scholarly journals Placental histopathology in IVF pregnancies resulting from the transfer of frozen-thawed embryos compared with fresh embryos

2020 ◽  
Vol 37 (5) ◽  
pp. 1155-1162 ◽  
Author(s):  
Yossi Mizrachi ◽  
Ariel Weissman ◽  
Gili Buchnik Fater ◽  
Maya Torem ◽  
Eran Horowitz ◽  
...  
Keyword(s):  
Fresh Embryos

scholarly journals Why we should transfer frozen instead of fresh embryos: the translational rationale

2014 ◽  
Vol 102 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Rachel Weinerman ◽  
Monica Mainigi
Keyword(s):  
Fresh Embryos

scholarly journals Conception rate after sex determination and cryopreservation of D7 bovine embryos:

2010 ◽  
Vol 55 (No. 1) ◽  
pp. 10-18 ◽  
Author(s):  
M. Lopatarova ◽  
S. Cech ◽  
P. Krontorad ◽  
L. Holy ◽  
H. Lalova ◽  
...  
Keyword(s):  
Sex Determination ◽  
Conception Rate ◽  
Embryonic Cells ◽  
Bovine Embryos ◽  
High Quality ◽  
Specific Primers ◽  
Transfer Programs ◽  
Commercial Exchange ◽  
Fresh Embryos ◽  
Fresh Transfer

The aim of this study was to evaluate conception rate after sex determination and subsequent freezing of Day 7 (D<sub>7</sub>) bovine embryos and to compare it with transfer of fresh female embryos. High quality embryos obtained from superovulated donors were biopsied and the embryonic cells (5–10) were analysed by PCR using specific primers for the Y-chromosome determinant. Fresh embryos were blade biopsied (<I>n</I> = 172) and subsequently transferred (ET) ipsilaterally to synchronized recipients. Selected embryos (<I>n</I>= 112) were biopsied by cell aspiration and cryopreserved for later transfer. Sex determination was successfully completed in 91.3% of fresh group embryos (44% female) and in 87.5% of freeze-thawed group embryos (45.9% female). The achieved pregnancy rate was 56.5% after fresh transfer of sexed (female) embryos whereas intact embryos (control 1) implanted in 61.9% recipients. 95.6% (43/45) of embryos survived biopsy and cryopreservation. After transfer of freeze-thawed sexed (female) embryos, pregnancy was established in 48.8% of recipients. A similar conception rate was found in intact embryos (50.7%, control 2). The results clearly demonstrate that the microsurgical technique used and subsequent PCR sex analysis allow the rapid commercial exchange of genetic resources on the basis of fresh or frozen sex-desired embryos in embryo transfer programs.

191 INFLUENCE OF THE DIFFERENT TIME COMPONENTS BETWEEN FLUSHING AND TRANSFER ON PREGNANCY RATES OF FROZEN CATTLE EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 203
Author(s):  
C. Ponsart ◽  
H. Quinton ◽  
A. Rohou ◽  
J. Kelhembo ◽  
G. Bourgoin ◽  
...  
Keyword(s):  
Pregnancy Rates ◽  
Chi Square ◽  
Frozen Embryos ◽  
Multivariate Logistic Model ◽  
Parity Number ◽  
Embryo Stage ◽  
Chi Square Analysis ◽  
Fresh Embryos ◽  
Donor Cows

Previous studies have shown that the time between flushing and freezing of bovine embryos can influence pregnancy rates (PRs) following embryo transfer (ET). The aim of this study was to determine which time components can influence ET results. Time components between flushing of a superovulated donor and freezing of the collected embryos were investigated under field conditions. Embryos were frozen in 1.5 M ethylene glycol (EG) for direct transfer. During January 2003, ET technicians (EmbryoTop, Rennes cedex, France) recorded systematically times corresponding to each step comprising the time spent in vitro (TIV) from 153 recovery sessions (RS) with freezing: end of flushing, beginning and end of search of embryos, start of equilibration in EG, beginning and end of straw loading, introduction to −7°C in the freezer, and seeding. Numbers of donor cows and ET technicians doing the freezing (n = 5) were noted for each RS. Embryo (stage, quality) and recipient (breed, parity) characteristics were also noted. A total of 548 frozen embryos were transferred and PRs were assessed. Variability of time components was investigated (Bourgoin et al. 2004 Reprod. Fertil. Dev. 16, 207). The influence of time components and other variation factors was tested on PRs (t-tests and chi-square analysis). The TIV averaged 210 ± 80 min and did not influence PR (≤4 h = 51.9% (n = 393) vs. >4 h = 55.5% (n = 155); P > 0.05), as well as duration of flushing (32 ± 8 min), interval between end of flushing and search (31 ± 27 min), duration of search (45 ± 25 min) and interval between end of search and beginning of freezing (101 ± 63 min). Only significant factors were kept for further analysis. The effects of recipient parity, number of donor cows per RS, and interval between introduction of straw to −7°C, and seeding were tested in a multivariate logistic model. PR varied strongly with parity of recipient (+25% in heifers vs. cows; P = 0.001). PRs were higher when the interval between straw introduction in the freezer and seeding lasted at least 5 min (2–4 min = 48.0% (n = 254) vs. 5–8 min = 57.1% (n = 294); P = 0.009). Time and operator effects were confounded. Overall PR results for the two technicians who used mostly 2–4 min intervals averaged 47% (operator values = 35.6, 48.9, and 54.5) whereas PRs were 54.9 and 60.5% for those waiting 5 min or more before inducing seeding (n = 2). PRs were higher when at least two donor cows were collected per RS (1 donor cow = 49% (n = 259) vs. ≥2 donor cows = 56.4% (n = 289); P = 0.003). This was not in agreement with previous observations in fresh embryos (Bourgoin et al. 2004). However, the number of donor cows strongly influenced the number of viable embryos per RS (1 donor cow = 11 ± 5 vs. ≥2 donor cows = 18 ± 8.5; P < 0.05) and could permit the choice of more embryos to be frozen. These results show that good PR may be achieved with a delay of several hours between flushing and freezing, when heifers are used as recipients. Moreover, confirmed from higher numbers of operators, these data show that it is better to wait at least 5 min to achieve equilibration of the embryo before seeding.

289 EFFECTS OF YEAR PERIOD, TECHNICAL TEAM, AND BREED ON THE PREGNANCY RATES AFTER TRANSFER OF IVF BOVINE EMBRYOS IN THE SOUTHERN REGION OF RIO DE JANEIRO

2010 ◽  
Vol 22 (1) ◽  
pp. 301
Author(s):  
B. G. Moura ◽  
J. Almeida ◽  
F. L. Lima ◽  
G. Balbi ◽  
R. Calmerani ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Dairy Cattle ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Chi Square Test ◽  
Few Data ◽  
Rectal Palpation ◽  
Fresh Embryos

The aim of the work was to study the effects of year period, technical team, breed, beef cattle and dairy cattle on the pregnancy rates in fresh embryos used in bovine transfer of IVF programs. The study was carried out at the fertilization laboratory In Vitro Nyltta Britto de Carvalho, in partnership with In Vitro Brazil, located at the Boa Vista farm, Barra do Pirai, during August 2007 to September 2008, seeking subsidies to improve the use of the technique in the field. During that period, aspirations and inovulations in 3 different periods I (August to December), II (January to April), and III (May to September) were carried out. The jobs were accomplished by 9 technical teams (A, B, C, D, E, F, G, H, and I) rendering services to the laboratory, by working with 2 beef breeds (Brahman and Nelore) and 3 dairy breeds (Gir, Girolando, and Holstein). The different breed receivers were synchronized, and in general, from 6 to 8 days after heat, they received embryo transfer, the cervical way, under low epidural anesthesia, where each female received 1 fresh embryo of IVF. All cows were submitted to gestation diagnosis by rectal palpation and ultrasonography, in general, 42 days after embryo transfer. The numbers of embryo transferred and pregnancy rates were submitted to the chi-square test, which presented significant differences (P < 0.05). There were pregnancy rates of 36.25%a (n = 960), 39.83%a (n = 1180), and 32.59%b (n = 919) in the I, II, and III periods, respectively. Among the 9 technical teams, there were verified pregnancy rates (%) of 33.51d (n = 1313), 30.30d (n = 330), 35.00cd (n = 405), 39.24cd (n = 1060), 59.25a (n = 7), 33.33d (n = 24), 53.57bc (n = 28), 43.31c (n = 157), and 58.33ab (n = 12) for A, B, C, D, E, F, G, H, and I teams, respectively. Among breeds there were rates (%) of 36.89ab (n = 412), 34.68b (n = 1286), 35.13ab (n = 74), 38.94a (n = 1140), and 37.80ab (n = 82) for Brahman, Nelore, Gir, Girolando, and Holstein, respectively. In the study, pregnancy rates (%) of 35.21b (n = 1698) in beef cattle and 38.65a (n = 1296) in dairy cattle were observed. The differences in pregnancy rates with respect to the evaluated factors, may be explained by individual, breed, and nutritional variations of the animals. There are few data in the literature with results on the embryo transfer use of IVF bovine under field conditions.

144 USE OF A NOVEL BOVINE EMBRYO CULTURE MEDIUM TO IMPROVE BLASTOCYST DEVELOPMENT AND SURVIVAL FOLLOWING VITRIFICATION

2010 ◽  
Vol 22 (1) ◽  
pp. 231
Author(s):  
J. Block ◽  
L. Bonilla ◽  
P. J. Hansen
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Essential Amino Acids ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Fresh Embryos ◽  
Hatching Rates

The objective of the present study was to determine whether culture of bovine embryos in a proprietary serum-free culture medium, Block-Bonilla-Hansen-7 (BBH-7), could improve development to the blastocyst stage and enhance survival following vitrification. For Exp. 1, embryos were produced in vitro and cultured in BBH-7 or modified synthetic oviductal fluid (mSOF; as in zygote 10:341 except with 10 μL mL-1 of nonessential amino acids, 20 μL mL-1 of essential amino acids, and 1 mg mL-1 of polyvinyl alcohol instead of albumin) in 5% (v/v) oxygen. Grade 1 expanded blastocysts were harvested at Day 7 post-insemination and vitrified using the open-pulled straw method (Vagta et al. 1998 Mol. Reprod. Dev. 51, 53-58). Vitrified embryos were thawed and cultured in vitro in either mSOF or BBH-7 supplemented with 10% fetal bovine serum and 50 μM dithiolthreitol. Re-expansion and hatching rates were recorded at 24, 48, and 72 h post-thaw. There was no effect of culture medium on cleavage rate. The proportion of oocytes that developed to the blastocyst and advanced blastocyst stages (expanded, hatching, and hatched) at Day 7 was higher (P < 0.001) for embryos cultured in BBH-7 than for embryos cultured in mSOF (41.9 ± 2.0 v. 14.7 ± 2.0% and 31.1 ± 1.3 v. 6.4 ± 1.3%, respectively). There was no effect of culture medium on re-expansion rates at 24, 48, and 72 h post-thaw or on hatching rates at 48 or 72 h. However, the proportion of embryos that were hatching or had hatched by 24 h post-thaw was higher (P < 0.001) for BBH-7 than for mSOF (59.0 ± 0.5 v. 26.7 ± 0.5%). For Exp. 2, late lactation and/or repeat breeder, lactating Holstein cows were synchronized for timed embryo transfer using the OvSynch-56 protocol. Embryos were produced in vitro and cultured in BBH-7 in 5% (v/v) oxygen. Vitrified embryos were produced as for Exp. 1. Fresh embryos were grade 1 expanded blastocysts harvested at Day 7 after insemination. A single embryo was transferred at Day 7 after putative ovulation to all cows with a corpus luteum confirmed by ultrasonography. Pregnancy was diagnosed at Day 28-30 of gestation by ultrasonography. There was no difference in the proportion of recipients that became pregnant after receiving either a fresh (7/18 = 39%) or vitrified (10/27 = 37%) embryo cultured in BBH-7. The results of the present study indicate that BBH-7 can be used to increase the proportion of oocytes that develop to the blastocyst stage. Moreover, the results demonstrate that vitrified embryos produced after culture in BBH-7 can achieve pregnancy rates similar to those obtained using fresh embryos. Support: USDA 2006-55203-17390 and Southeast Milk Checkoff Program.

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