Proportion Of Pregnant Females Research Articles

Bats (Mammalia: Chiroptera) in urban-rural interfaces: community structure associated with pathogen screening in São Paulo-the largest metropolitan region in Brazil.

Little is known about the influence of the urban environments on bat species 'ecology. The urbanization process potentially lead to critical ecological changes in bat communities' intra and interspecific pathogenic transmissions dynamics. To date, the monitoring of pathogens in bats in Brazil has only been done with bats found dead or alive in households, from rabies surveillance systems. The present work aimed to investigate how urbanization influenced bat richness, relative abundance and pathogen occurrence. Most captured bats were Phyllostomidae, especially Sturnira lilium, Artibeus lituratus, A. fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus, among others. From preserved-rural towards urban areas the lesser the bat richness, the higher the relative abundance of the captured bats. Noise level, luminosity and relative humidity correlated with bat abundance. The proportion of genders, sexually active bats and their size (weight, right forearm length, and body condition index) were stable throughout the investigation. Still, the proportion of pregnant females was higher in Spring and the number of juveniles in Summer, evidencing the seasonality of reproduction. Several Enterobacteria were isolated, evidencing a significant role of bats in the circulation of pathogens of medical and veterinary interest. These results are crucial in the pursuit of a harmonious coexistence between humans, bats and domestic animals in areas with different levels of anthropization.

Females treated for syphilis in Bialystok, Poland 2016-2020.

Syphilis is the third most frequent bacterial sexually transmitted disease globally. Untreated syphilis in a pregnant woman may results in a transmission of the infection to the foetus resulting in congenital syphilis. To characterise females treated for syphilis in Bialystok, north-east Poland, in years 2016-2020. Retrospective analysis of age, residency, marital status of patients, stage of syphilis, treatment and adherence to follow-up visits was conducted as well as a detailed analysis of clinical characteristics of pregnant women treated for syphilis. Sixteen women were treated for syphilis in 2016-2020, 11 (68.8%) of them were pregnant. The proportion of pregnant women among all syphilis female patients increased substantially as compared to years 2000-2015 (68.8% vs. 36.2%, respectively, P<0.05). Mean age of patients was 37.12±11.25 years, 10 (62.5%) were residents of urban areas and 10 were married. Late latent syphilis or latent of unknown duration was the most frequent stage of syphilis. Chlamydia trachomatis infection was detected in four (25%) patients with syphilis. Benzathine penicillin was mainly used in the treatment. More than half of patients did not complete follow-up. Only one pregnant woman was treated within the first trimester and five of them (45.45%) were lost to follow-up and the outcome of pregnancy was unknown. Syphilis in females, especially in pregnant ones, is an important problem in the Podlaskie voivodeship. The proportion of pregnant females among all female patients with syphilis is increasing. The detection and the treatment of infection is frequently delayed in pregnant females. The after treatment followup and the knowledge of outcome of pregnancy remains unsatisfactory. The collaboration between dermatovenereologists, gynaecologists and obstetricians should be improved.

Serum estradiol and progesterone profiles during estrus, pseudopregnancy, and active gestation in Steller sea lions.

While the proximate driver behind the decline of the Western stock of Steller sea lions (Eumetopias jubatus, >80% since 1970s) is likely multifactorial, the population reduction may have been powered by a decrease in fecundity. A harvest of Steller sea lions in the 1970s and 80s revealed a 30% reduction in the proportion of pregnant females from early (October-November) to late gestation (April-May). Identification and quantification of these reproductive failures are difficult when we lack species-specific data on endocrinology associated with discrete stages of the reproductive cycle (i.e., estrus, implantation, and gestation). We tracked changes in serum estradiol and progesterone in three adult female Steller sea lions from 2011 to 2015. In all years and most females, a discrete increase in estradiol was observed during the breeding season (June-August), indicative of estrus. Estradiol concentrations from October to May in a pregnant female compared to her corresponding values when non-pregnant did not consistently differ through gestation. An elevation in progesterone was observed in all females and all years beginning approximately in June and lasting through November. This likely results from progesterone production by the corpus luteum in both pregnant and pseudopregnant females. Serum progesterone shows promise as a diagnostic tool to identify pregnancy during months 3-5 (December-February) of the 8-month active gestation following embryonic implantation. This study provides ranges of key hormones during estrus, embryonic diapause/pseudopregnancy, and gestation in pregnant and non-pregnant females for studying reproduction in Steller sea lions.

Effects of a mining‐altered environment on individual fitness of amphibians and reptiles

AbstractPollution can affect wildlife directly through toxicity and indirectly through changes in biotic and abiotic factors, however, how these mechanisms interact in affecting free‐ranging animals remains poorly understood. By examining effects on individual fitness proxies, we aimed to determine the mechanisms behind documented amphibian and reptile declines in barren landscapes where vegetation was nearly decimated due to atmospheric metal and sulfur deposition from smelting operations in Sudbury, Ontario, Canada. We examined individual characteristics of snakes (Thamnophis sirtalis, Storeria occipitomaculata) and frogs (Lithobates clamitans, L. pipiens, L. septentrionalis) in replicated barren and reference sites, including standard metabolic rates (in snakes), body condition (all species), female reproductive status (snakes), limb deformity (frogs), and fluctuating asymmetry (all species). Frogs in barren sites (except L. septentrionalis) were in poor body condition, and all but one case of limb deformities in frogs were found in barren sites. However, neither frogs nor snakes exhibited elevated frequency of fluctuating asymmetry in barren sites. Standard metabolic rates (SMR) were not elevated in either snake species, suggesting that metal toxicity does not present an energetic burden. Instead, female T. sirtalis from barren sites exhibited lower SMR and were in poor body condition, which is a predicted response to reduced food intake. By contrast, SMR and body condition of S. occipitomaculata were not different between barren and reference sites. While physiological responses differed between T. sirtalis and S. occipitomaculata, both species exhibited lower reproductive rates (proportion of pregnant females) in barren sites compared to reference sites. Thus, energy deficiency may explain reduced reproduction in T. sirtalis while reduced availability of suitable gestation microhabitat may be a limiting factor for S. occipitomaculata. Populations in smelting‐impacted habitats include individuals with potentially compromised fitness. The low values of our measured fitness proxies appear to have resulted from pollution‐induced changes in biotic and abiotic factors, in addition to (for frogs) or rather than (for snakes) from the direct toxicity. These results suggest that impact assessment based solely on toxicological data and species distributions can underestimate the full impacts of pollution, highlighting the need for integrated examination at multiple levels of biological organization.

Male fertility is reduced by chronic intermittent hypoxia mimicking sleep apnea in mice.

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia and oxidative stress. However, it is unknown whether intermittent hypoxia mimicking OSA modifies male fertility. We tested the hypothesis that male fertility is reduced by chronic intermittent hypoxia mimicking OSA in a mouse model. Case-control comparison in a murine model. University research laboratory. Eighteen F1 (C57BL/6xCBA) male mice. Mice were subjected to a pattern of periodic hypoxia (20 sec at 5% O2 followed by 40 sec of room air) 6 h/day for 60 days or normoxia. After this period, mice performed a mating trial to determine effective fertility by assessing the number of pregnant females and fetuses. After euthanasia, oxidative stress in testes was assessed by measuring the expression of glutathione peroxidase 1 (Gpx1) and superoxide dismutase-1 (Sod1) by reverse-transcription polymerase chain reaction. Sperm motility was determined by Integrated Semen Analysis System (ISAS). Intermittent hypoxia significantly increased testicular oxidative stress, showing a reduction in the expression of Gpx1 and Sod1 by 38.9% and 34.4%, respectively, as compared with normoxia (P < 0.05). Progressive sperm motility was significantly reduced from 27.0 ± 6.4% in normoxia to 12.8 ± 1.8% in the intermittent hypoxia group (P = 0.04). The proportion of pregnant females and number of fetuses per mating was significantly lower in the intermittent hypoxia group (0.33 ± 0.10 and 2.45 ± 0.73, respectively) than in normoxic controls (0.72 ± 0.16 and 5.80 ± 1.24, respectively). These results suggest that the intermittent hypoxia associated with obstructive sleep apnea (OSA) could induce fertility reduction in male patients with this sleep breathing disorder.

Reducing exposure to long days from 75 to 30 days of extra-light treatment does not decrease the capacity of male goats to stimulate ovulatory activity in seasonally anovulatory females

The response of male goats exposed to different durations of long days (LD) during an extra-light treatment in autumn-winter, and their ability to induce ovulations in seasonally anovulatory goats were investigated in 2 experiments. In experiment 1, control males were exposed to natural photoperiod (n = 5), whereas 4 additional groups (n = 5/group) were exposed to 16 h of light per d during 75, 45, 30, or 15 d of LD. In the 4 groups, photoperiodic treatments ended on January 15th. Plasma concentrations of testosterone were determined in blood samples obtained once a week from October 15th to May 30th. The rise of testosterone levels occurred earlier in males from the 75-LD and 45-LD groups than in those from the 30-LD, 15-LD, and control groups (P < 0.05). In addition, the time during which levels of testosterone remained >5 ng/mL was longer in males from the 75-LD and 45-LD than in those from the 30-LD and 15-LD groups (P < 0.05). In experiment 2, a group of anovulatory goats (n = 13) was isolated from males, while 3 additional groups were put in contact during 15 d with males previously exposed to 75, 45, or 30 days of LD (n = 25, 27, and 26 females/group, respectively and n = 3 males per group). The proportion of goats that ovulated was higher in the 3 groups in contact with the photo-stimulated males (range: 88%–92%) than in the group isolated from them (0%; P < 0.05). The proportion of pregnant females did not differ between the 3 groups of does in contact with photo-stimulated males (range: 78%–92%; P > 0.05). We conclude that, in our experimental conditions, a photoperiodic treatment as short as 30 d of LD during autumn-winter, stimulated testosterone secretion of bucks during their period of sexual rest and rendered them able to induce ovulations in seasonal anestrous goats and to obtain pregnancies in these females.

Switching photo-stimulated males between groups of goats does not improve the reproductive response during the male effect

We aimed to determine whether the daily exchange of photo-stimulated males among subgroups of females improved the reproductive response of anestrous goats exposed to males. Bucks were rendered sexually active during the rest season by exposure to 2.5 months of long days from November 1st. In April, males (n=3) were put in contact with three subgroups of anestrous goats (one male per 12 females) where they remained throughout the study, constituting the fixed-group. Other males (n=3) were put in contact with three subgroups of females (one male per 11–12 females) and were rotated daily among them, constituting the rotated-group. The sexual behavior of all males was registered from 08:00 to 09:00 on days 0, 1, 2, and 8 after exchanging the males from the subgroups of females. Ovulation and pregnancy rates were determined by transrectal ultrasonography. The occurrences of ano-genital sniffing, nudging (days 1, 2, and 8), and mounting attempts (days 2 and 8) were greater in the rotated than in the fixed-group (P<0.01). The proportions of females that ovulated did not differ among goats from the fixed (92%) and rotated-group (94%; P>0.05). The proportion of pregnant females and the fertility at kidding did not differ between those from the rotated (79% and 59%) and fixed-group (83% and 61%; P>0.05). We conclude that the daily exchange of photo-stimulated males among subgroups induced an increase of their sexual behavior, but does not improve the pregnancy rates in seasonal anestrous goats.

Leptin controls rabbit ovarian function in vivo and in vitro: Possible interrelationships with ghrelin

The aim of these in vivo and in vitro studies was to examine the role of leptin in the control of plasma hormone concentrations, reproduction, and secretory activity of ovarian granulosa cells. In in vivo experiments, 15 female European domestic rabbit ( Oryctolagus cuniculus) were treated with leptin (5 μg animal −1 d −1 for 1 wk before induction of ovulation with 25 IU equine chorionic gonadotropin and 0.25 IU human chorionic gonadotropin), and 15 females constituted the control group (treated with phosphate-buffered saline). Plasma concentrations of progesterone (P 4), testosterone (T), estradiol (E 2), estrone sulfate (ES), and insulin-like growth factor I (IGF-I) were determined at the estimated day of ovulation by radioimmunoassay (RIA), and number, viability, and body weight of newborns were recorded at parturition. In in vitro experiments, granulosa cells were isolated from periovulatory ovarian follicles of five control and five females treated with ghrelin (10 μg animal −1 d −1 for 1 wk before induced ovulation). Isolated cells were cultured for 2 d with and without leptin (0, 1, 10, or 100 ng/mL medium). Secretion of P 4, T, E 2, IGF-I, and prostaglandin F (PGF) was assessed in culture medium by RIA. In in vivo experiments, leptin administrations reduced plasma P 4, T, E 2, ES, and IGF-I levels. Leptin treatments did not affect ovarian weight or total number and body mass of newborns, but the proportion of pregnant females and number of live newborns were significantly higher in leptin-treated females than that in control females. In in vitro experiments, leptin significantly decreased (at 1 and 10 ng/mL) or increased (at 100 ng/mL) P 4 secretion, promoted E 2 and IGF-I (both at 100 ng/mL) secretion, and reduced T (at 1 and 10 ng/mL) and PGF (at 10 ng/mL) secretion. Granulosa cells from ghrelin-treated animals secreted less P 4, T, E 2, and PGF, but not IGF-I, than that secreted by granulosa cells from control animals. Furthermore, pretreatment of animals with ghrelin suppressed or even reversed subsequent leptin effects on P 4, T, E 2, IGF-I, and PGF secretion by cultured granulosa cells. These observations (1) show for the first time that leptin can increase the number of live newborns in rabbits, (2) confirm previous data on the ability of leptin to control ovarian secretory activity both directly and via upstream mechanisms, (3) demonstrate the involvement of ghrelin in the control of rabbit ovarian secretory functions, and (4) suggest an antagonistic interrelationship between leptin and ghrelin in the rabbit.

Breeding like rabbits: global patterns of variability and determinants of European wild rabbit reproduction

The importance of European wild rabbitsOryctolagus cuniculusboth as a pest in some areas and as a key prey species in others emphasizes the need to understand what controls its population dynamics worldwide. In this study we aim to describe the variability in rabbit breeding parameters and identify the main factors that govern it at a global scale. Despite the species’ wide distribution, some reproductive traits such as short sexual maturity age, duration of gestation period, and existence of post‐partum oestrus are similar in all populations conferring the species a high breeding potential. Nevertheless, other aspects vary substantially among regions resulting in highly different population productivities and also across years. These latter parameters are the length of breeding season, proportion of pregnant females, age of first reproduction, and number and size of litters. Our results show that variability in these attributes is mainly affected by a combination of environmental controls (i.e. temperature, resource availability, and photoperiod) and individual properties (age and body weight). On the other hand, the effect of other factors such as population density could not be demonstrated. Knowledge about the factors driving global reproduction patterns of European wild rabbits will improve our understanding about their population dynamics, and thus will help to optimize the management and conservation of their populations.

Density‐dependent recruitment in grassland small mammals

1. Density dependence has an important influence on the dynamics of many species of small mammals. To regulate population growth, density must affect negatively a vital rate (e.g. fecundity); however, little is known about which vital rates are most affected by density. 2. We used a long-term data set for five species of rodents from north-eastern Kansas, USA to test for relationships between density and the proportion of pregnant females, per capita fecundity and recruitment. We estimated proportion of pregnant females using data collected in the field and fecundity using data on survival, proportion of pregnant females and literature-based density-dependent litter size for each species. We used reverse capture histories to estimate per-capita recruitment. 3. The proportion of pregnant females was related positively to density in most species. Fecundity was related negatively to density in the cotton rat (Sigmodon hispidus Say & Ord, 1825) and not related to density in the four remaining species. Recruitment was related negatively to density in all five species, although not all relationships were statistically significant. 4. The signature of density-dependent recruitment was strongest in the prairie vole [Microtus ochrogaster (Wagner, 1842)] and cotton rat and less so in the remaining species. 5. Our analyses indicate that density affects recruitment negatively in grassland small mammals either through a reduction in immigration or reduced survival of nestlings. Models that seek to include empirical estimates of density dependence may need to include immigration in addition to survival and fecundity.

Reproductive biology of the Iberian hare, Lepus granatensis, in Portugal

The Iberian hare (Lepus granatensis) is endemic to Iberia. Its distribution range covers most of the Iberian Peninsula and it is one of the most important local game species. However, information on several aspects of its biology, e. g., reproductive patterns, is scarce, limiting our ability to establish a sound management. Therefore, study of Iberian hare reproduction was carried out to: a) determine basic reproductive parameters; b) evaluate seasonal variation of breeding activity; and c) estimate annual productivity. Hares were captured every two months, from mid 1997 through 1999, in southern Portugal. In males, testes position, testes and epididymides weight, daily sperm production, extra-gonadal sperm reserves and serum concentration of testosterone were recorded. In females, weight of ovary, pregnancy rate, litter size, number of corpora lutea and placental scars, intra-uterine mortality, and potential production of young were assessed. Pregnant females and sexually active males were observed in all samples, indicating reproductive activity throughout the year. Mean testis weight was higher than 5 g in all sampled periods. The average numbers of daily sperm production and extra-gonadal sperm reserves were 356 × 106 and 1769 × 106 sperm cells, respectively. Testicular activity in males with intra-abdominal testes was established. Mean litter size, based on the number of embryos, was 1.56 ± 0.10 (range between 1 and 4). A significantly higher number of corpora lutea than embryos was observed in pregnant females. Pre-natal mortality (due to loss of ova and resorption of embryos) in pregnant females with at least one embryo was 21%. The proportion of pregnant females with pre-natal mortality was 26%. The estimated annual potential production of young (9.8) was similar to values observed in other hare species.

Nestling survival and population cycles in the prairie vole, Microtus ochrogaster

We live-trapped a population of the prairie vole, Microtus ochrogaster, occupying an alfalfa habitat twice weekly for 63 months. The population underwent four high-amplitude cycles during this time. The most consistent factor associated with population increases was an increase in the number of young animals recruited into the population. Recruitment of young was more a function of survival of offspring during the nestling period than of the proportion of pregnant females in the population. Increased adult survival and reproduction in the population only partly explained the increase phase of the cycles. The decline phases resulted from a combination of decreased reproduction and increased adult mortality. Precipitous declines were associated with major mortality episodes, some less than a week in duration.

Individual and demographic responses of the gray‐tailed vole to vinclozolin

AbstractWe tested the hypothesis that vinclozolin, a fungicide that has been demonstrated in the laboratory to disrupt hormonal activity of rats and mice, would have adverse effects on a field population of voles. We conducted two field experiments to determine whether exposure to vinclozolin following a standard application rate of Curalanr̀ fungicide had adverse effects on the reproductive development and demography of the gray‐tailed vole, Microtus canicaudus. In one experiment conducted during the rainy season, mean lengths of testes and seminal vesicles were smaller (p ≤ 0.08), levels of plasma testosterone were lower (p = 0.025), and proportion of pregnant females was lower (p = 0.05) in treatment than in control animals; however, this difference was not sufficient to affect juvenile recruitment, sex ratio, or population growth. In a second experiment conducted under drier conditions, no differences occurred in measurements of reproductive organs or demography of treatment and control populations. The results suggest that precipitation may have increased the potency of the chemical by washing it down to ground level and (or) by increasing the uptake of toxic metabolites by the plants, resulting in greater dietary exposure to the voles. Although our results revealed no biologically significant effects of vinclozolin at the population level under the conditions of our experiments, they do suggest that multiple applications or a higher application rate of a vinclozolin product may have negative effects on male reproductive development and demography in wild populations.

Effect of body size, body mass, and body condition on reproduction of female South African fur seals (Arctocephalus pusillus) in Namibia

The relationships between female reproductive parameters (fertility, pregnancy, and lactation status) and body mass, body condition, and body length in South African fur seals (Arctocephalus pusillus) were investigated over 4 years. Ovulation rate in every year was 100% despite interannual differences in female body condition index (BCI). The overall pregnancy rate was 79%. The proportion of pregnant females was related to BCI but not to body mass or body length. In good years, BCI decreased through the first part of the reproductive cycle to a minimum at implantation and increased again through pregnancy. In 1989, BCI declined over the whole reproductive cycle, and there was a higher proportion of nonpregnant females and failures of lactation. Thus, poor nutritional conditions may affect reproductive success through failure to rear a pup, and pup production the following year may also be reduced. This lower rate of pregnancy is partly explained by an increase in the incidence of spontaneous abortions, but other parameters such as a lower implantation rate are also likely to be involved.

The developmental toxicity of boric acid in rabbits.

Boric acid (BA), an ingredient of many pharmaceutical, cosmetic, and pesticide products, was previously shown to induce reproductive and developmental toxicity in laboratory rodents. In this study, BA (0, 62.5, 125, or 250 mg/kg/day, po) was administered on Gestational Days (GD) 6-19 to New Zealand White rabbits (18-23 pregnant/group). Maternal body weight, food consumption, and clinical condition were monitored at regular intervals throughout gestation. At termination (GD 30), the numbers of uterine implantations, resorptions, dead fetuses, and live fetuses were determined. Fetuses were weighed, and live fetuses examined for external, visceral, and skeletal defects. Maternal food intake decreased during treatment at 250 mg/kg/day and increased at >/=125 mg/kg/day after treatment. Maternal body weight (GD 9-30), weight gain during treatment, gravid uterine weight, and number of ovarian corpora lutea decreased at 250 mg/kg/day. In contrast, maternal corrected gestational weight gain increased at >/=125 mg/kg/day. Maternal liver weight was not affected. Relative (but not absolute) maternal kidney weight increased at 250 mg/kg/day, and microscopic evaluation revealed no treatment-related renal pathology. At 250 mg/kg/day, prenatal mortality was increased (90% resorptions/litter vs 6% for controls), the proportion of pregnant females with no live fetuses was increased (73% vs 0%), and live litter size was reduced (2.3 fetuses/litter vs 8.8). As a result, there were only 14 live fetuses (6 live litters) available for evaluation in the high-dose group, compared to 153-175 live fetuses (18-23 live litters) in the other groups. The percentage malformed fetuses/litter was increased at 250 mg/kg/day, primarily due to cardiovascular defects in 72% of high-dose fetuses vs 3% of controls. The most prevalent cardiovascular malformation (interventricular septal defect) was observed in 57% of high-dose fetuses compared to 0.6% among controls. At 250 mg/kg/day, average fetal body weight/litter was 92% of the average control weight (not statistically significant). In summary, no definitive maternal or developmental toxicity was observed at 62.5 or 125 mg/kg/day BA. Mild maternal effects and severe developmental toxicity were observed at 250 mg/kg/day.

The Developmental Toxicity of Boric Acid in Rabbits

Boric acid (BA), an ingredient of many pharmaceutical, cosmetic, and pesticide products, was previously shown to induce reproductive and developmental toxicity in laboratory rodents. In this study, BA (0, 62.5, 125, or 250 mg/kg/day, po) was administered on Gestational Days (GD) 6–19 to New Zealand White rabbits (18–23 pregnant/group). Maternal body weight, food consumption, and clinical condition were monitored at regular intervals throughout gestation. At termination (GD 30), the numbers of uterine implantations, resorptions, dead fetuses, and live fetuses were determined. Fetuses were weighed, and live fetuses examined for external, visceral, and skeletal defects. Maternal food intake decreased during treatment at 250 mg/kg/day and increased at ≥125 mg/kg/day after treatment. Maternal body weight (GD 9–30), weight gain during treatment, gravid uterine weight, and number of ovarian corpora lutea decreased at 250 mg/kg/day. In contrast, maternal corrected gestational weight gain increased at ≥125 mg/kg/day. Maternal liver weight was not affected. Relative (but not absolute) maternal kidney weight increased at 250 mg/kg/day, and microscopic evaluation revealed no treatment-related renal pathology. At 250 mg/kg/day, prenatal mortality was increased (90% resorptions/litter vs 6% for controls), the proportion of pregnant females with no live fetuses was increased (73% vs 0%), and live litter size was reduced (2.3 fetuses/litter vs 8.8). As a result, there were only 14 live fetuses (6 live litters) available for evaluation in the high-dose group, compared to 153–175 live fetuses (18–23 live litters) in the other groups. The percentage malformed fetuses/litter was increased at 250 mg/kg/day, primarily due to cardiovascular defects in 72% of high-dose fetuses vs 3% of controls. The most prevalent cardiovascular malformation (in terventricular septal defect) was observed in 57% of high-dose fetuses compared to 0.6% among controls. At 250 mg/kg/day, average fetal body weight/litter was 92% of the average control weight (not statistically significant). In summary, no definitive maternal or developmental toxicity was observed at 62.5 or 125 mg/kg/day BA. Mild maternal effects and severe developmental toxicity were observed at 250 mg/kg/day.