Superovulation, embryo recovery, and pregnancy rates from seasonally anovulatory donor mares treated with recombinant equine FSH (reFSH)

The aims of this study were to compare the embryo recovery rate in Angora goats based on application timing; at the beginning (September – October; Group 1) and end (December; Group 2) of the breeding season and to evaluate the viability and survivability of fresh or vitrified-thawed embryos when transferred. For this purpose, nine Angora goats were used as donors and thirthy Angora goats were used as recipients. Donor goats were synchronized and superovulated with traditional protocol and were mated with fertile bucks. At the 156th hour of the mating, embryos were collected surgically and evaluated under a stereo microscope. In group 1, 103 embryos and in group 2, 63 embryos were collected from nine goats. Fresh or vitrified-thawed embryos were transferred surgically to synchronized recipients. In Group 1 fresh/thawed embryos were transferred to 15/15 goats and in group 2, fresh/thawed embryos were transferred to 8/8 goats, respectively. Each recipient received 1 or 2 embryos ipsilateral to the ovary containing one or more corpora lutea. On day 30 of the transfer, goats were examined by transrectal ultrasonography, pregnancy rates of fresh/thawed embryos were 66.6%/26.6% for group 1 and 62.5%/62.5% for group 2. On day 100 of the transfer, goats were examined again by ultrasonography, and pregnancy rates were 46.6%/0% for group 1 and 37.5%/0% for group 2, respectively. After about 50 days, goats were kidded. In group 1, 3 twins and 4 single kids were born; in group 2, 2 twins were born. The total number of collected embryos and pregnancy rates among the groups were analysed using SPSS® (version 14.01, Chicago, IL, USA) and for all comparisons, differences were considered with a minimum of 5% significance level. After statistical analyses, the numbers of collected embryos at the beginning and at the end of the breeding season were compared. There was no difference in freezable/transferable embryo quality. As a result, embryos could be collected after superovulation protocols in Angora goats both at beginning and end of the breeding season, however there might be a decrease in numbers of collected embryos and the reasons for this might not be only the seasonal factors but also the environment, care, nutrition and previous superovulation protocols. The pregnancy rate following transfer of fresh embryos was satisfactory but not all does confirmed pregnant kidded; hence, reducing the number of recipients kidding. The pregnancy rate following transfer of vitrified-thawed embryos was generally low and unsatisfactory. Further research is warrented in improving the cryopreservation techniques and thus the embryo survival rate of Angora goat embryos. This study was financed with the University of Ankara Grant.

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170INFLUENCE OF FACTORS ASSOCIATED WITH EMBRYO RECOVERY AND POLICY OF TRANSFER ON PREGNANCY RATES AFTER TRANSFER OF BOVINE FRESH EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv16n1ab170 ◽

2004 ◽

Vol 16 (2) ◽

pp. 207

Author(s):

G. Bourgoin ◽

H. Quinton ◽

A. Rohou ◽

P. Humblot ◽

C. Ponsart

Keyword(s):

Embryo Quality ◽

Pregnancy Rates ◽

Data Set ◽

Paternal Origin ◽

Factors Associated ◽

Embryo Recovery ◽

Frozen Embryos ◽

Sources Of Variation ◽

Fresh Embryos ◽

Donor Cows

Success of embryo transfer (ET) is related to many well identified factors such as quality and stage of embryos, or parity of recipients. However, there are no data on the effects of factors associated with embryo recovery and ET policy (proportion of embryos transferred as fresh or frozen) on pregnancy rates (PR) after ET. A retrospective study was designed to study how these factors affect PR achieved with fresh embryos (FE). A total of 3380 embryo recovery sessions (RS) realized by Embryotop (France) between 1995 and 2002 were studied, corresponding to 14,755 transfers with FE. Forty-four RS were made with only frozen embryos and removed from data set. A total of 1716 RS involved transfer from both frozen and FE, whereas in 1620 RS all transfers were made with FE. The organization of RS was assessed by the number of operators (OP) per RS and per donor cow, the number of embryos collected per RS and per OP. The operator at RS and ET was also noted. Embryo characteristics such as stage and quality (according to IETS criteria), paternal origin, and breed of donor cow were recorded together with the breed, date of ET and parity of recipients. The association between each variable and PR was analyzed by Chi-square. Only the significant factors were considered for further analysis (P<0.05) and introduced with a stepwise procedure in a multivariate model of logistic regression to calculate adjusted odds ratio (OR). The number of RS was stable among years (463 to 493), whereas the number of embryos collected increased by 10% from 1995 to 2002. For 681 RS (20.4%), more than one donor cow were used for collection. Mean number of donor cows per RS and OP increased from 1.16 in 1995 to 1.34 in 2002. The mean number of transfers of FE per RS and OP was quite stable (3.82 in 1995 to 4.16 in 2002). This was explained by the increase in the number of frozen embryos per OP, averaging 1.99 in 1995 and 4.14 in 2002. The proportion of RS with only transfers of FE decreased by 20 points from 1995 (57%) to 2002 (36%). The number of transfers of FE per RS and OP was highly variable, ranging from 0 to 26. PR with FE averaged 52.1% and were significantly influenced by the number of donor cows per OP, operator of RS, embryo quality and paternal origin as well as recipient parity. Transfer of FE collected in RS with one donor cow resulted in higher PR than when more than one cow (53.0% v. 49.9%, OR=1.12, P=0.003). This could be partly explained by a higher mean number of transfers per RS and OP (1 donor cow=3.7±2.0 v.>1=5.3±3.1; P<0.05) as well as a higher proportion of RS with only FE transferred (1 donor cow=51.2% v.>1=38.5% ; P<0.05). Although the embryo quality was lower in RS combining ET of both frozen and FE than when only FE were transferred, these effects were not related to the lower quality of FE used in RS involving more than 1 donor cow (1 donor cow=1.74±0.50 v.>1=1.75±0.44; P>0.05), but may be explained by a longer time between embryo recovery and ET. After adjustment for the usually well identified sources of variation of PR, the conditions of RS as well as ET policy (leading to the selection of the best embryos for transfer as frozen and to influence on the quantity of work per OP) can significantly influence PR. These sources of variation should be taken into account when analyzing PR results.

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77 PREGNANCY RATES AFTER VITRIFICATION OF FRESH AND COOLED EQUINE EMBRYOS USING THE CRYOTOP METHOD

Reproduction Fertility and Development ◽

10.1071/rdv23n1ab77 ◽

2011 ◽

Vol 23 (1) ◽

pp. 144

Author(s):

C. Baca Castex ◽

G. Dalvit ◽

M. Miragaya ◽

A. Alonso ◽

M. Pinto ◽

...

Keyword(s):

Pregnancy Rate ◽

Pregnancy Rates ◽

Glass Capillary ◽

Routine Procedure ◽

Embryo Recovery ◽

Advanced Stages ◽

Vitrification Solution ◽

Almost All ◽

Cryopreservation Protocol ◽

Fresh Embryos

Cryopreservation of equine embryos is still not a routine procedure. Pregnancies have been obtained after transfer of vitrified embryos of less than 300 μm (Eldridge-Panuska et al. 2005). The aim of this study was to use the cryotop method (Kuwayama, 2007) to obtain pregnancies after transfer of vitrified thawed cooled and fresh embryos collected in our clinical embryo transfer programme. Embryos were assigned either to be vitrified within 3 h of collection or to be cooled for 18–24 h before vitrification. All embryos were vitrified and thawed by Cryotop Vitrification Kit® (Cryo Tech Laboratory®). Briefly, they were equilibrated in a solution containing ethylene glycol (EG), dimethylsulphoxide (DMSO) in TCM-199 for 10 to 25 min. Then they were moved to vitrification solution containing EG, DMSO, and sucrose in TCM-199 and loaded with a glass capillary onto the top of the film strip. After loading, almost all the solution was removed to leave only a thin layer covering the embryo, and the sample was quickly immersed into liquid nitrogen and covered with a protective cap. The time between entry to vitrification solution and nitrogen was from 1 to 3 min. At warming, the strip was immersed directly for 1 min into a 37°C medium containing sucrose in TCM-199. The embryo was incubated 3 min in a diluent solution, washed twice 5 min each in washing solution, and further cultured in DMEM F-12 with 10% FBS at 38.5°C 5% CO2 between 2 to 5 h. For transfer, the embryo was loaded in 0.5-mL straws. All recipient mares had ovulated 4 to 7 days before nonsurgical transfer. Pregnancies were detected 6 to 8 days later. A total of 15 embryos, grades 1 to 2, were obtained. Fresh embryos (n = 7) ranged between 250 and 800 μm, and refrigerated embryo (n = 8) diameter was between 130 and 550 μm. Pregnancy rates were 37.5% (3/8) for embryos cooled before vitrification and 28.6% (2/7) for embryos vitrified within 3 h. The overall pregnancy rate was 33.3% (5/15). Shipping cooled embryos allows maintaining a large number of recipients far away from donors, without decreasing pregnancy rate. It also makes it possible to send embryos to a specialised laboratory in order to be vitrified and preserved until recipients are available. Equine embryos collected 6 days after ovulation are generally smaller than 300 μm and have shown the highest survival rate after cryopreservation. However, the embryo recovery rate is higher when flushing is performed at Day 7 or 8. This cryopreservation protocol could provide a way to vitrify fresh and cooled embryos up to 550 μm, which would prevent the loss of valuable embryos collected in more advanced stages of development. In summary, pregnancies can be obtained after cooling for 18 to 24 h and vitrification of embryos collected 7 or 7.5 days after.

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Smoking During Pregnancy--Rates Drop Steadily in the 1990's, but among Teen Mothers Progress Has Stalled

PsycEXTRA Dataset ◽

10.1037/e480072006-001 ◽

2001 ◽

Author(s):

Keyword(s):

Pregnancy Rates ◽

Teen Mothers ◽

Smoking During Pregnancy

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Trends in Pregnancy Rates for the United States, 1976-97: An Update

PsycEXTRA Dataset ◽

10.1037/e509572006-001 ◽

2001 ◽

Cited By ~ 5

Author(s):

Stephanie J. Ventura ◽

William D. Mosher ◽

Sally C. Curtin ◽

Joyce C. Abma ◽

Stanley Henshaw

Keyword(s):

United States ◽

The United States ◽

Pregnancy Rates ◽

In Pregnancy

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EC On Hand Failed to Cut Pregnancy Rates

Family Practice News ◽

10.1016/s0300-7073(10)70474-6 ◽

2010 ◽

Vol 40 (6) ◽

pp. 39

Author(s):

SHARON WORCESTER

Keyword(s):

Pregnancy Rates

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Hormonal stimulation and some risk factors studied to improve bovine pregnancy rate at the Coastal areas of Barisal district of Bangladesh

Bangladesh Veterinary Journal ◽

10.32856/bvj-2018.030 ◽

2018 ◽

Vol 52 (1-4) ◽

pp. 22-30

Author(s):

A K Paul ◽

S M T Rahman

Keyword(s):

Pregnancy Rate ◽

Coastal Region ◽

Hormonal Treatment ◽

Coastal Areas ◽

Pregnancy Rates ◽

Hormonal Stimulation ◽

Crossbred Cows ◽

Treatment Groups ◽

History Of ◽

Group A

Hormonal treatment of cows at the coastal region of Barisal district of Bangladesh was performed to assess the improvement of pregnancy rate. A total of 100 cows and heifers with irregular history of cyclicity were selected randomly and divided into five treatment groups. The groups were A (treated with anthelmintic), B (treated with anthelmintic, vitamin ADE and multivitamin powder), C (treated with PGF2α), D (treated with GnRH) and E (treated with GnRH and PGF2α). Each group comprised of 20 animals. The age, breed and parity of experimental cows were considered during treatment. In the study, the cows treated with both GnRH and PGF2α (group E) showed significantly (p<0.05) higher estrus (80%) and pregnancy rate (60%) than that of group A, B, C and D. The overall estrus rates of local and crossbred cows were 64% and 70%, respectively and the pregnancy rates were 40 and 52%, respectively. The crossbred cows responded significantly (p<0.05) to hormonal treatment than that of local cows. Parity-2 cows showed higher estrus sign than that of other parities. However, the pregnancy rates were higher significantly (p<0.05) in parity-2 and parity ≥4 cows than that of parity-0, parity-1 and parity-3 cows. The pregnancy rate was also found higher in case of 4 to <5 years old cows than that of 2 to <3, 3 to <4, 5 to <6, and ≥6 years old. It may conclude that the hormonal regimen increases the pregnancy rate as well as decreases the undesired waiting of estrus and conception. Further study with more sample size will reveal the more effective treatment for cows at the coastal areas of Bangladesh.

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