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Results for “Embryo Transfer”

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PubMed1999

Embryo transfer in the rat as a tool to determine genetic components of the gestational environment.

Embryo transfer, with the recipient dam nursing the transferred progeny, was used to study the impact of the gestational environment on adult blood pressure (BP) in three inbred rat strains, the hypertensive Dahl salt-sensitive SS/JrCtr, the normotensive Dahl salt-hypertension resistant SR/Jr, and the normotensive Dark Agouti rat. Rats that had been cross-fostered within 6 h of birth were included as a control for lactational and nurturing factors. Systolic BP was measured by tail-cuff plethysmography twice a week in rats after the age of 7 weeks. Embryo transfer success, measured as the percentage of embryos transferred resulting in pups weaned at 4 weeks, was 27% between the SS/JrCtr and SR/Jr and 53% for the SS/JrCtr and Dark Agouti. This assessment included all failures, some of which probably were not associated with the transfer. If only the number of embryos transferred to dams with successful pregnancies was included, the success rate was 48% between the SS/JrCtr and SR/Jr and 82% between the SS/JrCtr and Dark Agouti strains. Anomalies in pups were not evident. In contrast to the lactational environment, the gestational milieu had a profound effect on basal blood pressure of the hypertensive SS/JrCtr progeny, less of an effect on that of the Dark Agouti, and no effect on that of the SR/Jr. Although the SS/JrCtr strain is significantly larger than the SR/Jr and Dark Agouti strains, neither embryo transfer nor cross-fostering altered body weight of rats at the age of 6 weeks. These data indicate that embryo transfer can be an easy and efficient method of isolating genetically determined factors of the gestational environment.

Animals↗

PubMed1984

Embryo production in superovulated cows: Transferable embryos correlated with total embryos.

Embryo production was studied in 1,263 donor cows. The number of transferable (good) embryos per collection was highly correlated with the total embryos and ova in a collection (r = 0.64). Total ova and embryos per collection averaged 10.1 with a range from 0-70; the number of good embryos averaged 4.5 with a range from 0-37. Of all collections, 15.3% failed to yield any embryos or ova, and 32.4% did not yield any good embryos. The percentage of good embryos averaged 46.1 while the ratio of good embryos produced (5,680) to total embryos and ova produced (12,699) was 0.45.

Journal Article↗

PubMed1986

Factors affecting embryo transfer success in recipient heifers under field conditions.

Recipient age at transfer (less than 525 d old or more than 525 d old), season (fall, winter, spring, summer), method of synchronization (natural or induced), and transfer technique (surgical or nonsurgical transfer) were associated with success of embryo transfer in a log-linear analysis. In a separate analysis, no significant association was found between success of transfer and transfer to the left or right uterine horn. Summer had the lowest proportion of successful transfers (58.9%). Pregnancy rates were 83% using the surgical transfer method and 68% with transcervical transfers. Proportion of pregnancies following a second transfer was not different from the proportion after first transfers. Success of embryo transfer was highest if recipients were greater than 525 d old and if transfers were performed surgically in spring following synchronization of recipients with cloprostenol, an analog of prostaglandin F2 alpha. Probability of success was lowest for transfers to young, prostaglandin-synchronized recipients, performed nonsurgically in summer.

Animals↗

PubMed2006

Elective single embryo transfer in women aged 36-39 years.

BACKGROUND: The elective single embryo transfer policy is the only effective strategy known to minimize the risk of multiple pregnancy. However, little is known about its applicability to women older than 35 years. METHODS: Analysis was carried out on 1224 fresh IVF/ICSI cycles with embryo transfer and 828 frozen embryo transfer (FET) cycles of women aged 36-39 years. In the fresh cycles, 335 elective single top quality embryo (eSET), 110 elective single non top quality embryo (nt-eSET), 194 compulsory single embryo (cSET) and 585 double embryo transfers (DET) were carried out. RESULTS: Pregnancy rate/embryo transfer (33.1 versus 29.9%) and live birth rate (26.0 versus 21.9%) in fresh cycles did not differ significantly between the eSET and the DET groups. However, women in the eSET group had a higher cumulative pregnancy rate (54.0% versus 35.0%) and a higher cumulative live birth rate (41.8% versus 26.7%, P < 0.0001) compared with those in the DET group. The cumulative multiple birth rate in the eSET group was 1.7%, whereas in the DET group it was 16.6% (P < 0.0001). CONCLUSIONS: The eSET policy can be applied also to patients aged 36-39 years, reducing the risk of multiple birth and increasing the safety of assisted reproduction technique (ART) in this age group.

Adult↗

PubMed2005

Influence of a prostaglandin synthesis inhibitor administered at embryo transfer on pregnancy rates of recipient cows.

Elevated uterine luminal concentrations of prostaglandin F(2alpha) (PGF(2alpha)) have been negatively associated with embryo quality and pregnancy rates. Two studies were performed in cows to determine PGF(2alpha) release from uterine endometrium following embryo transfer and to investigate administration of flunixin meglumine (FM), a prostaglandin synthesis inhibitor, on pregnancy rates following embryo transfer. In Experiment 1, blood samples were collected prior to and after embryo transfer from the posterior vena cava via saphenous vein cannulation. Serum profiles of PGF(2alpha) indicated that manipulation of the reproductive tract during embryo transfer was followed by increased release of PGF(2alpha) from the uterine endometrium. In Experiment 2, estrus (day=0) was synchronized in recipient animals and a single embryo transferred 7 days after estrus. At the time of non-surgical embryo transfer, animals were randomly assigned to receive either FM (FM; n=1300) or remain untreated (control (CON); n=797). Data collected at transfer included stage of embryo development, embryo quality, technician, and transfer quality score. Overall pregnancy rates of cows receiving FM (65%) were higher than control cows (60%; P<0.02). Pregnancy rates following transfer of quality 1 (good) embryos did not differ (P>0.05) between treatments. However, pregnancy rates of quality 2 (fair) embryos were higher in animals receiving FM than in CON (P<0.01). Moreover, pregnancy rates of transferred morula- and blastocyst-stage embryos were higher in FM-treated than in controls (P<0.06 and P<0.04, respectively). In conclusion, uterine release of PGF(2alpha) is elevated following embryo transfer and administration of a PGF(2alpha) synthesis inhibitor at the time of embryo transfer improved pregnancy rates in cows.

Animals↗

PubMedDate not supplied

Conception and realization of artificial dyed embryos for training in in vitro fertilization and embryo transfer (IVF and ET).

An artificial embryo model is proposed for current training in in vitro fertilization and embryo transfer. It consists in resin microballs of 180 micron diameter, stained either with fluoresceinamin or methylene blue. These microspheres release, even at the maximum dye concentrations tested, very negligible amounts of dye; heat stable they can be sterilized. This model, already checked for human embryo transfer, seems to be a useful tool in other reproduction studies such as embryo transport.

Education, Medical, Continuing↗

PubMed2002

A randomized controlled trial of a soft double lumen embryo transfer catheter versus a firm single lumen catheter: significant improvements in pregnancy rates.

BACKGROUND: Embryo transfer has changed little since originally described in 1978. Clinicians rate the type of catheter used as the third most important variable in embryo transfer, but there are no adequately powered randomized trials. We compared the clinical pregnancy rates with the single lumen catheter (TCC) and the double lumen catheter (CC) in a randomized single blind trial. METHODS: A total of 650 cycles of women from the Adelaide University reproductive medicine units in Australia were included in this trial. Patients were <40 years of age undertaking IVF and embryo transfer. Exclusion criteria were: known uterine abnormality, day 3 FSH >10 IU/l, previous difficult embryo transfer and pre-implantation genetic diagnosis. Cycles were randomized from numbered sealed envelopes immediately prior to embryo transfer with stratification for fresh or frozen cycles. RESULTS: There was a significantly higher pregnancy rate in the group treated with the CC compared with the TCC catheter [29.6 versus 20.5% per embryo transfer, odds ratio (OR) = 1.63 (95% confidence interval: 1.14-2.30), P = 0.0076]. The point estimate for the OR was similar for fresh and frozen cycles. CONCLUSIONS: The pregnancy rate was increased by 50% and this justifies the increased cost of the soft double lumen catheter and the training of clinical staff required.

Adult↗

PubMed1993

A comparison of early pregnancy failure and ongoing pregnancy rates between fresh and frozen embryo transfer following in vitro fertilization.

In order to compare pregnancy outcomes following fresh and frozen embryo transfer after in vitro fertilization (IVF), a retrospective analysis of data from the Royal North Shore IVF Programme was performed. Six hundred and sixty seven embryo transfers following routine IVF were performed during 1991 and 1992. Four hundred and twenty fresh embryo transfers were performed during that period, resulting in a clinical pregnancy rate of 21%. In comparison, 247 frozen transfers, where the initial procedure was routine IVF, were performed, resulting in a clinical pregnancy rate of 16.6%. This difference was not significant. When varying numbers of transferred embryos in the 2 groups were taken into account, there was a significant difference in the proportion of ongoing viable fetuses per embryo returned for 1991, but not for 1992. Although there were a greater number of abortions and ectopic pregnancies in the fresh transfer group, these differences did not achieve statistical significance. The implications of improving results from frozen embryo transfer are discussed.

Abortion, Spontaneous↗

PubMed2000

In vitro development of porcine nuclear transfer embryos constructed using fetal fibroblasts.

The in vitro development of porcine nuclear transfer embryos constructed using primary cultures from day 25 fetal fibroblasts which were either rapidly dividing (cycling) or had their cell-cycle synchronized in G0/G1 using serum starvation (serum-starved) was examined. Oocyte-karyoplast complexes were fused and activated simultaneously and then cultured in vitro for seven days to assess development. Fusion rates were not different for either cell population. The proportion of reconstructed embryos that cleaved was higher in the cycling group compared to the serum-starved group (79 vs. 56% respectively; P < 0.05). Development to the 4-cell stage was not different using either population. Both treatments supported similar rates of development to the morula (1.5 vs. 7%, cycling vs. serum-starved) and blastocyst stage (1.5 vs. 3%, cycling vs. serum-starved). The blastocyst produced using cycling cells had a total cell number of 10. Total cell numbers for the three blastocysts produced serum-starved cells were 22, 24, and 33. These blastocysts had inner cell mass numbers of 0, 15, and 4, respectively. Six hundred and thirty-five nuclear transfer embryos reconstructed using serum-starved cells were transferred to 15 temporarily mated recipients for 3-4 days. Of these, 486 were recovered (77% recovery rate) of which 106 (22%) had developed to the 4-cell stage or later. These were transferred to a total of 15 recipients which were either unmated or mated. Seven recipients farrowed a total of 51 piglets. Microsatellite analysis revealed that none of these were derived from the nuclear transfer embryos transferred.

Animals↗

PubMed1991

Study of relations between nutritional value of rations and success in embryo transfer in heifers.

Experimental observations on the influence of composition and nutritional value of rations upon the success of transfer of early embryos were realized in 134 recipients-heifers. Greater success of embryo transfers (66.0%) was observed in recipients at the age 18-22 months, live weight 330-380 kg at rations with 85-95% share of high quality roughage with moderately increased content and concentration of energy, good state of health and condition.

Animal Feed↗

PubMed2004

Detectable levels of interleukin-18 in uterine luminal secretions at oocyte retrieval predict failure of the embryo transfer.

BACKGROUND: Most implantation failures after successful in vitro fertilization-embryo transfer (IVF-ET) result from inadequate uterine receptivity. There is currently no way to predict this receptivity. METHODS: We investigated whether the detection of interleukin-(IL)18 by ELISA in uterine luminal secretions might predict implantation failure. Secretions of 133 patients enrolled in our IVF-ET program were sampled by uterine flushing immediately before oocyte retrieval. We assessed the following outcomes: pregnancy rate, multiple pregnancy rate, and implantation rate per embryo transferred. RESULTS: Interleukin-18 was detected in the flushing fluid of 38 patients (28.6%). Although the two groups were comparable for all other characteristics (age, etiology, ovarian reserve, number of embryos transferred, quality of embryos), all outcome variables differed significantly. The pregnancy rate was 37.9% in the IL-18 - ve group and 15% in the IL-18 + ve group, the multiple pregnancy rate 27.7% and 0%, and the implantation rate per embryo transferred 19.4% and 6.7% (all comparisons, P=0.02). Only embryos meeting good quality criteria were transferred to 65 patients: 50 IL-18 - ve and 15 IL-18 + ve. The pregnancy rate was 51% for the IL-18 - ve group and 20% for the IL-18 + ve group, the multiple pregnancy rate 36% and 0.0%, respectively, and the implantation rate 29% and 8.3% (P = 0.02). CONCLUSION: This non-invasive and simple method predicted inadequate uterine receptivity, independent of embryo quality.

Adult↗

PubMed2004

Monozygotic twinning associated with day 5 embryo transfer in pregnancies conceived after IVF.

BACKGROUND: This study examines the association between day of embryo transfer and monozygotic (MZ) twinning. METHODS: We used a population-based sample of 108,36 IVF/embryo transfer procedures in which the patients oocytes' were freshly fertilized (non-frozen; non-donor) and 39,98 resultant pregnancies from US clinics in 1999 and 2000. Cases were pregnancies for which the number of fetal hearts observed on ultrasound exceeded the number of embryos transferred. These pregnancies were considered to contain at least one set of MZ twins. A total of 226 MZ pregnancies were compared with two control groups: 23,880 singleton pregnancies (one fetal heart) and 15,092 other multiple-gestation pregnancies (> or = 2 fetal hearts but the number of fetal hearts on ultrasound was less than or equal to the number of embryos transferred). RESULTS: Cases of presumed MZ multiple-gestation pregnancies were more likely to have had a day 5 embryo transfer compared with day 3 embryo transfers than singleton pregnancies [adjusted odds ratio (AOR) = 3.92, 95% confidence interval (CI) = 2.97-5.17] or other multiple-gestation pregnancies (AOR = 3.91, 95% CI = 2.96-5.17) conceived with IVF/embryo transfer. CONCLUSIONS: Day 5 embryo transfer may be associated with increased MZ twinning.

Adult↗

PubMed1987

Bovine superfetation by natural conception secondary to an embryo transfer pregnancy.

There was only one embryo transferred to the recipient female. There was no chance for natural service to occur from 21 days prior to the transfer of the embryo to 31 days after the transfer of the 7 day old blastocyst. The surrogate female was palpated as being 38 days pregnant 31 days after the transfer of a 7 day old embryo by an experienced professional before being exposed to the natural service sire. The second fetus was of a different sex than the first and was approximately 60 days less mature. All other pregnancies within this well managed herd were accounted for and no other cows calved within the area close to that time. The remaining recipients carried pregnancies to the approximate expected calving date. Conclusion. This case report should support earlier evidence that superfetation in the bovine can and does occur.

Animals↗

PubMed2004

Multiple factors affecting the efficiency of multiple ovulation and embryo transfer in sheep and goats.

This review offers an overview of the basic characteristics of in vivo embryo technologies, their current status, the main findings and the advances gained in recent years, and the outstanding subjects for increasing their efficiency. The use of superovulation and embryo transfer procedures remains affected by a high variability in the ovulatory response to hormonal treatment and by a low and variable number of transferable embryos and offspring obtained. This variability has been classically identified with both extrinsic (source, purity of gonadotrophins and protocol of administration) and intrinsic factors (breed, age, nutrition and reproductive status), which are reviewed in this paper. However, emerging data indicate that the main causes of variability are related to endocrine and ovarian factors, and so the number of studies and procedures addressing a better understanding and control of these factors may be increased in the future. The accomplishment of this objective, the improvement of procedures for embryo conservation and for the selection and management of recipient females, will allow further development and application of this technology.

Animals↗

PubMed2004

[Analysis of pregnancy outcomes after in vitro fertilization-embryo transfer and intracytoplasmic sperm injection].

OBJECTIVE: To compare pregnancy and perinatal outcomes between in vitro fertilization-embryo transfer (IVF-ET) and intracytoplasmic sperm injection (ICSI). METHODS: A retrospective study was carried out to measure pre-clinical and clinical abortion, ectopic pregnancies, multiple gestations, birth weight, gestational age, congenital malformation and perinatal mortality in patients receiving either IVF-ET (n = 143, group 1) or ICSI (n = 173, group 2) from January 1999 to June 2001. The outcomes of singleton and twin were compared separately. RESULTS: The maternal age, infertility duration, parity and the number of transferred embryo were comparable between the two groups. There were no significant differences in abortion rate (16.1% vs 13.3%), birth rate (65.7% vs 74.6%) between IVF-ET and ICSI groups (P > 0.05). In singleton, the rates of low birth weight, small for gestational age and pre-term birth were 1.8%, 7.3%, 5.5% respectively in IVF-ET group and 6.8%, 8.1%, 14.9% respectively in ICSI group. In twin, the rates of low birth weight, small for gestational age and pre-term birth were 34.2%, 30.3%, 42.1% respectively in IVF-ET group and 42.6%, 38.0%, 46.3% respectively in ICSI group. There were no significant differences between the two groups (P > 0.05). But the rates of low birth weight, small for gestational age and pre-term birth were higher in twin than in singleton (P < 0.01). The incidence of congenital malformation was 2.2% and 1.6% in IVF-ET and ICSI group respectively (P > 0.05). CONCLUSIONS: The pregnancy and perinatal outcomes are similar between IVF-ET and ICSI groups. Twin is the main cause of low birth weight, small for gestational age and pre-term birth.

Adult↗

PubMed2006

Factors affecting patients' attitudes toward single- and multiple-embryo transfer.

OBJECTIVE: To identify factors that influence patient decision making concerning embryo transfer. DESIGN: Prospective analysis. SETTING: In vitro fertilization unit at a tertiary-care, university-affiliated teaching hospital. PATIENT(S): Seventy-nine women and 53 men who were referred consecutively for IVF treatment. INTERVENTION(S): Provision of risk information about complications of twin pregnancy. MAIN OUTCOME MEASURE(S): Rated desirability of different transfer options and twin pregnancy, together with standardized measures of depression and infertility stress. RESULT(S): Women's initial preference for two-embryo transfer (2ET) was related to beliefs that the chance of pregnancy was higher with 2ET vs. elective single-embryo transfer and that the personal chance of twins was relatively likely with 2ET but was not related to a specific desire for twins. Providing risk information increased the desirability of elective single-embryo transfer and decreased the desirability of twin pregnancy among both men and women. CONCLUSION(S): Cautious patients, preferring transfer of fewer embryos, balance desires to maximize the chance of pregnancy with acceptance of risks associated with twins. Less-cautious patients may be motivated by beliefs about the influence of age, desires for, and likelihood of twin pregnancy. Information about risks may affect these groups differently and diverse patient motivations may require tailored information to ensure informed consent.

Adult↗

PubMed2006

An ongoing pregnancy after frozen thawed embryo transfer in a patient with Klinefelter's syndrome.

BACKGROUND: Pregnancy following frozen thawed embryo transfer in a patient with nonmosaic Klinefelter's syndrome is extremely rare. A healthy ongoing pregnancy achieved with frozen thawed embryo transfer in a patient with nonmosaic Klinefelter's syndrome was described. METHOD: A case report from a tertiary center for assisted reproductive technologies. A 34-year-old man with azoospermia and nonmosaic Klinefelter's syndrome and his 26-year-old wife presented with primary infertility of 8 years' duration. Frozen thawed embryo transfer following intracytoplasmic sperm injection using surgically retrieved spermatozoa was performed. RESULTS: A healthy ongoing pregnancy with a normal 46,XY karyotype was achieved with day 3 frozen thawed embryo transfer. CONCLUSION: Frozen thawed embryo transfer may be a viable option to achieve pregnancy in patients with Klinefelter's syndrome.

Adult↗

PubMed2006

The effect of 6-dimethylaminopurine (6-DMAP) and cycloheximide (CHX) on the development and chromosomal complement of sheep parthenogenetic and nuclear transfer embryos.

The effects of activation by 6-dimethylaminopurine (6-DMAP) and cycloheximide (CHX) on the development and chromosomal complement of sheep parthenogenetic and SCNT embryos were investigated. The results revealed that the blastocyst development of parthenogenetic embryos was significantly higher (P < 0.05) in 6-DMAP activated oocytes, compared to those activated with CHX (21.0 +/- 0.9 vs. 14.9 +/- 0.5, respectively). In contrast, the blastocyst frequencies did not significantly differ (P > 0.05) between the two activation treatment groups for SCNT embryos. The 6-DMAP or CHX treatment did not result in any significant difference in the blastocyst total cell number in either parthenote or SCNT embryos. The chromosomal analysis revealed that all the parthenogenetic embryos (100.0%) derived from 6-DMAP treatment, were chromosomally abnormal whereas in CHX-treated embryos, it was significantly lowered (93.6%, P < 0.05). Conversely, the proportions of chromosomally abnormal SCNT embryos did not significantly differ (P > 0.05) among the 6-DMAP and CHX- treated embryo groups (60.0% vs. 56.2%, respectively). This study demonstrated that oocyte activation agents such as DMAP and CHX have differing effects on meiotic or mitotic nuclei. The study also highlighted the feasibility of using bovine X and Y chromosome specific painting probes in sheep embryos.

Adenine↗