5 Heat stress during pregnancy compromises intrauterine development and reproductive parameters of female progeny in C57BL/6J mice

2021 ◽  
Vol 33 (2) ◽  
pp. 110
Author(s):  
T. F. M. Bento ◽  
J. R. N. da Silva ◽  
J. M. G. Souza-Fabjan ◽  
R. C. Silva ◽  
S. B. Silva ◽  
...  
Keyword(s):  
Heat Stress ◽  
Pregnancy Rate ◽  
Chorionic Gonadotrophin ◽  
Reproductive Capacity ◽  
Oocyte Nucleus ◽  
Reproductive Parameters ◽  
Intrauterine Development ◽  
Population Total ◽  
Primordial Follicles ◽  
Somatic Development

Heat stress (HS) affects the reproduction of many species, causing subfertility by reducing gametogenesis. This study assessed the effect of HS at different stages of pregnancy in C57BL/6J mice on the somatic development and reproductive parameters of F1 females. A total of 40 females and 40 males aged between 5 and 6 weeks old were mated (1:1). After mating confirmation (vaginal plug presence) the females were subjected to HS during pregnancy in the first half (FP, from Day 1 to 10; n=10), the second half (SP, from Day 11 to delivery; n=10), or the total pregnancy (TP, n=10). A control group (C, n=10) was maintained in normothermic conditions (25°C, 45% relative humidity) throughout the experiment. The HS was induced (41°C for 2h daily) in an environmental chamber heated by 2 red lamps. After delivery, birthweight was recorded and somatic development of the F1 females was monitored weekly until 8 weeks of age. They were superovulated with 5IU of equine chorionic gonadotrophin (eCG) and 5IU of human chorionic gonadotrophin (hCG) 48h later and mated with control F1 males in four groups: FP×C; SP×C; TP×C; and C×C, female and male, respectively. At 72h after mating confirmation, uterine flushing was performed with 0.5mL of phosphate-buffered saline + 0.4% bovine serum albumin and embryos classified. Ovaries were collected for histological analysis of the follicular population with the formula: follicles per ovary×n section×section thickness/n section observed×average diameter of the oocyte nucleus. Pregnancy rate was analysed by chi-squared test. Data of pups born per female, birthweight, somatic development, follicular population, total and viable structures recovered by female were tested for normality by the Shapiro-Wilk test, before ANOVA and Tukey test. Values of P<0.05 were considered to indicate a difference and P<0.10a tendency. No difference (P>0.05) among groups was detected in pregnancy rate (C=80; FP=40; SP=60; TP=60%) or in the number of pups born per female (C=7.0±1.0; FP=6.0±1.5; SP=6.5±1.5; TP=5.1±1.5). Birthweight was lower (P<0.05) for FP (1.1g) and TP (1.2g) than for C (2.2g) and SP (1.8g). However, this difference disappeared (P>0.05) in the third week of development and remained similar until the eighth week (C=21.0; FP=20.4, SP=20.3, TP=20.0g). Similar (P>0.05) follicular population by ovary (total, primordial, primary, secondary, and antral) was observed between the C and HS groups. However, among HS groups, the total number of follicles and number of primordial follicles, respectively, were lower (P<0.05) in the FP (1623; 942) compared with SP (2735; 1918) and TP (2626; 2352); with no difference in primary, secondary, and antral follicles. This resulted in similar (P>0.05) total number of structures recovered by females (C=11.8±5.0, FP=7.6±2.4, SP=10.8±5.5, TP=6.9±3.1), with a tendency (P=0.06) to fewer viable embryos in TP (4.3±2.7) compared with C (9.5±4.6). Considering the increasing global temperature, it is imperative to understand the effects of HS on animal reproductive capacity. In conclusion, gestational HS impaired mice intrauterine development and changed the ovarian follicular population in the F1 generation.

scholarly journals Dose-response effects of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) on early embryonic development and viable pregnancy rate in rats

Reproduction ◽  
2001 ◽  
pp. 283-287 ◽  
Author(s):  
CF Tain ◽  
HH Goh ◽  
SC Ng
Keyword(s):  
Embryonic Development ◽  
Pregnancy Rate ◽  
Dose Response ◽  
Early Embryo ◽  
Chorionic Gonadotrophin ◽  
Early Embryonic Development ◽  
Embryo Yield ◽  
Female Wistar Rats ◽  
High Doses

The present study examined the dose-response effects of eCG treatment alone and in combination with various doses of hCG on early embryonic development in vivo and viable pregnancy rate in rats. Mated female Wistar rats were treated with eCG alone (0, 10, 20 or 40 iu), or with 20 iu eCG in combination with various doses of hCG (10, 20, 40 or 80 iu) administered 48 h later. The animals were killed on days 2, 3, 4, 5 or 14 of pregnancy and the numbers of embryos and fetuses recovered were scored. All rats treated with 0 or 10 iu eCG were pregnant. The pregnancy rate was reduced from 62.5% on day 2 to 25% on day 14 and from 31% on day 2 to 10% on day 14 in the groups treated with 20 and 40 iu eCG, respectively. The reduction in pregnancy rate induced by 20 iu eCG was negated by the increasing doses of hCG used. A 100% pregnancy rate was noted on days 2 and 3 in the groups treated with doses of hCG between 10 and 80 iu and from day 2 to day 4 in the groups treated with doses of hCG between 20 and 80 iu. However, a higher viable pregnancy rate was observed only in the group treated with 10 iu hCG compared with the group treated with 20 iu eCG and 0 iu hCG. These results imply that hyperstimulation of rats with high doses of eCG compromises pregnancy rate and markedly reduces litter size and that the addition of hCG is required for complete ovulation, which results in higher embryo yield and a delay in early embryo demise.

Reproductive change in the 10-year cycle of snowshoe hares

1979 ◽  
Vol 57 (2) ◽  
pp. 375-390 ◽  
Author(s):  
John R. Cary ◽  
Lloyd B. Keith
Keyword(s):  
Pregnancy Rate ◽  
Litter Size ◽  
Weight Change ◽  
Ovulation Rate ◽  
Population Cycle ◽  
Snowshoe Hare ◽  
Cyclic Variation ◽  
Reproductive Parameters ◽  
Snowshoe Hares ◽  
Hare Population

Reproduction was monitored during a 16-year study of snowshoe hare (Lepus americanus) populations near Rochester, Alberta. Pregnancy rate, ovulation rate, and litter size changed markedly between successive litters within the breeding season; these parameters were thus further categorized by litter in our analyses. Most reproductive components varied significantly between years; a significant '10-year' periodicity was the dominant source of this variation. The cyclic fluctuations of reproductive parameters were broadly synchronous and tended to precede the population cycle by about 3 years, thereby producing a range in potential natality annually of 7.5 to 17.9 young per female. The year-to-year variability of pregnancy rate, ovulation rate, and litter size was markedly larger in the later litters than in the early ones. Paunched weight, mean age, incidence of endoparasites, liver and spleen weights, and midwinter-to-spring weight change also possessed significant 10-year cycles; paunched weight cycled directly with the hare population, but the others cycled either directly with or counter to reproduction. We believe that the correspondence between midwinter-to-spring weight change and reproduction implicates winter nutrition as the primary cause of the cyclic variation. Onset of spring accounted for a significant amount of variability in onset of breeding, adding to that due to the periodic change.

A new way to estimate the age of bowhead whales (Balaena mysticetus) using ovarian corpora counts

2011 ◽  
Vol 89 (9) ◽  
pp. 840-852 ◽  
Author(s):  
J.C. George ◽  
E. Follmann ◽  
J. Zeh ◽  
M. Sousa ◽  
R. Tarpley ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Sexual Maturity ◽  
Standard Errors ◽  
Reproductive Parameters ◽  
Balaena Mysticetus ◽  
Bowhead Whales ◽  
Aspartic Acid Racemization ◽  
Sexually Mature ◽  
Age Estimates

We used lengths and reproductive data for bowhead whales ( Balaena mysticetus L., 1758) harvested by Alaskan Eskimos to estimate female reproductive parameters and age. Data from 117 females determined that 75 were sexually mature and 42 were immature. Estimated length at sexual maturity was 13.35 m. Counts of ovarian corpora were obtained from 50 mature females. Corpora and baleen data were used with aspartic acid racemization (AAR) data to obtain estimated age at sexual maturity (ASM) at ≈26 years. The number of corpora counted in both ovaries (or estimated when only one ovary was counted) was used with ASM and estimated ovulation rate (OR) to obtain corpora age estimates ranging from 26 to 149 years. A stone harpoon tip recovered from whale 92B2 was consistent with her corpora age of 133 years. The correlation between corpora and AAR age estimates was 0.77. Estimated standard errors of corpora ages tended to be somewhat higher than those for comparable AAR ages. A sample of potentially mature females examined for maturity and presence of a corpus luteum and (or) fetus provided an OR value of 0.332·year–1 and an estimated pregnancy rate of 0.326·year–1, implying intervals between ovulations and pregnancies of 3.0 and 3.1 years.

scholarly journals Effects of in utero heat stress on subsequent reproduction performance of first-calf Holstein heifers

2020 ◽  
Vol 18 (2) ◽  
pp. e0404
Author(s):  
María I. Chavez ◽  
José E. García ◽  
Francisco G. Véliz ◽  
Leticia R. Gaytán ◽  
Ángeles De Santiago ◽  
...  
Keyword(s):  
Heat Stress ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Fold Increase ◽  
In Utero ◽  
Northern Mexico ◽  
Reproduction Performance ◽  
In Pregnancy

Aim of study: To determine the reproductive performance of heifers gestated under maternal conditions of heat stress in late gestation.Area of study: Northern Mexico (25° 32’ N, 103° 23’ W).Material and methods: The study included reproductive records of 4976 first-calf Holstein heifers in a hot environment.Main results: Heifers born to cows experiencing no heat stress three months before parturition but with a THI >83 at calving were older (p<0.05) at first calving (743 ± 67 vs. 729 ± 55 days) than heifers gestated under maternal conditions of heat stress. A two-fold increase (p<0.01) in pregnancy rate occurred in heifers gestated under maternal conditions of no heat stress during two or three months before pregnancy and no heat stress at parturition, compared with heifers gestated under maternal conditions of no heat stress. Overall, across in utero heat stress one, two or three months before calving, pregnancy rate to all services was higher (p<0.05) for first-calf heifers gestated under maternal conditions of no heat stress during delivery, compared with heifers gestated under maternal conditions of heat stress (66.7 vs. 51.1%). Median days for getting pregnant was higher (140 d) for heifers whose dams were exposed to THI >83 at calving than heifers whose mothers were exposed to <76 or 76-83 (117 and 114 d) at calving.Research highlights: These data suggest that in utero heat stress during the last three months of gestation negatively affects the reproductive performance of first-calf Holstein heifers.

scholarly journals Reproductive capacity and recurrence of disease after surgery for moderate and severe endometriosis – a retrospective single center analysis

2020 ◽  
Author(s):  
Cordula Schippert ◽  
Yvonne Witte ◽  
Janina Bartels ◽  
Guillermo-José Garcia-Rocha ◽  
Matthias Jentschke ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Pregnancy Rate ◽  
Logistic Regression Analysis ◽  
Stage Iv ◽  
Hormonal Treatment ◽  
Reproductive Capacity ◽  
Stage Iii ◽  
Partial Relief ◽  
Endometriosis Surgery

Abstract Background: Endometriosis can be associated with considerable pain and sterility. After surgical excision of moderate or severe endometriosis lesions, the rate of recurrence reaches up to 67%. The objective of this retrospective study was to establish the recurrence and pregnancy rates following surgical resection of stage III/IV endometriosis lesions. Indications for operation were endometriosis symptoms, sonographic findings and/or infertility. Methods : A total of 456 patients who underwent stage III/IV endometriosis surgery between 2004 and 2014 were sent a questionnaire relating to their postoperative medical treatment, pregnancies, relief of symptoms and recurrence. Responses of 206 patients (45.2%) and their clinical data were analysed for this study. Results : A total of 66.5% (N=137) of patients had stage III disease, and 33.5% (N=69) had stage IV disease. The average age was 37 years (17-59). A total of 63.1% (N=130) of surgeries were performed by laparoscopy, 21.8% (N=45) were performed by laparotomy and 15% (N=31) were performed by conversion. Complete resection of endometriosis lesions was achieved in 90.8% of patients (N=187). After surgery, 48.5% (N=100) of the women did not receive hormonal treatment; the main reason was the desire for children in 53%. Complete or partial relief in complaints was achieved in 93.2% (N=192). The rate of recurrence was 21.8% (N=45). The statistically significant factors that was associated with a higher risk to develop recurrence was an age <35 (p<0.005).After surgery, 65.8% (79/120) of patients who wished to have children became pregnant. There was a statistically significant association among a higher postoperative pregnancy rate and age <35 (p<0.003) in multivariante logistic regression analysis and laparoscopic surgical access in univariante logistic regression analysis (p<0.01). Conclusion: We assessed the high percentage of complete or partial relief of symptoms of 93.2%, the high postoperative pregnancy rate of 65.8% and the low rate of recurrence of 21.8% compared to international literature to be very encouraging for women suffering from moderate and severe endometriosis. Though laparoscopy is considered the ´gold standard` of endometriosis surgery, laparotomy still may be indicated in patients with extensive endometriosis especially to preserve reproductive function.

scholarly journals Current Understandings of Core Pathways for the Activation of Mammalian Primordial Follicles

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1491
Author(s):  
Yu Zhao ◽  
Haiwei Feng ◽  
Yihui Zhang ◽  
Jian V. Zhang ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Current Knowledge ◽  
Primordial Follicle ◽  
Reproductive Capacity ◽  
Molecular Networks ◽  
Female Reproduction ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Follicle Activation

The mammalian ovary has two main functions—producing mature oocytes for fertilization and secreting hormones for maintaining the ovarian endocrine functions. Both functions are vital for female reproduction. Primordial follicles are composed of flattened pre-granulosa cells and a primary oocyte, and activation of primordial follicles is the first step in follicular development and is the key factor in determining the reproductive capacity of females. The recent identification of the phosphatidylinositol 3 kinase (PI3K)/phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signaling pathway as the key controller for follicular activation has made the study of primordial follicle activation a hot research topic in the field of reproduction. This review systematically summarizes the roles of the PI3K/PTEN signaling pathway in primordial follicle activation and discusses how the pathway interacts with various other molecular networks to control follicular activation. Studies on the activation of primordial follicles have led to the development of methods for the in vitro activation of primordial follicles as a treatment for infertility in women with premature ovarian insufficiency or poor ovarian response, and these are also discussed along with some practical applications of our current knowledge of follicular activation.

scholarly journals Effect of high doses of equine chorionic gonadotrophin (eCG) treatments on follicular developments, ovulation and pregnancy rate in boer goats

2014 ◽  
Vol 13 (12) ◽  
pp. 1374-1378 ◽  
Author(s):  
Shuib Mohamad Mohtar Mohamad ◽  
Wahid Haron Abd ◽  
Yusoff Rosnina ◽  
Zuki Abu Bakar Md ◽  
Malik Abdul
Keyword(s):  
Pregnancy Rate ◽  
Chorionic Gonadotrophin ◽  
High Doses ◽  
Boer Goats

Association between heat stress during intrauterine development and the calving-to-conception and calving-to-first-service intervals in Holstein cows

2021 ◽  
Author(s):  
Sebastián Recce ◽  
Emilia Huber ◽  
Ulises S. Notaro ◽  
Fernanda M. Rodríguez ◽  
Hugo H. Ortega ◽  
...  
Keyword(s):  
Heat Stress ◽  
Holstein Cows ◽  
Intrauterine Development

scholarly journals PSVII-20 Heat stress alters reproductive phenotypic impacts of Zearalenone in pre-pubertal gilts

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 214-214
Author(s):  
Crystal M Roach ◽  
Edith J Mayorga ◽  
Jason W Ross ◽  
Lance H Baumgard ◽  
Aileen F Keating
Keyword(s):  
Heat Stress ◽  
Heat Dissipation ◽  
Reproductive Toxicity ◽  
Delayed Puberty ◽  
Reproductive Parameters ◽  
Heat Accumulation ◽  
Estrous Cycles ◽  
Ovarian Weight ◽  
Treatment Groups ◽  
Puberty Onset

Abstract Zearalenone (ZEA) is an estrogenic mycotoxin produced by strains of Fusarium and is often inadvertently consumed via feed contamination. Heat stress (HS) occurs when heat accumulation exceeds heat dissipation resulting in increased body temperature. Independently, HS and ZEA cause swine reproductive dysfunction such as delayed puberty onset, altered circulating steroid hormones and irregular estrous cycles. During HS, gilts become hyperinsulinemic and insulin regulates hepatic and ovarian chemical metabolism. We hypothesized that during HS, ZEA-induced alterations to reproductive parameters are heightened such that HS is additive to ZEA-induced reproductive toxicity. Prepubertal crossbred gilts (n = 38) were randomly assigned to six treatment groups: thermal neutral (TN) ad libitum fed controls (TNCT; n = 6); TN + ZEA (2 ppm; TNZ; n = 6); pair-fed (PF) control (PFCT; n = 6); PF + ZEA (2 ppm; PFZ; n = 6); cyclical HS control (HSCT; n = 7); and HS + ZEA (2 ppm; HSZ; n = 7) for 7 d. Ovarian and uterine weights (g) were measured, and nipple and vulva diameters (l × w; mm2) were assessed by digital calipers. Ovarian weight was decreased (P = 0.04) in the PFZ relative to PFCT, but ZEA did not affect ovarian weight in the other groups (P &gt; 0.73). There was no impact of ZEA exposure on uterine weight (P &gt; 0.22) or nipple diameter (P &gt; 0.51) in any treatment groups, respectively. There was no effect of ZEA on vulva size in either of the TN groups; however, vulva diameter increased (P = 0.04) in the HSZ relative to HSCT. These data suggest that HS exaggerates some ZEA-induced phenotypic effects in prepubertal gilts. This project was supported by the Iowa Pork Producers Association.

Sign in / Sign up

Export Citation Format

Share Document