A meta-analysis of ultrasound-guided versus clinical touch embryo transfer

OBJECTIVE: To determine the relative efficacy of ultrasound-guided embryo transfer and embryo transfer by clinical touch alone. DESIGN: Systematic review and meta-analysis of randomized, controlled trials comparing ultrasound-guided embryo transfer with embryo transfer by clinical touch alone. SETTING: Infertility centers providing treatment with in vitro fertilization/embryo transfer. PATIENT(S): Women undergoing embryo transfer. INTERVENTION(S): Embryo transfer with or without transabdominal ultrasound guidance. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate and embryo implantation rate. RESULT(S): A total of eight prospective controlled trials were identified. Of these studies, four were nonrandomized or quasi-randomized and four were genuinely randomized. Meta-analysis demonstrated a significantly increased chance of clinical pregnancy following ultrasound-guided embryo transfer in all studies and in the genuinely randomized subgroup. The embryo implantation rate was also significantly increased following ultrasound-guided embryo transfer. CONCLUSION(S): Ultrasound-guided embryo transfer significantly increases the chance of clinical pregnancy and significantly increases the embryo implantation rate.     

The influence of abdominal ultrasound-guided embryo transfer on pregnancy rate: a preliminary report

To determine whether the use of abdominal ultrasound-guided embryo transfer improves the clinical pregnancy rate in patients undergoing in vitro fertilization, 50 fresh cycles with day 3 embryo transfer were studied; 27 patients were randomized to ultrasound-guided transfers, and 23 patients were randomized to clinical touch transfers. Although the clinical pregnancy rate was not statistically different (18.5% in the ultrasound-guided group vs. 17.4% in the clinical touch group), the use of abdominal ultrasound during the embryo transfer procedure provided a greater degree of confidence and satisfaction to both patients and physicians.     

Implantation, clinical pregnancy and miscarriage rates after introduction of ultrasound-guided embryo transfer

The purpose of this study was to compare the reproductive outcome of ultrasound-guided (USG) embryo transfers versus clinical touch embryo transfers. A statistically powered retrospective analysis of women undergoing fresh and frozen embryo transfers in a National Health Service-based tertiary referral centre in the Department of Reproductive Medicine, St Mary's Hospital, Manchester was carried out. A total of 1723 embryo transfers were included in the analysis. The implantation rate was significantly higher in the USG embryo transfer group compared with the non-USG embryo transfer group (fresh: 19.9 versus 9.5%, P < 0.0001; frozen: 13.1 versus 7.3%, P < 0.0004). The clinical pregnancy rate was also significantly higher in the former group (fresh: 26.9 versus 12.5%, P < 0.0001; frozen: 15.6 versus 8.9%, P < 0.0015). For the frozen embryos, the miscarriage rate was significantly elevated among the USG embryo transfer group [unadjusted rate ratio (RR) = 1.65, 95% CI: 1.04, 2.62], but this was of borderline significance when the model was adjusted for the potential confounders (adjusted RR = 1.56, 95% CI: 0.997, 2.45). There was no difference in the ectopic pregnancy rates between the two groups. The findings of this study show that the practice of USG embryo transfer is associated with statistically higher implantation and clinical pregnancy rates in IVF.     

Effect of passive uterine straightening during embryo transfer: a systematic review and meta-analysis

BACKGROUND: Part of the success of ultrasound-guided embryo transfer has been associated with the beneficial effect of uterine straightening by passive bladder distention. Even so, this has not been properly analysed in the literature. METHODS: This is a systematic review and meta-analysis of prospective, randomised, controlled trials, comparing embryo transfer with a full versus empty bladder. Electronic (e.g. PubMed, EMBASE, Cochrane Library) and hand searches were performed to locate trials. Primary outcomes were live-birth, ongoing and clinical pregnancy rates. Secondary outcomes were rates of implantation, miscarriage, multiple and ectopic pregnancies, and retained embryos. Also, the ease of transfer, need for instrumental assistance, and presence of blood on the catheter tip were evaluated. Four studies were identified, of which 1 study was excluded. Meta-analysis was conducted with the Mantel-Haenszel method, utilising the fixed-effect model. RESULTS: For the primary outcome measures, no data was available for the LBR rate. There was a significantly higher chance of an ongoing pregnancy [OR=1.44 (95% CI=1.04-2.04)] and clinical pregnancy [OR=1.55 (95% CI=1.16-2.08)] with a full bladder. For the secondary outcomes, there was a significantly greater incidence of difficulty, or need for instrumental assistance, with an empty bladder. Other outcome measures were not significantly different. CONCLUSION: There is evidence in the literature advising to fill the bladder prior to embryo transfer.     

Pregnancy rates after embryo transfer depend on the provider at embryo transfer

OBJECTIVE: To evaluate the effect of individual providers on pregnancy outcome after embryo transfer. DESIGN: Retrospective data analysis. SETTING: University-based tertiary-care assisted reproductive technology program with 10 physician-providers. PATIENT(S): Six hundred and seventeen women who underwent 854 fresh embryo transfers between January 1996 and January 1999. INTERVENTION(S): Pregnancies after embryo transfer were recorded for each provider. MAIN OUTCOME MEASURE(S): Establishment of a clinical pregnancy. RESULT(S): Three hundred ninety-three clinical pregnancies resulted from 854 embryo transfers, for an overall clinical pregnancy rate of 46.0% per embryo transfer. Three hundred forty-seven (40.6%) pregnancies were ongoing. The clinical pregnancy rate varied significantly between providers: for example, 17.0% (47 transfers) vs. 54.3% (57 transfers) (P<.05). Similarly, the ratio of high-grade embryos required to produce a gestational sac differed between providers. The number or quality of embryos transferred did not differ significantly. CONCLUSION(S): Significant differences were observed in pregnancy rates after embryo transfer done by different providers, suggesting that embryo transfer technique may influence pregnancy outcome in assisted reproductive technology.     

Ectopic pregnancy is not more likely following fresh vs frozen embryo transfer

PURPOSE: To determine if the risk of ectopic pregnancy is greater following frozen vs fresh embryo transfer (ET). METHODS: Retrospective review of pregnancy outcome from January 1, 1997 to November 30, 2003. Cryopreservation was used as a simple freezing method and one-step removal of cryoprotectant. The cycles consisted mostly of graduated estradiol and progesterone supplementation. RESULTS: The ectopic pregnancy rate in 1,445 clinical pregnancies from fresh ET was 2.6% vs 2.0% of 975 clinical pregnancies resulting from frozen ET. CONCLUSION: In contrast to the conclusions of two previous studies, the present study evaluating twice as many clinical pregnancies than the two aforementioned studies combined failed to show any greater risk of ectopic pregnancy when transfers were performed on day 3.     

Transabdominal ultrasound-guided embryo transfer does not increase pregnancy rates in oocyte recipients

OBJECTIVE: To determine whether transabdominal ultrasound guidance during embryo transfer (ET) is a useful tool for increasing pregnancy rates in patients undergoing oocyte donation.DESIGN: Prospective, randomized, controlled trial.SETTING: In vitro fertilization academic center.PATIENT(S): Three hundred seventy-four infertile patients undergoing oocyte donation.INTERVENTION(S): Transabdominal ultrasound-guided ET.MAIN OUTCOME MEASURE(S): We measured the pregnancy rate and implantation rate after transabdominal ultrasound-guided ET versus the rates in a control group who did not receive transabdominal ultrasound-guided ET.RESULT(S): Clear visualization at ultrasound during ET was achieved in 90.8% of the patients who had ultrasound-guided ET. A similar number of easy transfers were performed in both the ultrasound-guided and the control groups (84.5% vs. 86.6%). The pregnancy rate was comparable between the groups (59.9% ultrasound vs. 55.1% control), as was the implantation rate (30.6% ultrasound vs. 26.3% control). No differences were found in the miscarriage rate (10.7% ultrasound vs. 9.1% control) or in the multiple pregnancy rate (21.4% ultrasound vs. 22.5% control). Although all ectopic pregnancies occurred in the group that did not receive ultrasound guidance, the differences were not statistically significant (0 vs. 2.7%).CONCLUSION(S): We could not show any benefit in terms of pregnancy rate in oocyte recipients for whom ET was performed under direct transabdominal ultrasound visualization of the endometrial cavity. There was a lower ectopic pregnancy rate when ultrasound guidance was used, but this rate was not statistically significant in comparison with the pregnancy rate without ultrasound guidance.     

Air fluid versus fluid-only models of embryo catheter loading: a systematic review and meta-analysis

The objective of this systematic review was to determine the beneficial or detrimental effect of using air bubbles to bracket the embryo-containing medium during embryo transfer. To test this theory, a meta-analysis of randomized trials comparing air fluid versus fluid-only methods was performed. The primary outcome measures were live birth, ongoing and clinical pregnancy rates. The secondary outcome measures were the rates of implantation, miscarriage, multiple and ectopic pregnancies and retained embryos. Electronic (e.g.PubMed, EMBASE, Cochrane Library) and hand searches of the literature revealed two included studies (298 women). Meta-analysis was conducted using the Mantel-Haenszel method (fixed-effect model). For the primary outcome measures, there were no significant differences between the two methods with regards to live birth (OR = 1.34; 95% CI = 0.59-3.07), ongoing pregnancy (OR = 1.34; 95% CI = 0.59-3.07) and clinical pregnancy (OR = 1.13; 95% CI = 0.70-1.83) rates. For the secondary outcomes, there were no significant differences between the two groups. In conclusion there is insufficient evidence to suggest that the fluid-only method is superior to the use of air brackets during embryo loading. There is a need for well-designed and powered randomized trials to determine any possible benefit to either method.     

Ectopic pregnancy rates in frozen versus fresh embryo transfer in in vitro fertilization: A systematic review and meta-analysis

ObjectiveTo evaluate whether the rate of ectopic pregnancy differs between fresh and frozen embryo transfers.DesignSystematic review and meta-analysis.SettingCenters for reproductive care.Materials and methodsAn electronic literature search in MEDLINE through PubMed was performed through December 2013. We included clinical trials comparing outcomes of in vitro fertilization (IVF) cycles between fresh and frozen embryo transfers.Main outcome measuresEctopic pregnancy rates from fresh versus frozen IVF cycles.ResultsA meta-analysis revealed no significant difference between ectopic pregnancy rates in fresh versus frozen embryo transfer. Similarly, there was no difference between ectopic pregnancy rates in natural-cycle frozen embryo transfer versus programmed cycles.ConclusionsDifferences in the hormonal milieu of the uterine environment between fresh and frozen embryo transfer stimulation do not appear to affect the ectopic pregnancy rate. More directed studies are needed before a definite recommendation can be made as to which is safer for prevention of ectopic pregnancy– fresh or frozen embryo transfer.     

Human chorionic gonadotropin levels after blastocyst transfer are highly predictive of pregnancy outcome.

OBJECTIVE: To determine the predictive value(s) of beta-hCG serum levels for pregnancy outcome following blastocyst transfer. DESIGN: Retrospective review. SETTING: University-based assisted reproductive technology (ART) program. PATIENTS: All ART patients enrolled from January 1998 to December 1999. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Beta-hCG serum levels and pregnancy outcomes. RESULT(S): Of the 836 ART cycles initiated, 608 embryo transfers met study criteria and were assigned to one of two groups: 248 day 5 blastocyst transfers or 360 day 3 embryo transfers. In the day 5 blastocyst group, 147 pregnancies occurred (59.2%), and day 3 transfers resulted in 165 pregnancies (45.8%). For day 3 and day 5 transfers, mean values of beta-hCG on day 16 post-retrieval of spontaneous abortions were lower than ongoing pregnancies (P< .05). A beta-hCG value on day 16 of >300 mIU/mL predicted an ongoing pregnancy for day 5 transfer group in 97% of pregnancies compared with 92% for day 3 embryo transfers. A multiple gestation was observed in 70% of pregnancies with a beta-hCG level >400 mIU/mL in the day 5 group compared with 63% for the day 3 group. The incidence of higher-order multiple gestations was significantly lower in the day 5 blastocyst group (P< .05). CONCLUSION(S): Beta-hCG serum levels on day 16 post-retrieval were highly predictive of pregnancy outcome after a blastocyst transfer.     

Serum oestradiol and beta-HCG measurements after day 3 or 5 embryo transfers in interpreting pregnancy outcome

The aim of this study was to assess the clinical value of serum oestradiol concentration 8 days after embryo transfer (D8E2) and beta-human chorionic gonadotrophin (HCG-beta) concentration 12 days after embryo transfer (D12HCG-beta) in the prediction of pregnancy and the outcome of pregnancy following assisted reproduction, taking into account the day of transfer, which was either day 3 (D3) or day 5 (D5). The objective was to improve patient counselling by giving quantitative and reliable predictive information instead of non-specific uncertainties. A total of 2035 embryo transfer cycles performed between January 2003 and June 2005 were analysed retrospectively. Biochemical pregnancy, ectopic pregnancy and first-trimester abortions were classified as non-viable pregnancies; pregnancies beyond 12 weeks gestation were classified as ongoing pregnancies (OP). Significantly higher D8E2 and D12HCG-beta were obtained in D5 transfers compared with D3 transfers with regard to pregnancy and OP (P相似文献   

Embryo fragmentation in vitro and its impact on treatment and pregnancy outcome

OBJECTIVE: To determine the impact of embryo fragmentation on pregnancy, obstetric, and perinatal outcome. DESIGN: Retrospective analysis of embryo transfers that were homogeneous in regard to the degree of fragmentation. SETTING: Fertility center. PATIENT(S): A cohort of 460 fresh embryo transfers. INTERVENTION(S): A total of 164 pregnancies were analyzed for the incidence of antepartum complications during gestation, obstetric (multiple pregnancy, preterm delivery, cesarean section), and perinatal outcome (sex, birth weight, admission to neonatal intensive care unit, malformations). MAIN OUTCOME MEASURE(S): Implantation and clinical pregnancy rate, obstetric and perinatal outcome. RESULT(S): Embryo fragmentation and number of embryos per transfer showed a significant influence on clinical pregnancy and implantation rate. No such relation was found concerning complications, multiple pregnancy rate, incidence of cesarean section, gestation week, birth weight, and average time at the neonatology. On the other hand, pregnancies derived from bad-quality embryos had a significantly higher rate of malformations. CONCLUSION(S): The higher percentage of malformations found in bad-quality embryos may be due to a higher percentage of apoptotic features and chromosomal disorders. For ethical reasons, the transfer of embryos with >50% fragmentation should be considered only after consultation with the patient.     

Successful birth after transfer of vitrified human blastocysts with use of a cryoloop containerless technique

OBJECTIVE: Clinical application of vitrification for the cryopreservation of human blastocysts. DESIGN: Clinical trial of vitrification of human blastocysts. SETTING: Private assisted reproductive technology clinic. PATIENT(S): Supernumerary blastocysts after fresh blastocyst transfer were vitrified for subsequent transfer. INTERVENTION(S): Culture of pronuclear embryos to the blastocyst stage in sequential media and subsequent vitrification of supernumerary blastocysts using a cryoloop technique. MAIN OUTCOME MEASURE(S): Clinical outcome after transfer of vitrified blastocysts. RESULT(S): A total of 60 vitrified blastocysts from 21 patients were warmed, and the survival rate at 2 hours after warming was 63%. Six clinical pregnancies were achieved after 19 transfers. One healthy baby was born, four pregnancies are ongoing, and one ended in miscarriage. CONCLUSION(S): Human blastocysts can be successfully vitrified by suspension on a small nylon loop and a direct plunge into liquid nitrogen. A delivery and ongoing pregnancies prove the safety of this method. This report documents the first successful pregnancy and delivery achieved by blastocyst vitrification using the cryoloop containerless technique.     

A Comparison of Early Pregnancy Failure and Ongoing Pregnancy Rates Between Fresh and Frozen Embryo Transfer Following In Vitro Fertilization

Summary: In order to compare pregnancy outcomes following fresh and frozen embryo transfer after invitro 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.     

胚胎移植技术对体外受精-胚胎移植结果的影响——653例临床分析

目的:分析胚胎移植技术与体外受精后临床妊娠、种植率和继续妊娠率之间的关系。方法:回顾性分析653例新鲜胚胎移植,比较移植情况和临床结果之间的关系。结果:腹部超声引导下胚胎移植后临床妊娠率为47.3%,种植率25.0%,继续妊娠39.7%。移植管顶端位于宫内不同位置以及血染情况不影响结果。8.8%困难移植明显降低种植率(20%比26%),临床妊娠率也降低(35.8%比48.3%),但无统计学差异。结论:腹部超声引导下胚胎移植可以达到较好的临床结果。胚胎放置在宫腔内不同位置以及移植管血染不影响临床结果,但要尽量避免困难移植.     

Difficult embryo transfers or blood on catheter and assisted reproductive outcomes: a systematic review and meta-analysis

We performed a systematic review and meta-analysis to examine whether a difficult embryo transfer or the presence of blood on the transfer catheter affects assisted reproduction outcomes. We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS). We aimed to determine the risk ratio (RR) associated with difficult embryo transfer or the presence of blood on the transfer catheter for the following outcomes: live birth, clinical pregnancy, and miscarriage. We identified 3066 papers, of which 194 were reviewed and nine were included. The outcome of live birth was not reported in any of the included studies and the effect on miscarriage was too imprecise for any conclusions. Pooled analysis of five studies demonstrated lower clinical pregnancy rates following a non-easy embryo transfer (RR = 0.75; 95% CI = 0.66–0.86). This included three studies showing subjectively difficult transfers reducing clinical pregnancies (RR = 0.67; 95% CI = 0.51–0.87) and two studies in which the need for additional manoeuvers reduced clinical pregnancies (RR = 0.78; 95% CI = 0.67–0.91). The presence of blood on the transfer catheter did not affect clinical pregnancy rates (RR = 0.96; 95% CI = 0.82–1.14) in five studies. We concluded that low quality evidence suggests that a difficult embryo transfer but not a bloody catheter reduces the chance of achieving a clinical pregnancy. More good quality studies are needed to evaluate the effect of difficult embryo transfer and the presence of blood on the catheter on the main outcomes of assisted reproduction.     

Impact of transabdominal ultrasound guidance on performance and outcome of transcervical uterine embryo transfer

Purpose : To determine the impact of transabdominal ultrasound guidance on embryo transfer during IVF therapy. Methods : Retrospective analysis of 823 consecutive embryo transfers. Three hundred and sixty-seven procedures performed with transabdominal ultrasound guidance were compared to 456 cases performed with the clinical touch method. Results : Ultrasound-guided embryo transfer yielded higher, but not statistically significant, clinical pregnancy (48% vs. 44%) and implantation rates (22% vs. 20%). The incidence of multiple pregnancies, ectopic and multiple pregnancy rates were similar. The frequency of negative factors typically associated with difficult transfers, such as requirement of use of tenaculum, and presence of blood or mucus in the catheter tip, were significantly lower in the ultrasound-guided group in comparison with the clinical touch group. Ultrasound-guided embryo transfer was associated with a significantly increased easiness of transfer performance; 95% of the transfers were rated as very easy in the ultrasound-guidance group compared to 87% in the clinical touch group. The use of a soft pass catheter was the only variable independently and significantly associated with pregnancy success (odds ratio = 2.74). Conclusion(s) : Ultrasound-guidance facilitates embryo transfer and in combination with the use of a soft catheter should be implemented to optimize embryo transfer results.     

The impact of embryo quality and quantity on implantation and the establishment of viable pregnancies

The role of cleavage rates, number of embryos transferred, and some other variables in pregnancy outcome in 222 human embryo transfers was studied. Pregnancy rates were significantly higher in a group of 117 patients receiving at least one embryo that had reached the four-cell stage at 40 hr postinsemination (26% total pregnancies/transfer and 18% ongoing pregnancies/transfer) than in the 105 patients receiving embryos developing at a slower rate (7% total pregnancies/transfer and 2% ongoing pregnancies/transfer). Of the 23 ongoing or term pregnancies produced, 21 came from transfers of at least one embryo that had reached four-cell stage by 40 hr postinsemination. Pregnancy rates were unaffected in either the fast-cleaving or the slower-cleaving embryos by culturing in vitro for an additional 24 hr. The presence of anucleate cell fragments also had no effect on pregnancy rates. Pregnancy rates increased progressively with the transfer of more embryos per transfer. These results suggest that procedures to improve ovulation induction and in vitro embryo culture technique may better the success of in vitro fertilization by providing a high number of rapidly cleaving embryos for transfer.     

卵巢高反应患者全胚冷冻临床应用研究

目的 探讨卵巢高反应患者新鲜移植周期与冻融胚胎移植(frozen-thawed embryo transfer, FET)周期妊娠结局的差异,了解促排卵药物对新鲜周期子宫内膜容受性的影响。方法 回顾性分析2011年1月至2013年12月在中国医科大学附属盛京医院生殖中心促排卵周期行新鲜胚胎移植(582例)和全部胚胎冷冻再行FET(167例)周期的临床妊娠率、生化妊娠率、种植率、胚胎停育率、异位妊娠率、流产率、持续妊娠率和多胎妊娠率。结果 582例促排卵周期新鲜胚胎移植与167例FET周期比较临床妊娠率（42.44% vs. 69.46%）,生化妊娠率（7.22% vs. 2.99%）,种植率（28.27% vs. 48.99%）,胚胎停育率（8.10% vs. 7.76%）,异位妊娠率（5.26% vs. 4.31%）,流产率（8.10% vs. 6.90%）,持续妊娠率（34.19% vs. 59.88%）,多胎率（35.22% vs. 37.93%）。组间比较临床妊娠率、生化妊娠率、种植率、持续妊娠率差异均有统计学意义(P<0.05)。结论 全胚冷冻再行冻融周期移植可显著提高卵巢高反应患者临床妊娠率、种植率及持续妊娠率,不增加多胎率的发生,可获得更为理想的妊娠结局。新鲜周期高雌激素可能对子宫内膜容受性有损害作用。     

Ectopic pregnancies after in vitro fertilization and embryo transfer

Objective Our objective was to analyze the risk factors, stimulation characteristics, and future fecundity of patients with ectopic pregnancies after in vitro fertilization (IVF).Methods We retrospectively evaluated all cases of ectopic pregnancy occurring between January 1989 and March 1993 (Cornell series 1 to 17). A case-control group of intrauterine pregnancies was used for comparison of the stimulation and transfer characteristics.Results Twenty-seven of 1123 pregnancies (2.4%) were ectopic, following 2812 fresh IVF embryo transfers, while 8 of 105 pregnancies (7.6%) were ectopic, following 405 frozen-thawed embryo transfers. Tubal factor was the cause of infertility in the majority (85.7%) of ectopic pregnancies. No difference was found between the ectopics and the matched controls in stimulation and transfer characteristics. Thirty ectopic pregnancies were ampullary, two were interstitial, two were cervical, and one was heterotopic. Twenty of the patients subsequently underwent 29 IVF attempts, with a pregnancy rate of 41.4% per transfer.Conclusions Ectopic pregnancy after IVF appears to be related to preexisting tubal pathology; embryo transfer of cryopreserved thawed embryos in a natural cycle may result in a higher ectopic rate in these patients; in subsequent IVF cycles the intrauterine pregnancy rate of these patients is not decreased.