation describes a model in which the parameter a is the proportion of women who are potentially fertile under the conditions of treatment, and in which the parameter b is the pregnancy rate per cycle (or fecundity) of these fertile women. For 259 AID patients with no previous pregnancy a was 65% while for 57 AID patients with a previous pregnancy after AID 'a' was 99.9%. The values of b were similar for the two groups of patients, being 20% and 22% respectively. Women without fertility problems who had become pregnant after discontinuing oral contraception provided the reference group. Since only pregnant women were selected, a was 100% by definition. The values of b for the reference group were 22% for 100 primigravid women and 20% for 100 multigravid women. Only 65% of the AID patients were potentially fertile with AID, but those that were fertile became pregnant at the same rate as normal women who discontinued oral contraception.

Adult↗
PubMed1975

[Fertility and fertility problems in some beef herds in Sweden (author's transl)].

The purpose of the study was to investigate the fertility level, some factors affecting fertility and problems of infertility in selected Swedish beef herds. The investigation included 31 herds, 19 of which had Herefords, 13 Charolais, 2 Aberdeen Angus and 1 Limousins. The total number of mature females was 703, including 147 feifers of breeding age. Most data were collected at personal visits to the herds. The results are presented in Tables I--XV and Figures 1--2. The service period coincided roughly with the grazing period and lasted usually 4--5 months. Seventyfive per cent of the females calved during the period February-May. The fertility levels were comparatively good. The percentage of pregnancy at rectal examination performed at the end of the service period was 89.5; however the average calving percentage was only 87.5. The highest calving percentages were recorded for Aberdeen Angus and crossbreds. Also the calf crop, it is the number of calves born alive and surviving 24 hours per mature female was the highest for these two groups; 0.91 and 0.90 respectively. The mean interval from calving to conception was 80.3 days in Herefords, 83.4 days in Aberdeen Angus, 85.6 days in crossbreds and 92.3 days in Charolais. The percentage of animals pregnant within 90 days after calving was on an average slightly more than 50 per cent. The interval from calving to conception rose gradually when the interval from calving to expoure to bull exceeded 40 days. Mean percentages of still born calves were 5.9 in cows and 13.7 in heifers. As far as the fertility level is concerned there does not seem to be any disadvantage in keeping the bull together with the females during the calving period. However, in this case the next calvings will occur over an extended period of time. If the intention is to concentrate 50 per cent of the calvings within the period of one month then the females should be exposed to the bull from 41--60 days after calving at the earliest. In case the females were exposed to the bull from 41--60 days after calving and onwards, 95 per cent of the females finally pregnant had conceived at the end of a 3 months service period. Under such conditions a bull may be able to serve two groups of females within the same grazing period. Cows calving during July-September had the lowest pregnancy rate and those calving during October-December the highest at the following service period. The incidence of ovarian cysts was very low. About 1/3 of those buls serving at least 10 females each obtained calving percentages less than or equal to 80. Herds recording low calving percentages had to a great extent used young bulls, 12--15 months of age at the beginning of the service period. Only for two groups of females out of eleven which had been served by young bulls calving percentages greater than 80 were noted. A more efficient control of the fertility of the bulls could markedly improve the fertility of some herds.

Abortion, Veterinary↗
PubMed1989

[Role of sperm passage through cervical mucus: fertilizing capacity tested by in vitro fertilization with zona-free hamster eggs].

The effect of sperm passage through cervical mucus (CM) on the fertilizing capacity of human spermatozoa was examined in the in vitro fertilization system of zona-free hamster eggs. Each drop of ejaculated semen and BWW culture medium was connected by a small capillary tube filled with preovulatory CM, egg white or BWW medium under liquid paraffin oil in a plastic petri dish. After 2 hours, zona-free hamster eggs were added to the drop of BWW culture medium containing spermatozoa which had passed through the capillary tube and the mixture was incubated for various lengths of time at 37 degrees C under 5% CO2 in air. Human spermatozoa, which were washed and preincubated for 2 hours in BWW medium, were capable of fertilizing zona-free hamster eggs but needed a longer incubation time than spermatozoa which had passed through CM. Fertilization rates of spermatozoa which had passed through CM and egg white were very similar, but no fertilization occurred in the drop containing spermatozoa which had passed through BWW medium, presumably because of the contamination with seminal plasma. These results indicate that the most important role of CM may be to separate motile spermatozoa from seminal plasma components hostile to fertilization.

Animals↗
PubMed1985

A prospective multicentre study to develop universal immunochemical tests for predicting the fertile period in women. World Health Organisation Task Force on Methods for the Determination of the Fertile Period, Special Programme of Research, Development and Research Training in Human Reproduction.

Two immunochemical tests for predicting the fertile period have been adapted for application throughout the world. The estrone test involves the measurement of estrone-3-glucuronide (E1-3-G) in daily samples of early morning urine. The start of the fertile period is identified by a sustained rise in the concentration of E1-3-G (as determined by cumulative sum analysis); the end of potential fertility occurs 120 hours (5 days) after the peak level. Alternatively, the ratio of E1-3-G to pregnanediol-3 alpha-glucuronide (Pd-3 alpha-G) can be calculated and the fertile period identified between a defined rise in this index and the peak value plus 144 hours (6 days). One hundred thirty-one women from 10 countries provided samples from 557 menstrual cycles, and the results from 455 (82%) were accepted for statistical analysis. There were highly significant differences (P less than 0.0001) in the concentrations of the metabolites between centres, but the time intervals between both the rise and peak days and the day of the luteinizing hormone (LH) peak were less significantly different (P less than 0.05) for the estrone test and not significantly different for the ratio test. The fertile period was defined as the day of the LH peak -3 to the day of the LH peak +2. The estrone test successfully delineated this phase in 78% of menstrual cycles, and the ratio test, in 74%. The mean lengths of the derived fertile periods by both methods were 9.3 (SD 2.3) and 10.0 (SD 2.4) 24-hour periods (or days), respectively.

Adult↗
PubMed1988

Computer modeling of human fertility: the impact of reproductive heterogeneity on measures of fertility.

As a result of the paucity of biological markers for both reproductive events and exposure to reproductive toxicants, it is likely that individual members of populations will be misclassified with respect to reproductive performance and xenobiotic exposure. A four-parameter computerized model of fertility (frequency of intercourse, male fecundity, female fecundity, and spontaneous abortion) was developed to explore the effect of misclassification of populations on several measures of fertility. The measures of fertility explored include cumulative percent pregnant, time to pregnancy, cycle specific fertility, and fecundability ratio. The cumulative percent pregnant and time to pregnancy appeared to be insensitive to small changes in reproductive competence. The fecundability ratio decreased in proportion to the size of population exposed to a reproductive toxicant. The three reproductive parameters, time to pregnancy, cumulative percent pregnant, and fecundability, do not appear useful as measures of reproductive heterogeneity in populations. The reproductive heterogeneity of a population was best defined by the change in cycle-specific fertility rate over the period of observation. These simulations suggest that the change in the cycle-specific fertility rate should be evaluated and comparable in all population groups over the period of observation to assure reproductive homogeneity.

Abortion, Spontaneous↗
PubMed1977

[The decline of fertility in Western Europe. II. Which fertility rate would be desirable in France? (author's transl)].

A way to try and assess the significance of such or such level in long term fertility is to work out population projections based on a variety of assumptions and to compare their different implications. The age pyramids of France until 2100 that derive from four contrasted evolutions of fertility are studied in the present article: completed fertility in birth cohorts ranging from 1.4 to 2.6 children per woman. While some demographic parameters are not much sensitive to the assumption made for the fertility level (e.g. percent of economically active people in total population), others are closely related to fertility (such as total number of inhabitants, percent of younger people or of older people in total population, annual rate of entry into economically active population). In France, where population density is much lower than in most neighbouring countries, a fertility level that would lay at -- or a little higher than -- replacement (i.e. 2.1 children per woman) can be considered as a desirable target.

Adolescent↗
PubMedDate not supplied

Polynuclear fertilization in various stimulation protocols in in vitro fertilization.

OBJECTIVE: To investigate the effect of some clinical characteristics, especially various ovarian stimulation protocols, on the occurrence of polypronuclear fertilization. METHODS: One hundred forty-eight consecutive cycles in 121 patients were treated in our IVF program and 735 oocytes were analyzed retrospectively. RESULTS: Multipronuclear fertilization occurred in 33 of 530 fertilized oocytes, an incidence of 6.2%. No significant difference in the incidence of polyploidy was observed between the three stimulation protocols (CC/hMG, hMG, GnRHa/hMG). Number of polypronuclear embryos was found to be correlated with the fertilization rate, concentration of sperm inseminated, and maturity of the oocytes. CONCLUSIONS: The maturity of the oocytes and the sperm fertilizing capacity should be examined to reduce the incidence of polypronuclear fertilization.

Clomiphene↗
PubMedDate not supplied

Fertility inhibiting effects of the intermediate fertility variables in two Nigerian sub-groups.

"In this paper, the fertility-inhibiting effects of the intermediate fertility variables among the Ikale-Yoruba are contrasted against those of the Ekiti, another Yoruba group for which more conventional family building practices have been reported. The objectives of the comparative approach are as follows: (a) to show that abstinence is not a factor in the reduction of marital fertility among the Ikale-Yoruba, as it is in other sub-groups studied so far; (b) that alternative outlets of fertility reduction, such as reliance on the protection offered by post-partum amenorrhoea, and some practice of folk and modern methods of contraception, are employed." The data, which were collected in Nigeria in 1977, concern 460 currently married Ikale-Yoruba women and some of their husbands, and 535 eligible Ekiti-Yoruba women. The results show that although total fertility rates between the two groups were similar, there were significant differences concerning the relative reliance by each group on postpartum abstinence and contraception. (summary in FRE, ITA)

Africa↗