Selective single blastocyst transfer reduces the multiple pregnancy rate and increases pregnancy rates: a pre- and postintervention study

Comparing endometrial preparation methods in frozen embryo transfers - Does a previous live birth make a difference?

RESEARCH QUESTION

Does the outcome of a medicated or natural endometrial preparation for a frozen cycle differ if a patient has previously experienced a failed fresh cycle?

DESIGN

Retrospective matched case-controlled study to investigate frozen embryo transfer (FET) outcomes in women undergone medicated or natural endometrial preparation, with adjustment to the history of previous live birth. 878 frozen cycles were included for analysis, over a period of 2 years.

RESULTS

After adjusting for the number of embryos transferred, endometrial thickness and the number of previous embryo transfers, there was no difference in live birth rate (LBR) between medicated-FET and natural-FET groups regardless of the previous fertility outcome (p = 0.08).

CONCLUSIONS

A previous live birth does not affect the outcome of a subsequent frozen cycle, regardless of whether medicated- or natural endometrial preparation is used.

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.

Outcomes of Preimplantation Genetic Testing for Single Gene Defects in a Privately Funded Period and Publicly Funded Period: A North-American Single Center Experience

BACKGROUND

The purpose of this study was to assess whether the outcomes from IVF-preimplantation genetic testing (IVF-PGT) cycles for single gene defects (SGD) (PGT-M) differ between a privately funded period (PRP) and publicly funded period (PUP).

METHODS

A retrospective cohort study was conducted in a North-American single tertiary center. The PRP (March 1998 to July 2010) comprised 56 PGT-M cycles from 58 IVF cycles in 38 couples, and the PUP (August 2010 to May 2015) comprised 59 PGT-M cycles from 87 IVF cycles in 38 couples. One PGT-M cycle is defined as one biopsy procedure from one or serial IVF cycles. A p-value of 0.05 was considered statistically significant.

RESULTS

The clinical pregnancy rates (CPR) per PGT-M cycle were 30.4% and 52.5% in each period, respectively (p=0.021). The live birth rates (LBR) per PGT-M cycle were 21.5% versus 40.9% in each period, respectively (p=0.037). A sub-analysis within the PUP comparing 39 PGT-M cycles from 39 IVF cycles with 20 PGT-M cycles from 49 IVF cycles yielded CPRs per PGT-M cycle of 64.1% and 30.0% and LBRs per PGT-M cycle of 53.8% and 15.0%, in each group, respectively (p< 0.05 for both).

CONCLUSION

The transition from private to public funding and a single embryo transfer (ET) guideline has little impact on embryological and clinical outcomes of PGT-M cycles, and results in lower rates of multiple pregnancies. However, these two systems may serve different populations.

High implantation and clinical pregnancy rates with single vitrified-warmed blastocyst transfer and optional aneuploidy testing for all patients

This study reports the results of a 2-year long IVF programme ('One by One') in which all patients (median age 40 years; range 27-45 years) were offered preimplantation genetic testing for aneuploidy (PGT-A) and had all blastocysts vitrified (freeze-only), followed later by single vitrified-warmed blastocyst transfer (vSET) in managed cycles. Between January 2016 and December 2017, a total of 155 patients started 222 treatment cycles and 99 (45%) cycles resulted in one or more vitrified blastocysts (untested or with normal copy number for all chromosomes) available for transfer. Seventeen patients (11%) aged ≤35 years opted out of PGT-A. Over this period, 85 vSETs in 74 patients resulted in an implantation rate of 80% (68/85) and a singleton clinical pregnancy rate of 66% (56/85). Cumulative live birth rates will not be known for 1-2 years. Nevertheless, these high success rates with vSET confirm larger studies using selected patients and are likely to deliver similar, if not higher, live birth rates per cycle started than rates typically reported in national registries with conventional IVF and transfer of one or more fresh and/or frozen embryos.

Effects of patient education on desire for twins and use of elective single embryo transfer procedures during ART treatment: A systematic review

Twin births among users of assisted reproductive technology (ART) pose serious risks to both mothers and infants. However, patients may prefer twins and may be unaware of the risks of twin pregnancies. Increasing use of elective single embryo transfers (eSET) through improved patient education could help to reduce twin births and related adverse health consequences. A systematic review of PUBMED and EMBASE databases was conducted to evaluate the effectiveness of patient education among ART users on knowledge of twin pregnancy risks, desire for twins, preference for or use of eSET, and twin pregnancy rates. Of 187 references retrieved, six met the selection criteria. Most focused on patients undergoing their first ART cycle aged < 35 years. Patient education was delivered via written materials, DVDs or discussion. Four studies reporting on knowledge of risks or desire for twins showed significant effects of oral and written descriptions of multiple pregnancy complications, risks of twins versus singletons, and DVDs with factual information. Five studies showed increased eSET use or preference after patients were educated on the risks of multiple pregnancy and success rates associated with different types of ART procedures, when combined with clinic policies that supported single blastocyst transfers or provided options for insurance. In younger ART users, patient education on twin pregnancy risks and success rates of eSET may improve knowledge of twin pregnancy risks and increase use of eSET, and may be important for wider implementation of eSET in countries such as the USA where the use of eSET remains low. Clinic policies of single blastocyst transfers or financial incentives may strengthen these effects.

Association Between Progesterone Elevation on the Day of Human Chronic Gonadotropin Trigger and Pregnancy Outcomes After Fresh Embryo Transfer in In Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles

Progesterone elevation (PE) during the late follicular phase of controlled ovarian stimulation in fresh embryo transfer in vitro fertilization (IVF)/intracytoplasmic sperm injection cycles has been claimed to be associated with decreased pregnancy rates. However, the evidence is not unequivocal, and clinicians still have questions about the clinical validity of measuring P levels during the follicular phase of stimulated cycles. We reviewed the existing literature aimed at answering four relevant clinical questions, namely (i) Is gonadotropin type associated with PE during the follicular phase of stimulated cycles? (ii) Is PE on the day of human chorionic gonadotropin (hCG) associated with negative fresh embryo transfer IVF/intracytoplasmic sperm injection (ICSI) cycles outcomes in all patient subgroups? (iii) Which P thresholds are best to identify patients at risk of implantation failure due to PE in a fresh embryo transfer? and (iv) Should a freeze all policy be adopted in all the cycles with PE on the day of hCG? The existing evidence indicates that late follicular phase progesterone rise in gonadotropin releasing analog cycles is mainly caused by the supraphysiological stimulation of granulosa cells with exogenous follicle-stimulating hormone. Yet, the type of gonadotropin used for stimulation seems to play no significant role on progesterone levels at the end of stimulation. Furthermore, PE is not a universal phenomenon with evidence indicating that its detrimental consequences on pregnancy outcomes do not affect all patient populations equally. Patients with high ovarian response to control ovarian stimulation are more prone to exhibit PE at the late follicular phase. However, in studies showing an overall detrimental effect of PE on pregnancy rates, the adverse effect of PE on endometrial receptivity seems to be offset, at least in part, by the availability of good quality embryo for transfer in women with a high ovarian response. Given the limitations of the currently available assays to measure progesterone at low ranges, caution should be applied to adopt specific cutoff values above which the effect of progesterone rise could be considered detrimental and to recommend "freeze-all" based solely on pre-defined cutoff points.

Public health implications of a North American publicly funded in vitro fertilization program; lessons to learn

PURPOSE

A retrospective study was conducted to determine trends in practice and outcomes that occurred since the implementation of the publicly funded in vitro fertilization (IVF) and single embryo transfer (SET) program in Quebec, in August, 2010.

METHODS

Data presented was extracted from an advisory report by the Health and Welfare Commissioner, and from a report by the Ministry of Health and Social Services published in June 2014 and October 2013, respectively. This data is publicly available, and was collected from all six private and three public-assisted reproduction centers in Quebec providing IVF services. Data pertains to all IVF cycles performed from the 2009-2010 to 2012-2013 fiscal years.

RESULTS

SET was performed in 71 % of cycles in 2012. The number of children born from IVF was 1057 in 2009-2010 and 1723 in 2012-2013 (p < 0.0001). Multiple birth rates from IVF were 24 % in 2009-2010 (before the program began) and 9.45 % in 2012-2013 (p < 0.0001). The proportions of IVF babies that were premature, that were the result of multiple births, or that required neonatal intensive care unit admission (NICU) all decreased by 35.5 % (p < 0.0001), 55 % (p < 0.0001), and 37 % (p < 0.0001), respectively, from 2009-2010 to 2012-2013. The cost per NICU admission for an IVF baby increased from $19,990 to $28,418 from 2009-2010 to 2011-2012.

CONCLUSION

This first North American publicly funded IVF program with a SET policy shows that such a program contributes substantially to number of births. It has also succeeded in increasing access to treatment and decreasing perinatal morbidity by decreasing multiple birth rates from IVF. A substantial increase in global public health care costs occurred as well.

The periconceptional environment and cardiovascular disease: does in vitro embryo culture and transfer influence cardiovascular development and health?

Assisted Reproductive Technologies (ARTs) have revolutionised reproductive medicine; however, reports assessing the effects of ARTs have raised concerns about the immediate and long-term health outcomes of the children conceived through ARTs. ARTs include manipulations during the periconceptional period, which coincides with an environmentally sensitive period of gamete/embryo development and as such may alter cardiovascular development and health of the offspring in postnatal life. In order to identify the association between ARTs and cardiovascular health outcomes, it is important to understand the events that occur during the periconceptional period and how they are affected by procedures involved in ARTs. This review will highlight the emerging evidence implicating adverse cardiovascular outcomes before and after birth in offspring conceived through ARTs in both human and animal studies. In addition, it will identify the potential underlying causes and molecular mechanisms responsible for the congenital and adult cardiovascular dysfunctions in offspring whom were conceived through ARTs.

Maternal age and intracytoplasmic sperm injection outcome in infertile couples at Khartoum, Sudan

Background

Intracytoplasmic sperm injection (ICSI) was considered as the mainstay of treatment for male infertility. Nowadays, the scope of ICSI has been widened to include other causes of infertility. There are few published data on ICSI in countries with low incomes.

Aims

A cross-sectional study was conducted at Saad AbuAlla and Banoun Centers, Khartoum, Sudan to investigate outcomes of ICSI and to determine the parameters that might predict pregnancy success rate following ICSI.

Methods

The study included 191 infertile couples who underwent 296 ICSI cycles between 1st April 2013 and 31 March 2014.

Results

One hundred and ninety one couples (comprising 296 cycles of ICSI) were enrolled to the study. The mean (SD) number of retrieved oocytes was 9.7 (7.5).  The mean (SD) number of transferred embryos was 2.9 (1.0). Out of these, 50 (26.2%) and 40 (20.9%) had chemical and clinical pregnancy, respectively. Thirty–six couples (18.8%) and five couples (2.6%) had miscarriage and had ectopic pregnancy, respectively. Under logistic regression, younger age (OR = 0.8, 95% CI= 0.81 ─ 0.96, P = 0.004) and endometrial thickness (OR = 1.3, 95% CI= 1.07─1.60, P = 0.009) were the significant predictors for the success of ICSI in inducing pregnancy.

Conclusion                

The rates of successful fertilisation and pregnancy-to-term rates in this setting depend mainly on the maternal age.

Anticoagulation and in vitro fertilization and ovarian stimulation

Assisted reproductive technology is widely used to treat couples affected by infertility. Complications associated with assisted reproduction include venous thromboembolism, ovarian hyperstimulation syndrome, and recurrent implantation failure. It has also been proposed that thrombophilia may be associated with an increased likelihood of these events. Although data are limited, antithrombotic therapy is frequently used to enhance the likelihood of successful assisted reproduction. This chapter reviews the risks of venous and arterial thromboembolism associated with assisted reproduction, as well as available data regarding the impact of thrombophilia on the risks of thromboembolism and failure of implantation. The role of antithrombotic therapy in reducing the likelihood of these events, along with recommendations from various guidelines, are also discussed.

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.

Comparable clinical outcomes and live births after single vitrified-warmed and fresh blastocyst transfer

Selective single-blastocyst transfer (SBT) in fresh cycles has been effective in reducing multiple pregnancies. However, we do not know whether this successful strategy of fresh transfer cycles is suitable for cryopreserved cycles. The present study was undertaken to evaluate the feasibility and value of SBT in vitrified-warmed cycles. Clinical pregnancy rate (CPR) was similar with vitrified and fresh SBT (46.61% versus 52.15% respectively). Of the pregnant patients, monozygotic twin, miscarriage and ectopic pregnancy rates were similar with vitrified and fresh SBT. For the newborns, no significant difference was observed in live birth, low birthweight, premature delivery and birth defects rates between vitrified and fresh SBT. With respect to the quality of transferred blastocysts (from BB to AA), a similar CPR and miscarriage rate was obtained for both vitrified and fresh SBT when a similar blastocyst cohort graded ≥ 3BB was transferred. The data show that vitrified SBT is an effective means of reducing multiple pregnancy and that comparable clinical outcomes and live births are achieved if single blastocysts graded ≥ 3BB are transferred for both vitrified and fresh SBT. These data should encourage clinics to evaluate their embryo transfer policy and adopt vitrified SBT as everyday practice. Selective single-blastocyst transfer in fresh cycles has been an effective method to reduce the multiple pregnancies. However, due to a lack of adequate studies, we do not know whether this successful strategy in fresh transfer cycles is suitable in cryopreserved cycles. The present study was undertaken to explore the feasibility and value of single-blastocyst transfer in vitrified-warmed cycles. We found that single-blastocyst transfer in vitrified-warmed cycles is an effective means of reducing multiple pregnancy, and comparable clinical outcomes and live births were achieved if single blastocysts graded ≥ 3BB were transferred for both vitrified-warmed and fresh blastocyst transfer. These data should encourage clinics to evaluate their embryo transfer policy and adopt single-blastocyst transfer in cryopreserved cycles as their everyday practice.

Trends and factors associated with the Day 5 embryo transfer, assisted reproductive technology surveillance, USA, 2001-2009

STUDY QUESTION

What characteristics are associated with a Day 5 embryo transfer?

SUMMARY ANSWER

The use of the Day 5 embryo transfer has increased over time, with clinicians allowing women with typically 'poorer' prognostic characteristics to undergo a Day 5 embryo transfer. The mean number of embryos per Day 5 transfer decreased from 2001 to 2009, although the prevalence of the Day 5 single embryo transfer remains low and the rate of multiple births remains substantial.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Day 5 embryo transfer may reduce the rate of multiple gestation pregnancy. US trends over time in the prevalence of the Day 5 transfer, changes in characteristics of patients receiving Day 5 transfer, and number of embryos transferred are unknown.

DESIGN

We used 2001-2009 US National assisted reproductive technology (ART) Surveillance System (NASS) data on 620,295 fresh IVF cycles derived from autologous oocytes with a Day 3 or 5 embryo transfer. Trends in the mean number of embryos transferred from 2001 to 2009 were assessed by the day of transfer. For 349,947 cycles from clinics performing both Days 3 and 5 embryo transfers, multivariable logistic regression was used to determine the characteristics associated with the Day 5 embryo transfer. We also compared the characteristics of the Day 5 embryo cycles in 2001 and 2009.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, the proportion of ART cycles using the Day 5 embryo transfer increased from 12% in 2001 to 36% in 2009 (P<0.0001), while the mean number of embryos transferred decreased from 2.4 to 2.1 (P<0.0001). Among Day 5 transfers, the rate of the single embryo transfer tripled from 4.5% in 2001 to 14.8% in 2009 (P<0.0001); and the rate of multiple births decreased from 44.8 to 41.1% (P<0.0001). In cycles initiated after 2001, maternal age<35 years, no prior ART cycles, ≥1 prior pregnancies, baseline follicle stimulating hormone<10 international units and ≥10 oocytes retrieved were associated with the Day 5 embryo transfer. Compared with 2001, in 2009, a broader range of candidates received the Day 5 transfer. BIAS Women undergoing multiple ART cycles over time are not linked.

CONFOUNDING FACTORS AND OTHER REASONS FOR CAUTION

We ran multivariable logistic regression to lessen the effects of the confounding factors. Cycle cancelation rates by the day of embryo transfer are unknown.

GENERALIZABILITY TO OTHER POPULATIONS

Generalizable to ART clinics included in NASS.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the Centres for Disease Control. The authors have no competing interests to declare.

In vitro fertilization at a public hospital in Nigeria

OBJECTIVE

To assess the results of an in vitro fertilization program newly established within a conventional infertility program at a university hospital in Nigeria.

METHODS

From June 1, 2007, to June 30, 2011, following unsuccessful conventional treatments, 600 couples were offered in vitro fertilization with (if needed) intracytoplasmic sperm injection in batches of 30 couples. The outcomes measured were duration of ovarian stimulation and rate of ovarian hyperstimulation syndrome; numbers of follicles aspirated, oocytes retrieved, oocytes fertilized, and embryos transferred; and clinical pregnancy rate.

RESULTS

The mean duration of stimulation was 11.8 ± 1.6 days and 1% of the women had severe ovarian hyperstimulation syndrome. The mean number of follicles aspirated was 8 ± 2.8; of oocytes retrieved 6 ± 3.2; and fertilized 3 ± 1.8. The maximum number of embryos transferred per woman was 3. The rates of clinical pregnancy and multiple pregnancy were 30% and 6.0%. The rates of abortion and ectopic pregnancy were 6.6% and 0.6%. The preterm delivery rate was 2.5%.

CONCLUSION

Successfully conducting an assisted reproduction program at a public health facility is feasible in a low-resource country. Treating couples in batches was cost effective, with a low complication rate.

The search for a practice model to reduce miscarriage after assisted reproduction

The analysis of 52,874 clinical pregnancies recorded on the Australian and New Zealand Assisted Reproduction Database (ANZARD) between 2004 and 2008 showed that maternal age and obstetrics history are closely related to the risk of miscarriage, and that the transfer of fresh embryos is associated with fewer miscarriages than transfer of frozen-thawed embryos. It also suggested a higher miscarriage rate is associated with the transfer of thawed blastocysts compared with transfer of thawed cleavage-stage embryos or the blastocysts that ensued from them. Therefore, the authors proposed a practice model of transferring fresh blastocysts and freezing of cleavage-stage embryos to reduce the miscarriage rate after assisted reproduction. This model may have practical limitation and would need validation in a randomized trial. Retrospective analysis of large national databases is useful in identifying trends and generating hypothesis, but evaluation of these hypotheses in randomized trials remains necessary for objective validation.

Reducing multiple pregnancies after assisted reproduction treatment: Québec says 'Yes, we can!'

Multiple pregnancy (MP) is widely recognized as the single biggest risk to children born as a result of assisted reproduction treatment. There is an emerging trend in Europe and Canada to promote single-embryo transfer (SET). In this issue, Gleicher argues that twin pregnancies should not be seen as an unfavourable outcome of assisted reproduction treatment. He argues that SET policies 'make no sense' since they will aggravate already unsatisfactory population growth in some countries. He also argues that governmental intervention to impose SET policies, despite proving successful in reducing MP, are inappropriate. The overwhelming evidence in the literature indicates that his opinion is not supported by credible data. Views should be based on solid data rather than personal judgement. Governmental interventions to reduce twin pregnancies, as demonstrated previously in Belgium and now in Québec, have been successful. The risks of twin pregnancies are real and borne by women and children, not their doctors. Doctors managing infertile couples are no longer entitled to take risks with the health of the next generation.

Epidemiology of multiple pregnancy and the effect of assisted conception

Multiple pregnancy is one of the greatest perinatal challenges facing clinicians today. In a society of rising expectations among fertility and maternity service users, the potential for adverse outcomes associated with multiple pregnancy is a source of concern. This article examines the impact of assisted conception on the incidence of multiple pregnancies and associated complications. It explores some of the reasons for the strong association between assisted reproductive technology and multiple pregnancies and suggests possible ways of addressing this continuing problem.

ESHRE PGD consortium best practice guidelines for organization of a PGD centre for PGD/preimplantation genetic screening

In 2005, the European Society for Human Reproduction and Embryology (ESHRE) PGD Consortium published a set of Guidelines for Best Practice PGD to give information, support and guidance to potential, existing and fledgling PGD programmes. Subsequent years have seen the introduction of new technologies as well as the evolution of current techniques. Additionally, in light of recent advice from ESHRE on how practice guidelines should be written/formulated, the Consortium believed it was timely to update the PGD guidelines. Rather than one document that covers all of PGD, the new guidelines are separated into four documents, including one relating to organization of the PGD centre and three relating to the methods used: DNA amplification, fluorescence in situ hybridization and biopsy/embryology. Here, we have updated the sections on organization of the PGD centre. One area that has continued to expand is Transport PGD, in which patients are treated at one IVF centre, whereas their gametes/embryos are tested elsewhere, at an independent PGD centre. Transport PGD/preimplantation genetic screening (PGS) has a unique set of challenges with respect to the nature of the sample and the rapid turn-around time required. PGS is currently controversial. Opinions of laboratory specialists and clinicians interested in PGD and PGS have been taken into account here. Current evidence suggests that PGS at cleavage stages is ineffective, but whether PGS at the blastocyst stage or on polar bodies might show improved delivery rates is still unclear. Thus, in this revision, PGS has been included. This document should assist everyone interested in PGD/PGS in developing the best laboratory and clinical practice possible.

Deep phenotyping to predict live birth outcomes in in vitro fertilization

Nearly 75% of in vitro fertilization (IVF) treatments do not result in live births and patients are largely guided by a generalized age-based prognostic stratification. We sought to provide personalized and validated prognosis by using available clinical and embryo data from prior, failed treatments to predict live birth probabilities in the subsequent treatment. We generated a boosted tree model, IVFBT, by training it with IVF outcomes data from 1,676 first cycles (C1s) from 2003-2006, followed by external validation with 634 cycles from 2007-2008, respectively. We tested whether this model could predict the probability of having a live birth in the subsequent treatment (C2). By using nondeterministic methods to identify prognostic factors and their relative nonredundant contribution, we generated a prediction model, IVF(BT), that was superior to the age-based control by providing over 1,000-fold improvement to fit new data (p<0.05), and increased discrimination by receiver-operative characteristic analysis (area-under-the-curve, 0.80 vs. 0.68 for C1, 0.68 vs. 0.58 for C2). IVFBT provided predictions that were more accurate for approximately 83% of C1 and approximately 60% of C2 cycles that were out of the range predicted by age. Over half of those patients were reclassified to have higher live birth probabilities. We showed that data from a prior cycle could be used effectively to provide personalized and validated live birth probabilities in a subsequent cycle. Our approach may be replicated and further validated in other IVF clinics.

Assisted Reproductive Technologies (ART) with baboons generate live offspring: a nonhuman primate model for ART and reproductive sciences

Human reproduction has benefited significantly by investigating nonhuman primate (NHP) models, especially rhesus macaques. To expand the Old World monkey species available for human reproductive studies, we present protocols in baboons, our closest Old World primate relatives, for assisted reproductive technologies (ART) leading to live born offspring. Baboons complement rhesus by confirming or modifying observations generated in humans often obtained by the study of clinically discarded specimens donated by anonymous infertility patient couples. Here, baboon ART protocols, including oocyte collection, in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), preimplantation development to blastocyst stage, and embryo transfer techniques are described. With baboon ART methodologies in place, motility during baboon fertilization was investigated by time-lapse video microscopy (TLVM). The first ART baboons produced by ICSI, a pair of male twins, were delivered naturally at 165 days postgestation. Genetic testing of these twins confirmed their ART parental origins and demonstrated that they are unrelated fraternal twins not identicals. These results have implications for ART outcomes, embryonic stem cell (ESC) derivation, and reproductive sciences.

Single-embryo transfer versus multiple-embryo transfer

Despite the progress made in assisted reproductive technology, live birth rates remain disappointingly low. Multiple-embryo transfer has been an accepted practice with which to increase the success rate. This has led to a higher incidence of multiple-order births compared with natural conception, which not only increase the risk of mortality and morbidity to both mother and children but are also associated with social and economic consequences. Elective single-embryo transfer (eSET) was developed in an effort to increase singleton pregnancies in assisted reproduction. Studies comparing eSET with multiple-embryo transfer highlight the benefit of this approach and suggest that, with careful patient selection and the transfer of good-quality embryos, the risk of a multiple-order pregnancy can be reduced without significantly decreasing live birth rates. Although the use of eSET has gradually increased in clinical practice, its acceptance has been limited by factors such as availability of funding and awareness of the procedure. An open discussion of eSET is warranted in an effort to enable a broader understanding by physicians and patients of the merits of this approach. Ultimately, eSET may provide a more cost-effective, potentially safer approach to patients undergoing assisted reproduction technology.

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.

Preimplantation genetic diagnosis as a source of human embryonic stem cells for disease research and drug discovery

Embryos surplus to therapeutic requirements following preimplantation genetic diagnosis can be used to derive human embryonic stem cell (hESC) lines carrying mutations significant to human disease. These cells provide a powerful in vitro tool for modelling disease progression in a number of cell types as well as having the potential to revolutionise drug discovery. Robust and reproducible directed differentiation protocols are needed to maximise the potential of these cells. In this review, we explore the current use of hESC and induced pluripotent stem cells in disease-specific research and discuss the use of stem cell technology in drug discovery and toxicity testing.

Elective single embryo transfer: guidelines for practice British Fertility Society and Association of Clinical Embryologists

Assisted conception treatment is the single most important cause in the increase in multiple pregnancy and births over the last 25 years. Multiple births are associated with significant peri natal morbidity and mortality. Europe has led the way in reducing multiple births by widespread adoption of an elective single embryo policy, which in Belgium is linked to an increase in state funding. Randomized controlled trials suggest that an eSET policy must include the ability to cryopreserve and transfer any remaining quality embryos to obtain parity with a double embryo transfer. This document provides a review of the available evidence with guidelines for practice, to help facilitate the introduction of an eSET policy in the UK.

Revisiting oocyte-somatic cell interactions: in search of novel intrafollicular predictors and regulators of oocyte developmental competence

Prediction and improvement of oocyte competence are two critical issues in assisted reproductive technology to improve infertility therapy. The lack of reliable and objective predictors of oocyte developmental competence for oocyte/embryo selection during in vitro fertilization hampers the effectiveness of this technology. Likewise, the low pregnancy rate resulting from in vitro maturation of human oocytes represents a major obstacle for its clinical application. Oocyte competence is progressively acquired during follicular development, and the oocyte plays a dominant role in regulating granulosa cell functions and maintaining the microenvironment appropriate for the development of its competence. Hence, granulosa cell functions are reflective of oocyte competence, and molecular markers of granulosa cells are potentially reliable predictors of oocyte quality. With the advent of the functional genomics era, the transcriptome of granulosa cells has been extensively characterized. Experimental data supporting granulosa cell markers as predictors of oocyte competence are now emerging in both animal models and humans. Future efforts should focus on integrating granulosa cell genetic markers as parameters for oocyte/embryo selection. Moreover, novel in vitro evidence highlights the effectiveness of exogenous oocyte-secreted factors in promoting oocyte developmental competence in animal models. The challenge in evaluating the effect of oocyte-secreted factors on oocyte quality in a clinical setting is to standardize the various preparations of these recombinant proteins and decipher their complex interactions/cooperativity within the germline-somatic cell regulatory loop.

Clinical outcome of frozen blastocyst transfer; single vs. double transfer

PURPOSE

Frozen embryo transfer has been established as an indispensable ART procedure for both the effective use of surplus embryos and the prevention of ovarian hyperstimulation syndrome. The frequency of frozen embryo transfer is increasing in our clinic, and we report that frozen embryo transfer is effective for patients with repeat failures. We present our clinical outcome of frozen blastocyst transfer (FBT).

METHODS

In 2006, 470 patients received FBT (562 cycles (IVF: 354 cycles; ICSI: 208 cycles)). One frozen blastocyst was transferred in 412 cycles (335 patients) and two blastocysts were transferred in 150 cycles (135 patients). Assisted hatching was performed in all cases.

RESULTS

In 412 cycles (average age: 34.6 years) who received a single FBT, the rate of clinical pregnancy per cycle was 40.7%, the live birth rate was 29.1%, the abortion rate was 21.6%, the ectopic pregnancy rate was 1.2%, the frequency of monochorionic twins was 2.3%, and the cesarean section rate was 38.3%. In 150 cycles (average patient age 34.8 years) who received two FBTs, the clinical pregnancy rate was 46%, the live birth rate was 35.3%, the abortion rate was 16.3%, the ectopic pregnancy rate was 4.4%, the frequency of twins was 15.9% and the cesarean section rate was 39.6%. A significant difference in the ectopic pregnancy rate and the twinning rate was found between single transfers and double transfers (P < 0.05). When IVF and ICSI were compared, there was no statistically significant difference in the abortion rate, the ectopic pregnancy rate, and the cesarean section rate.

CONCLUSIONS

The clinical pregnancy rate was similar for the transfer of one and two blastocysts. Single FBT decreases obstetrical risk without reducing the pregnancy rate.

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.