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PubMed1999

Influence of paternal exposure to oil and oil products on time to pregnancy and spontaneous abortions.

The objective of this study was to evaluate the influence of exposure to oil and oil products among men on the time taken for their wives to conceive and on the incidence of spontaneous abortion among them. A cross-sectional study was performed by posting questionnaires to 1,269 men employed as offshore mechanics, offshore operators, offshore drilling personnel, car mechanics (the 'exposed' occupations) and carpenters ('unexposed'). The married men were asked to give a separate questionnaire to their wives for details about their pregnancies. The time elapsed between the beginning of coitus without contraception and the wife becoming pregnant (time to pregnancy) was analyzed with Cox regression analysis by calculating fecundability ratios for the pregnancies for the men exposed to oil and oil products as compared with the men who were not exposed. Spontaneous abortions were analyzed with logistic regression by calculating odds ratios for the pregnancies in which the men were exposed vs. not exposed. A total of 741 (58%) men returned the questionnaires. A total of 301 pregnancies were analyzed for time taken to conceive and 580 for spontaneous abortion. The results were adjusted for variables that could significantly influence conception time (previous infections of the reproductive system and coffee drinking) or the incidence of spontaneous abortion (mother's age, parity and smoking). The outcomes between the exposed and unexposed pregnancies showed no significant differences. Car mechanics had a lower fecundability ratio before 1992 than after 1992. Paternal exposure to hydrocarbons in the occupations studied did not seem to have had a major influence on time to conception or the incidence of spontaneous abortion among the wives of the men exposed to oil products.

Abortion, Spontaneous↗
PubMed1999

Effects of pesticide exposure on time to pregnancy: results of a multicenter study in France and Denmark. ASCLEPIOS Study Group.

The aim of this study was to determine whether there was a relation between male exposure to pesticides and the amount of time needed to conceive (time to pregnancy) for farmers and agricultural workers in France and Denmark. The authors used retrospective studies to compare the time to pregnancy of couples in which the man was exposed to pesticides during the year before the birth of their youngest child with that of couples in which the man was not exposed. In 1995 and 1996, the authors studied 362 French rural workers (142 exposed to pesticides and 220 not exposed), 449 Danish farmers (326 conventional farmers exposed to pesticides and 123 nonexposed organic farmers), and 121 Danish greenhouse workers exposed to pesticides. The fecundability ratio for exposure to pesticides (Cox model, before and after adjustment for confounding factors) did not differ from 1 in any of the three populations. In France, the adjusted fecundability ratio was 1.17 (95% confidence interval (CI) 0.89-1.55) for exposed and nonexposed agricultural workers. In Denmark, it was 1.09 (95% CI 0.82-1.43) for exposed and nonexposed farmers and 0.83 (95% CI 0.69-1.18) for greenhouse workers and nonexposed farmers. Thus, this study found no relation between fertility (time to pregnancy) and male exposure to pesticides.

Adult↗
PubMed1996

Comparison of salivary steroid profiles in naturally occurring conception and non-conception cycles.

Oestradiol and progesterone profiles from naturally occurring conception and exposed non-conception cycles were compared to assess the impact of natural variation in concentrations of ovarian steroid hormones on female fecundity. In a prospective, longitudinal study, 24 women collected saliva samples twice daily and recorded intercourse for up to 1 year or until a pregnancy was clinically confirmed. Oestradiol and progesterone concentrations were measured by a salivary radioimmunoassay. Average mid-follicular oestradiol concentrations were significantly higher in conception than in non-conception cycles (12.6 +/- 1.7 versus 8.5 +/- 0.6 pmol/l, P < 0.01). A separate analysis, including only cycles from those women who contributed both conception and non-conception cycles, demonstrated an even more pronounced difference in mid-follicular oestradiol concentrations, not just for conception and non-conception cycles as groups (14.5 +/- 2.3 versus 6.5 +/- 0.7 pmol/l, P < 0.001), but also between the conception and average non-conception concentrations of individual women. Among these women, relative mid-follicular oestradiol concentration was highly correlated with the probability of successful conception. In addition, relative body weight was significantly positively correlated with mid-follicular oestradiol concentration. These findings indicate that variation in follicular development, reflected in variation in follicular oestradiol concentrations, is an important indicator of fecundity.

Adult↗
PubMed1992

Studies on direct intraperitoneal insemination in the management of male factor, cervical factor, unexplained and immunological infertility.

One-hundred-and-twenty couples with male factor, cervical factor, unexplained or immunological infertility underwent direct intraperitoneal insemination (DIPI) of capacitated spermatozoa, combined with ovarian stimulation for a total of 254 cycles. Pregnancy occurred in 47 cycles, resulting in an overall pregnancy rate of 40.5% per patient (two pregnancies occurred in two patients) and a cycle fecundity of 18.5%. Of the patients, 23 have delivered live infants (one twins, 22 singletons), 15 (32%) miscarried and 9 have ongoing pregnancies. The cycle fecundity rates increased with increasing sperm concentration and total progressive motile count, both before and after sperm preparation (r = 0.8161, r = 0.8717 and r = 0.759, r = 0.795, respectively). However, there were two pregnancies where the inseminates had a count of 0.1 x 10(6) total motile spermatozoa. DIPI as an outpatient, in-vivo conception procedure offers encouraging results and is recommended before attempting more costly and invasive assisted reproduction techniques.

Female↗
PubMed1993

Morphological characteristics of preimplantation stage endometrium in the rhesus monkey.

The morphological characteristics of endometrium on day 6 after ovulation of conception (group 1) and non-fecund, menstrual (group 2) cycles have been studied in the rhesus monkey (n = 30). A conception cycle was distinguished by the presence of a developmentally normal, age-stage-synchronized embryo. Thus, 78% of the mated cycles (n = 18) yielding synchronous embryos (12 zona-encased and two zona-free blastocysts) were used for this study. On day 6 after ovulation, no significant changes in the serum concentrations of oestrogen and progesterone were seen in conception cycles (n = 14) compared with the non-mated, normal ovulatory cycles (n = 12). Morphometric analyses revealed that on day 6 of gestation (n = 8), endometrium differed from the corresponding non-mated luteal phase (n = 7) with significant increases in epithelial mitosis (P < 0.01), height of glandular epithelium (P < 0.05), volume ratio of gland cell to gland (P < 0.03), degree of pseudostratification (P < 0.02), and higher frequency of supranuclear, adluminal accumulation of vacuoles in gland cells (P < 0.05). The degree of stromal oedema was higher (P < 0.02) in fecund cycles but there was no change in venular diameter. In a separate set of experiments, estimates of tissue vascular response revealed a higher (P < 0.02) endometrial extravascular albumin space on the same day of gestation; there were no differences, however, in endometrial blood volume, or in the number of von Willebrand antigen-positive capillaries and small vessels between the two groups (group 1, n = 6; group 2, n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Homologous intra-uterine insemination has no advantage over timed natural intercourse when used in combination with ovulation induction for the treatment of unexplained infertility.

The objective was to evaluate the role of homologous intrauterine insemination compared with timed natural intercourse, both combined with ovulation induction, in the management of unexplained infertility. A total of 48 couples presenting at a large teaching hospital infertility clinic with unexplained infertility of at least 3 years duration comprised the main study group, and 36 couples with identical entry criteria but under the care of another clinician made up a parallel control group. A randomized design of treatment cycles with within-group and between-group controls was used. Couples in the main study group were treated with either homologous intra-uterine insemination or timed natural intercourse in gonadotrophin-releasing hormone analogue down-regulated cycles, in which ovulation was induced with human menopausal gonadotrophin and human chorionic gonadotrophin. Alternate cycles were monitored to enable optimum timing of natural intercourse provided within-group controls. Couples in the control group underwent timed homologous intravaginal artificial insemination. Cycle fecundity and pregnancy outcome in treated and control groups were monitored. Cycle fecundity of 0.11 in 85 ovulation-induced cycles was significantly higher than 0.02 in 62 within-group and 0.01 in 103 between-group control cycles. There was no difference in conception rates between homologous intra-uterine insemination and timed natural intercourse cycles with ovulation induction. Of the 11 established pregnancies in the ovulation induced group, nine delivered healthy babies (five singleton, three twin, one triplet) and two were ectopic. Results confirmed the value of active management for couples with long-standing unexplained infertility but failed to demonstrate any advantage of homologous intra-uterine insemination over ovulation induction alone.

Adult↗
PubMed1993

Age, pregnancy and miscarriage: uterine versus ovarian factors.

This study was performed to evaluate the relative contribution of oocyte and uterine factors to the age-related reduction in fecundity. The pregnancy and miscarriage rates in women receiving donated oocytes were compared to those in women using their own oocytes in in-vitro fertilization (IVF) and gamete intra-Fallopian transfer (GIFT) procedures. Oocyte donation with embryo transfer was performed on 241 women in 371 cycles; 116 of these women became pregnant (48% per patient and 31.5% per cycle) of whom 40 (35%) miscarried, giving a live birth rate of 20.5%. Assisted conception, in the form of IVF/GIFT procedures, was performed on 1331 women using their own oocytes in 2194 cycles; 627 of these women became pregnant (47% per patient and 28.7% per cycle), of whom 228 (36%) miscarried, giving a live birth rate of 18.2%. Neither the age of the donor nor the age of the recipient was related to pregnancy rate. The age of the donor, however, was directly related to the miscarriage rate. On the other hand, the age of patients undergoing IVF/GIFT was inversely related to the pregnancy rate and directly related to the miscarriage rate. In women of 40 years or over, the overall pregnancy and live birth rates were significantly higher and the miscarriage rate was significantly lower in the group receiving donated oocytes compared to the group using their own oocytes. In summary, we suggest that the age-related decline in fecundity is associated with the age of the oocytes rather than the age of the uterus.

Abortion, Spontaneous↗
PubMed1994

Spontaneous ovulatory cycle donor insemination programme: prognostic indicators of a successful pregnancy.

The effects of female and male infertility factors as well as the insemination regime on the outcome of donor insemination (DI) during 1001 spontaneous ovulatory cycles were assessed. Overall, the average monthly fecundability was 4.4% and the cumulative conception rate after nine cycles was 45%. Female DI recipients' age, nulligravidity or the presence of other infertility factors were associated with a significantly lower pregnancy rate. DI recipients of azoospermic partners had a significantly higher pregnancy rate. The likelihood of a successful pregnancy was higher when more frequent (> or = 1) inseminations were used or in association with higher cervical score and larger follicle diameter at the time of insemination. We suggest that female recipients of DI should be fully investigated before commencing DI treatment. Early resort to other methods of assisted reproduction should be considered in DI recipients aged > or = 35 years, or in younger women if they fail to conceive after nine cycles of DI. More frequent and better timing of inseminations is expected to improve the fecundability rate during spontaneous ovulatory DI cycles.

Adult↗
PubMed1999

Prospective approaches to avoid flock fertility problems: predictive assessment of sperm function traits in poultry.

This paper discusses why it is important to evaluate males as individuals and how advances made in understanding and measurement of sperm function can be used to improve reproductive efficiency in poultry. Commercial turkey breeding relies on pooling semen from multiple toms. It generally is assumed that sperm in good quality semen from all toms are equally fecund. (Fecund is defined, for males, as an individual whose semen contains a majority of sperm with the potential of producing fertilized eggs, which includes success at all steps in the fertilization process: sperm movement, storage in the hens' sperm storage tubules, binding and penetrating the perivitelline layer, and fertilization.) However, when DNA fingerprinting was used to determine paternity efficiency after pooling ejaculates from seven or more toms, it was found that 18 of 26 males produced very few, or no, offspring. In addition, the traditional measures of poultry semen quality: semen volume, sperm concentration, sperm viability, and subjective motility assessment, were poor predictors of paternity. In recent years, a concentrated effort has been made to develop and evaluate methods that quantify sperm function in poultry. Methods to measure some of these traits are reviewed: sperm motility, sperm storage in the hen, and sperm binding and penetration of the ovum. Data supporting use of these tools for managing flock fertility from the male perspective are explored.

Animal Husbandry↗
PubMed2001

Fitness parameters and DNA effects are sensitive indicators of copper-induced toxicity in Daphnia magna.

This study compared the effects occurring at molecular and population levels in Daphnia magna exposed to copper concentrations in the range of 15-120 microg/l. The qualitative and quantitative modifications arising in random amplified polymorphic DNA (RAPD) profiles as a measure of DNA effects were compared with a number of key ecological fitness parameters, namely, the age-specific survival, age-specific fecundity, net reproductive rate, and intrinsic rate of population increase. Results suggested that growth, reproduction, and most of the fitness parameters as well as genomic template stability (a qualitative measure reflecting changes in RAPD profiles) were significantly affected at copper concentrations of 90 and 120 microg/l. Among the fitness parameters, the age-specific fecundity and net reproductive rate were the most sensitive parameters of toxicity. Changes in RAPD patterns generally occurred at copper concentrations of 90 and 120 microg/l, but with one primer, changes significantly arose at all copper concentrations. Overall, molecular and population parameters compared well and represented a sensitive means to measure toxicity induced by copper in Daphnia magna. In conclusion, the measurement of parameters at both molecular and population levels is valuable for investigating the specific effects of agents interacting with DNA. Ultimately, this methodology may allow the ecotoxicological examination of the link between molecular alterations and measurable adverse effects at higher levels of biological organization.

Animals↗
PubMed2005

Intracytoplasmic sperm injection effects in infertile azh mutant mice.

Several reports in the literature describe men with infertility resulting from abnormal sperm head shape or decapitation defects of their spermatozoa. These defects are similar to those shown for the spermatozoa from azh (abnormal spermatozoon head shape) mice. The present study examines the efficiency and effects of intracytoplasmic sperm injection (ICSI) in successive generations of azh mice generated with this method. Three successive generations of azh mice were produced with ICSI. In all three ICSI series, more than 80% of 2-cell embryos were obtained, and more than 35% of embryos transferred gave rise to normal live offspring. In addition, ICSI was used to cross homozygous azh/azh males with homozygous azh/azh females, and live offspring were obtained. The ICSI-derived males were tested for their fecundity and abnormalities of sperm morphology. Spermatozoa from ICSI-derived azh/+ males did not show any impairment of fecundity in in vitro fertilization. These spermatozoa successfully fertilized oocytes from both C57BL/6 and B6D2F1 females, with fertilization rates ranging from 70%- 92%. The proportion of morphologically normal spermatozoa was similar in azh/+ males from three successive generations of ICSI (57.8%, 54.8%, and 49.0%, respectively), and no differences were noted when comparing ICSI-derived males with males derived by mating (57.6%) and with wild-type controls (61.6%). Detailed analysis differentiating between specific types of anomalies of sperm morphology did not reveal significant differences among the examined groups. The results of the present study demonstrate that ICSI does not enhance the azh mutation phenotype in the offspring and brings no risks when applied continuously. Moreover, serial (successive generations) ICSI is highly efficient in maintaining valuable mice with fertility problems.

Animals↗
PubMed1998

Reproductive aging in the Djungarian hamster, Phodopus campbelli.

Changes in fertility (delivery success), fecundity (litter size and weaning success), sensitivity to pregnancy-blocking stimuli (mate removal after 24 h), and hypothalamic-pituitary-ovarian function were assessed during reproductive aging in the Djungarian hamster, Phodopus campbelli. All indices of aging occurred earlier in the Djungarian hamster than they do in other laboratory models, including the mouse. Fertility and fecundity were halved by 8 mo of age, and the response to pregnancy-blocking stimuli disappeared by 4-6 mo. Pup birth weight increased with maternal age and decreasing litter size. Older females also tended to lose entire litters rather than to reduce litter size and successfully wean remaining pups. Impaired ovarian function was a major contributor to reproductive aging. Numbers of large antral follicles developing in aged females and in aged females receiving eCG treatment were similar to those in young females. However, a few preovulatory follicles routinely failed to ovulate from each ovary. Healthy preovulatory follicles in old females secreted the large quantities of estradiol-17 beta typical of estrous cycles, but eCG-induced preovulatory follicles did not. As young females of this species have smaller folicular reserves than other rodent species, and follicle numbers in older females are further reduced (with a high incidence of completely degenerate ovaries), follicular exhaustion was coincident with reproductive failure. Neuroendocrine aging of the hypothalamus was also implicated in the loss of a pregnancy-blocking response and the failure of maternal care with increasing maternal age. Similarities to reproductive aging in long-cycle species (including primates) suggest that the Djungarian hamster is a useful laboratory model that deserves further investigation.

Aging↗
PubMed1999

Variations of light and temperature regimes and resulting effects on reproductive parameters in medaka (Oryzias latipes).

In seasonally breeding fish species, altered fecundity, fertility, and spawning interval are associated with changes in environmental cues such as temperature and photoperiod. To determine quantitative impact of these cues on a suite of reproductive endpoints, groups of medaka (Oryzias latipes; two breeding pairs per group) were subjected to varying photoperiod and temperature regimes. Embryo production ceased after photoperiod reduction from 16L:8D to 8L:16D (at 25 degrees C). A severe decline in production was observed after a temperature decrease of 10 degrees C (25 degrees C to 15 degrees C [16L:8D]). Under reduced photoperiod, histologic analysis showed no mature ova and moderate oocyte atresia in all individuals. However, reduced temperature (15 degrees C) produced only mild oocyte atresia and fewer mature ova. Under both reduced photoperiod and reduced temperature regimes, mature spermatozoa were observed. Offspring viability, along with spawning interval, were not affected by photoperiod reduction. Temperature change had no effect on offspring viability but caused an increase in spawning interval. A shortened photoperiod profoundly affected medaka reproduction, whereas decreased temperature reduced, but did not arrest, fertility; reduced photoperiod decreased fecundity. These findings have important implications for culture of medaka as well as use of this teleost model for reproductive toxicology studies.

Animals↗
PubMed1996

Seasonal variation in the time to pregnancy: avoiding bias by using the date of onset.

To study seasonality in human fecundability, measured indirectly by time to the first pregnancy, we used data from 18,970 French-Canadian women who married for the first time during the 17th or 18th century. The time to pregnancy was approximated by the interval between marriage and first birth minus 38 weeks. We used the week of marriage and the week of conception as references to study seasonality. We found a minor seasonal pattern in time to pregnancy when using the week of marriage as a reference. The proportions of women with a short time to pregnancy were highest during December-January and June-July, indicating that these may be the most fecund periods. In contrast, we found an obvious seasonal pattern when using the date of conception as a reference. This pattern can be largely explained by a strong seasonal pattern in pregnancy planning (in this case, in marriages). When studying seasonal variation in the time to pregnancy, the date of onset of the time to pregnancy should be used as reference, not the date of conception. Otherwise, results will be biased owing to seasonality in pregnancy planning. The same is true for studies on seasonally bound exposures in relation to time to pregnancy.

Adolescent↗
PubMed2000

Time to pregnancy among the wives of men occupationally exposed to lead.

We conducted a retrospective study on time to pregnancy among the wives of men biologically monitored for lead to assess whether paternal occupational exposure to inorganic lead is associated with decreased fertility. After three mailings, 554 (72.2%) wives of the monitored men participated. The final study population consisted of 502 couples who did not use contraception at the beginning of the pregnancy. We assessed lead exposure from blood lead measurements and from questionnaires completed by the men. We calculated the relative fecundability density ratios with discrete proportional hazards regression. The fecundability density ratios, adjusted for potential confounders, were 0.92 [95% confidence interval (95% CI) = 0.73-1.16], 0.89 (95% CI = 0.66-1.20), 0.58 (95% CI = 0.33-0.96), and 0.83 (95% CI = 0.50-1.32) for blood lead categories 0.5-0.9, 1.0-1.4, 1.5-1.8, and > or =1.9 micromol/L, respectively, as compared with <0.5 micromol/L. The findings provide limited support for the hypothesis that paternal exposure to lead is associated with decreased fertility.

Abnormalities, Drug-Induced↗
PubMed2002

Prolonged time to pregnancy in female workers exposed to ethylene glycol ethers in semiconductor manufacturing.

BACKGROUND: Previous research on reproductive effects of working in the semiconductor industry is limited and has produced conflicting results. METHODS: This retrospective cohort study was designed to investigate the risk factors for female fertility in a wafer-manufacturing company of Taiwan in 1997. Waiting time to pregnancy and potential confounders were collected by face-to-face interview. Exposure was assessed by directors and senior engineers in manufacturing, administrative, and safety and health departments according to safety records, personnel records, and job histories from questionnaires, using a tiered exposure-assessment approach. Of a total 842 female workers, 720 (85.5%) participated. There were 292 pregnancies from 173 workers eligible for analysis. Relative fecundability (fecundability ratio, or FR) was calculated using Cox's proportional hazard models to evaluate the effect of occupational exposure to ethylene glycol ethers on female fertility. RESULTS: Waiting time to pregnancy of female workers in the photolithography area was longer than that of those in the nonfabrication area (FR = 0.77; 95% CI = 0.45-1.32), and those who were potentially exposed to ethylene glycol ethers showed longer time to pregnancy compared with those not exposed (FR = 0.59; 95% CI = 0.37-0.94). CONCLUSION: This study provides further evidence that ethylene glycol ethers may cause female subfertility.

Ethers↗
PubMed1990

HIV infection among lower socioeconomic strata prostitutes in Nairobi.

A cohort of 418 lower socioeconomic strata prostitutes were enrolled in a study of the epidemiology of sexually transmitted diseases (STDs) between January and April 1985. Sixty-two per cent of the women were seropositive for HIV infection at enrollment. Significant associations were found between HIV seropositivity and Tanzanian origin (OR = 2.12, CI 95% = 1.18-3.81, P less than 0.03), younger age, a shorter duration of prostitution, reduced fecundity, use of oral contraceptives (OR = 1.8, CI 95% = 1.1-2.9, P less than 0.05) and genital ulcer disease (OR = 3.32, P less than 0.00001). No associations were noted with other STD. Stepwise logistic regression analysis confirmed independent associations between HIV infection and Tanzanian origin (OR = 2.27, CI 95% = 1.25-4.14, P less than 0.007), reduced fecundity (OR = 0.83, CI 95% = 0.74-0.94, P less than 0.003), oral contraceptive use (OR = 2.02, CI 95% = 1.22-3.35, P less than 0.006) and duration of prostitution (OR = 0.39, CI 95% = 0.23-0.65, P less than 0.004). Oral contraceptives may increase susceptibility to HIV or may be a marker for other factors which increase risk of acquisition. Further studies are necessary to confirm this association.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Physiological benefits from low levels of ionizing radiation.

Extensive literature indicates that minute doses of ionizing radiation benefit animal growth and development, fecundity, health and longevity. Specific improvements appear in neurologic function, growth rate and survival of young, wound healing, immune competence, and resistance to infection, radiation morbidity, and tumor induction and growth. Decreased mortality from these debilitating factors results in increased average life span following exposure to minute doses of ionizing radiation. The above phenomena suggest the possibility that ionizing radiation may be essential for life. Limited data with protozoa suggest that reproduction rates decrease when they are maintained in subambient radiation environments. This may be interpreted to be a radiation deficiency. Evidence must now be obtained to determine whether or not ionizing radiation is essential for growth, development, nutrient utilization, fecundity, health and longevity of higher animals. Whether or not ionizing radiation is found to be essential for these physiologic functions, the evidence reviewed indicates that the optimal amount of this ubiquitous agent is imperceptibly above ambient levels.

Animals↗