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At least 19 recordsLinked to original sources
PubMed1988

Effect of chronic protein-energy malnutrition on fecundability, fecundity and fertility in rats.

To assess the effect of chronic protein-energy malnutrition on fecundability (ovulation rate), fecundity (percentage of animals bred that conceived) and fertility (live fetuses at d 18 of pregnancy), 42-d-old female rats were assigned to six groups: two dietary treatment groups and, within each treatment group, three outcome groups. Rats were fed ad libitum (AL) or were chronically restricted (CR) to 50% of AL intake for 28 d before ovulation was assessed and then until implantation and fetal viability were measured. In the ovulation groups, corpora lutea were counted at estrus. In the implantation groups, blastocyst implantation sites were quantified by using Pontamine Blue dye at d 5 of pregnancy. In the viability groups, live and dead fetuses and metrial nodes were counted at d 18 of pregnancy. CR rats had 74% as many corpora lutea as AL rats; however, fecundity did not differ between dietary treatments. CR rats had 71% as many blastocyst implantation sites and 65% as many viable fetuses as AL rats. Chronic malnutrition negatively affected weight gain before and during pregnancy as well as reproductive performance. These findings help to explain why CR rats have fewer progeny.

Animals↗
PubMed1989

The relationship of sperm parameters to cycle fecundity in superovulated women undergoing intrauterine insemination.

Semen parameters of raw and prepared (post-swim-up) specimens from 451 cycles of intrauterine insemination (IUI) were analyzed in relation to cycle fecundity in 232 patients undergoing ovarian stimulation with sequential clomiphene citrate/menotropin therapy. Pregnancy occurred in 42 cycles, resulting in an overall pregnancy rate of 17.7%, and a cycle fecundity of 9.3%. Cycle fecundity was positively correlated with the parameters of post-swim-up log sperm density (r = 0.994), and with log total motile sperm inseminated (r = 0.964; inseminates were limited to a maximum of 20 million total motile sperm). Post-swim-up motility did not correlate (r = 0.308) with cycle fecundity; however, most specimens had a motility of greater than 40% post-swim-up. Only one pregnancy occurred when less than 1 million motile sperm were inseminated (38 cycles), which resulted in a cycle fecundity of 2.6% for these cycles. This may represent the threshold of effectiveness for IUI in this setting. Highest cycle fecundity was obtained with an inseminate containing approximately 10 million or more motile sperm. Parameters of raw samples correlated less well with cycle fecundity than did prepared specimens. Analysis of post-swim-up semen parameters can provide useful prognostic information for women undergoing IUI with ovarian stimulation; this information is helpful in counseling patients regarding their chances of success with this therapy.

Adult↗
PubMed1986

The fecundity of Schistosoma mansoni in chronic nonhuman primate infections and after transplantation into naive hosts.

Adult Schistosoma mansoni worms were transplanted from 8 nonhuman primates with chronic infections into 8 naive recipients, in an effort to test the hypothesis that worm fecundity reduction in chronic infections is the result of host immunity or some other host effect. Techniques for perfusing living donors without the added use of anti-schistosomal drugs and for reducing the likelihood of post-operative bacterial endotoxemia and septic shock are described. Fecundity values in terms of eggs per day per female worm were obtained for the worms in their original and in their new hosts and compared. In 3 experiments, perfusions were incomplete and the donors were saved, enabling direct comparisons of fecundity to be made in subpopulations of worms in both their original and new hosts, after equal life spans. In only 1 of the 8 transplantations was there a clear increase in fecundity after surgical introduction into a naive host. Therefore, these experiments fail to support the hypothesis that reduced fecundity of S. mansoni worms in permissive nonhuman primate hosts is a reversible result of host immunity or some other host-derived factor. Despite this negation, further evidence for reduced worm fecundity in older infections was obtained. In the absence of in vivo evidence for immune-mediated antifecundity, worm senescence is the most likely explanation for this finding, with irreversible immune damage to the worms being a less attractive alternative hypothesis.

Animals↗
PubMed1989

Reduced fecundability in women with prenatal exposure to cigarette smoking.

Animal studies have suggested that fertility may be impaired by transplacental exposures, but little is known about human prenatal exposures and subsequent adult reproduction. A possible relation between prenatal exposure to cigarette smoking and adult fecundability in women was explored, with the use of data from a prospective study of 221 North Carolina couples. These couples were recruited during 1983-1985, at the time they stopped using birth control in order to become pregnant. The relative fecundability of exposed compared with unexposed women was estimated by applying a discrete-time proportional probabilities model to the cycle-by-cycle conception rates. Women with prenatal exposure to their mother's cigarette smoking had reduced fecundability. The fecundability ratio associated with prenatal exposure to mother's smoking, adjusted for age, frequency of intercourse, current smoking status, age at menarche, and childhood exposure to cigarette smoking, was 0.5 (95% confidence interval 0.4-0.8). This association was not changed by further adjustment for other possible confounding variables, including educational level, reproductive history, body weight, and consumption of alcohol and caffeine. Thus, women whose mothers smoked while pregnant with them may be on average substantially less fecund than women whose mothers did not smoke during pregnancy.

Adult↗
PubMed1991

A study of the mortality and fecundity of Haemonchus contortus in sheep following experimental infections.

The regulation of the fecundity and mortality of H. contortus in sheep was examined using a series of mathematical models. Six-month-old Dorset crossbred lambs were infected once only with various doses of infective H. contortus larvae (500-20,000 larvae). Parasite mortality was found to be an increasing linear function of the magnitude of the initial infection over the range of doses examined. Parasite fecundity was found to remain constant over the intensity and duration of the infection. The average fecundity for H. contortus at the time of slaughter was found to be 7037 eggs per female worm per day. There was no evidence of time-dependent changes in fecundity or density-dependent regulation of fecundity.

Animals↗
PubMed1991

The relationship between intestinal location and fecundity in adult Trichinella spiralis.

Adult female worms recovered from the jejunum of rats infected per os with 1000 larvae of Trichinella spiralis were significantly more fecund (peak jejunal fecundity = 35.7 +/- 3.1 newborn larvae per female) than females recovered from the terminal ileum (9.3 +/- 4.1 larvae per female) in the same infections. The majority of the adult worms were established in those sections of the small intestines that produced the most fecund females (r = 0.92; P less than 0.05). Worm fecundity is believed to be location-specific because adult females that were surgically implanted into the jejunum were significantly more fecund that were implanted into only the ileum. It is concluded that the physico-chemical conditions of the anterior small intestines are optimal for the parasites' reproductive fitness and this exerts a strong selective pressure on habitat selection behavior.

Animals↗
PubMed1991

The regulation of mortality and fecundity in Schistosoma mattheei following a single experimental infection in sheep.

The regulation of mortality and fecundity of Schistosoma mattheei in sheep was examined using a series of mathematical models applied to data culled from the literature. Parasite mortality (mu) was found to be an increasing linear function of the magnitude of the initial infection over the ranges of doses examined (200-91,000 cercariae) where mu = 9.78 x 10(-3) + 3.476 x 10(-7) infection dose. Parasite fecundity (lambda) was found to be inversely related to the duration of the infection. The best fit model for parasite fecundity was one in which fecundity decreased exponentially with time since initial infection, lambda = lambda 0e-delta(t-tau). There was no evidence for density-dependent regulation of fecundity.

Animals↗
PubMed1991

A comparative analysis of the cycle fecundity rates associated with combined human menopausal gonadotropin (hMG) and intrauterine insemination (IUI) versus either hMG or IUI alone.

Human menopausal gonadotropin (hMG) superovulation combined with washed intrauterine insemination (IUI) has been advocated for the treatment of various forms of infertility when more traditional therapy has failed. To assess the relative efficacy of combined treatment with hMG and IUI compared with either hMG or IUI alone, pregnancy outcomes of the three treatment groups were compared in couples having infertility because of male factor, cervical factor, endometriosis, or unexplained. A total of 751 cycles were analyzed from 322 couples. The mean cycle fecundity rate associated with hMG/IUI therapy was significantly higher than either hMG or IUI therapy alone for all patients (hMG/IUI = 19.6%, hMG = 6.3%, IUI = 3.4%). The improvement in cycle fecundity rates with hMG/IUI therapy was also observed when the couples were separated by infertility diagnostic groups: male factor (hMG/IUI = 15.3%, hMG = 4.4%, IUI = 3.0%), cervical factor (hMG/IUI = 26.3%, hMG = 7.9%, IUI = 5.1%), endometriosis (hMG/IUI = 12.85%, hMG = 6.6%), and unexplained infertility (hMG/IUI = 32.6%, hMG = 5.5%, IUI = 0%). Moreover, in patients who had failed to conceive with hMG or IUI alone, the cycle fecundity rate when they were switched to hMG/IUI therapy equaled that of patients who received combined therapy from the onset. We conclude that cycle fecundity rates and cumulative pregnancy rates are significantly greater using a combination of hMG and IUI compared with either modality alone in the treatment of male factor, cervical factor, endometriosis, or unexplained infertility. Indeed, in couples with nontubal related infertility, cycle fecundity rates with hMG/IUI approach the rates seen with in vitro fertilization and gamete intrafallopian tube transfer.

Endometriosis↗
PubMed1992

The mortality and fecundity of Haemonchus contortus in parasite-naive and parasite-exposed sheep following single experimental infections.

Parasite-exposed lambs and their parasite-naive controls were experimentally infected once only with 30,000 H. contortus larvae at 3, 9, 12, and 20 weeks following termination of a moderate immunizing infection of 30,000 H. contortus larvae. Previously exposed lambs, challenged at 3 weeks, had a significant reduction in the total H. contortus worm burden as compared to parasite-naive controls. No difference in the total H. contortus worm burden was found between parasite-exposed or parasite-naive lambs challenged at 9 weeks or thereafter. Female worms were found to be significantly smaller in lambs previously exposed to the parasite as compared to those found in parasite-naive lambs. The average parasite fecundity was 4700 eggs per female worm per day. Previous exposure of the lambs to the parasite had no effect on parasite fecundity. Various mathematical models were used to examine parasite fecundity. Parasite fecundity was found to increase in the initial post-challenge period reaching a constant value approximately 58 days after challenge infection. No density-dependent constraints on fecundity were observed.

Animals↗
PubMed1992

Abnormal findings on hysterosalpingography: effects on fecundity in a donor insemination program using frozen semen.

OBJECTIVE: We sought to evaluate the effect of abnormal baseline hysterosalpingography (HSG) on subsequent fecundity during the first six cycles of treatment. METHODS: Hysterosalpingography was performed on 208 asymptomatic ovulatory women with no history of pelvic disease who were referred for donor insemination. The findings were categorized into five groups: 1) normal study, 2) uterine anomaly or filling defect with bilateral tubal patency, 3) normal uterine anatomy with unilateral tubal patency, 4) normal uterine anatomy with bilateral tubal blockage, and 5) normal uterine anatomy with hydrosalpinx. Subjects in groups 4 and 5 received inseminations only if patency of at least one fallopian tube was demonstrated with laparoscopy. Life-table analysis was performed to calculate the average monthly fecundity and cumulative conception rates for each group. The Mantel-Haenszel test was used to compare group fecundities. RESULTS: A total of 1460 donor insemination cycles were performed. The number of cycles in each group were as follows: group 1, 1173 (80%); group 2, 153 (10%); group 3, 90 (6.2%); group 4, 16 (1.1%); and group 5, 28 (1.9%). None of the patients in group 4 or 5 conceived. The cumulative conception rates in the first three groups were 46, 34, and 40%, respectively, and were not significantly different from one another (P greater than .05). Although a high incidence of uterine filling defects and unilateral tubal blockage was observed (19.2%), the incidence of an abnormal HSG finding that significantly decreased fecundity was only 2.8%. CONCLUSION: In women with no history of tubal or uterine disease, routine HSG before initiation of donor insemination is of limited value for identifying decreased treatment fecundity.

Adult↗
PubMed1992

Relationship of follicle number and other factors to fecundability and multiple pregnancy in clomiphene citrate-induced intrauterine insemination cycles.

OBJECTIVE: To determine characteristics associated with pregnancy and multiple gestation after clomiphene citrate (CC)-intrauterine insemination (IUI). DESIGN: Prospective study of all patients undergoing CC-IUI between January 1, 1983 and December 31, 1989. SETTING: Private fertility clinic. PATIENTS: Eight hundred forty-nine patients undergoing 1,974 cycles of CC-IUI. MAIN OUTCOME MEASURES: Relationship between number and size of preovulatory follicles, age, additional infertility diagnosis, medication, and initial semen quality to fecundity, birth, and multiple gestation. RESULTS: Uncorrected, per cycle fecundity was 7.2%. The number of follicles greater than or equal to 12 mm (r = 0.055, P less than 0.05) was and the number greater than or equal to 15, 18, and 21 mm was not correlated with fecundity. Endometriosis with (P = 0.013) or without (P less than 0.0005) tubal adhesions and tubal adhesions alone (P = 0.005), decreased fecundability by 50%. Initial semen quality did not affect fecundity, unless semen concentration was less than 5 x 10(6)/mL or motility was less than 20%. Multiple pregnancy was not associated with the dose of CC, use of human chorionic gonadotropin, or number of follicles. CONCLUSIONS: Multiple pregnancy was unrelated to follicle numbers or to CC dose. The highest birth rates after CC-IUI occurred when initial sperm concentration was greater than or equal to 5 x 10(6)/mL, motility was greater than or equal to 20%, and no endometriosis or adhesions were present.

Clomiphene↗
PubMed1991

The effect of age on female fecundity.

To determine the relationship between age and female fecundity, 210 women were studied prospectively. The subjects had negative infertility evaluations and were receiving therapeutic donor insemination. Life-table analysis was performed on 751 donor insemination cycles. For comparison, patients were divided into five separate age groups and into two separate groups, ages 19-34 and 35-45. Monthly fecundity and cumulative conception rates were calculated for each group. A significant difference was found when all age groups were compared (P = .05) and when those at or above age 35 and those below age 35 were compared (P less than .05). Frozen semen was used in 92% of all cycles. The average monthly fecundity of all patients treated with frozen semen was 16%. This study confirms a progressive decline in fecundity with age in a completely evaluated group of women undergoing therapeutic donor insemination and demonstrates that frozen semen can yield acceptable fecundity provided sufficient numbers of motile sperm are used for each procedure.

Adult↗
PubMed1978

Effects of various factors on selection for family planning status and natural fecundability: a simulation study.

The effect of various factors on selection for family planning status and for natural fecundability is studied in a simulation that incorporates a beta distribution of fecundability among women. The mean fecundabilities of current spacers, current limiters, current nonusers, and pregnant women are compared. These ratios are influenced by duration of marriage and by desired number of children. Effects of different levels of contraception are measured. Another strategy, spacing the last two wanted births, is also studied. It is found that breast-feeding status has little effect on fecundability selection. The women usually found to have greatest fecundability are not those recently pregnant at durations of marriage five and ten years, unless they wanted fewer than two children, but rather those who are using contraception to limit the number of children.

Adult↗
PubMed1986

Experimental infection of Tribolium confusum (Coleoptera) by Hymenolepis diminuta (Cestoda): host fecundity during infection.

Some effects of Hymenolepis diminuta on the fecundity of Tribolium confusum are described. Host fecundity is observed to be reduced exponentially with increasing parasite burden/host, although there are differences in the ability of individual hosts to respond to parasitism. Of particular interest is the finding that host fecundity is greatly reduced in young beetles on or by day 14 post-infection (p.i.). This age-related reduction in host fecundity is discussed in relation to the population dynamics of this host-parasite relationship.

Aging↗
PubMed1990

Artificial insemination of Cashmere goats: effects on fertility and fecundity of intravaginal treatment, method and time of insemination, semen freezing process, number of motile spermatozoa and age of females.

The experiments, using a total of 1833 Cashmere does, were conducted to examine the effects on fertility and fecundity of intravaginal treatment for control of ovulation, time of insemination by cervical and laparoscopic methods, semen processing in pellets and straws, and number of frozen-thawed motile spermatozoa. Adult does (greater than or equal to 2.5 years) that had previously kidded were inseminated into the cervix, and maiden (kid: 6-8 months; hogget: 18 months) and adult does were inseminated laparoscopically. The rates of pregnancy determined by ultrasonic scanning (75-80 days after insemination) for cervical (Experiment 1) and laparoscopic (Experiments 2 and 3) insemination were 39.1%, 63.6% and 52.1%. The number of motile spermatozoa did not affect fertility after cervical (80, 120 and 160 x 10(6) or laparoscopic (Experiment 2: 15, 30 and 60 x 10(6); Experiment 3:5, 10 and 20 x 10(6) insemination. The method of insemination or number of motile spermatozoa did not affect fecundity. With cervical insemination, fertility and fecundity improved with increasing depth of insemination into the reproductive tract. Intravaginal sponges containing fluorogestone acetate and controlled internal drug release (CIDR) devices containing progesterone were equally effective for control of ovulation when combined with an injection of pregnant mare's serum gonadotrophin (PMSG; 200 i.u.) before insemination. Fertility was higher when does were inseminated before than after ovulation. After laparoscopic insemination, results were similar for semen frozen as pellets and in straws, and for 3-, 6- and 24-fold pre-freezing dilution of semen. For kid, hogget and adult does in Experiment 3, pregnancy rates were 34.0%, 55.4% and 63.9% and rates of fecundity were 1.17, 1.22 and 1.27 fetuses/pregnant doe.

Administration, Intravaginal↗
PubMed1987

Fecundity and size in the housefly: investigations of some environmental sources and genetic correlates of variation.

Environmental sources and genetic correlates of variation in fecundity and size were studied in field and laboratory housefly populations in central Iowa, U.S.A. Electrophoresis of enzymatic proteins was used to monitor genotypes and heterozygosity. In the field, mean fecundity declined as adult densities increased. Fecundity varied greatly within breeding seasons. Fly body size varied spatially and temporally during summer and winter. Fecundity and size were positively correlated. Size was independent of genotypes at the six loci studied. No relationship was observed between heterozygosity and the magnitude or variability of body size.

Analysis of Variance↗