Experience with the elective transfer of two embryos under the conditions of the german embryo protection law: results of a retrospective data analysis of 2573 transfer cycles

Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection

BACKGROUND

Transfer of more than one embryo during in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) increases multiple pregnancy rates resulting in an increased risk of maternal and perinatal morbidity. Elective single embryo transfer offers a means of minimising this risk, but this potential gain needs to be balanced against the possibility of jeopardising the overall live birth rate (LBR).

OBJECTIVES

To evaluate the effectiveness and safety of different policies for the number of embryos transferred in infertile couples undergoing assisted reproductive technology cycles.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group specialised register of controlled trials, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to March 2020. We handsearched reference lists of articles and relevant conference proceedings. We also communicated with experts in the field regarding any additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different policies for the number of embryos transferred following IVF or ICSI in infertile women. Studies of fresh or frozen and thawed transfer of one to four embryos at cleavage or blastocyst stage were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial eligibility and risk of bias. The primary outcomes were LBR and multiple pregnancy rate. The secondary outcomes were clinical pregnancy and miscarriage rates. We analysed data using risk ratios (RR), Peto odds ratio (Peto OR) and a fixed effect model.

MAIN RESULTS

We included 17 RCTs in the review (2505 women). The main limitation was inadequate reporting of study methods and moderate to high risk of performance bias due to lack of blinding. A majority of the studies had low numbers of participants. None of the trials compared repeated single embryo transfer (SET) with multiple embryo transfer. Reported results of multiple embryo transfer below refer to double embryo transfer. Repeated single embryo transfer versus multiple embryo transfer in a single cycle Repeated SET was compared with double embryo transfer (DET) in four studies of cleavage-stage transfer. In these studies the SET group received either two cycles of fresh SET (one study) or one cycle of fresh SET followed by one frozen SET (three studies). The cumulative live birth rate after repeated SET may be little or no different from the rate after one cycle of DET (RR 0.95, 95% CI (confidence interval) 0.82 to 1.10; I² = 0%; 4 studies, 985 participants; low-quality evidence). This suggests that for a woman with a 42% chance of live birth following a single cycle of DET, the repeated SET would yield pregnancy rates between 34% and 46%. The multiple pregnancy rate associated with repeated SET is probably reduced compared to a single cycle of DET (Peto OR 0.13, 95% CI 0.08 to 0.21; I² = 0%; 4 studies, 985 participants; moderate-quality evidence). This suggests that for a woman with a 13% risk of multiple pregnancy following a single cycle of DET, the risk following repeated SET would be between 0% and 3%. The clinical pregnancy rate (RR 0.99, 95% CI 0.87 to 1.12; I² = 47%; 3 studies, 943 participants; low-quality evidence) after repeated SET may be little or no different from the rate after one cycle of DET. There may be little or no difference in the miscarriage rate between the two groups. Single versus multiple embryo transfer in a single cycle A single cycle of SET was compared with a single cycle of DET in 13 studies, 11 comparing cleavage-stage transfers and three comparing blastocyst-stage transfers.One study reported both cleavage and blastocyst stage transfers. Low-quality evidence suggests that the live birth rate per woman may be reduced in women who have SET in comparison with those who have DET (RR 0.67, 95% CI 0.59 to 0.75; I² = 0%; 12 studies, 1904 participants; low-quality evidence). Thus, for a woman with a 46% chance of live birth following a single cycle of DET, the chance following a single cycle of SET would be between 27% and 35%. The multiple pregnancy rate per woman is probably lower in those who have SET than those who have DET (Peto OR 0.16, 95% CI 0.12 to 0.22; I² = 0%; 13 studies, 1952 participants; moderate-quality evidence). This suggests that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following a single cycle of SET would be between 2% and 4%. Low-quality evidence suggests that the clinical pregnancy rate may be lower in women who have SET than in those who have DET (RR 0.70, 95% CI 0.64 to 0.77; I² = 0%; 10 studies, 1860 participants; low-quality evidence). There may be little or no difference in the miscarriage rate between the two groups.

AUTHORS' CONCLUSIONS

Although DET achieves higher live birth and clinical pregnancy rates per fresh cycle, the evidence suggests that the difference in effectiveness may be substantially offset when elective SET is followed by a further transfer of a single embryo in fresh or frozen cycle, while simultaneously reducing multiple pregnancies, at least among women with a good prognosis. The quality of evidence was low to moderate primarily due to inadequate reporting of study methods and absence of masking those delivering, as well as receiving the interventions.

The impact of the embryo quality on the risk of multiple pregnancies

The aim of the present study was to determine the chance of pregnancy and the risk of multiple pregnancies taking into account the number and quality of transferred embryos in patients >36 years old or ≤36 years old. For this study, 1497 patients undergoing intra-cytoplasmic sperm injection (ICSI) cycles in a private assisted reproduction centre were split into groups according to the number and quality of the transferred embryos on the third or fifth day of development. The pregnancy rate and multiple pregnancy rate were compared between the embryo quality groups in patients <36 years old or ≥36 years old. In patients <36 years old, for the day 3 embryo transfer, no significant difference was noted in the pregnancy rate when the groups were compared. However the multiple pregnancy rate was increased by the transfer of an extra low-quality embryo (17.1 versus 28.2%, P = 0.020). For day 5 embryo transfer, the transfer of an extra blastocyst significantly increased the pregnancy rate (36.0 versus 42.4%, P < 0.001) and the multiple pregnancy rate (4.4 versus 16.9%, P < 0.001). In older patients, no significant difference was noted in the pregnancy rate when the groups were compared. However, when an extra low-quality embryo was transferred, a significantly increased rate of multiple pregnancies was observed for day 3 (18.2 versus 26.4%, P = 0.049) and day 5 embryo transfers (5.2 versus 16.1%, P < 0.001). In conclusion, the transfer of an extra low-quality embryo may increase the risk of a multiple pregnancy. In younger patients, the transfer of an extra low-quality blastocyst may also increase the chance of pregnancy.

Embryo culture and selection: morphological criteria

In this chapter, we have outlined the various morphological criteria for selection of the best embryo at each important milestone encountered in the progress from the oocyte to the blastocyst. As Gerris et al. stated, a combination of one, two, or even three selection points should lead to a more accurate selection of the best embryo, as no one criterion is better than the other. An embryo that fails to meet the entire set of selection criteria must be avoided as culture cannot correct an impaired embryo.

The combination of pronuclear and blastocyst morphology: a strong prognostic tool for implantation potential

PURPOSE

To (i) investigate a possible association between different features of pronuclear (PN) morphology and different features of blastocyst morphology, (ii) evaluate the combination of PN and blastocyst morphologies as a predictive factor for ICSI outcomes and (iii) identify possible contributing factors to poor PN morphology.

METHODS

This study included 908 normally fertilised zygotes reaching full blastocyst stage, obtained from 350 patients undergoing ICSI cycles, in which the implantations rates were 0 % or 100 %. The influence of PN morphology on blastocyst morphology and on the rates of pregnancy and miscarriage was investigated. Embryos were graded and split into three groups, taking into consideration both the PN and the blastocyst status. The pregnancy rate was compared among these groups.

RESULTS

Inner cell mass (ICM) alterations were correlated with the number of nucleolar precursor bodies (NPB), while trophectoderm alterations were correlated with the size of the pronuclei and the distribution of the NPB. The distribution of the NPB had an impact on the chances of pregnancy. A significant difference was observed among the groups regarding the pregnancy rate. The maternal age, number of aspirated follicles and number of retrieved oocytes influenced the incidence of PN defects.

CONCLUSIONS

These findings suggest that a lower oocyte yield may lead to higher-quality PN zygotes. In addition, different PN features may influence further embryo development, especially the quality of the blastocyst. Moreover, the association between PN and blastocyst morphology may be used as a prognostic tool for implantation.

Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection

BACKGROUND

Multiple embryo transfer during in vitro fertilisation (IVF) increases multiple pregnancy rates causing maternal and perinatal morbidity. Single embryo transfer is now being seriously considered as a means of minimising the risk of multiple pregnancy. However, this needs to be balanced against the risk of jeopardising the overall live birth rate.

OBJECTIVES

To evaluate the effectiveness and safety of different policies for the number of embryos transferred in couples who undergo assisted reproductive technology (ART).

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, from inception to July 2013. We handsearched reference lists of articles, trial registers and relevant conference proceedings and contacted researchers in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different policies for the number of embryos transferred following IVF or intra-cytoplasmic sperm injection (ICSI) in subfertile women. Studies of fresh or frozen and thawed transfer of one, two, three or four embryos at cleavage or blastocyst stage were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias and extracted the data. The overall quality of the evidence was graded in a summary of findings table.

MAIN RESULTS

Fourteen RCTs were included in the review (2165 women). Thirteen compared cleavage-stage transfers (2017 women) and two compared blastocyst transfers (148 women): one study compared both. No studies compared repeated multiple versus repeated single embryo transfer (SET). DET versus repeated SETDET was compared with repeated SET in three studies of cleavage-stage transfer. In these studies the SET group received either two cycles of fresh SET (one study) or one cycle of fresh SET followed by one frozen SET in a natural or hormone-stimulated cycle (two studies). When these three studies were pooled, the cumulative live birth rate after one cycle of DET was not significantly different from the rate after repeated SET (OR 1.22, 95% CI 0.92 to 1.62, three studies, n=811, I(2)=0%, low quality evidence). This suggests that for a woman with a 40% chance of live birth following a single cycle of DET, the chance following repeated SET would be between 30% and 42%. The multiple pregnancy rate was significantly higher in the DET group (OR 30.54, 95% CI 7.46 to 124.95, three RCTs, n = 811, I(2) = 23%, low quality evidence), suggesting that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following repeated SET would be between 0% and 2%. Single-cycle DET versus single-cycle SETA single cycle of DET was compared with a single cycle of SET in 10 studies, nine comparing cleavage-stage transfers and two comparing blastocyst-stage transfers. When all studies were pooled the live birth rate was significantly higher in the DET group (OR 2.07, 95% CI 1.68 to 2.57, nine studies, n = 1564, I(2) = 0%, high quality evidence). This suggests that for a woman with a 40% chance of live birth following a single cycle of DET, the chance following a single cycle of SET would be between 22% and 30%. The multiple pregnancy rate was also significantly higher in the DET group (OR 8.47, 95% CI 4.97 to 14.43, 10 studies, n = 1612, I(2) = 45%, high quality evidence), suggesting that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following a single cycle of SET would be between 1% and 4%. The heterogeneity for this analysis was attributable to a study with a high rate of cross-over between treatment arms. Other comparisons Other fresh cycle comparisons were evaluated in three studies which compared DET versus transfer of three or four embryos. Live birth rates did not differ significantly between the groups for any comparison, but there was a significantly lower multiple pregnancy rate in the DET group than in the three embryo transfer (TET) group (OR 0.36, 95% CI 0.13 to 0.99, two studies, n = 343, I(2) = 0%).

AUTHORS' CONCLUSIONS

In a single fresh IVF cycle, single embryo transfer is associated with a lower live birth rate than double embryo transfer. However, there is no evidence of a significant difference in the cumulative live birth rate when a single cycle of double embryo transfer is compared with repeated SET (either two cycles of fresh SET or one cycle of fresh SET followed by one frozen SET in a natural or hormone-stimulated cycle). Single embryo transfer is associated with much lower rates of multiple pregnancy than other embryo transfer policies. A policy of repeated SET may minimise the risk of multiple pregnancy in couples undergoing ART without substantially reducing the likelihood of achieving a live birth. Most of the evidence currently available concerns younger women with a good prognosis.

The effects of acupuncture on rates of clinical pregnancy among women undergoing in vitro fertilization: a systematic review and meta-analysis

BACKGROUND Recent systematic reviews of adjuvant acupuncture for IVF have pooled heterogeneous trials, without examining variables that might explain the heterogeneity. The aims of our meta-analysis were to quantify the overall pooled effects of adjuvant acupuncture on IVF clinical pregnancy success rates, and evaluate whether study design-, treatment- and population-related factors influence effect estimates. METHODS We included randomized controlled trials that compared needle acupuncture administered within 1 day of embryo transfer, versus sham acupuncture or no adjuvant treatment. Our primary outcome was clinical pregnancy rates. We obtained from all investigators additional methodological details and outcome data not included in their original publications. We analysed sham-controlled and no adjuvant treatment-controlled trials separately, but since there were no large or significant differences between these two subsets, we pooled all trials for subgroup analyses. We prespecified 11 subgroup variables (5 clinical and 6 methodological) to investigate sources of heterogeneity, using single covariate meta-regressions. RESULTS Sixteen trials (4021 participants) were included in the meta-analyses. There was no statistically significant difference between acupuncture and controls when combining all trials [risk ratio (RR) 1.12, 95% confidence interval (CI), 0.96-1.31; I(2) = 68%; 16 trials; 4021 participants], or when restricting to sham-controlled (RR 1.02, 0.83-1.26; I(2) = 66%; 7 trials; 2044 participants) or no adjuvant treatment-controlled trials (RR 1.22, 0.97-1.52; I(2) = 67%; 9 trials; 1977 participants). The type of control used did not significantly explain the statistical heterogeneity (interaction P = 0.27). Baseline pregnancy rate, measured as the observed rate of clinical pregnancy in the control group of each trial, was a statistically significant effect modifier (interaction P < 0.001), and this covariate explained most of the heterogeneity of the effects of adjuvant acupuncture across all trials (adjusted R(2) = 93%; I(2) residual = 9%). Trials with lower control group rates of clinical pregnancy showed larger effects of adjuvant acupuncture (RR 1.53, 1.28-1.84; 7 trials; 1732 participants) than trials with higher control group rates of clinical pregnancy (RR 0.90, 0.80-1.01; 9 trials; 2289 participants). The asymmetric funnel plot showed a tendency for the intervention effects to be more beneficial in smaller trials. CONCLUSIONS We found no pooled benefit of adjuvant acupuncture for IVF. The subgroup finding of a benefit in trials with lower, but not higher, baseline pregnancy rates (the only statistically significant subgroup finding in our earlier review) has been confirmed in this update, and was not explained by any confounding variables evaluated. However, this baseline pregnancy rate subgroup finding among published trials requires further confirmation and exploration in additional studies because of the multiple subgroup tests conducted, the risk of unidentified confounders, the multiple different factors that determine baseline rates, and the possibility of publication bias.

Differences in the transcriptional profiles of human cumulus cells isolated from MI and MII oocytes of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women. The abnormalities of endocrine and intra-ovarian paracrine interactions may change the microenvironment for oocyte development during the folliculogenesis process and reduce the developmental competence of oocytes in PCOS patients who are suffering from anovulatory infertility and pregnancy loss. In this microenvironment, the cross talk between an oocyte and the surrounding cumulus cells (CCs) is critical for achieving oocyte competence. The aim of our study was to investigate the gene expression profiles of CCs obtained from PCOS patients undergoing IVF cycles in terms of oocyte maturation by using human Genome U133 Plus 2.0 microarrays. A total of 59 genes were differentially expressed in two CC groups. Most of these genes were identified to be involved in one or more of the following pathways: receptor interactions, calcium signaling, metabolism and biosynthesis, focal adhesion, melanogenesis, leukocyte transendothelial migration, Wnt signaling, and type 2 diabetes mellitus. According to the different expression levels in the microarrays and their putative functions, six differentially expressed genes (LHCGR, ANGPTL1, TNIK, GRIN2A, SFRP4, and SOCS3) were selected and analyzed by quantitative RT-PCR (qRT-PCR). The qRT-PCR results were consistent with the microarray data. Moreover, the molecular signatures (LHCGR, TNIK, and SOCS3) were associated with developmental potential from embryo to blastocyst stage and were proposed as biomarkers of embryo viability in PCOS patients. Our results may be clinically important as they offer a new potential strategy for competent oocyte/embryo selection in PCOS patients.

Number of embryos for transfer following in-vitro fertilisation or intra-cytoplasmic sperm injection

BACKGROUND

Multiple embryo transfer during IVF has increased multiple pregnancy rates (MPR) causing maternal and perinatal morbidity. Elective single embryo transfer (SET) is now being considered as an effective means of reducing this iatrogenic complication.

OBJECTIVES

To determine in couples undergoing IVF/ICSI (intra-cytoplasmic sperm injection) whether:(1) elective transfer of two embryos improves the probability of livebirth compared with:(a) elective single embryo transfer,(b) three embryo transfer (TET) or(c) four embryo transfer (FET).(2) elective transfer of three embryos improves the probability of livebirth compared with:(a) elective single embryo transfer, or(b) elective four embryo transfer.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group's trials register (searched March 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library, Issue 1, 2008), MEDLINE (1970 to 2008), EMBASE (1985 to 2008) and reference lists of articles. Relevant conference proceedings were hand-searched and researchers in the field contacted.

SELECTION CRITERIA

Randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility and quality of trials.

MAIN RESULTS

For the update in 2008 five trials compared DET with SET. DET versus TET and DET versus FET were evaluated in a single small trial each. The difference in cumulative livebirth rates (CLBR) after DET and those after SET followed by transfer of a single frozen thawed embryo (1FZET) was not statistically significant (OR 0.81, 95% CI 0.59 to 1.11; p=0.18). There was no statistically significant difference in CLBR after a single fresh cycle of DET versus two fresh cycles of SET (OR 1.23, 95% CI 0.56 to 2.69, p= 0.60 ). The live birth rate (LBR) per woman in a single fresh treatment was higher following DET than SET (OR 2.10, 95% CI 1.65 to 2.66, p<0.00001). The MPR was lower following SET (OR 0.04, 95% CI 0.01 to 0.11; p< 0.00001). The CLBR following two fresh cycles of DET versus two fresh cycles of TET (OR 0.77, 95%CI 0.22 to 2.65, p=0.67) and CLBR after three fresh cycles of DET versus three fresh cycles of TET showed no statistically significant differences (OR 0.77, 95% CI 0.24 to 2.52; p=0.67). There were no statistically significant differences between DET and TET in terms of LBR (OR 0.40, 95%CI 0.09 to 1.85; p=0.24) and MPR (OR 0.17, 95%CI 0.01 to 3.85; p= 0.27). DET led to lower LBR than FET but the difference was not statistically significant (OR 0.35, 95% CI 0.11 to 1.05; p = 0.06).

AUTHORS' CONCLUSIONS

In a single fresh IVF cycle, SET is associated with a lower LBR than DET. However there is no significant difference in CLBR following SET+ 1FZET and the LBR following a single cycle of DET. MPR are lowered following SET compared with other transfer policies. There are insufficient data on the outcome of two versus three and four embryo transfer policies.

Affordable ART for developing countries: a cost benefit comparison of low dose stimulation versus high dose GnRH antagonist protocol

OBJECTIVE

Low dose stimulation (LS) is emerging as an alternative regime in assisted reproductive technology (ART). This study aimed to compare the cost-effectiveness of LS to the high dose GnRH antagonist (Atg) regime.

METHODS

An observational prospective study conducted at an academic infertility unit from January to June 2007. Outcome measures included the numbers of follicles, oocytes and embryos, morphological quality of oocytes and embryos, clinical pregnancy (PR) and complication rate.

RESULT

Ninety five first attempt ICSI cycles consisting of 54 LS and 41 Atg were analyzed. Subjects in both groups had comparable sociodemographics and reproductive characteristics. LS generated significantly fewer follicles, total oocytes, mature oocytes (all p < 0.0005) and immature oocytes (p = 0.009) than Atg but the number of excellent quality oocytes was similar. Significantly fewer embryos were available in LS although the proportion of usable embryos was higher, 83.2% vs. 67.0% for Atg. Mean embryos per transfer was 2.0 +/- 1.1 vs. 2.6 +/- 1.0 (p = 0.02) for a clinical PR per transfer of 43.2% vs. 50.0% for LS and Atg respectively. LS regime had a shorter gonadotrophin administration period with resultant COH cost one third of the Atg protocol (both, p < 0.0005). The cost per live birth per started cycle worked out to be USD 13,200 and 24,900 for LS and Atg respectively. Furthermore, LS had fewer incidences of OHSS compared to the Atg regime, 3.7% vs. 12.2%.

CONCLUSION

LS cost benefits included lower amounts of gonadotrophin used and fewer injections. It is a viable alternative regime in producing comparable clinical PR at lower cost and less complication in ART.

Effects of acupuncture on rates of pregnancy and live birth among women undergoing in vitro fertilisation: systematic review and meta-analysis

OBJECTIVE

To evaluate whether acupuncture improves rates of pregnancy and live birth when used as an adjuvant treatment to embryo transfer in women undergoing in vitro fertilisation.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Cochrane Central, Embase, Chinese Biomedical Database, hand searched abstracts, and reference lists. Review methods Eligible studies were randomised controlled trials that compared needle acupuncture administered within one day of embryo transfer with sham acupuncture or no adjuvant treatment, with reported outcomes of at least one of clinical pregnancy, ongoing pregnancy, or live birth. Two reviewers independently agreed on eligibility; assessed methodological quality; and extracted outcome data. For all trials, investigators contributed additional data not included in the original publication (such as live births). Meta-analyses included all randomised patients.

DATA SYNTHESIS

Seven trials with 1366 women undergoing in vitro fertilisation were included in the meta-analyses. There was little clinical heterogeneity. Trials with sham acupuncture and no adjuvant treatment as controls were pooled for the primary analysis. Complementing the embryo transfer process with acupuncture was associated with significant and clinically relevant improvements in clinical pregnancy (odds ratio 1.65, 95% confidence interval 1.27 to 2.14; number needed to treat (NNT) 10 (7 to 17); seven trials), ongoing pregnancy (1.87, 1.40 to 2.49; NNT 9 (6 to 15); five trials), and live birth (1.91, 1.39 to 2.64; NNT 9 (6 to 17); four trials). Because we were unable to obtain outcome data on live births for three of the included trials, the pooled odds ratio for clinical pregnancy more accurately represents the true combined effect from these trials rather than the odds ratio for live birth. The results were robust to sensitivity analyses on study validity variables. A prespecified subgroup analysis restricted to the three trials with the higher rates of clinical pregnancy in the control group, however, suggested a smaller non-significant benefit of acupuncture (odds ratio 1.24, 0.86 to 1.77).

CONCLUSIONS

Current preliminary evidence suggests that acupuncture given with embryo transfer improves rates of pregnancy and live birth among women undergoing in vitro fertilisation.

Pregnancy outcomes after assisted reproductive technology

OBJECTIVE

To review the effect of assisted reproductive technology (ART) on perinatal outcomes, to provide guidelines to optimize obstetrical management and counselling of Canadian women using ART, and to identify areas specific to birth outcomes and ART requiring further research.

OPTIONS

Perinatal outcomes of ART pregnancies in subfertile women are compared with those of spontaneously conceived pregnancies. Perinatal outcomes are compared between different types of ART.

OUTCOMES

This guideline discusses the adverse outcomes that have been recorded in association with ART, including obstetrical complications, adverse perinatal outcomes, multiple gestations, structural congenital abnormalities, chromosomal abnormalities, imprinting disorders, and childhood cancer.

EVIDENCE

The Cochrane Library and MEDLINE were searched for English-language articles from 1990 to February 2005, relating to assisted reproduction and perinatal outcomes. Search terms included assisted reproduction, assisted reproductive technology, ovulation induction, intracytoplasmic sperm injection (ICSI), embryo transfer, and in vitro fertilization (IVF). Additional publications were identified from the bibliographies of these articles as well as the Science Citation Index. Studies assessing gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) were excluded since they are rarely used in Canada. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key studies and supporting data for each recommendation are summarized with evaluative comments and referenced.

VALUES

The evidence collected was reviewed by the Genetics Committee and the Reproductive Endocrinology Infertility Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the Evaluation of Evidence Guidelines developed by the Canadian Task Force on the Periodic Health Examination.

BENEFITS, HARMS, AND COSTS

The type and magnitude of benefits, harms, and costs expected for patients from guideline implementation. This guideline has been reviewed by the Genetics Committee and the Reproductive Endocrinology and Infertility Committee, and approved by the Executive and Council of the Society of Obstetricians and Gynaecologists of Canada and the Board of the Canadian Fertility and Andrology Society.

RECOMMENDATIONS

1. Spontaneous pregnancies in untreated infertile women may be at higher risk for obstetrical complications and perinatal mortality than spontaneous pregnancies in fertile women. Further research is required to clarify the contribution of infertility itself to adverse obstetrical and perinatal outcomes. (II-2A) 2. All men with severe oligozoospermia or azoospermia should be offered genetic/clinical counselling for informed consent and offered karyotyping for chromosomal abnormalities before attempting IVF-ICSI. They should be made aware of the availability of tests for Y chromosome microdeletion. Some patients may consider the option of donor insemination. (II-3B) 3. Couples exploring IVF-ICSI when the man has obstructive azoospermia should be offered genetic/clinical counselling for informed consent and offered genetic testing for alterations in genes associated with cystic fibrosis (CF) before attempting IVF-ICSI. (II-2A) 4. Pregnancies achieved by ovarian stimulation with gonadotropins and intrauterine insemination are at higher risk for perinatal complications, and close surveillance during pregnancy should be considered. It remains unclear if these increased risks are attributable to the underlying infertility, characteristics of the infertile couple, or use of assisted reproductive techniques. Multiple gestations remain a significant risk of gonadotropin treatment. (II-2A) 5. Pregnancies achieved by IVF with or without ICSI are at higher risk for obstetrical and perinatal complications than spontaneous pregnancies, and close surveillance during pregnancy should be considered. It remains unclear if these increased risks are attributable to the underlying infertility, characteristics of the infertile couple, or use of assisted reproductive techniques. (II-2A) 6. Women undergoing ART should be informed about the increased rate of obstetrical interventions such as induced labour and elective Caesarean delivery. (II-2A) 7. Couples suffering from infertility who are exploring treatment options should be made aware of the psychosocial implications of ART. Further research into the psychosocial impact of ART is needed. (II-2A) 8. Singleton pregnancies achieved by assisted reproduction are at higher risk than spontaneous pregnancies for adverse perinatal outcomes, including perinatal mortality, preterm delivery, and low birth weight, and close surveillance during pregnancy should be available as needed. (II-2A) 9. A significant risk of ART is multiple pregnancies. Infertile couples need to be informed of the increased risks of multifetal pregnancies. Although dichorionic twins are most common, the incidence of monochorionic twins is also increased. Risks of multiple pregnancies include higher rates of perinatal mortality, preterm birth, low birth weight, gestational hypertension, placental abruption, and placenta previa. Perinatal mortality in assisted conception twin pregnancies appears to be lower than in spontaneously conceived twin pregnancies. (II-2A) 10. When multifetal reduction is being considered for high-order multiple pregnancies, psychosocial counselling should be readily available. Careful surveillance for fetal growth problems should be undertaken after multifetal reduction. (II-2A) 11. To reduce the risks of multiple pregnancies associated with ART and to optimize pregnancy rates, national guidelines should be developed on the number of embryos replaced according to characteristics such as patient's age and grade of embryos. (II-2A) 12. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks to childhood and long-term growth and development associated with ART. (II-2A) 13. Discussion of options for prenatal screening for congenital structural abnormalities in pregnancies achieved by ART is recommended, including appropriate use of biochemical and sonographic screening. (II-2A) 14. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks of congenital abnormalities associated with ART. (II-2A) 15. Couples considering IVF-ICSI for male-factor infertility should receive information, and if necessary formal genetic counselling, about the increased risk of de novo chromosomal abnormalities (mainly sex chromosomal anomalies) associated with their condition. Prenatal diagnosis by chorionic villus sampling (CVS) or amniocentesis should be offered to these couples if they conceive. (II-2A) 16. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks of chromosomal abnormalities associated with ART. (II-2A) 17. Discussion of options for prenatal screening and testing for aneuploidy in pregnancies achieved by ART, adapted for maternal age and number of fetuses, is recommended, including appropriate use of biochemical and sonographic screening. (II-2A) 18. The precise risks of imprinting and childhood cancer from ART remain unclear but cannot be ignored. Further clinical research, including long-term follow-up, is urgently required to evaluate the prevalence of imprinting disorders and cancers associated with ART. (II-2A) 19. The clinical application of preimplantation genetic diagnosis must balance the benefits of avoiding disease transmission with the medical risks and financial burden of in vitro fertilization. Further ethical discussion and clinical research is required to evaluate appropriate indications for preimplantation genetic diagnosis. (III-B).

Elective cryopreservation of all pronuclear oocytes after GnRH agonist triggering of final oocyte maturation in patients at risk of developing OHSS: a prospective, observational proof-of-concept study

BACKGROUND

A bolus dose of GnRH agonist can substitute for hCG as a trigger for the resumption of meiosis in ovarian stimulation with GnRH antagonists, which has been suggested to reduce the risk of ovarian hyperstimulation syndrome (OHSS). As the efficacy of this measure in fresh embryo transfer (ET) cycles is unclear, we evaluated a new clinical concept of GnRH-agonist triggering.

METHODS

In this prospective, observational proof-of-concept study, 20 patients considered at increased risk of developing OHSS (> or = 20 follicles > or = 10 mm or estradiol > or = 4000 pg/ml, or a history of cycle cancellation due to OHSS risk or the development of severe OHSS in a previous cycle) after ovarian stimulation and concomitant GnRH-antagonist administration had final oocyte maturation triggered with 0.2 mg triptorelin s.c. All two pronucleate (2 PN) oocytes were cryopreserved by vitrification, and frozen-thawed ETs (FT-ETs) were performed in an artificial cycle. Main outcome measures were the cumulative ongoing pregnancy rate per patient and the ongoing pregnancy rate per first ET. Secondary outcomes included the incidence of moderate-to-severe OHSS.

RESULTS

Of the 20 patients triggered with GnRH agonist, 19 patients underwent 24 FT-ETs in the observational period. The cumulative ongoing pregnancy rate was 36.8% (95% confidence interval: 19.1-59.0%). The ongoing pregnancy rate per first FT-ET was 31.6% (15.4-54.0%). No cases of moderate or severe OHSS were observed.

CONCLUSIONS

The present study is the proof of the concept that GnRH-agonist triggering of final oocyte maturation in combination with elective cryopreservation of 2 PN oocytes offers OHSS risk patients a good chance of pregnancy achievement, while reducing the risk of moderate and severe OHSS.

Early cleavage: an additional predictor of high implantation rate following elective single embryo transfer

The value of early cleavage (EC) assessment is still being debated. The aim of this prospective study was to examine the predictive value of EC assessment performed exactly 26 h after insemination by IVF or intracytoplasmic sperm injection (ICSI) in a programme of elective single embryo transfer (SET) performed at day 2. If day 2 scoring demonstrated several embryos with high implantation potential, an EC embryo was transferred preferentially. EC was assessed only during normal laboratory hours so that there were two groups: EC assessed, and EC not assessed, the latter being the control. A total of 277 elective SET were performed in women under 37 years undergoing their first IVF or ICSI cycle (mean age 30.5 years, range 21-37). The overall clinical and ongoing pregnancy rates were 40.1% (111/277) and 32.9% (91/277) respectively. Significantly higher overall clinical and ongoing pregnancy rates were obtained after transfer of an EC embryo than a non-EC embryo: 49.4 versus 33.3% (P < 0.05) and 42.4 versus 25.9% (P < 0.02) respectively. However there was no significant difference between the EC assessed and control groups: 40.4 versus 39.3% and 33.2 versus 32.1 respectively. These findings confirm the value of EC assessment for selection of embryos with high implantation potential.

Elective transfer of two embryos: reduction of multiple gestations while maintaining high pregnancy rates

PURPOSE

To determine if the elective transfer of two embryos reduced the incidence of multiple gestations while maintaining high pregnancy rates.

METHODS

IVF patients and recipients of oocyte donation with an elective day-3 transfer of 2 or 3 embryos were studied.

RESULT(S)

In IVF, the elective transfer of 2 embryos resulted in similar pregnancy rate but significantly reduced the overall incidence of multiple gestations (20% versus 39%) when compared to the elective transfer of 3 embryos. Twin gestations decreased from 28% to 19%, and triplets significantly decreased from 9% to 1%. In oocyte donation, the elective transfer of 2 embryos resulted in similar pregnancy rate but also significantly reduced the overall incidence of multiple gestations (26% versus 48%), with twins decreasing from 34% to 24%, and with a significant reduction of triplets (13% versus 2%).

CONCLUSIONS

In IVF and oocyte donation, the elective transfer of 2 embryos resulted in similar pregnancy rates and significantly reduced multiple gestation rates when compared to the elective transfer of 3 embryos.

Guidelines for the number of embryos to transfer following in vitro fertilization

OBJECTIVE

To review the effect of the number of embryos transferred on the outcome of in vitro fertilization (IVF), to provide guidelines on the number of embryos to transfer in IVF-embryo transfer (ET) in order to optimize healthy live births and minimize multiple pregnancies.

OPTIONS

Rates of live birth, clinical pregnancy, and multiple pregnancy or birth by number of embryos transferred are compared.

OUTCOMES

Clinical pregnancy, multiple pregnancy, and live birth rates.

EVIDENCE

The Cochrane Library and MEDLINE were searched for English language articles from 1990 to April 2006. Search terms included embryo transfer (ET), assisted reproduction, in vitro fertilization (IVF), ntracytoplasmic sperm injection (ICSI), multiple pregnancy, and multiple gestation. Additional references were identified through hand searches of bibliographies of identified articles.

VALUES

Available evidence was reviewed by the Reproductive Endocrinology and Infertility Committee and the Maternal-Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada and the Board of the Canadian Fertility and Andrology Society, and was qualified using the Evaluation of Evidence Guidelines developed by the Canadian Task Force on the Periodic Health Exam.

BENEFITS, HARMS, AND COSTS

This guideline is intended to minimize the occurrence of multifetal gestation, particularly high-order multiples (HOM), while maintaining acceptable overall pregnancy and live birth rates following IVF-ET.

A retrospective study of New Zealand case law involving assisted reproduction technology and the social recognition of ‘new’ family

The New Zealand Human Assisted Reproductive Technology (HART) Act became law in 2004. In this article, we provide a retrospective analysis of New Zealand case law from September 1990 to March 2004, leading up to the creation of the HART Act. We examine the new understandings of parenting (developed through the routine use of ART in New Zealand) which the case law attempted to test. We examine these concepts against the previous understandings of family enshrined in the pre-existing legislation, which formed the basis for judicial rulings in the various cases to which we refer. In conclusion, we provide a brief summary of the 2004 HART legislation and draw comparisons between the old and new legislative and bureaucratic frameworks that define and support New Zealand family structure. We suggest that a change in cultural backdrop is occurring from the traditional western ideology of the nuclear family towards the traditional Maori concept of family formation, which includes a well-accepted traditional practice of guardianship and a more open and extended family structure. This 'new' structure reflects the contemporary lived experience of family kinship in western societies as individualized and open to choice.

Transfert électif d'un seul embryon : une option justifiée pour une population de patientes sélectionnées

OBJECTIVE

Prevention of twin pregnancies using elective Single Embryo Transfer (e-SET) is now considered by many Assisted Reproductive Techniques teams as a necessity. The aim of this study was to assess the efficacy of e-SET in a prospective manner in a selective population of patients using Take Home Baby Rate per couple as principal parameter.

PATIENTS AND METHODS

This prospective study was conducted from January 2003 to December 2004. Elective Single Embryo was proposed to women above 37 years in their first IVF or ICSI attempt. It was then performed only in cases when at least one embryo with high implantation potential (score-4 embryo in our embryo scoring) was obtained for transfer and one more (score-3 or score-4 embryo) was available for freezing.

RESULTS

e-SET was proposed and accepted in 225 couples (25% of eligible couples and 7.8% of total population) and was possible in 96 of these). Two embryos were transferred in all other eligible patients (Double Embryo Transfer group=DET). Cumulative delivery rate after fresh embryo transfers and, if necessary, after frozen-thawed embryo transfers were 39.5% per couple e-SET group and 41.7% in DET group (NS). On the other hand, the percentage of twin pregnancies was significantly different between the two groups (2.6% vs 26.6% respectively; P<0.01).

DISCUSSION AND CONCLUSION

In women younger than 37 years in their first IVF/ICSI attempt, the elective transfer of only one embryo with high implantation potential strongly allowed to avoid twin pregnancies without any significant delivery rate decrease. This transfer policy is particularly efficient in laboratories displaying good results in their embryo freezing program.

The limited importance of pronuclear scoring of human zygotes

BACKGROUND

Several studies have shown a correlation between the pronuclear morphology score (PNMS) and subsequent embryo development and implantation. Embryos with poor pronuclear score, elsewhere referred to as Z3 and Z4, are often not transferred or cryopreserved because it is believed that they have poor pregnancy potential. The objective of this study is to report our data on the use of the pronuclear score and its effect on pregnancy outcome.

METHODS

Retrospective analysis of IVF/ICSI-embryo transfer cycles completed over the course of 1 year (n = 334). Comparisons were made only in those groups of patients in whom cohorts of similarly scored PNMS embryos were transferred. The proportion of such homologous cohorts was 104/334 (31%). All other replacements were excluded from final analysis as they were dissimilar as far as PNMS is concerned. Pregnancy outcomes were evaluated.

RESULTS

The incidence of live birth resulting from the transfer of single pronuclear score homologous embryo types was 56 (14/25), 41 (13/32), 54 (23/43) and 0% (0/4) for PNMS scores 1, 2, 3 and 4, respectively. There was no correlation between PNMS category of the embryos transferred and live birth rates (P = 0.139).

CONCLUSIONS

PNMSs of 1, 2 or 3 do not correlate with live birth rates when assessing unique PNMS embryo transfers. In particular, previously considered poor (type 3) embryos can result in pregnancy with normal live birth rates. Whether type 4 embryos are compatible with normal development remains to be shown.

A modified embryo cryopreservation method increases post-thaw survival with a concomitant increase in implantation

OBJECTIVE

To achieve maximum post-thaw survival of frozen embryos.

DESIGN

Historical controlled study.

SETTING

Hospital-based fertility center.

PATIENT(S)

One hundred forty-five patients whose embryos were frozen and thawed according to the standard method, and 56 patients whose embryos were frozen and thawed according to a modified method.

INTERVENTION(S)

Modifications were made to the various steps of cryopreservation: freezing and thawing solutions, loading of embryos into the straws, and warming rates.

MAIN OUTCOME MEASURE(S)

Post-thaw survival, implantation, and pregnancy rates.

RESULT(S)

With the modified method, 138 (93%) of the 149 embryos thawed for 56 patients survived freezing, and 79.8% had all their blastomeres intact, which is almost double the result obtained (41.8%) for patients whose embryos were thawed with the standard method. The implantation and pregnancy rates were also significantly higher with the modified method compared with the standard method.

CONCLUSION(S)

Greater post-thaw embryo survival was achieved, with a concomitant increase in implantation and pregnancy rates, by modifying the various steps in the standard cryopreservation methodology. This has important implications in IVF practice.

The value of pronuclear scoring for the success of IVF and ICSI-cycles

BACKGROUND

Pronuclear scoring helps to identify good quality embryos already at the pronuclear stage. There are no data available, however, to demonstrate whether patients benefit from a higher pregnancy rate after pronuclear scoring.

METHODS

In a retrospective, matched cohort study 338 cycles in which patients chose to score their oocytes at the pronuclear stage (scoring group) were compared with 338 cycles without scoring (control group). The cycles were matched for maternal age, number of previous IVF and ICSI cycles, cryopreservation (yes/no) and diagnosis of primary infertility.

RESULTS

The pregnancy rate was not significantly different between the scoring group and the control group (24.0 vs. 21.0%, NS) in spite of more cycles with grade A embryos and a higher number of embryos transferred. The presence of a Z1 pronuclear oocyte was found to be associated with the retrieval of more oocytes, a higher fertilization rate and more grade A embryos, as well as a non-significant increase in pregnancy rates (25.1 vs. 18.8%).

CONCLUSIONS

Benefit from pronuclear scoring seems to be small. Apparently, experienced biologists are able to select "good-quality" pronuclear oocytes in the same way they would do after scoring. However, the results might be biased by differences between the groups.

A lower ongoing pregnancy rate can be expected when GnRH agonist is used for triggering final oocyte maturation instead of HCG in patients undergoing IVF with GnRH antagonists

BACKGROUND

Eliciting an endogenous LH surge by GnRH-agonist for the induction of final oocyte maturation may be more physiological compared with the administration of HCG. However, the efficacy of this intervention in patients treated for IVF with GnRH antagonists remains to be assessed.

METHODS

106 patients were randomized to receive either 10 000 IU urinary HCG or 0.2 mg Triptorelin for triggering final oocyte maturation. Ovarian stimulation for IVF was performed with a fixed dose of 200 IU recombinant FSH and GnRH antagonist was started on stimulation day 6. Luteal phase was supported with micronized vaginal progesterone and oral estradiol. The study was monitored continuously for safety and stopping rules were established.

RESULTS

No significant differences were present in the number of cumulus-oocyte complexes retrieved, in the proportion of metaphase II oocytes, in fertilization rates or in the number and quality of the embryos transferred between the two groups. However, a significantly lower probability of ongoing pregnancy in the GnRH agonist arm prompted discontinuation of the trial, according to the stopping rules established (odds ratio 0.11; 95% confidence interval 0.02-0.52).

CONCLUSIONS

Lower probability of ongoing pregnancy can be expected when GnRH agonist is used for triggering final oocyte maturation instead of HCG in patients undergoing ovarian stimulation for IVF with GnRH antagonists.

The singleton, term gestation, and live birth rate per cycle initiated: a 1-year experience in in vitro fertilization cycles with native and donated oocytes

OBJECTIVE

To investigate the singleton, term gestation, and live birth rate per cycle initiated in our IVF program during a 1-year period.

DESIGN

Retrospective study of all first IVF cycles performed in the year 2002, with or without intracytoplasmic sperm injection (ICSI), with day 2/3 embryo transfer and using native or donated oocytes.

SETTING

Instituto Valenciano de Infetilidad (IVI), Valencia, Spain.

PATIENT(S)

Of 3,158 IVF cycles initially considered, 165 were excluded because of embryo freezing, follow-up loss, or embryo reduction. Of the remaining cycles, only 1,836 were first cycles with day 2/3 embryo transfer; of these, native oocytes were employed in 1,095 and donated oocytes in 741.

INTERVENTION(S)

No patient underwent any additional procedure or intervention.

MAIN OUTCOME MEASURE(S)

The singleton, term gestation, and live birth rate per cycle initiated was used as a primary outcome measure. Results were analyzed according to the origin of the oocytes (native vs. donated) and the woman's age (<37 and > or =37 years old).

RESULT(S)

The ectopic pregnancy rate was higher in the native oocyte group. The singleton, term gestation, and live birth rate per cycle initiated was similar in native and donated oocyte groups (15.3% vs. 13.4%). In the native oocyte group, patients <37 years old showed a significantly better outcome. The singleton, term gestation, and live birth rate per cycle initiated was 16.7% and 10.8% in younger and older women, respectively.

CONCLUSION(S)

The singleton, term gestation, and live birth rate per cycle initiated constitutes an essential parameter for determining the real possibility of a healthy baby for a specific assisted reproduction technology (ART).

Recombinant luteinizing hormone supplementation to recombinant follicle-stimulating hormone induced ovarian hyperstimulation in the GnRH-antagonist multiple-dose protocol

BACKGROUND

Suppression of endogenous LH production by mid-follicular phase GnRH-antagonist administration in controlled ovarian hyperstimulation protocol using recombinant (rec) FSH preparations void of LH activity may potentially affect ovarian response and the outcome of IVF treatment. The present study prospectively assessed the effect of using a combination of recFSH and recLH on ovarian stimulation parameters and treatment outcome in a fixed GnRH-antagonist multiple dose protocol.

METHODS

127 infertile patients with an indication for IVF or ICSI were recruited and randomized (using sealed envelopes) to receive a starting dose of either 150 IU recFSH (follitropin alpha) or 150 IU recFSH plus 75 IU recLH (lutropin alpha) for ovarian hyperstimulation. GnRH-antagonist (Cetrorelix) 0.25 mg was administered daily from stimulation day 6 onwards up to and including the day of the administration of recombinant HCG (chorion gonadotropin alpha). Gonadotropin dose adjustments were allowed from stimulation day 6 onwards, HCG was administered as soon as three follicles > or =18 mm were present. The primary outcome parameter was treatment duration until administration of HCG.

RESULTS

Exogenous LH did not shorten the time necessary to reach ovulation induction criteria. Serum estradiol (E(2)) and LH levels were significantly higher on the day of HCG administration in the recLH-supplemented group (1924.7 +/- 1256.4 vs 1488.3 +/- 824.0 pg/ml, P < 0.03), and 2.1 +/- 1.4 vs 1.4 +/- 1.5 IU/l, P < 0.01, respectively).

CONCLUSIONS

Except for higher E(2) and LH levels on the day of HCG administration, no positive trend in favour of additional LH was found as defined by treatment outcome parameters.

Low-level gonosomal mosaicism in women undergoing ICSI cycles

PURPOSE

Females with low-level gonosomal mosaicism (LLGM) scheduled for ICSI were retrospectively analyzed and compared to control groups. The prevalence of this mosaicism as well as its impact for an ICSI treatment were evaluated.

METHODS

Routine cytogenetic analysis was done in 891 females scheduled for ICSI treatment. For comparison 294 females with recurrent abortions and 104 women with clinical or cytogenetical affected children, who also had routine chromosome analysis, were acquired.

RESULTS

In the ICSI group the incidence of LLGM was significantly lower compared to the group of females with recurrent abortions (3.9% vs. 8.5%, p < 0.01). The incidence was similar between the groups of ICSI females and females with cytogenetical or clinically affected children (5.8%, p = 0.43). Neither anamnestic factors nor outcome parameters were different between females with and without LLGM undergoing ICSI.

CONCLUSION

There is no higher incidence of LLGM in females undergoing ICSI. In those who show LLGM, fertility capacity is not reduced.

Single embryo transfer and IVF/ICSI outcome: a balanced appraisal

This review considers the value of single embryo transfer (SET) to prevent multiple pregnancies (MP) after IVF/ICSI. The incidence of MP (twins and higher order pregnancies) after IVF/ICSI is much higher (approximately 30%) than after natural conception (approximately 1%). Approximately half of all the neonates are multiples. The obstetric, neonatal and long-term consequences for the health of these children are enormous and costs incurred extremely high. Judicious SET is the only method to decrease this epidemic of iatrogenic multiple gestations. Clinical trials have shown that programmes with >50% of SET maintain high overall ongoing pregnancy rates ( approximately 30% per started cycle) while reducing the MP rate to <10%. Experience with SET remains largely European although the need to reduce MP is accepted worldwide. An important issue is how to select patients suitable for SET and embryos with a high putative implantation potential. The typical patient suitable for SET is young (aged <36 years) and in her first or second IVF/ICSI trial. Embryo selection is performed using one or a combination of embryo characteristics. Available evidence suggests that, for the overall population, day 3 and day 5 selection yield similar results but better than zygote selection results. Prospective studies correlating embryo characteristics with documented implantation potential, utilizing databases of individual embryos, are needed. The application of SET should be supported by other measures: reimbursement of IVF/ICSI (earned back by reducing costs), optimized cryopreservation to augment cumulative pregnancy rates per oocyte harvest and a standardized format for reporting results. To make SET the standard of care in the appropriate target group, there is a need for more clinical studies, for intensive counselling of patients, and for an increased sense of responsibility in patients, health care providers and health insurers.

Number of embryos for transfer following in-vitro fertilisation or intra-cytoplasmic sperm injection

BACKGROUND

The traditional reliance on the transfer of multiple embryos during in vitro fertilisation (IVF) in order to maximise the chance of pregnancy, has resulted in increasing rates of multiple pregnancies. Women undergoing IVF had a 20 - fold increased risk of twins and 400 - fold increased risk of higher order pregnancies (Martin 1998). The maternal and perinatal morbidity and mortality as well as national health service costs associated with multiple pregnancies is significantly high in comparison with singleton births (Luke 1992; Callahan 1994; Goldfarb 1996). Single embryo transfer is now being considered as an effective means of reducing this iatrogenic complication. This systematic review evaluates the effectiveness of elective two embryo transfer in comparison with single and more than two embryo transfer following IVF and ICSI (intra cytoplasmic sperm injection) treatment.

OBJECTIVES

The aim of this review is to determine, whether in couples who undergo IVF/ICSI: (1) the elective transfer of two embryos improves the probability of livebirth compared with: (a) Single embryo transfer, (b) Three embryo transfer or (c) Four embryo transfer.(2) the elective transfer of three embryos improves the probability of livebirth compared with: (a) Single embryo transfer, or (b) Four embryo transfer,

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group's trials register (searched June 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2003), MEDLINE (1970 to 2003), EMBASE (1985 to 2003) and reference lists of articles. We also handsearched relevant conference proceedings and contacted researchers in the field.

SELECTION CRITERIA

Only randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility and quality of trials.

MAIN RESULTS

We found no studies that compared a policy of transferring multiple embryos on one cycle versus a policy of cryo- preservation and transfer of a single embryo over multiple cycles. We also found no trials comparing transfer of two versus three embryos. Three small, poorly reported trials compared transfer of two versus one embryo in a single cycle, and one small, poorly reported trial compared transfer of two versus four embryos in a single cycle. The clinical pregnancy rate per woman/couple associated with two embryo transfer was significantly higher compared to single embryo transfer (OR 2.08, 95% CI 1.24 to 3.50; test for overall effect p = 0.006). The live birth rate per woman/couple associated with two embryo transfer was also significantly higher than that associated with single embryo transfer (OR 1.90, 95% CI 1.12 to 3.22, test for overall effect p=0.02). The multiple pregnancy rate was significantly lower in women who had single embryo transfer (OR 9.97, 95% CI 2.61 to 38.19; p = 0.0008). The effectiveness of double embryo transfer versus four embryo transfer was tested in a single trial. There was no statistically significant differences in the clinical pregnancy rate (OR 0.75, 95% CI 0.26 to 2.16; p=0.6), and multiple pregnancy rates (OR 0.44. 95% CI 0.10 to 1.97; p = 0.28) between the two groups. The livebirth rate in the four embryo transfer group was higher compared to the two embryo transfer group, but the results were not statistically significant (OR 0.35, 95% CI 0.11 to 1.05; p = 0.06).

REVIEWERS' CONCLUSIONS

The results of this systematic review suggest that live birth and pregnancy rates following single embryo transfer are lower than those following double embryo transfer as are the chances of multiple pregnancy including twins. As such, it is unlikely that the conclusions are robust enough to catalyse a change in clinical practice. The studies included are limited by their small sample size, so that even large differences might be hidden. Cumulative livebirth rates are seldom reported. The data were inadequate to draw conclusions about single embryo transfer and first frozen single embryo transfer (1FZET) or subsequent single frozen embryo transfers. Until more evidence is available single embryo transfer may not be the preferred choice for all patients undergoing IVF/ICSI. Clinicians may need to individualise protocols for couples based on their risks of multiple pregnancy. A definitive pragmatic, large multi centre randomised controlled trial comparing single embryo versus double embryo transfer in terms of clinical and cost effectiveness as well as acceptability is required. The primary outcome measured should be cumulative livebirth per woman/couple.

[Prognostic factors of implantation]

One of the negative aspects of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) is the increased risk of multiple pregnancies. There is an epidemic of twin pregnancies with a higher risk of obstetric, perinatal and neonatal complications than singleton pregnancies and with an important psychosocial, economic and financial impact for the parents to be. A reduction in the number of twins can only be obtained by the transfer of one embryo. Single embryo transfer with an acceptable pregnancy rate might be considered if a top quality embryo is available. The need to characterize embryos with optimal implantation potential is obvious. A top quality embryo is characterized by the presence of 4 or 5 blastomeres at day 2 and at least 7 blastomeres on day 3 after insemination, the absence of multinucleated blastomeres and<20% cellular fragments on day 2 and day 3 after fertilization. Others prognostic factors of implantation are discussed in this review. Judicious application of eSET can halve the twinning rate while maintaining the overall pregnancy rate.

Joseph Price oration. The multiple gestation epidemic: the role of the assisted reproductive technologies

Human IVF has transformed so many lives, but there has been one major drawback--namely the so-called epidemic of multiple gestations.

Cumulative pregnancy rates and drop-out rates in a German IVF programme: 4102 cycles in 2130 patients

Cumulative pregnancy rates are useful in counselling couples on their chance of conceiving during infertility treatment. Patients also have to be counselled about the physical and psychological stress of infertility treatment. Beside the pregnancy rates, drop-out rates are a direct, and may be the most important, marker of physician quality in an IVF programme. Data from 4102 IVF cycles in 2130 patients in Germany were analysed retrospectively. Data were analysed using descriptive statistics as well as the Kaplan-Meier procedure. A real cumulative pregnancy rate of 31.2% was achieved after four cycles with an expected cumulative pregnancy rate (ECPR) of 53.3%. Age was a significant factor regarding pregnancy rates (ECPR after four cycles: 57.1% <35 years, 44.8% > or =35 years, 35.4% > or =40 years). The drop-out rate of non-pregnant patients increased from 39.9% after the first cycle to 62.2% after the fourth cycle, indicating the enormous stress and frustration that increased during the course of treatment. The drop-out rate should be used as an important marker of quality control. The presented data give, for the first time, a good basis for this counselling procedure in Germany.

Impact of reproductive history on in vitro fertilization and intracytoplasmic sperm injection outcome: evidence from the German IVF Registry

OBJECTIVE

To evaluate the effect of reproductive history on the outcome of different procedures in assisted reproductive technologies (ART) comparing IVF, ICSI, and cryopreserved embryo transfer (CPE).

DESIGN

Prospective registration of ART cycles and their outcomes.

SETTING

One hundred three reproductive programs in Germany.

PATIENT(S)

Women undergoing 174,909 ART procedures from January 1998 through December 2000.

INTERVENTION(S)

Data analysis of reproductive history collected by the German IVF Registry; multiple logistic regression modeling of success rates.

MAIN OUTCOME MEASURE(S)

Effect of type of conception and outcome of previous pregnancies, duration of infertility, female's age, and type of ART on clinical pregnancy rate per retrieval. Odds ratios with 95% CIs are reported.

RESULT(S)

More than one previous pregnancy was negatively correlated with outcome of IVF, ICSI, or CPE. This association disappeared when female age was restricted to a maximum of 35 years. A previous pregnancy achieved by spontaneous conception had less impact on outcome of IVF, ICSI or CPE outcome than did a previous assisted conception. Previous live births and miscarriages demonstrated a statistically significant increase compared with ectopic pregnancies and induced abortions.

CONCLUSION(S)

Reproductive history must be considered when counseling subfertile couples. Female age, method of conception, and previous pregnancy outcome have a significant effect on IVF, ICSI, and CPE outcome.

Patient-friendly ovarian stimulation

The ultimate goal of successful IVF is the birth of a healthy child with no maternal complications. Advances in ovarian stimulation protocols using gonadotrophin-releasing hormone agonists (GnRHa) and high doses of gonadotrophins have resulted in increased oocyte numbers with improved pregnancy and birth rates. However, the efficacy of such therapy is controversial when measured against the potential side effects. These side effects include those arising from oestrogen deprivation during desensitization, complications associated with an increased risk of ovarian hyperstimulation syndrome (OHSS), and an increased possibility of multiple births. Additionally, the increased cost due to more frequent monitoring and increased drug dosage negatively impacts on patient care. Thus, refinements in drug regimens are needed not only to address these side effects, but also to target the quality, not the quantity, of oocytes. In studies comparing GnRH antagonist (GnRHnt) to GnRHa, patients receiving GnRHnt underwent a shorter induction using less gonadotrophin, the incidence of OHSS was reduced and they reported a better quality of life. While larger studies are needed to confirm these promising findings, it appears that milder stimulation protocols could represent an interesting option, at least for selected patients.

Reducing the incidence of twins and triplets

Multiple pregnancy rates remain high after assisted conception because of a misconceived assumption that transferring three or more embryos will maximize pregnancy rates. Maternal morbidity is sevenfold greater in multiple pregnancies than in singletons, perinatal mortality rates are fourfold higher for twins and sixfold higher for triplets, while cerebral palsy rates are 1-1.5% in twin and 7-8% in triplet pregnancies. Therefore, multiple pregnancies must be considered a serious adverse outcome of assisted reproductive techniques. Primary prevention of multiple pregnancies is the solution. The overwhelming evidence presented in this chapter demonstrates that limiting the embryo transfer in in vitro fertilization to two embryos would significantly reduce adverse maternal and perinatal outcomes by reducing the incidence of high order multiple pregnancies without reducing take-home-baby rates. Secondary prevention by multifetal pregnancy reduction is effective, but not acceptable to all patients. New developments in blastocyst culture, single embryo transfer, embryo cryopreservation and pre-implantation aneuploidy exclusion, should allow improvements in pregnancy rates without increasing multiple pregnancies.

Heterotopic triplet pregnancy with bilateral tubal and intrauterine pregnancy after IVF

Heterotopic pregnancy in a spontaneous cycle is rare, but the incidence increases with the introduction of assisted reproductive technologies. This report describes a case of combined bilateral tubal and intrauterine pregnancy after IVF and embryo transfer. The diagnostic and therapeutic problems will be discussed both in terms of the case report and the literature. Heterotopic pregnancies after IVF and resulting problems are further reasons to encourage the transfer of only one embryo. This could be difficult to achieve without simultaneously decreasing pregnancy rates, as embryo selection is not permitted in Germany.

Tailoring the GnRH antagonist cetrorelix acetate to individual patients' needs in ovarian stimulation for IVF: results of a prospective, randomized study

INTRODUCTION

This study was performed to evaluate whether a tailored approach to the administration of the GnRH antagonist cetrorelix acetate according to follicular size leads to a reduction in the amount of Cetrotide vials used and/or an increased number of monitoring visits.

METHODS

Sixty patients were prospectively randomized (using sealed envelopes) to receive either the fixed multiple dose antagonist protocol starting on day 6 of stimulation (group 1), or an individualized protocol with the time of antagonist start according to follicle size (14 mm, group 2), or an individualized single dose protocol (group 3). Recombinant human (rh)FSH was used. The primary endpoints were the number of Cetrotide vials and number of monitoring visits. Statistical power for the parameter Cetrotide vials was 80%.

RESULTS

Patients in group 1 needed significantly more Cetrotide vials (6.81 +/- 1.61) than patients of group 2 (4.59 +/- 1.65; P < 0.01). The number of monitoring visits was similar between the three groups. Surprisingly, the number of retrieved oocytes was significantly higher in the individualized groups as compared with group 1. Despite a significantly lower total amount of rhFSH used, estradiol levels were significantly higher in group 2 as compared with group 1.

CONCLUSION

Tailoring of GnRH antagonist protocols leads to an optimization of ovarian stimulation with more oocytes retrieved despite less rhFSH used, and the same number of monitoring visits.

Comparison of cryopreservation outcome with gonadotropin-releasing hormone agonists or antagonists in the collecting cycle

OBJECTIVE

To compare the pregnancy rates of frozen-thawed 2-pronucleate (2PN) oocytes obtained either in a long protocol or in an antagonist protocol and ovarian stimulation with either human menopausal gonadotropin (hMG) or recombinant follicular stimulating hormone (recFSH).

DESIGN

Retrospective data analysis.

SETTING

Academic infertility center.

PATIENT(S)

Three hundred forty-two infertile couples who underwent a transfer of cryopreserved 2PN oocytes.

INTERVENTION(S)

hMG (n = 194) or recFSH (n = 92) in a long protocol or hMG (n = 16) or recFSH (n = 40) stimulation under pituitary suppression with the GnRH antagonist Cetrotide was used. The 2PN oocytes were transferred after endometrial preparation using E(2) valerate and vaginal progesterone (Crinone 8% vaginal gel).

MAIN OUTCOME MEASURE(S)

Implantation, pregnancy, and abortion rates.

RESULT(S)

Implantation rates in the freeze-thaw cycles were 5.6% (hMG) and 3.8% (recFSH) with 2PN oocytes from the long protocol and 7% from the antagonist cycles, irrespective of whether hMG or recFSH was used. Pregnancy rates were similar independent of whether they resulted from the long-protocol cycles with hMG (15.4%) and recFSH (13.1%) or from the antagonist protocol cycles with hMG (25.0%) and recFSH (17.5%).

CONCLUSION(S)

The potential to implant is independent of the gonadotropin-releasing hormone analogue and gonadotropin chosen for the collection cycle when previously cryopreserved 2PN oocytes were replaced after thawing in the cleavage stage.

Early cleavage of human embryos: an effective method for predicting successful IVF/ICSI outcome

BACKGROUND

The need for effective parameters for selecting the best embryos is paramount when a large number of them are available for transfer. Other studies have reported that transfer of pre-selected embryos, based on cleavage to the 2-cell stage at 25 h and 27 h post-insemination/intracytoplasmic sperm injection (ICSI), increases implantation and pregnancy rates. We investigated whether extending the time for selection of cleaved embryos to 29 h post-insemination/ICSI had a similar effect on pregnancy and implantation rates.

METHODS

Cleavage to the 2-cell stage was assessed at 25, 27 and 29 h post-insemination/ICSI. Embryos that had cleaved at any of these time points were designated as 'early cleavage' (EC), while others were designated as 'non-early cleavage' (NEC). EC embryos were selected and preferentially transferred.

RESULTS

EC occurred in 57% of the cycles (61% IVF; 51% ICSI). Significantly (P = 0.02) more clinical pregnancies occurred in the EC group (23/42, 55%) compared with the group that had no embryo undergoing first cleavage up to 29 h post-insemination/ICSI (8/32, 25%). The EC group of patients was significantly younger than the NEC.

CONCLUSION

Transfer of selected embryos that reached the 2-cell stage between 25 and 29 h post-insemination/ICSI is a reliable prognostic tool for patients undergoing assisted reproduction techniques.