SEARCH · PubMed Health

Results for “Embryo Transfer”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed2004

[Impact of embryo transfer techniques on implantation rates].

Embryo transfer is an important step in the success of IVF treatment. All efforts should be made to avoid difficult embryo transfers provoking bleeding or uterine contractions. Evaluation before IVF treatment, including a trial transfer and a uterine ultrasonography, should allow one to evaluate the transfer step, anticipate problems, and thus improve treatment. An hysteroscopy can be useful for uterine cavity exploration. It is also important to remove cervical mucus before introduce the transfer catheter. It is essential to deposit embryos as gently as possible during IVF, avoiding manoeuvres that might trigger uterine contractions which could adversely affect the results of this treatment. Soft catheters perform better, and ultrasound-guidance facilitates embryo transfer. Progesterone administration starting on the day of oocyte retrieval induces a decrease in uterine contraction frequency on the day of ET (embryo transfer). Both Wallace and CDD catheters perform similarly. Trial catheterization on the day of ET could prevent most of the unanticipated procedural difficulties during the transfer.

Catheterization↗

PubMed2000

Comparison of blastocyst transfer with day 3 embryo transfer in similar patient populations.

OBJECTIVE: To compare implantation and pregnancy rates (PRs) achieved with blastocyst transfer (BT) and day 3 ET in similar patient populations. DESIGN: Retrospective analysis. SETTING: Academic infertility center. PATIENT(S): One hundred consecutive patients <40 years undergoing IVF, each with more than three eight-cell embryos on day 3. INTERVENTION(S): Patients used their own eggs for IVF or IVF and intracytoplasmic sperm injection. Embryos were cultured in P1 medium (Irvine Scientific, Santa Ana, CA) until day 3, when they were either transferred or, in the case of embryos for BT, incubated in Blastocyst Medium (Irvine Scientific), followed by transferring on day 5. MAIN OUTCOME MEASURE(S): Implantation and PRs. RESULT(S): There were no statistically significant differences in patient age, FSH level, or number of oocytes or zygotes. The BT group had fewer embryos transferred (mean, 2.4) compared with the day 3-ET group (mean, 4.6). The viable PR (cardiac activity at 6-7 weeks was considered indicative of a viable pregnancy) was higher with BT (68%, 34/50) than with day 3 ET (46%, 23/50). The implantation rate was increased with BT (47%, 56 sacs/120 embryos) compared with day 3 ET (20%, 46 sacs/231 embryos). CONCLUSION(S): The BT group in our study had higher implantation and PRs compared with the day 3-ET group. Better embryo selection, improved embryo-uterine synchrony, and decreased cervical mucus on day 5 may have accounted for the enhanced outcome. Our data support the use of BT to limit the number of embryos transferred while improving PRs.

Adult↗

PubMed2001

Embryo score is a better predictor of pregnancy than the number of transferred embryos or female age.

OBJECTIVE: To compare the value of 17 IVF variables, including a new mean score of transferred embryos (MSTE), in predicting pregnancy rate. DESIGN: Retrospective study. SETTING: Private IVF unit. PATIENT(S): Women who underwent 10,000 embryo transfers. MAIN OUTCOME MEASURE(S): Duration of infertility, type of infertility, female age, rank of IVF attempt, type of ovarian treatment, progesterone level, sperm count, sperm motility, sperm morphology, number of retrieved oocytes, number of mature oocytes, maturation rate, number of embryos obtained, fertilization rate, number of transferred embryos, cumulative embryo score (CES), mean score of transferred embryos (MSTE), and pregnancy rate. RESULT(S): Outcome of IVF-ET was significantly correlated with female age, type of infertility, number of retrieved oocytes, number of mature oocytes, maturation rate, embryos obtained, fertilization rate, transferred embryos, CES, and MSTE. Multivariate analysis demonstrated that MSTE was a better predictor of pregnancy than the number of transferred embryos and female age. CONCLUSION(S): Embryo quality is the best predictor of pregnancy. The embryo score described herein should be used in IVF-ET programs to choose the best embryos for transfer.

Adult↗

PubMed1976

Baboon infant produced by embryo transfer.

An embryo was recovered surgically from a naturally ovulating, naturally inseminated Papio cynocephalus female on day 5 of gestation and transferred surgically to a naturally synchronized, nonmated Papio cynocephalus female on 20 March 1975. A male baboon weighing 875 grams was delivered by cesarean section on 5 September 1975, 174 days after estimated ovulation time.

Animals↗

PubMed1997

Nonsurgical embryo transfer in the common marmoset monkey.

A technique for nonsurgical embryo transfer in common marmosets was developed. Transfers were either synchronous (ST) or asynchronous (AT). Synchronous transfers (embryo donor and the embryo recipient ovulated on the same day) were performed 5 to 8 days post-ovulation. Asynchronous transfers (embryo donor had ovulated at least 2 days before the embryo recipient) were performed when the recipient was 2 to 4 days post-ovulation (donor was 6 to 8 days post-ovulation). Four pregnancies from nine transfers (44%) were established by AT, and three pregnancies were carried to term. Only 1 of 11 transfers (9%) from ST resulted in a pregnancy, which was lost by Day 40 of gestation. Significantly more infants were born from AT (6 infants from 17 embryos; 35%) than from ST (0 infants from 22 embryos; 0%; p < 0.005). This technique allows experimental analysis of primate postimplantation development and provides a tool for conservation of endangered Callithrichid species.

Animals↗

PubMed1999

Estradiol-17 beta-oxytocin-induced cervical dilation in sheep: application to transcervical embryo transfer.

Experiments were conducted to determine whether exogenous estradiol-17beta (E2) and oxytocin (OT) can be used to improve transcervical (TC) embryo transfer (ET) procedures for sheep. Our concerns that the E2-OT treatment may alter luteal function prompted Exp. 1, in which 32 ewes were assigned to treatments in a 2x2 factorial array. On d 7 after onset of estrus, ewes received i.v. either 100 microg of E2 or diluent; 12 h later, ewes received i.v. either 400 USP units of OT or saline. To monitor luteal function, progesterone was measured in jugular blood collected from d 7 to 18. The treatments did not affect progesterone concentrations. Two trials were conducted in Exp. 2. In Trial 1, ewes were assigned to one of three treatments: TC transfer with E2-OT treatment to dilate the cervix, laparoscopic ET with E2-OT treatment, or laparoscopic ET with an equivalent diluent that did not dilate the cervix. In Trial 2, ewes were assigned to treatments in a 2x2 factorial array: TC or laparoscopic ET on d 6; E2-OT treatment for cervical dilation or diluents on d 6. Transferred embryos were recovered on d 12 in Trial 1 and d 14 in Trial 2, evaluated morphologically for development, and scored. Treatments did not affect the percentage of transferred embryos recovered. However, mode of transfer decreased (P<.01) the mean embryo development score. The E2-OT treatment increased (P<.01) the development score of embryos transferred transcervically, indicating that cervical dilation may improve the chances of embryos surviving after TC transfer. In conclusion, E2-OT treatment did not affect luteal function, and the E2-OT treatment can be used to enhance the success of TC embryo transfer in sheep.

Animals↗

PubMed2002

Optimizing the embryo transfer technique.

The technique of embryo transfer is very crucial and great attention and time should be given to this step. In order to optimize the embryo transfer technique, several precautions should be taken. The first and most important is to avoid the initiation of uterine contractility. This can be achieved by the use of soft catheters, gentle manipulation and by avoiding touching the fundus. Secondly, proper evaluation of the uterine cavity and utero-cervical angulation is very important, and can be achieved by performing dummy embryo transfer and by ultrasound evaluation of the utero-cervical angulation and uterine cavity length. Another important step is the removal of cervical mucus so that it does not stick to the catheter and inadvertently remove the embryo during catheter withdrawal. Finally, one has to be absolutely sure that the embryo transfer catheter has passed the internal cervical os and that the embryos are delivered gently inside the uterine cavity.

Cervix Mucus↗

PubMed1996

[Reproductive medicine in transition: new developments in embryo transfer].

Successful application of embryo transfer (ET) has become common practice in cattle, horses, sheep, goats and a variety of other species held in captivity. Yet in cattle only has the technique been established commercially. In 1994 more than 100,000 bovine embryos have been transferred in European countries. Important progress in transvaginal ovum pick up (OPU), in vitro production (IVP) and cryopreservation have further improved the applicability of ET. Direct transfer simplifies the procedure considerably allowing individual transfers and eliminating the need of synchronizing recipients. In Switzerland the organization 'Veterinary Society for Embryo Transfer' (TIGET) has been founded in 1995 to support practitioners performing embryo transfer.

Animals↗

PubMed2001

Preventing experimental vertical transmission of scrapie by embryo transfer.

This study investigated whether the transmission of naturally occurring scrapie in sheep can be prevented using embryo transfer. Embryos were collected from 38 donor ewes in a Suffolk sheep flock with a high incidence of naturally occurring scrapie, treated with a sanitary procedure (embryo washing) recommended by the International Embryo Transfer Society and then transferred to 58 scrapie-free recipient ewes. Ninety-four offspring were produced. None of the offspring or the recipient ewes developed scrapie. Furthermore, offspring derived from embryos collected from donor ewes bred to the immunohistochemically positive ram did not develop scrapie. We conclude that scrapie was not transmitted to offspring via the embryo nor was the infective agent transmitted to recipient ewes during embryo transfer procedures.

Animals↗

PubMed2004

Effect of treating sperm with low hypo-osmotic swelling test scores with chymotrypsin on pregnancy rates after conventional in vitro fertilization-embryo transfer.

The embryos formed from fertilizing oocytes with sperm with subnormal hypo-osmotic swelling tests with conventional insemination rather than intracytoplasmic sperm injection are very unlikely to implant. The toxic factor transferred to the zona pellucida by such sperm can be negated by pretreating the sperm with the protein digestive enzyme chymotrypsin, resulting in markedly improved implantation rates.

Embryo Transfer↗

PubMed1999

Efficacy of timed embryo transfer with fresh and frozen in vitro produced embryos to increase pregnancy rates in heat-stressed dairy cattle.

Our objective was to determine whether pregnancy rates in heat-stressed dairy cattle could be enhanced by timed embryo transfer of fresh (nonfrozen) or frozen-thawed in vitro-derived embryos compared to timed insemination. Ovulation in Holstein cows was synchronized by a GnRH injection followed 7 d later by PGF2 alpha and a second treatment with GnRH 48 h later. Control cows (n = 129) were inseminated 16 h (d 0) after the second GnRH injection. On d 7, a fresh (n = 133) or frozen-thawed (n = 142) in vitro-derived embryo was transferred to cows assigned for timed embryo transfer after categorizing the corpus luteum by palpation per rectum as 3 (excellent), 2 (good or fair), 1 (poor), and 0 (nonpalpable). Response to the synchronization treatment, determined by plasma progesterone concentration (ng/ml) < or = 1.5 on d 0 and > or = 2.0 on d 7, was 76.2%. Mean plasma progesterone concentration on d 7 increased as the quality of corpus luteum improved from category 0 to 3. Concentrations of progesterone in plasma were elevated (> or = 2.0 ng/ml) at 21 d in 64.7 (fresh embryo), 40.3 (frozen embryo), and 41.4 +/- 0.1% (timed insemination) of cows, respectively. Cows that received a fresh embryo had a greater pregnancy rate at 45 to 52 d than did cows that received a frozen-thawed embryo or timed insemination (14.3 > 4.8, 4.9 +/- 2.3%). Body condition (d 0) of cows influenced the pregnancy rate and plasma progesterone concentrations. In summary, timed embryo transfer with fresh in vitro-produced embryos in heat-stressed dairy cattle improved pregnancy rate relative to timed insemination.

Animals↗

PubMed1997

Potentially important variables identified by transvaginal ultrasound-guided embryo transfer.

Transvaginal ultrasound-guided embryo transfer was performed on 121 consecutive patients. Observation was made of guiding cannula and transfer catheter placement in relation to the endometrial surface and uterine fundus during embryo transfer. The position and movement of a transfer-associated air bubble and the impact of subendometrial myometrial contraction leading to endometrial movement was observed. Results indicate that tactile assessment of embryo transfer catheter placement is unreliable: in 17.4% of transfers the outer guiding catheter inadvertently abutted the fundal endometrium. The outer guiding cannula indented the endometrium in 24.8% and the transfer catheter embedded in the endometrium in 33.1%. Unavoidable sub-endometrial transfers occurred in 22.3% of transfers. Ultrasound-guided transfer avoided accidental tubal transfer in 7.4% of transfers. Transfer catheter withdrawal did not significantly affect embryo transfer-associated air bubble position. Endometrial movement due to sub-endometrial myometrial contraction was obvious in 36.4% of cases, with active motion of the transfer-associated air bubble occurring in 28.1%. Pregnancies occurred in 45.5% of transfers with endometrial movement compared to 15.6% (P < 0.001) without.

Adult↗

PubMed1995

Two instead of three embryo transfer in in-vitro fertilization.

The rational of transferring two instead of three embryos was studied through 468 in-vitro fertilization (IVF) treatment cycles in 287 couples. The quality of 1224 embryos was determined according to the fragmentation rate and the morphology as good (A) and poor (B). The influence of the number of embryos transferred (two or three) on the pregnancy rate when the same quality or combinations of good and poor quality embryos transferred was examined. When only good quality embryos were transferred the pregnancy rates in double (AA) and triple (AAA) embryo transfer were 40.5 (17/42) and 42.9% (30/70) respectively (not significant). When only poor quality embryos were transferred, the pregnancy rates in double (BB) and triple (BBB) embryo transfers were 11.0% (11/100) and 22.9% (16/70) respectively (P < 0.001). On the other hand, when good and poor quality embryos were transferred together as AB in double and as AAB and ABB in triple embryo transfer, the pregnancy rates were 36.8 (14/38) and 39.9% (59/148) respectively (not significant). There was no difference in the miscarriage rate between double and triple embryo transfers; 16.7 and 18.1% respectively. The multiple pregnancy rate was 14.3% for double embryo transfers and 32.4% for triple embryo transfers (P < 0.001). This study demonstrates that if there is at least one good quality embryo available for transfer, then double instead of triple embryo transfer will not yield a significantly lower pregnancy rate. The influence of the number of embryos transferred on the pregnancy rate became significant when only poor quality embryos were transferred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2006

Should a patient's own IVF physician perform the embryo transfer?

PURPOSE: To compare pregnancy rates of embryo transfers performed by a patient's own IVF physician to pregnancy rates of embryo transfers performed by other physicians on the IVF team. METHODS: Retrospective cohort study; University hospital. RESULTS: A total of 3029 embryo transfers were included. 434 patients (14%) had an embryo transfer by their own IVF physician. There was no difference in pregnancy rates comparing patients who had embryos transferred by a different physician than their own IVF physician when all cycle attempts were analyzed [Odds ratio (OR) 1.1; Confidence interval (CI) 0.9-1.4]. There was no significant difference between the groups' population characteristics. A subset analysis of 1st cycle only embryo transfers (n=1416) also revealed no difference in pregnancy rates [OR 1.1; CI 0.8-1.5]. CONCLUSIONS: Patients can be reassured that their chances of pregnancy are the same whether their embryo transfer is performed by their own physician or another physician in the practice.

Embryo Transfer↗

PubMed1989

Transcervical embryo transfer in performance mares.

Pregnancy was established by transcervical transfer of embryos from performance mares into recipient mares. Estrus was synchronized between donor (n = 17) and recipient (n = 43) mares. After a greater than or equal to 25-mm follicle was detected, donor mares were bred artificially daily until ovulation. Day of ovulation was recorded. Uterine flushes (n = 111) were performed on donor mares 7 days after ovulation, and recovered embryos were transferred transcervically to recipient mares within 2 hours. Embryos were recovered from 40.5% of uterine flushes. Of transferred single embryos, 65.7% resulted in pregnancy, detectable by ultrasonographic examination 23 days after transfer. Only 35.3% of twin embryos resulted in pregnancy. Results over a 4-year period were as follows: uteri were flushed on 14, 44, 31 and 22 occasions, and 8, 21, 15, and 11 embryos were recovered (1 embryo was not transferred), with 6, 11, 4, and 6 resulting in 30-day pregnancy in years 1 to 4, respectively.

Animals↗

PubMed2005

Live birth rate is significantly higher after blastocyst transfer than after cleavage-stage embryo transfer when at least four embryos are available on day 3 of embryo culture. A randomized prospective study.

INTRODUCTION: In a randomized controlled trial, we assessed whether pregnancy outcome would be improved by extending embryo culture to day 5 and transferring a blastocyst in patients with at least four good-quality embryos on day 3. METHODS: Multifollicular ovarian stimulation was performed with a GnRH agonist in 44% of patients and with a GnRH antagonist in 56%. Overall, 164 patients younger than 37 years fulfilled embryo quality criteria (at least four having at least six cells on the morning of day 3, maximum 20% anucleate fragments) on the third day of culture and were randomized to the day 3 (n = 84) or day 5 (n = 80) groups. Equal numbers of embryos (n = 2) were transferred in each group. RESULTS: Demographics, stimulation parameters and embryological data were comparable in the two groups. Blastocyst-stage transfer resulted in a significantly higher ongoing pregnancy rate [51.3 versus 27.4%; odds ratio (OR) 2.78, 95% confidence interval (CI) 1.45-5.34] and live birth rate (47.5 versus 27.4%; OR 2.40, 95% CI 1.25-4.59) compared with day-3 embryo transfer. A high twin birth rate was observed in both groups (36.8 versus 30.4%; P > 0.05). CONCLUSIONS: A threshold of four good embryos on the third day of embryo culture appears to indicate that the patient will benefit from embryo transfer at the blastocyst stage and have a better chance of achieving a live delivery than with cleavage-stage embryo transfer.

Adult↗

PubMed2002

Pregnancy rates following timed embryo transfer with fresh or vitrified in vitro produced embryos in lactating dairy cows under heat stress conditions.

Timed embryo transfer (TET) using in vitro produced (IVP) embryos without estrus detection can be used to reduce adverse effects of heat stress on fertility. One limitation is the poor survival of IVP embryos after cryopreservation. Objectives of this study were to confirm beneficial effects of TET on pregnancy rate during heat stress as compared to timed artificial insemination (TAI), and to determine if cryopreservation by vitrification could improve survival of IVP embryos transferred to dairy cattle under heat stress conditions. For vitrified embryos (TET-V), a three-step pre-equilibration procedure was used to vitrify excellent and good quality Day 7 IVP Holstein blastocysts. For fresh IVP embryos (TET-F), Holstein oocytes were matured and fertilized; resultant embryos were cultured in modified KSOM for 7 days using the same method as for production of vitrified embryos. Excellent and good quality blastocysts on Day 7 were transported to the cooperating dairy in a portable incubator. Nonpregnant, lactating Holsteins (n = 155) were treated with GnRH (100 microg, i.m., Day 0), followed 7 days later by prostaglandin F2alpha (PGF2alpha, 25 mg, i.m.) and GnRH (100 microg) on Day 9. Cows in the TAI treatment (n = 68) were inseminated the next day (Day 10) with semen from a single bull that also was used to produce embryos. Cows in the other treatments (n = 33 for TET-F; n = 54 for TET-V) received an embryo on Day 17 (i.e. Day 7 after anticipated ovulation and Day 8 after second GnRH treatment). The proportion of cows that responded to synchronization based on plasma progesterone concentrations on Day 10 and Day 17 was 67.7%. Pregnancy rate for all cows on Day 45 was higher (P < 0.05) in the TET-F treatment than for the TAI and TET-V treatments (19.0 +/- 5.0,6.2 +/- 3.6, and 6.5 +/- 4.1%). For cows responding to synchronization, pregnancy rate was also higher (P < 0.05) for TET-F than for other treatments (26.7 +/- 6.4, 5.0 +/- 4.3, and 7.4 +/- 4.7%). In the TET-F treatment group, cows producing more milk had lower (P < 0.05) pregnancy rates than cows producing less milk. In conclusion, ET of fresh IVP embryos can improve pregnancy rate under heat stress conditions, but pregnancy rate following transfer of vitrified embryos was no better than that following TAI.

Animals↗

PubMedDate not supplied

Clinical practice of embryo transfer.

In this review, several embryo transfer methods are considered, together with factors involved in achieving an effective transfer. The approach most used is transcervical intrauterine transfer. This is described in detail, together with the many variables influencing success, e.g. technical ability and training of personnel, catheter choice, value of a previous 'dummy transfer' and the need to minimize trauma during transfer and so prevent damage to the uterine lining, bleeding and uterine contractions. These factors can each negatively impact on pregnancy rates. Emphasis is put on quality, developmental stage and number of embryos to be transferred to limit multiple pregnancies and their unwanted side-effects. Culture to blastocyst stages and single embryo transfer when optimal quality embryos are available are discussed as means of avoiding multiple pregnancies. Reference is made to embryo cryopreservation and fertility following frozen embryo transfer. Other techniques, such as ultrasound-controlled transcervical intrauterine transfer, and ultrasound-controlled transmyometrial transfer, are reviewed. More invasive procedures, generically grouped as surgical embryo transfer, including gamete intra-Fallopian transfer (GIFT), zygote intra-Fallopian transfer (ZIFT), pronuclear stage transfer and embryo intra-Fallopian transfer (EIFT), are also described. These techniques had a place in IVF when the need to apply assisted reproductive techniques exceeded the capacity of most laboratories, but not today thanks to refined laboratory technology and improved understanding of implantation. Alternative assisted reproductive technologies, such as direct intra-follicular insemination (DIFI), Fallopian spermatic perfusion (FSP), peritoneal oocyte stage and sperm transfer and intra-vaginal culture (IVC), are mentioned briefly.

Cryopreservation↗