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Results for “Embryo Transfer”

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PubMed1993

A prospective randomized comparison of zygote intrafallopian transfer and in vitro fertilization-embryo transfer for nontubal factor infertility.

OBJECTIVE: To evaluate the efficacy of zygote intrafallopian transfer (ZIFT) versus standard IVF-ET for the treatment of nontubal factor infertility. DESIGN: A prospective randomized trial. PARTICIPANTS: Fifty-nine couples undergoing oocyte retrieval for nontubal infertility in a university hospital-based IVF-ET program. INTERVENTIONS: A maximum of four cleaving embryos were transferred into the fallopian tube or uterine cavity 48 or 55 hours after oocyte retrieval, respectively. MAIN OUTCOME MEASURES: Rates of implantation, pregnancy, and spontaneous abortion (SAB) were compared. RESULTS: Clinical pregnancies occurred after 26.5% versus 12% of retrievals and 29% versus 14.3% of transfers in IVF-ET versus ZIFT cycles, respectively. Pregnancy, implantation, and SAB rates did not differ between the groups. CONCLUSIONS: This prospective randomized trial failed to demonstrate any therapeutic improvement associated with the increased complexity of ZIFT as compared with standard IVF-ET.

Adult↗

PubMed1994

Outcome of thaw embryo transfer after cryopreservation of all embryos in patients at risk of ovarian hyperstimulation syndrome.

OBJECTIVE: To determine the incidence of ovarian hyperstimulation syndrome (OHSS) and subsequent pregnancy rates (PRs) if ET is delayed in patients at risk of OHSS by allocating all embryos to cryopreservation. DESIGN: Retrospective analysis of clinical and laboratory data from 724 consecutive stimulated cycles of IVF. SETTING: University hospital-based IVF program. PATIENTS: Consecutive patients undergoing IVF between September 1989 and December 1992. MAIN OUTCOME MEASURES: Fertilization rates, cryosurvival rates, subsequent PRs, and the occurrence of severe OHSS. RESULTS: Ten of the 564 patients (1.8%) who had ET in the stimulation cycle developed severe OHSS. Sixty-nine patients had all embryos frozen because of the risk of OHSS, of which one (1.4%) developed severe OHSS. The subsequent PR after thaw transfer was 25.2% per transfer, with a cumulative PR per patient after additional thaw transfers of 40.6%. CONCLUSIONS: Cryopreservation of all embryos and delayed ET in patients at risk of OHSS results in a low incidence of severe OHSS. Oocyte quality, fertilization rates, and cryosurvival of frozen embryos are equal to those for patients who have a normal stimulation profile. Subsequent thaw embryo replacements result in a satisfactory PR.

Adult↗

PubMed1996

The obstetric outcome of in vitro fertilization and embryo transfer in women with congenital uterine malformation.

OBJECTIVE: Our purpose was to analyze 3 obstetric outcomes according to the various forms of congenital uterine malformation after in vitro fertilization and embryo transfer. STUDY DESIGN: We conducted a retrospective analysis of data from 24 patients with the following types of congenital uterine malformation: 6 unicomuate, 9 bicomuate, 5 septate, and 4 uterus didelphys. All patients underwent in vitro fertilization and embryo transfer at Boum Hall Clinic, a tertiary infertility referral center. RESULTS: Twenty-four patients conceived a total of 19 clinical pregnancies in 51 embryo transfer cycles. The clinical pregnancy rate was 19 of 51 (37.3%) per embryo transfer and 17 of 24 (70.8%) per patient. There were no significant differences in the clinical pregnancy rates when the various forms of uterine malformation were compared. There was a trend for the group with unicomuate uteri and uterus didelphys to have the highest rate of term delivery (6/9, 66.7%) and the lowest rate of first-trimester miscarriages (0/9, 0%) as compared with the group with septate and bicomuate uteri, in whom the term delivery rate was 1 of 10 (10%) and the spontaneous abortion rate was 3 of 10 (30%). The multiple pregnancy rate was 6 of 15 (40%) for women who had three embryos transferred, as compared with 0 in women who had two embryos or one embryo transferred. There was a high rate of preterm delivery (6/13, 46.2%) and cesarean section (10/13, 76.9%). CONCLUSION: In vitro fertilization and embryo transfer in women with congenital uterine malformation is associated with good pregnancy rates, and the patients should be counseled about the risks involved, in particular, the increased rate of preterm delivery and cesarean section.

Adult↗

PubMed1994

Transvaginal embryo transfer during the zygote intrafallopian tube transfer procedure.

OBJECTIVE: Our purpose was to evaluate a tactile non-ultrasonographically directed approach to transvaginal tubal cannulation and embryo transfer during the zygote intrafallopian tube transfer procedure. STUDY DESIGN: We studied the application of the tactile approach to transvaginal tubal cannulation and embryo transfer in 68 consecutive zygote intrafallopian tube transfer cycles. RESULTS: The tactile approach to transvaginal tubal cannulation and subsequent embryo transfer was successful in 93% of couples. Pregnancy occurred in 16 of the 63 (25%) women undergoing a successful transvaginal embryo transfer. CONCLUSION: The tactile approach to transvaginal tubal cannulation was found to be easily learned and provided a safe and convenient method of tubal embryo transfer. This low-cost approach, which has application to transfer of both embryos and gametes, deserves further study.

Catheterization↗

PubMedDate not supplied

[Embryo transfer in the goat--a review].

The available techniques for the control of the estrous cycle and superovulation in goats are covered. Most commonly the estrous cycle is controlled by means of progestagen pessaries or s.c. implants. To superovulate goats, FSH is more suitable than PMSG. As an alternative, goats may be immunized against inhibin. Premature regression of corpora lutea is a common complication in superovulated goats. Collection and transfer of embryos is usually accomplished via laparotomy. Occasionally endoscopic techniques are utilized. A recently invented technique for transcervical embryo collection is touched upon. Methods of in vitro culture and preservation of embryos resemble those commonly applied in cattle. Satisfactory success rates are achieved with the transfer of frozen-thawed blastocysts. Vitrification of goat embryos is feasible. There are reports on successful splitting and fusion (chimaera formation) of goat embryos and on in vitro fertilization (IVF). The goat may serve as a suitable model for the invention of new approaches in biotechnology in ruminants.

Animals↗

PubMed2004

Single or multiple embryo transfer following in vitro fertilisation for improved neonatal outcome: a systematic review of the literature.

BACKGROUND: The aim of the current review was to determine if single versus two or more embryos, or double versus three or more embryos, transferred to the woman of a subfertile couple at in vitro fertilisation (IVF) maximises the likelihood of pregnancy, while minimising the likelihood of multiple pregnancy and adverse sequelae. METHODS: Studies were identified that reported maternal, infant and cost outcomes following embryo transfer at IVF. RESULTS: Three randomised trials and 17 cohort studies were included. From two randomised trials, single embryo transfer was found to result in decreased incidence of clinical pregnancy, multiple pregnancy and low birthweight. In the cohort studies for single embryo transfer compared with transfer of two or more embryos the incidence of live birth and singleton pregnancies was unchanged, and the incidence of multiple pregnancies and low birthweight was reduced. For double embryo transfer compared with the transfer of three or more embryos, the incidence of clinical pregnancy, live birth, preterm birth and low birthweight babies was reduced. CONCLUSIONS: Information on neonatal and maternal outcomes following transfer of different numbers of embryos is limited. Transfer of one embryo does not alter the likelihood of a singleton pregnancy or birth when compared to transfer of two or more embryos. Transfer of one or two embryos decreases the risk of a multiple pregnancy, preterm birth and low birthweight. Further large, well-designed randomised trials are required to provide maternal and neonatal outcomes of relevance to a couple undergoing IVF.

Australia↗

PubMed1998

Nurses performing embryo transfer: the development and results of the Birmingham experience.

Although in-vitro fertilization treatment is doctor-led, many of its steps are performed by nurses. The embryo transfer step, however, is performed exclusively by doctors in the majority of units. In our unit, doctors performed embryo transfers from June 1994 until December 1995 (period I). From January 1996 until May 1997 (period II) the nurses, after appropriate training, performed the procedure. When they experienced difficulties during the mock transfer performed immediately before the real transfer, or if they were not available to do the procedure, a doctor performed it. In period I, 488 embryo transfers were performed (all by doctors), with a pregnancy rate per transfer of 35% and an implantation rate of 16%. In period II, 522 embryo transfers were performed. Nurses performed 371 (71%) and doctors 151 (29%) of the procedures. The pregnancy rate per nurse-transfer was 40.2% and per doctor-transfer 41%. The corresponding implantation rates were 16.9% and 17%. None of these differences were statistically significant (P > 0.05). These data indicate that, with appropriate training and medical back-up, nurses can perform the majority of embryo transfers with ease and outcome comparable to that of doctor embryo transfer.

Embryo Implantation↗

PubMed2003

Effectiveness of 2-step (consecutive) embryo transfer. Comparison with cleavage-stage transfer.

OBJECTIVE: To evaluate the effectiveness of 2-step (consecutive) embryo transfer (ET), in which two cleaved embryos are transferred on day 2 (first step of ET) and a single blastocyst is transferred on day 5 (second step of ET) in comparison with conventional day 2 ET. STUDY DESIGN: Observational comparative study at different time periods. Subjects were those who had > or = 4 embryos on day 2 after oocyte retrieval. Those in the conventional group (n = 60) received conventional day 2 ET, in which 3 cleaved embryos were transferred on day 2 between January 1999 and June 2000. Those in the 2-step group (n = 124) received 2-step embryo transfer, in which 2 cleaved embryos were transferred on day 2 and a blastocyst was transferred on day 5 between September 2000 and February 2002. Patients who planned to receive 2-step ET but could not proceed to the second step of ET because of failure to produce blastocysts were included in the 2-step group. RESULTS: The ongoing pregnancy rate with 2-step ET (51.6%) was significantly higher than with conventional ET (26.7%) (P < .01). The clinical pregnancy rate and implantation rate in conventional and 2-step ET were 30.0% vs. 59.7% and 11.1% vs. 27.8%, respectively (P < .001). CONCLUSION: Two-step ET may benefit patients who can obtain a sufficient number of embryos.

Adult↗

PubMed2005

Single embryo transfer: a mini-review.

This paper provides a concise review of single embryo transfer (SET) in cycles using fresh embryos as well as in cycles using frozen-thawed embryos. Relevant studies were identified by a computerized search in PubMed for the period 1995-2004. The pregnancy rates, delivery rates and multiple pregnancy/birth rates were evaluated after fresh or frozen embryo transfer as well as cumulative delivery rates after fresh and frozen SET. The results of four randomized controlled trials (RCT) and seven observational studies using fresh embryo transfers are analysed. No RCT with SET in freezing-thawing cycles was identified, while one observational study was identified. The effects of a change in the rules from the National Board of Health and Welfare in Sweden in 2003 regarding the implementation of SET in Sweden are summarized.

Cryopreservation↗

PubMed1993

Conversion from a failed transcervical zygote intrafallopian transfer to a successful delayed uterine embryo transfer.

Transcervical ZIFT is an alternative to IVF-ET and laparoscopic GIFT. However, tubal catheterization cannot be accomplished in all cases. We describe a successful twin pregnancy that resulted from delayed uterine transfer of four embryos following unsuccessful TC-ZIFT transfer. Further data are needed to determine optimal management in cases of failed transcervical tubal transfer procedures.

Adult↗

PubMed2004

Minimizing embryo expulsion after embryo transfer: a randomized controlled study.

BACKGROUND: The aim of this work was to modify the embryo transfer technique to prevent expulsion of the embryos by exerting gentle mechanical pressure on the cervix using the vaginal speculum. METHODS: A total of 639 infertile patients undergoing ICSI were prospectively randomized into two groups using sealed dark envelopes. In the study group (n=325) the screw of the vaginal speculum was loosened in order to exert a gentle pressure on the portiovaginalis of the cervix before ejecting the embryos, and was maintained for 7 min afterwards. In the control group (n=314) no pressure was applied on the cervix during embryo transfer and the vaginal speculum was removed after transferring the embryos. RESULTS: The clinical pregnancy rate was significantly higher in the study group than in the control group [207/325 (67%) versus 150/314 (47.8%); odds ratio (OR) 1.39; 95% confidence interval (CI) 1.11-1.74]. The implantation rate was also significantly higher in the study group [304/913 (33.3%) versus 198/920 (21.5%); OR 1.54; 95% CI 1.26-1.89]. CONCLUSIONS: Applying gentle mechanical pressure on the portiovaginalis of the cervix using the vaginal speculum during and after transferring the embryos significantly improved clinical pregnancy and implantation rates.

Adult↗

PubMed2002

Effect of partial incision of the zona pellucida by piezo-micromanipulator for in vitro fertilization using frozen-thawed mouse spermatozoa on the developmental rate of embryos transferred at the 2-cell stage.

Cryopreservation of mouse spermatozoa is widely used, although considerable strain differences in fertilization rates using frozen-thawed mouse spermatozoa have been described. The C57BL/6 mouse strain is a very widely used for establishment of transgenic mice, but the fertilization rate associated with the use of cryopreserved C57BL/6 spermatozoa is very low compared with rates for other inbred strains. We have recently solved this difficulty by in vitro fertilization (IVF) in combination with partial zona pellucida dissection (PZD). However, this technique requires culture of fertilized eggs with PZD in vitro up to morula or blastocyst stage before transfer into the uterus because blastomeres are lost after transfer into the oviduct because of the relatively large artificial slit in the zona pellucida. To overcome this problem, we performed a partial zona pellucida incision by using a piezo-micromanipulator (ZIP) for IVF with frozen-thawed mouse spermatozoa. The blunt end of the micropipette touched the surface of the zona pellucida of the oocytes, and piezo pulses were used to incise the zona pellucida while the pipette was moved along by the surface of zona pellucida. The length of the incision was pir/6 microm. When cumulus-free ZIP and PZD oocytes were inseminated with frozen-thawed genetically modified C57BL/6J spermatozoa, the fertilization rates of ZIP and PZD oocytes were 52% and 48%, respectively. After embryo transfer at the 2-cell stage, 18% and 2% of the transferred embryos with ZIP and PZD developed to term, respectively. This difference was significant (P < 0.05). When ZIP and PZD zygotes were cultured to blastocyst stage and subsequently transferred to uterine horns of recipient animals, the difference between ZIP and PZD zygotes for development rate to full term was not significant. Our results indicate that ZIP is an effective alternative technique for IVF using cryopreserved mouse spermatozoa and subsequent embryo transfer.

Animals↗

PubMed1980

Commercial aspects of bovine embryo transfer.

Superovulated beef cows and heifers were nonsurgically collected 6 to 8 days post estrus. Commercial production results for 1976 through 1978 were 4979 pregnancies from 7814 embryos transferred for an overall pregnancy rate of 63%. In 1978, 519 superovulation procedures averaged 9.95 +/- 8.4 (S.D.) ova collected, 8.2 +/- 7.55 ova fertilized, 5.96 +/- 5.37 embryos transferred and 3.63 +/- 5.37 pregnancies per procedure. Embryos were transferred to recipient cows in estrus 12 hr before the donor (-12) the same time (0) or 12 hr after the donor (+12). The +12 group had a significantly lower pregnancy rate (61%, P<.05) than the 0 group (67%) or -12 group (66%). Transfer of early morula stage embryos resulted in a lower pregnancy rate (61%, P<.05) than late morula (67%) early blastocyst (67%) or late blastocyst (71%) stage embryos. A higher pregnancy rate (P<.05) was obtained with embryos of good morphological quality (71%) than with embryos graded fair and poor (55%). The pregnancy rate for embryos transferred nonsurgically was lower (44%) than the pregnancy rate for embryos transferred surgically during the same time period (66%). Pregnancy rates for three operators performing the nonsurgical transfers were 48%, 53%, 28%. No difference in pregnancy rate was found between embryos cultured 24 hr in BMOC-3 at 37C (62%) and embryos transferred the same day as collection (60%). Pregnancy rates for cultured embryos transferred to recipient cows in estrus 12, 24 or 36 hr after the donor were 68%, 62% and 60%, respectively. Embryos recovered on days 6, 7 and 8 were frozen in 1.5M DMSO and stored in liquid nitrogen several days to several weeks. Of 68 embryos frozen, 34 were viable post thaw. Upon transfer to recipient cows, the 34 viable embryos produced 23 confirmed pregnancies.

Journal Article↗

PubMed2006

Meclofenamic acid extends donor-recipient asynchrony in equine embryo transfer.

REASONS FOR PERFORMING STUDY: A level of synchrony between embryo and uterine environment is essential for the establishment of pregnancy when performing embryo transfer. The ability to extend the acceptable degree of asynchrony would allow more efficient use of recipient mares. OBJECTIVES: To establish if administration of the prostaglandin synthetase inhibitor, meclofenamic acid, to asynchronous recipient mares could widen the acceptable window of asynchrony for embryo transfer. HYPOTHESIS: The prostaglandin synthetase inhibitory action of meclofenamic acid may act to suppress luteolysis and thereby allow for a greater degree of asynchrony between donor and recipient mares. METHODS: A total of 72 Grade 1 horse embryos were transferred nonsurgically into the uteri of recipient mares that had ovulated 2 (n = 20), 3 (n = 20), 4 (n = 16) or 5 (n = 16) days before the donor. Half of the mares in each group were treated orally with 1 g meclofenamic acid, beginning on Day 9 after ovulation and continuing for 7 days after embryo transfer. RESULTS: Comparison of recipient:donor asynchrony between treated and untreated mares was: +2 days, 9/10 pregnancies vs. 8/10 (P= 1.00); by +3 days, 8/10 vs. 2/10 (P= 0.025); by +4 days, 5/8 vs. 1/8 (P = 0.121); and by +5 days 3/8 vs. 0/8 (P = 0.20). In 10/11 meclofenamic acid-treated and 23/25 untreated recipient mares that failed to become pregnant, luteolysis occurred at the normal time (14-19 days) after ovulation. CONCLUSION: Treatment with meclofenamic acid supported the establishment of pregnancy in recipient mares that ovulated before the donors. However, meclofenamic acid appeared to provide this support in a manner other than by suppression of luteolysis. POTENTIAL RELEVANCE: Pregnancy rates can be increased in recipient mares that ovulate 3 days before the donor by administration of meclofenamic acid.

Animals↗

PubMed2005

Dissecting why superovulation and embryo transfer usually work on some farms but not on others.

Bovine embryo transfer is a well-established commercial industry that is often associated with veterinary practices. Practitioners offering embryo transfer services may possess a very high standard of technical expertise; however, success in the production of embryos and the impregnation of recipients cannot be achieved unless the cattle are healthy and maintained in a well-managed cattle operation. In addition to appropriate gonadotropin treatments of donor cattle, the use of highly fertile semen, known to have been properly stored and handled is required for success. Recipient cattle must be managed with the same attention to detail as donors. Traditionally, PGF has been used for the synchronization of recipients. However, PGF is limited in its effectiveness early and late in the bovine estrus cycle. Recipient estrus synchronization with progesterone releasing intravaginal inserts has been successful and high pregnancy rates have resulted following embryo transfer.

Animals↗

PubMed2003

Single embryo transfer and multiple pregnancy rate reduction in IVF/ICSI: a 5-year appraisal.

One of the most problematic issues of assisted reproduction is the high incidence of multiple pregnancies, resulting from the transfer of more than one embryo. Particularly at risk are young women who have good quality embryos. The only strategy to reduce the incidence of multiple pregnancies, including twin pregnancies, after assisted reproduction is single embryo transfer (SET). In 1997, the present authors therefore introduced elective SET (eSET) in this particular target group. The proportion of eSET increased from 1.5 (1997-1998) to 17.5% (1999-2002) of all transfers. In 2002, 20% of all transfers were SET. Comparing these two periods, an overall pregnancy rate of 35 and 34% per transfer, respectively, was obtained, while the overall twinning rate dropped from 30 to 21%. The twinning rate dropped to 14% in 2002, and in the eSET group there was only one monozygotic twin. These results demonstrate that a decline in the twinning rate is feasible without a drop in overall pregnancy rates. Comparing eSET with elective double embryo transfer (eDET), it was found that ongoing pregnancy and implantation rates were the same in both groups, but the proportion of twins was clearly different. It was further observed that the mean birthweight of singleton children born after eSET was significantly higher than that after DET. This could reflect a better developmental or implantation potential of these embryos, but this finding remains to be confirmed.

Adult↗

PubMed1987

Factors influencing the success rate of human embryo freezing in an in vitro fertilization and embryo transfer program.

Certain factors influencing the success of embryo cryopreservation were analyzed from 124 cycles of in vitro fertilization and embryo transfer (IVF-ET) program in which 193 1- or 2-day embryos were frozen and had already been thawed. There were 100 transfers of one or two surviving embryos from which 26 pregnancies were initiated. Several factors significantly influenced embryo survival after thawing. They were: the developmental stage of frozen embryos; the appearance of the embryo at the time of freezing; and the mode of ovarian stimulation in the IVF cycle. The pregnancy rate after frozen-thawed embryo transfer was higher with 4-cell frozen embryos than with embryos at all other stages combined. There were also tendencies for the pregnancy rate to be higher if a spontaneous luteinizing hormone surge occurred in the transfer cycle or if the duration of embryo storage did not exceed 1 to 2 months. The results obtained support a new policy in IVF-ET programs: it should be advantageous for the sterile couple if the immediate fresh embryo transfer is only performed with the categories of embryos that demonstrate a poor aptitude for survival following cryopreservation procedures.

Embryo Transfer↗

PubMed2001

Handling and culture of bovine embryos: survey of media used by 26 embryo transfer companies in the USA.

Embryo transfer has evolved from a few highly centralized clinics to a widespread number of clinics offering both clinic and on-the-farm services. Practitioners in the field have made very few changes in the handling and culture of embryos. A short review of general handling techniques, plus a survey of media used by 26 companies in the USA, is presented here. Currently, phosphate-bufferend saline (PBS) plus two other commercially available media (EMCARE and ViGro) are used by these companies. Fourteen different combinations of these products were reported and only 11 of the 26 consistently used the same medium for flushing, culture and freezing.

Animals↗