Reducing the number of embryos transferred in Sweden-impact on delivery and multiple birth rates

Multifetal Pregnancy After Implementation of a Publicly Funded Fertility Program

Importance

A publicly funded fertility program was introduced in Ontario, Canada, in 2015 to increase access to fertility treatment. For in vitro fertilization (IVF), the program mandated an elective single-embryo transfer (eSET) policy. However, ovulation induction and intrauterine insemination (OI/IUI)-2 other common forms of fertility treatment-were more difficult to regulate in this manner. Furthermore, prior epidemiologic studies only assessed fetuses at birth and did not account for potential fetal reductions that may have been performed earlier in pregnancy.

Objective

To examine the association between fertility treatment and the risk of multifetal pregnancy in a publicly funded fertility program, accounting for both fetal reductions and all live births and stillbirths.

Design, Setting, and Participants

This population-based, retrospective cohort study used linked administrative health databases at ICES to examine all births and fetal reductions in Ontario, Canada, from April 1, 2006, to March 31, 2021.

Exposure

Mode of conception: (1) unassisted conception, (2) OI/IUI, or (3) IVF.

Main Outcomes and Measures

The main outcome was multifetal pregnancy (ie, a twin or higher-order pregnancy). Modified Poisson regression generated adjusted relative risks (ARRs) and derived population attributable fractions (PAFs) for multifetal pregnancies attributable to fertility treatment. Absolute rate differences (ARDs) were used to compare the era before eSET was promoted (2006-2011) with the era after the introduction of the eSET mandate (2016-2021).

Results

Of all 1 724 899 pregnancies, 1 670 825 (96.9%) were by unassisted conception (mean [SD] maternal age, 30.6 [5.2] years), 24 395 (1.4%) by OI/IUI (mean [SD] maternal age, 33.1 [4.4] years), and 29 679 (1.7%) by IVF (mean [SD] maternal age, 35.8 [4.7] years). In contrast to unassisted conception, individuals who received OI/IUI or IVF tended to be older, reside in a high-income quintile neighborhood, or have preexisting health conditions. Multifetal pregnancy rates were 1.4% (95% CI, 1.4%-1.4%) for unassisted conception, 10.5% (95% CI, 10.2%-10.9%) after OI/IUI, and 15.5% (95% CI, 15.1%-15.9%) after IVF. Compared with unassisted conception, the ARR of any multifetal pregnancy was 7.0 (95% CI, 6.7-7.3) after OI/IUI and 9.9 (95% CI, 9.6-10.3) after IVF, with corresponding PAFs of 7.1% (95% CI, 7.1%-7.2%) and 13.4% (95% CI, 13.3%-13.4%). Between the eras of 2006 to 2011 and 2016 to 2021, multifetal pregnancy rates decreased from 12.9% to 9.1% with OI/IUI (ARD, -3.8%; 95% CI, -4.2% to -3.4%) and from 29.4% to 7.1% with IVF (ARD, -22.3%; 95% CI, -23.2% to -21.6%).

Conclusions and Relevance

In this cohort study of more than 1.7 million pregnancies in Ontario, Canada, a publicly funded IVF program mandating an eSET policy was associated with a reduction in multifetal pregnancy rates. Nevertheless, ongoing strategies are needed to decrease multifetal pregnancy, especially in those undergoing OI/IUI.

First 15 Years of Assisted Reproductive Technology Using Washed Sperm in HIV-Positive Individuals Under Antiretroviral Therapy: Sweden's Nationwide Outcomes

Antiretroviral therapy has made HIV a chronic infectious disease. In Sweden, assisted reproductive technologies using sperm washing were implemented in 2004 for treatment of all HIV-positive males in serodiscordant couples at Karolinska Hospital in Stockholm. This study aimed to assess efficacy and safety of this approach and to investigate the effect of antiretroviral regimens on sperm quality of men treated for HIV. The study included all HIV-positive men (n = 53) adherent to antiretroviral treatment, including nucleoside/nucleotide analog reverse-transcriptase inhibitors (NRTIs) combined with non-nucleoside reverse-transcriptase inhibitors (NNRTIs) in 22 cases, or with other medication in 31 cases wishing fertility treatment. Sperm was washed using gradient centrifugation with a double tube system, frozen and thawed. Thereafter, single spermatozoa were injected in oocytes by intracytoplasmic sperm injection (ICSI). Treatment outcomes were compared to those of hepatitis B virus (HBV)-seropositive men in serodiscordant couples (n = 56), undergoing similar sperm washing protocols and ICSI at the center. In total, 82 fresh and 39 frozen/thawed embryo transfer (FET) cycles were performed in discordant HIV couples and 92 fresh and 36 FET cycles in HBV. Fertilization rates (69.2% vs. 64.6%, p = 0.310), clinical pregnancy rates (39.2% vs. 32.6%, p = 0.378), and live birth rates (35.8% vs. 31.5%, p = 0.565) were similar between the groups and the cumulative results yielded similar outcomes with a live birth rate of 52.8% and 51.8% (p = 0.913), respectively. No post-wash sperm sample was found positive for HIV viral particles. No partner seroconversion or offspring infection was reported. NNRTI-treated men had significantly lower motile sperm concentration than non-NNRTI-treated patients (54.48% vs. 36.41%, p < 0001). This study showed that in vitro fertilization/ICSI treatment with sperm washing was safe in individuals compliant to antiretroviral treatment and the reproductive outcome was similar to that of HBV-positive men. The observed moderate negative impact on sperm motility of NNRTI regimens may be overcome by using ICSI.

Cerebral palsy in children born after assisted reproductive technology in Norway: Risk, prevalence, and clinical characteristics

INTRODUCTION

The aim was to investigate the risk, prevalence, and clinical characteristics of cerebral palsy among children born after assisted reproductive technology (ART) in Norway.

MATERIAL AND METHODS

All liveborn children from 2002 to 2015 were included. Information was collected from the Medical Birth Registry of Norway, linked to the Norwegian Quality and Surveillance Registry for Cerebral Palsy as of December 31, 2022. Logistic regression analyses were used to calculate the prevalence of cerebral palsy per 1000 live births after ART and natural conception with birth year as covariate, crude odds ratios (OR) for cerebral palsy among children born after ART using children born after natural conception as reference, and OR adjusted for potential confounders, with 95% confidence intervals (CI). Potential mediators of the association were studied in stratified analyses. Descriptive statistics were used to compare proportions in clinical characteristics among children with cerebral palsy born after ART and natural conception.

RESULTS

Among 833 645 livebirths, 23 645 children were born after ART and of the latter 97 were diagnosed with cerebral palsy. The overall prevalence of cerebral palsy after ART was 4.10 per 1000 live births (95% CI 3.36-5.00), decreasing from 7.79 per 1000 in 2002 to 3.55 in 2015. Compared with children born after natural conception, the OR for cerebral palsy was 2.01 (95% CI 1.63-2.47) adjusted for mother's age at birth, parity, and pre-pregnancy health. When restricted to singletons born at term, the adjusted OR for cerebral palsy was 1.13 (95% CI 0.76-1.69). The distribution of cerebral palsy subtypes and the severity of gross and fine motor function and associated impairments did not differ significantly between children with cerebral palsy born after ART and natural conception.

CONCLUSIONS

Children born after ART had a risk of cerebral palsy that was twice that of children born after natural conception. The increased risk of cerebral palsy after ART is likely attributed to multiple pregnancies and preterm births. The prevalence of cerebral palsy after ART decreased significantly during the study period, despite an increased use of ART in the population. The distribution of clinical characteristics did not differ between children with cerebral palsy born after ART and those born after a natural conception, suggesting that the risk factors for, and causes of cerebral palsy were similar.

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.

Association between transferred embryos and multiple pregnancy/live birth rate in frozen embryo transfer cycles: A retrospective study

Background

Physicians need an appropriate embryo transfer strategy to address the challenge of reducing multiple birth rates, while maintaining the couples' live birth rate during assisted reproductive technology.

Methods

We included 10,060 frozen embryo transfer cycles from January 2015 to March 2020 in reproductive medical center of Ruijin hospital, Shanghai, China. Patients were grouped according to the number and grade of cleavage-stage embryo or blastocysts transferred. Live birth rate and multiple live birth rate were compared among groups of women of different ages. Multivariable logistic regression models were used to estimate the risk of multiple live birth using different combinations of transferred embryos.

Results

The transfer of double good-quality embryos was an independent predictor for multiple birth in women aged <30 years and those aged 36-39 years [<30 years: aOR =1.54 (95% CI: 1.14-2.06, P < 0.01); 36-39 years: aOR =1.84 (95% CI: 1.0-3.4, P < 0.01)]. Further, for women aged <36 years, the transfer of good-quality + poor-quality blastocysts was an independent predictor for multiple birth rate [<30 years: aOR=2.46 (95% CI: 1.45-4.18, P < 0.01); 31-35 years: aOR =4.45 (95% CI: 1.97-10.06, P < 0.01)].

Conclusions

Single-good-quality blastocyst transfer is recommended for women of all ages. When good-quality cleavage embryos are available, the choice of single or double embryo transfer with good- or average-quality embryo should depend on the age of women. Double embryo transfer with the highest possible grade of embryos is recommended for women aged ≥40 years.

Nucleation status of Day 2 pre-implantation embryos, acquired by time-lapse imaging during IVF, is associated with live birth

The primary purpose of this time-lapse data analysis was to identify the association between the nucleation status of a Day 2 preimplantation embryo and live births following in vitro fertilization (IVF). The retrospective data analysis was based on 2769 transferred embryos from 1966 treatment cycles and utilised only Known Implantation Data (KID) for live births. Nucleation errors (NE) such as micronucleation, binucleation, multinucleation and minor error groups, were annotated in the time-lapse images which were taken every 15 minutes for a minimum of 44 hours post insemination. Further, factors that may impact NE and the relationship of early morphological attributes and morphokinetic variables with NE occurrence were explored. The frequency of NE among the transferred embryos was 23.8%. The reversibility of NE evidenced by their presence at the two-cell stage, but absence at the four-cell stage was 89.6%. Embryos exhibiting nucleation errors at the two-cell stage had significantly lower live birth rates compared to embryos with no nucleation errors, constituting a significant predictor. A Generalized Additive Mixed Model was used to control for confounders and for controlling clustering effects from dual embryo transfers. Increased incidences of NE were observed with increasing age, with delayed occurrence of cell divisions and in oocytes inseminated with surgically retrieved spermatozoa. NE assessment and their impact on live birth provides valuable markers for early preimplantation embryo selection. In addition, the high incidence of reversibility of NE and their possible impact on live birth suggest that incorporating two-cell nuclear status annotations in embryo selection, alongside morphology and morphokinetics, is of value.

Extended culture of cleavage embryo to blastocyst embryo is among the good predictors of successful outcome in vitrified-thawed ICSI cycles

Background

Previous studies showed that top-quality embryo transfer (ET), number of transferred embryos, endometrial preparation with natural cycles or mild stimulation, and female BMI independently affected the outcome in frozen-thawed ET. However, the effect of culturing thawed cleavage embryos to blastocyst stage on the outcome was not sufficiently elucidated. Our objective is to evaluate the role of this extended culturing as predictor of cycle outcome in vitrified-thawed ICSI cycles.

Materials and methods

One thousand forty-two consecutive cycles of vitrified-thawed ET done in a single IVF unit [Mansoura Integrated Fertility Centre (MIFC)] were reviewed during a period from 2014 to 2017. Endometrial preparation methods were natural, stimulation by antiestrogen and/or gonadotropins, or replacement using sequential estradiol (E2) and progesterone (P4). The primary outcome was the clinical pregnancy rate while the secondary outcome was the chemical and ongoing pregnancy rate.

Results

Overall clinical pregnancy rate (CPR) is 298/1042 is 28.5%, chemical pregnancy rate (326/1042) 31.3%, and ongoing pregnancy rate (167/615) 27.2%. Comparing clinically pregnant (n = 298) and non-pregnant (n = 744) showed, respectively, the following: age 28.76 ± 5.0, 28.85 ± 5.18 (p = 0.8); BMI 31.06 ± 5.9, 32.45 ± 5.9 (p = 0.002); infertility duration 4.17 ± 3.2, 4.6 ± 3.5 (p = 0.038); endometrial thickness 10.82 ± 1.6, 10.13 ± 2.06 (p = 0.0001); and no. of ET 3.35 ± 1.5, 3.12 ± 1.60 (p = 0.035). The clinical pregnancy rate when vitrification was done on cleavage embryos was 198/502 (39.4%), and when vitrification done on blastocyst stage 100/ 536 (18.7%) (P < 0.0001); endometrial preparation: natural 72/240(29.1%), stimulated 204/680 (30.0%) replacement 17/90 (18.8%) (p = 0.09); extended culture of cleavage embryos to blastocyst stage: clinical pregnancy rate 116/194 (59.7%) chemical pregnancy rate 125/194 (64.1%), ongoing pregnancy rate 87/165 (52.7%) and non extended culture clinical pregnancy rate 182/848 (21.4%), chemical pregnancy rate 201/848 (23.7%), and ongoing pregnancy rate 80/450 (17.7%) (P < 0.0001).

Conclusion

Top-quality ET, number of transferred embryos and extended culture of cleavage embryos to blastocyst stage, cleavage embryos but not infertility duration, BMI, endometrial thickness, or hCG trigger of ovulation independently predict successful outcome in frozen cycle ET and extended culture of cleavage embryos significantly improved clinical and chemical and ongoing pregnancy rates.

Twinning in ART: Single embryo transfer policy

It is more than thirty years that perinatologists and healthcare personnel aim to reduce the morbidity associated with multiple pregnancy. In many cases, these complications stem from pregnancies achieved through artificial reproductive technologies (ART). Although dramatic measures have been taken to control those risks by increasing the proportion of single embryo transfers, the multiple pregnancy rate still remains relatively high among patient conceived through ART, carrying risks to both mothers and newborns, and is coupled with the related economic burden associated with prematurity. The aim of this review is to provide the current evidence regarding single embryo transfer to assist decision-makers and to promote patient knowledge toward an elective policy to reduce the risk of twinning. Single embryo transfer may aid in the further reduction of multiple pregnancy and, in most cases, will maintain patient autonomy and right of choice.

Maternal, Perinatal and Neonatal Outcomes of Triplet Pregnancies According to Chorionicity: A Systematic Review of the Literature and Meta-Analysis

Triplet pregnancies are rare events that affect approximately 93 in 100,000 deliveries in the world, especially due to the increased use of assisted reproductive techniques and older maternal age. Triplet pregnancies are associated with a higher risk of fetal and maternal morbidity and mortality compared to twins and singletons. Chorionicity has been proposed as a major determinant of perinatal and maternal outcomes in triplet pregnancies, although further evidence is needed to clarify the extent and real influence of this factor. Thus, the aim of this study was to conduct a systematic review of the literature and a meta-analysis of the maternal and perinatal outcomes of triplet pregnancies, evaluating how chorionicity may influence these results. A total of 46 studies with 43,653 triplet pregnancies and 128,145 live births were included. Among the main results of our study, we found a broad spectrum of fetal and maternal complications, especially in the group of monochorionic and dichorionic pregnancies. Risk of admission to NICU, respiratory distress, sepsis, necrotizing enterocolitis, perinatal and intrauterine mortality were all found to be higher in non-TCTA pregnancies than in TCTA pregnancies. To date, our meta-analysis includes the largest population sample and number of studies conducted in this field, evaluating a wide variety of outcome measures. The heterogeneity and retrospective design of the studies included in our research represent the main limitations of this review. More evidence is needed to fully assess outcome measures that could not be studied in this review due to scarcity of publications or insufficient sample size.

Cerebral palsy in ART children has declined substantially over time: a Nordic study from the CoNARTaS group

STUDY QUESTION

Are the decreasing multiple birth rates after ART associated with a simultaneous drop in the incidence of cerebral palsy (CP) in ART children over time?

SUMMARY ANSWER

The relative odds of CP in ART children have declined in the Nordic countries over the past two decades concurrently with declining multiple birth rates.

WHAT IS KNOWN ALREADY

In the Nordic countries, the rate of twin pregnancies after ART has decreased from 30% in the early 1990s to 4-13% in 2014, following the implementation of elective single embryo transfer (SET). Consequently, preterm birth rates have declined substantially in ART pregnancies. However, whether the risk of CP, a known consequence of preterm birth, has decreased correspondingly is still unknown.

STUDY DESIGN, SIZE, DURATION

Retrospective register-based cohort study based on data on all singletons, twins, and higher-order multiples born in Denmark (birth year 1994-2010), Finland (1990-2010), and Sweden (1990-2014), corresponding to 111 844 ART children and 4 679 351 spontaneously conceived children.

PARTICIPANTS/MATERIAL, SETTING, METHODS

Data were obtained from a large Nordic cohort of children born after ART and spontaneous conception initiated by the Committee of Nordic ART and Safety-CoNARTaS. The CoNARTaS cohort was established by cross-linking national register data using the unique personal identification number, allocated to every citizen in the Nordic countries. Data from the National Medical Birth Registers, where information on maternal, obstetric, and perinatal outcomes is recorded, were cross-linked to data from the National ART- and Patients Registers to obtain information on fertility treatments and CP diagnoses. Relative risks of CP for ART compared to spontaneous conception were estimated as odds ratios from multivariate logistic regression analyses across all birth years, as well as for the following birth year categories: 1990-1993, 1994-1998, 1999-2002, 2003-2006, 2007-2010, and 2011-2014. Analyses were made for all children and for singletons and twins, separately.

MAIN RESULTS AND THE ROLE OF CHANCE

The main outcome measure was the relative odds of CP in different time periods for ART versus spontaneously conceived children. CP was diagnosed in 661 ART children and 16 478 spontaneously conceived children born between 1990 and 2014. In 1990-1993, the relative odds of CP were substantially higher in all ART children (adjusted odds ratio (aOR) 2.76 (95% CI 2.03-3.67)) compared with all spontaneously conceived children, while in 2011-2014, it was only moderately higher (aOR 1.39 (95% CI 1.01-1.87)). In singletons, the higher relative odds of CP in ART children diminished over time from 1990 to 1993 (aOR 2.02 (95% CI 1.22-3.14)) to 2003-2006 (aOR 1.18 (95% CI 0.91-1. 49)) and was not significantly increased for birth cohorts 2007-2010 and 2011-2014. For ART twins versus spontaneously conceived twins, the relative odds of CP was not statistically significantly increased throughout the study period.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of the study was a shorter follow-up time and younger age at first CP diagnosis for ART children compared with spontaneously conceived children. However, analyses ensuring a minimum of bias from differences in age at CP diagnosis and follow-up time confirmed the results, hence, we do not consider this to cause substantial bias.

WIDER IMPLICATIONS OF THE FINDINGS

A SET policy in ART treatments has the potential to reduce the increased risk of cerebral palsy in the ART population due to lower rates of multiple deliveries. At a time with high survival rates of frozen/thawed embryos, this study provides a strong argument against the continued use of multiple embryo transfer in most ART settings. Larger cohort studies including also the number of gestational sacs in early pregnancy will be preferable to show an effect of vanishing twins on the risk of CP in the ART population.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by grants from NordForsk (grant number 71450), Elsass Foundation (19-3-0444), the ALF-agreement (ALFGBG 70940), and The Research Fund of Rigshospitalet, Copenhagen University Hospital. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Factors Influencing the Live Birth Rate Following Fresh Embryo Transfer Cycles in Infertile Women After Endometrioma Cystectomy

Background: Reproductive outcomes after fresh in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles are diverse in infertile women with a history of ovarian cystectomy for endometriomas. We aimed to develop a logistic regression model based on patients' characteristics including number of embryos transferred and stimulation protocols to predict the live birth rate in fresh IVF/ICSI-ET cycles for such patients. Methods: We recruited 513 infertile women with a history of ovarian cystectomy for endometriomas who underwent their first fresh ET with different stimulation protocols following IVF/ICSI cycles in our unit from January 2014 to December 2018. One or two embryo are implanted. Clinical and laboratory parameters potentially affecting the live birth rate following fresh ET cycles were analyzed. Univariable and multivariable analyses were performed to assess the relationship between predictive factors and live birth rate. Results: The overall live birth rate was 240/513 (46.8%). Multivariable modified Poisson regression models showed that two factors were significantly lowers the probability of live birth: female age ≥ 5 years (aOR 0.603; 95% CI 0.389-0.933; P = 0.023); BMI range 21-24.99 kg/m² compared with BMI <21 kg/m² (aOR 0.572; 95% CI 0.372-0.881, P = 0.011). And two factors significantly increased the probability of live birth: AFC >7 (aOR 1.591; 95% CI 1.075-2.353; P = 0.020); two embryos transferred (aOR 1.607; 95% CI 1.089-2.372; P = 0.017). Conclusions: For these infertile women who had undergone ovarian cystectomy for endometriosis, female age <35 years, AFC > 7, and two embryos transferred might achieve better clinical fresh IVF/ICSI-ET outcomes. BMI <21 kg/m² or ≥25 kg/m² might also have positive effects on the live birth rate, but different ovarian stimulation protocols had no significant effects. However, a larger sample size may be needed for further study.

Mining of variables from embryo morphokinetics, blastocyst's morphology and patient parameters: an approach to predict the live birth in the assisted reproduction service

Based on growing demand for assisted reproduction technology, improved predictive models are required to optimize in vitro fertilization/intracytoplasmatic sperm injection strategies, prioritizing single embryo transfer. There are still several obstacles to overcome for the purpose of improving assisted reproductive success, such as intra- and inter-observer subjectivity in embryonic selection, high occurrence of multiple pregnancies, maternal and neonatal complications. Here, we compare studies that used several variables that impact the success of assisted reproduction, such as blastocyst morphology and morphokinetic aspects of embryo development as well as characteristics of the patients submitted to assisted reproduction, in order to predict embryo quality, implantation or live birth. Thereby, we emphasize the proposal of an artificial intelligence-based platform for a more objective method to predict live birth.

Statistical Modelling Outcome of In Vitro Fertilization and Intracytoplasmic Sperm Injection: A Single Centre Study

BACKGROUND

Assisted reproductive techniques (ART) have been extensively used to treat infertility. Inaccurate prediction of a couple's fertility often leads to lowered self-esteem for patients seeking ART treatment and causes fertility distress.

OBJECTIVE

This prospective study aimed to statistically analyze patient data from a single reproductive medical center over a period of 18 months, and to establish mathematical models that might facilitate accurate prediction of successful pregnancy when ART are used.

METHODS

In the present study, we analyzed clinical data prospectively collected from 760 infertile patients visiting the second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University between June 1, 2016 and December 31, 2017. Various advanced statistical methods, including broken-line regression, were employed to analyze the data.

RESULTS

Age remained the most important factor affecting the outcome of IVF/ICSI. Using the broken-line regression model, the fastest clinical pregnancy declining age was between 25 and 32. Female infertility type was found to be a key predictor for the number of good-quality embryos and successful pregnancy, along with the antral follicle count (AFC), total number of embryos, recombinant follicle stimulating hormones (rFSH) dosage, estradiol (E2) on the trigger day, and total number of oocytes retrieved. rFSH dosage was also significantly associated with the number of oocytes retrieved and the number of frozen embryos.

CONCLUSION

The fastest clinical pregnancy declining age is ranged between 25 and 32, and female infertility type is evidenced as another key predictive factor for the cumulative outcome of ART.

Reduced live-birth rates after IVF/ICSI in women with previous unilateral oophorectomy: results of a multicentre cohort study

STUDY QUESTION

Is there a reduced live-birth rate (LBR) after IVF/ICSI treatment in women with a previous unilateral oophorectomy (UO)?

SUMMARY ANSWER

A significantly reduced LBR after IVF/ICSI was found in women with previous UO when compared with women with intact ovaries in this large multicentre cohort, both crudely and after adjustment for age, BMI, fertility centre and calendar period and regardless of whether the analysis was based on transfer of embryos in the fresh cycle only or on cumulative results including transfers using frozen-thawed embryos.

WHAT IS KNOWN ALREADY

Similar pregnancy rates after IVF/ICSI have been previously reported in case-control studies and small cohort studies of women with previous UO versus women without ovarian surgery. In all previous studies multiple embryos were transferred. No study has previously evaluated LBR in a large cohort of women with a history of UO.

STUDY DESIGN, SIZE, DURATION

This research was a multicentre cohort study, including five reproductive medicine centres in Sweden: Carl von Linné Clinic (A), Karolinska University Hospital (B), Uppsala University Hospital (C), Linköping University Hospital (D) and Örebro University Hospital (E). The women underwent IVF/ICSI between January 1999 and November 2015. Single embryo transfer (SET) was performed in approximately 70% of all treatments, without any significant difference between UO exposed women versus controls (68% versus 71%), respectively (P = 0.32), and a maximum of two embryos were transferred in the remaining cases. The dataset included all consecutive treatments and fresh and frozen-thawed cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The exposed cohort included 154 women with UO who underwent 301 IVF/ICSI cycles and the unexposed control cohort consisted of 22 693 women who underwent 41 545 IVF/ICSI cycles. Overall, at the five centres (A-E), the exposed cohort underwent 151, 34, 35, 41 and 40 treatments, respectively, and they were compared with controls of the same centre (18 484, 8371, 5575, 4670 and 4445, respectively). The primary outcome was LBR, which was analysed per started cycle, per ovum pick-up (OPU) and per embryo transfer (ET). Secondary outcomes included the numbers of oocytes retrieved and supernumerary embryos obtained, the Ovarian Sensitivity Index (OSI), embryo quality scores and cumulative pregnancy rates. We used a Generalized Estimating Equation (GEE) model for statistical analysis in order to account for repeated treatments.

MAIN RESULTS AND THE ROLE OF CHANCE

The exposed (UO) and control women's groups were comparable with regard to age and performance of IVF or ICSI. Significant differences in LBR, both crude and age-adjusted, were observed between the UO and control groups: LBR per started cycle (18.6% versus 25.4%, P = 0.007 and P = 0.014, respectively), LBR/OPU (20.3% versus 27.1%, P = 0.012 and P = 0.015, respectively) and LBR/ET (23.0% versus 29.7%, P = 0.022 and P = 0.025, respectively). The differences in LBR remained significant after inclusion of both fresh and frozen-thawed transfers (both crude and age-adjusted data): LBR/OPU (26.1% versus 34.4%, P = 0.005 and P = 0.006, respectively) and LBR/ET (28.3% versus 37.1%, P = 0.006 and P = 0.006, respectively). The crude cancellation rate was significantly higher among women with a history of UO than in controls (18.9% versus 14.5%, P = 0.034 and age-adjusted, P = 0.178). In a multivariate GEE model, the cumulative odds ratios for LBR (fresh and frozen-thawed)/OPU (OR 0.70, 95% CI 0.52-0.94, P = 0.016) and LBR (fresh and frozen-thawed)/ET (OR 0.68, 95% CI 0.51-0.92, P = 0.012) were approximately 30% lower in the group of women with UO when adjusted for age, BMI, reproductive centre, calendar period and number of embryos transferred when appropriate. The OSI was significantly lower in women with a history of UO than in controls (3.6 versus 6.0) and the difference was significant for both crude and age-adjusted data (P = <0.001 for both). Significantly fewer oocytes were retrieved in treatments of women with UO than in controls (7.2 versus 9.9, P = <0.001, respectively).

LIMITATIONS, REASONS FOR CAUTION

Due to the nature of the topic, this is a retrospective analysis, with all its inherent limitations. Furthermore, the cause for UO was not possible to obtain in all cases. A diagnosis of endometriosis was also more common in the UO group, i.e. a selection bias in terms of poorer patient characteristics in the UO group cannot be completely ruled out. However, adjustment for all known confounders did not affect the general results.

WIDER IMPLICATIONS OF THE FINDINGS

To date, this is the largest cohort investigated and the first study indicating an association of achieving reduced live birth after IVF/ICSI in women with previous UO. These findings are novel and contradict the earlier notion that IVF/ICSI treatment is not affected, or is only marginally affected by previous UO.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

Not applicable.

Does ovarian stimulation regimen affect IVF outcome? a two-centre, real-world retrospective study using predominantly cleavage-stage, single embryo transfer

In this study, ovarian stimulation using highly purified human menopausal gonadotrophin (HP-HMG) and recombinant FSH (rFSH) for IVF were compared in two large assisted reproduction technique centres in Sweden. A total of 5902 women underwent 9631 oocyte retrievals leading to 8818 embryo transfers (7720 on day 2): single embryo transfers (74.2%); birth rate per embryo transfer (27.7%); multiple birth rate (5.0%); incidence of severe ovarian hyperstimulation syndrome (0.71%). Compared with ovarian stimulation with rFSH, women who received HP-HMG were older, had higher dosages of gonadotrophins administered, fewer oocytes retrieved and more embryos transferred. After multivariate analysis controlling for age and generalized estimating equation model, no differences were found in delivery outcomes per embryo transfers between HP-HMG and rFSH, independent of gonadotrophin releasing hormone analogue (GnRH) used. Logit curves for live birth rate suggested differences for various subgroups, most prominently for women with high oocyte yield or when high total doses were used. Differences were not significant, perhaps owing to skewed distributions of the FSH compounds versus age and other covariates. These 'real-life patients' had no differences in live birth rate between HP-HMG and rFSH overall or in subgroups of age, embryo score, ovarian sensitivity or use of GnRH analogue regimen.

Fertility Treatments in the United States: Improving Access and Outcomes

The recently released National Public Health Action Plan for the Detection, Prevention, and Management of Infertility calls for better access to high-quality infertility services and improved safety of fertility treatments. Both assisted reproductive technology (ART) and non-ART fertility treatments have allowed millions of patients worldwide to overcome infertility-a disease of the reproductive system and important public health issue. However, there are substantial disparities in access to effective treatments in the United States, largely attributable to high out-of-pocket costs, especially for ART. Moreover, the outcomes of fertility treatments are often complicated by the large proportion of multiple births with substantial health risks for both neonates and mothers. Prevention of multiple births is difficult during non-ART fertility treatments but can be effective with single-embryo transfer during ART. Several U.S. states have enacted legislative mandates that require private insurers to cover some portion of the costs associated with fertility treatments and thus reduce the financial pressure to transfer multiple embryos during ART. Although studies have shown that insurance coverage reduces per-cycle multiple births to a certain degree, states with insurance mandates have more ART-related multiple births attributable to substantially larger number of ART-conceived neonates. Experience from other countries shows that access to ART can be improved without concomitant increases in multiple births by providing reimbursement for ART in combination with restrictions on the number of embryos transferred per cycle. Such approaches may or may not be successful in the United States with its unique and complex health care system.

"One for Sorrow, Two for Joy?": American embryo transfer guideline recommendations, practices, and outcomes for gestational surrogate patients

In January 2016, Melissa Cook, a California gestational surrogate experiencing a multiple-birth pregnancy following the in vitro fertilization (IVF) transfer of three embryos comprised of donor eggs and sperm provided by the intended father, went to the media when the intended father requested that she undergo a fetal reduction because twins were less expensive to raise than triplets. Much of the legal interest in this case to date has centered on the enforceability of surrogacy contracts. However, the Cook case also raises troubling issues about fertility treatment practices involving gestational surrogates, twin preference, and third-party reproduction medical decision-making. This paper focuses on multiple-embryo transfers in the context of US surrogacy arrangements. Offering an original analysis of data obtained from the US national-assisted reproduction registry, it examines single- and multiple-embryo transfer trends over a 12-year period (2003 to 2014). Findings reveal that recommended guidelines were followed in fewer than 42% of the cases in 2014. The paper argues that ensuring equitable medical treatment for all recipients of IVF requires the adoption of treatment guidelines tailored to, and offering protections for, specific patient groups, and that, once in place, guidelines must be robustly implemented.

Promoting the use of elective single embryo transfer in clinical practice

Background

The transfer of multiple embryos after in vitro fertilization (IVF) increases the risk of twins and higher-order births. Multiple births are associated with significant health risks and maternal and neonatal complications, as well as physical, emotional, and financial stresses that can strain families and increase the incidence of depression and anxiety disorders in parents. Elective single embryo transfer (eSET) is among the most effective methods to reduce the risk of multiple births with IVF.

Main body

Current societal guidelines recommend eSET for patients <35 years of age with a good prognosis, yet even this approach is not widely applied. Many patients and clinicians have been reluctant to adopt eSET due to studies reporting higher live birth rates with the transfer of two or more embryos rather than eSET. Additional barriers to eSET include risk of treatment dropout after embryo transfer failure, patient preference for twins, a lack of knowledge about the risks and complications associated with multiple births, and the high costs of multiple IVF cycles. This review provides a comprehensive summary of strategies to increase the rate of eSET, including personalized counseling, access to educational information regarding the risks of multiple pregnancies and births, financial incentives, and tools to help predict the chances of IVF success. The use of comprehensive chromosomal screening to improve embryo selection has been shown to improve eSET outcomes and may increase acceptance of eSET.

Conclusions

eSET is an effective method for reducing multiple pregnancies resulting from IVF. Although several factors may impede the adoption of eSET, there are a number of strategies and tools that may encourage the more widespread adoption of eSET in clinical practice.

Trends in ectopic pregnancy rates following assisted reproductive technologies in the UK: a 12-year nationwide analysis including 160 000 pregnancies

STUDY QUESTION

Have the advancement of assisted reproductive technologies (ART) and changes in the incidence of specific causes of infertility-altered ectopic pregnancy (EP) rates following ART over time in the UK?

SUMMARY ANSWER

EP rates in the UK following IVF/ICSI have progressively decreased, and this appears to be associated with a reduction in the incidence of tubal factor infertility and the increased use of both a lower number of embryos transferred and extended embryo culture.

WHAT IS KNOWN ALREADY

Historically, EP rates following ART are known to have increased over time. However, the impact of progress in ART procedures and changes in both policy and the incidence of specific causes of infertility on the overall EP rate in the UK has yet to be studied.

STUDY DESIGN, SIZE, DURATION

A population-based retrospective analysis was carried out on all pregnancies following ART cycles carried out in the UK between 2000 and 2012 included in the anonymized database of the Human Fertilisation and Embryology Authority.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall, 161 967 treatment cycles resulting in a pregnancy were included in the analysis. Among them, 8852 pregnancies occurred after intrauterine insemination (IUI) and 153 115 following IVF/ICSI.

MAIN RESULTS AND THE ROLE OF CHANCE

During this period of 12 years, ∼1.4% (n = 2244) of all pregnancies following ART were an EP. Crude EP rates were significantly higher after IVF/ICSI when compared with following IUI (1.4 versus 1.1%, P = 0.043). The incidence of EP decreased significantly over time for IVF/ICSI cycles [incidence rate ratios (IRR) 0.96 per year, 95% confidence interval (CI) 0.94-0.97], but not after IUI (IRR 0.96 per year, 95% CI 0.91-1.03).Among pregnancies resulting from IVF/ICSI, multivariable logistic regression analysis demonstrated that the major risk factor for EP was the presence of tubal infertility [adjusted odds ratio (aOR) 2.23, 95% CI 1.93-2.58), followed by the increased number of embryos transferred (aOR 1.29 for 2 versus 1 embryo transferred, 95% CI 1.11-1.49; aOR 1.69 for 3 or more versus 1 embryo transferred, 95% CI 1.35-2.11). The use of extended embryo culture to Days 3-4 or 5-7 significantly reduced the risk of EP, when compared with the transfer of early cleavage (Days 1-2) embryos (respectively, aOR 0.85, 95% CI 0.76-0.94; and aOR 0.73, 95% CI 0.63-0.84). Finally, frozen embryo transfer (ET) had no effect on the risk of EP following IVF/ICSI (aOR 0.92, 95% CI 0.76-1.11).

LIMITATIONS, REASONS FOR CAUTION

Owing to the use of this particular registry data, well-established risk factors of EP, such as smoking habits or uterine surgery, could not be assessed.

WIDER IMPLICATIONS OF THE FINDINGS

Our results provide the first evidence of a potential benefit-in terms of the reduction in EP rates-of the implementation of national programmes aiming to reduce the incidence of tubal infertility, such as the National Chlamydia Screening Programme. In addition, campaigns for the widespread introduction of single ET may not only reduce the incidence of multiple pregnancies but also the incidence of EP following IVF/ICSI.

STUDY FUNDING/COMPETING INTERESTS

No funding was obtained for this study, and there are no conflicts of interest to declare.

Increasing The Number of Embryos Transferred from Two to Three, Does not Increase Pregnancy Rates in Good Prognosis Patients

BACKGROUND

To compare the pregnancy outcomes after two embryos versus three embryos transfers (ETs) in women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

MATERIALS AND METHODS

This retrospective study was performed on three hundred eighty seven women with primary infertility and with at least one fresh embryo in good quality in order to transfer at each IVF/ICSI cycle, from September 2006 to June 2010. Patients were categorized into two groups according to the number of ET as follows: ET2 and ET3 groups, indicating two and three embryos were respectively transferred. Pregnancy outcomes were compared between ET2 and ET3 groups. Chi square and student t tests were used for data analysis.

RESULTS

Clinical pregnancy and live birth rates were similar between two groups. The rates of multiple pregnancies were 27 and 45.2% in ET2 and ET3 groups, respectively. The rate of multiple pregnancies in young women was significantly increased when triple instead of double embryos were transferred. Logistic regression analysis indicated two significant prognostic variables for live birth that included number and quality of transferred embryos; it means that the chance of live birth following ICSI treatment increased 3.2-fold when the embryo with top quality (grade A) was transferred, but the number of ET had an inverse relationship with live birth rate; it means that probability of live birth in women with transfer of two embryos was three times greater than those who had three ET.

CONCLUSION

Due to the difficulty of implementation of the elective single-ET technique in some infertility centers in the world, we suggest transfer of double instead of triple embryos when at least one good quality embryo is available for transfer in women aged 39 years or younger. However, to reduce the rate of multiple pregnancies, it is recommended to consider the elective single ET strategy.

Embryo transfer practices and multiple births resulting from assisted reproductive technology: an opportunity for prevention

OBJECTIVE

To evaluate assisted reproductive technology (ART) ET practices in the United States and assess the impact of these practices on multiple births, which pose health risks for both mothers and infants.

DESIGN

Retrospective cohort analysis using the National ART Surveillance System data.

SETTING

US fertility centers reporting to the National ART Surveillance System.

PATIENT(S)

Noncanceled ART cycles conducted in the United States in 2012.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Multiple birth (birth of two or more infants, at least one of whom was live-born).

RESULT(S)

Of 134,381 ART transfer cycles performed in 2012, 51,262 resulted in live births, of which 13,563 (26.5%) were multiple births: 13,123 twin and 440 triplet and higher order births. Almost half (46.1%) of these multiple births resulted from the following four cycle types: two fresh blastocyst transfers among favorable or average prognosis patients less than 35 years (1,931 and 1,341 multiple births, respectively), two fresh blastocyst transfers among donor-oocyte recipients (1,532 multiple births), and two frozen/thawed ETs among patients less than 35 years (1,452 multiple births). More than half of triplet or higher order births resulted from the transfer of two embryos (52.5% of births among fresh autologous transfers, 67.2% of births among donor-oocyte recipient transfers, and 42.9% among frozen/thawed autologous transfers).

CONCLUSION(S)

A substantial reduction of ART-related multiple (both twin and triplet or higher order) births in the United States could be achieved by single blastocyst transfers among favorable and average prognosis patients less than 35 years of age and donor-oocyte recipients.

Debating Elective Single Embryo Transfer after in vitro Fertilization: A Plea for a Context-Sensitive Approach

The number of embryos transferred after in vitro fertilization (IVF) have been a topic of debate for over a decade now. Due to the risk associated with multiple pregnancy, there has been a global effort at reducing the multiple pregnancy rates to a minimum while maintaining an acceptable level of successful IVF pregnancy rate. Elective single embryo transfer (eSET) is advocated in most European countries. In Belgium and Sweden, eSET is mandatory for couples with a good prognosis. However, despite clinical recommendations and policy statements, patients in clinical practice frequently do request for the transfer of multiple embryos in order to have twins. Such requests conflict with policy guidelines and create an ethical dilemma for physicians: Should the physician do as the couple requests, and there with respect the autonomy of patients, or adhere to medical policy that takes the health of the mother and children at heart? This article provides an exploration of the arguments found in the literature that plays a role in the discussion on this topic and eventually argues that what a physician should do depends on the specificities of the context in which patients and physicians are implicated. These contextual issues can be taken into account in a shared decision-making procedure, which allows reflections and the responsibilities of both patients and physicians to be attended in decision about assisted reproduction.

In search of real autonomy for fertility patients

Nearly one in eight infants in the United States is born preterm. A variety of factors are associated with preterm birth, including multiplicity. In the United States fertility treatments are currently associated with high rates of multiplicity, but these rates could be reduced significantly if changes can be made to fertility treatment policy and practice. These include reducing the financial pressure on patients to prioritize pregnancy chances over safety by expanding insurance coverage and altering the way we calculate success rates and insurance benefits so that two consecutive single embryo transfers is equivalent to one double embryo transfer.

Number of embryos transferred after in vitro fertilization and good perinatal outcome

OBJECTIVE

To assess the association between number of embryos transferred and a measure of assisted reproductive technology success that emphasizes good perinatal outcome.

METHODS

We analyzed assisted reproductive technology cycles initiated in 2011 that progressed to fresh embryo transfer among women using autologous oocytes and reported to the U.S. National Assisted Reproductive Technology Surveillance System (n=82,508). Percentages of good perinatal outcome (live birth of a term [at or after 37 weeks of gestation], normal birth weight [2,500 g or greater] singleton) were stratified by prognosis (favorable, average, less favorable), age, embryo stage (day 3, day 5), and number of embryos transferred. Differences in the percentages by number of embryos transferred were evaluated using Fisher's exact test with Bonferroni correction.

RESULTS

Among patients younger than 35 years with a favorable prognosis, chances of a good perinatal outcome were higher with transferring a single (compared with double) day 5 (43% compared with 27%) or day 3 embryo (36% compared with 30%). Likewise, a higher chance of a good perinatal outcome was observed with transferring a single day 5 embryo in patients 35-37 years old with a favorable prognosis (39% compared with 28%) or patients younger than 35 years old with an average prognosis (35% compared with 26%). A higher chance of good perinatal outcome was associated with transferring two (compared with one) day 3 embryos among patients aged 40 years or younger with an average prognosis or patients younger than 35 years old with a less favorable prognosis.

CONCLUSION

The association between number of embryos transferred and the birth of a term, normal birth weight singleton is described. Among patients younger than 35 years of age undergoing in vitro fertilization with a favorable prognosis, the highest chance of good perinatal outcome is associated with a single embryo transfer.

LEVEL OF EVIDENCE

II.

Perinatal mortality following assisted reproductive technology treatment in Australia and New Zealand, a public health approach for international reporting of perinatal mortality

BACKGROUND

There is a need to have uniformed reporting of perinatal mortality for births following assisted reproductive technology (ART) treatment to enable international comparison and benchmarking of ART practice.

METHODS

The Australian and New Zealand Assisted Reproduction Database was used in this study. Births of ≥ 20 weeks gestation and/or ≥ 400 grams of birth weight following embryos transfer cycles in Australia and New Zealand during the period 2004 to 2008 were included. Differences in the mortality rates by different perinatal periods from a gestational age cutoff of ≥ 20, ≥ 22, ≥ 24, or ≥ 28 weeks (wks) to a neonatal period cutoff of either < 7 or < 28 days after birth were assessed. Crude and specific (number of embryos transferred and plurality) rates of perinatal mortality were calculated for selected gestational and neonatal periods.

RESULTS

When the perinatal period is defined as ≥ 20 wks gestation to < 28 days after birth, the perinatal mortality rate (PMR) was 16.1 per 1000 births (n = 630). A progressive contraction of the gestational age groups resulted in marked reductions in the PMR for deaths at < 28 days (22 wks 11.0; 24 wks 7.7; 28 wks 5.6); and similarly for deaths at < 7 days (20 wks 15.6, 22 wks 10.5; 24 wks 7.3; 28 wks 5.3). In contrast, a contraction of the perinatal period from < 28 to < 7 days after birth only marginally reduced the PMR from 16.2 to 15.6 per 1000 births which was consistent across all gestational ages.The PMR for single embryo transfer (SET) births (≥ 20 weeks gestation to < 7 days post-birth) was significantly lower (12.8 per 1000 SET births) compared to double embryo transfer (DET) births (PMR 18.3 per 1000 DET births; p < 0.001, Fisher's Exact Test). Similarly, the PMR for SET births (≥ 22 weeks gestation to < 7 days post-birth) was significantly lower (8.8 per 1000 SET births, p < 0.001, Fisher's Exact Test) when compared to DET births (12.2 per 1000 DET births). The highest PMR (50.5 per 1000 SET births, 95% CI 36.5-64.5) was for twins following SET births (≥ 20 weeks gestation to < 7 days post-birth) compared to twins following DET (23.9 per 1000 DET births, 95% CI 20.8-27.1).

CONCLUSION

Reporting of perinatal mortality of ART births is an essential component of quality ART practice. This should include measures that monitor the impact on perinatal mortality of multiple embryo transfer. We recommend that reporting of perinatal deaths following ART treatment, should be stratified for three gestation-specific perinatal periods of ≥ 20, ≥ 22 and ≥ 28 completed weeks to < 7 days post-birth; and include plurality specific rates by SET and DET. This would provide a valuable international evidence-base of PMR for use in evaluating ART policy, practice and new research.

Risk disparities in the globalisation of assisted reproductive technology: the case of Asia

This paper analyses the disparities in risks associated with biomedical technology focusing on the results of assisted reproductive technology (ART). ART among biomedical technologies transferred to Asia is a representative case that reveals in its clinical use and related scientific research the global politics of technology. This study notes the global politics at work in the recognition of and reaction to such risks. While many Asian countries aggressively pursue technological development, weak legislative and administrative regulations have created various problems and controversial cases. This study asserts that risks associated with technology are characterised as social facts not natural ones or mere 'side effects', since technological development and risk are closely intertwined.

Mistaken advocacy against twin pregnancies following IVF

PURPOSE

A recent publication by Swedish Colleagues in Fertility & Sterility for the first time, statistically correctly, attempted to assess risks of twin IVF pregnancies in comparison to two consecutive singleton IVF pregnancies. Historic comparisons have been statistically incorrect, comparing risks of one twin to one singleton pregnancy. We here analyze data and conclusions presented in this Swedish study.

METHODS

We reviewed the manuscript by Sazonova et al. (Fertil Steril, 2013) (doi: 10.1016/j.fertnstert.2012.11.023 ).

RESULTS

Based on incorrect statistical methodology, twins after in vitro fertilization (IVF) have come under attack as "adverse" outcomes. Above noted study recently, for the first time, correctly compared one twin to two consecutive singleton pregnancies. Investigators, however, in our opinion interpreted their own data incorrectly by claiming "dramatically" higher maternal and neonatal risks in twin pregnancies. Our interpretation of reported data, indeed, in contrast suggests surprisingly minor differences in observed twin-risks. Moreover, such minor risk increases do not offer adequate compensatory benefits for significantly lower pregnancy chances in first IVF cycles with eSET in comparison to two-embryo transfers (2-ET).

CONCLUSIONS

As significantly higher maternal and neonatal risks of twin IVF pregnancies represent the principal rationale for eSET, the Swedish study actually suggests that eSET offers neither patient-friendly nor cost-effective treatment options for IVF, except where patients object to twins or have medical contraindications. The need for a second pregnancy to achieve equal outcome (2 children), resulting treatment delays, increased efforts and costs, in absence of any guarantees that a second successful singleton pregnancy/delivery will ever be accomplished, invalidates eSET as a routine procedure.

[Reduction of multiple pregnancies in ART with large SET procedures over the period 2001-2010]

OBJECTIVE

To evaluate delivery rate and multiple pregnancy rates in ART (assisted reproductive techniques) following introduction of an elective single embryo tranfer (eSET) policy. This strategy was started in 2002 including transfer of one embryo for women less than 35 years with a least two good quality embryo during their first or second attempts.

PATIENTS AND METHODS

Retrospective study including all IVF cycles performed in the IVF centre of Clermont-Ferrand University Hospital from 01/01/2001 to 31/12/2010. Main outcome measures were number of embryos transferred, cumulative delivery and multiple pregnancy rates (including fresh and frozen embryo transfers). A subgroup analysis including patients' age was done.

RESULTS

Cumulative delivery rate reached 27,3% in 2010 with a significant drop in multiple pregnancy rate: from 30% in 2001 to 7,9% in 2010. The average number of transferred embryo decreased from 2.29 to 1.55 in the same period. In our centre, eSET was performed in 85% of first IVF attempt and in 34,4% of second attempts for women less than 35 years.

CONCLUSION

The implementation of an eSET policy does not change the delivery rate but significantly decrease the number of multiple pregnancies compared to double embryo transfer. eSET should be carried out during the 1st and 2nd attempts in patients under 35 years when at least two good quality embryos were obtained.

The irrational attraction of elective single-embryo transfer (eSET)

In this issue of the journal, Niinimäki et al., colleagues from a pioneering Finnish center in the development of elective single-embryo transfer (eSET), propose the expansion of eSET to suitable women at ages of 40-44 years. This paper offers not only a critique of their proposal but also of eSET in general.

The Swedish Twin Registry: establishment of a biobank and other recent developments

The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.

Temporal trends in the frequency of twins and higher-order multiple births in Canada and the United States

BACKGROUND

The dramatic increase in multiple births is an important public health issue, since such births have elevated risks for adverse perinatal outcomes. Our objective was to explore the most recent temporal trends in rates of multiple births in Canada and the United States.

METHODS

Live birth data from Canada (excluding Ontario) and the United States from 1991-2009 were used to calculate rates of twins, and triplet and higher-order multiples (triplet+). Temporal trends were assessed using tests for linear trend and absolute and relative changes in rates.

RESULTS

Twin live births in the United States increased from 23.1 in 1991 to 32.2 per 1,000 live births in 2004, remained stable between 2004 and 2007, and then increased slightly to an all-time high of 33.2 per 1,000 live births in 2009. In Canada, rates also increased from 20.0 in 1991 to 28.3 per 1,000 live births in 2004, continued to increase modestly between 2004 and 2007, and rose to a high of 31.4 per 1,000 in 2009. Rates of triplet+ live births in the United States increased dramatically from 81.4 in 1991 to 193.5 per 100,000 live births in 1998, remained stable between 1998 and 2003 and then decreased to 148.9 per 100,000 in 2007. The rate declined marginally in 2008, but then rose again in 2009 to 153.5 per 100,000. Rates of triplet+ live births were much lower in Canada, although the temporal pattern of change was similar.

CONCLUSION

The rate of twin live births in the United States and Canada continues to increase, though more modestly than during the 1990s. Recent declines in rates of triplet+ live births in both countries have been followed by unstable trends.

Multiple births associated with assisted human reproduction in Canada

OBJECTIVE

Assisted human reproduction has been associated with increased rates of multiple births. Data suggest that twins and higher order multiple pregnancies are at risk for pre- and postnatal health complications that contribute to stress on both the family and the Canadian health care system. No published Canadian data estimate the contribution of assisted human reproduction to multiple birth rates. This study was designed to determine the contributions of age and assisted human reproduction to multiple birth rates in Canada.

METHODS

We performed analyses of existing Canadian databases, using a mathematical model from the Centers for Disease Control and Prevention. More specifically, data from the Canadian Vital Statistics: Births and Stillbirths database were combined with data from the Canadian Assisted Reproductive Technologies Register collected by the Canadian Fertility and Andrology Society. Datasets were standardized to age distributions of mothers in 1978.

RESULTS

RESULTS suggest that in vitro fertilization, ovulation induction, and age each contribute more to the rates of triplets than to twins. As expected, the contribution of natural factors was higher to twins than to triplets.

CONCLUSION

These are the first Canadian data analyzed to separate and measure the contributions of age and assisted reproductive technologies to multiple birth rates. Our findings are important for guiding physician and patient education and informing the development of treatment protocols that will result in lower-risk pregnancies and improved long-term health for women and their offspring.

Supernumerary blastocyst cryopreservation: a key prognostic indicator for patients opting for an elective single blastocyst transfer (eSBT)

OBJECTIVE

To determine if patients, less than 40 years of age with or without day 5 cryopreservation (d5 cryo), compromise their pregnancy rate (PR) by choosing an eSBT.

DESIGN

Retrospective analysis

SETTING

University IVF center

PATIENTS

2,203 non-donor fresh IVF cycles in women <40 years of age from January 2004 to January 2010.

INTERVENTIONS

None

MAIN OUTCOME MEASURE(S)

Eggs retrieved, Embryos cryopreserved, Implantation Rates, Clinical Pregnancy Rates, Live Birth Rates, Spontaneous Abortion Rates

RESULTS

Pregnancy outcomes in women <40 years with or without d5 cryo were compared according to whether patients underwent an eSBT versus a 2BT in non-donor fresh IVF cycles. Overall, eSBT was associated with elimination of twinning while maintaining a high clinical pregnancy rate in both groups with d5 cryo (75 % eSBT versus 72 % 2BT) and groups without d5 cryo (48 % eSBT versus 56 % 2BT).

CONCLUSIONS

In this study, patients <40 years of age have eliminated twinning by electively choosing to transfer a single blastocyst without compromising their PR if embryos are available for d5 cryo, and suffer only a non-statistically significant drop in their PR if there are no embryos available for d5 cryo in exchange for the benefit of eliminating the obstetrical risk of twinning.

Selection of single blastocysts for fresh transfer via standard morphology assessment alone and with array CGH for good prognosis IVF patients: results from a randomized pilot study

BACKGROUND

Single embryo transfer (SET) remains underutilized as a strategy to reduce multiple gestation risk in IVF, and its overall lower pregnancy rate underscores the need for improved techniques to select one embryo for fresh transfer. This study explored use of comprehensive chromosomal screening by array CGH (aCGH) to provide this advantage and improve pregnancy rate from SET.

METHODS

First-time IVF patients with a good prognosis (age <35, no prior miscarriage) and normal karyotype seeking elective SET were prospectively randomized into two groups: In Group A, embryos were selected on the basis of morphology and comprehensive chromosomal screening via aCGH (from d5 trophectoderm biopsy) while Group B embryos were assessed by morphology only. All patients had a single fresh blastocyst transferred on d6. Laboratory parameters and clinical pregnancy rates were compared between the two groups.

RESULTS

For patients in Group A (n = 55), 425 blastocysts were biopsied and analyzed via aCGH (7.7 blastocysts/patient). Aneuploidy was detected in 191/425 (44.9%) of blastocysts in this group. For patients in Group B (n = 48), 389 blastocysts were microscopically examined (8.1 blastocysts/patient). Clinical pregnancy rate was significantly higher in the morphology + aCGH group compared to the morphology-only group (70.9 and 45.8%, respectively; p = 0.017); ongoing pregnancy rate for Groups A and B were 69.1 vs. 41.7%, respectively (p = 0.009). There were no twin pregnancies.

CONCLUSION

Although aCGH followed by frozen embryo transfer has been used to screen at risk embryos (e.g., known parental chromosomal translocation or history of recurrent pregnancy loss), this is the first description of aCGH fully integrated with a clinical IVF program to select single blastocysts for fresh SET in good prognosis patients. The observed aneuploidy rate (44.9%) among biopsied blastocysts highlights the inherent imprecision of SET when conventional morphology is used alone. Embryos randomized to the aCGH group implanted with greater efficiency, resulted in clinical pregnancy more often, and yielded a lower miscarriage rate than those selected without aCGH. Additional studies are needed to verify our pilot data and confirm a role for on-site, rapid aCGH for IVF patients contemplating fresh SET.

Frozen-thawed embryo transfer cycles in China: clinical outcomes of two and three multicellular embryos transfers

PURPOSE

To analyze the clinical outcomes of frozen embryo transfer (FET) cycles when two or three multicellular embryos were transferred in Chinese women.

METHODS

A retrospective study was conducted to analyze 980 FET cycles performed between January 2007 and October 2010. Two (785 cycles) or three (195 cycles) multicellular embryos were transferred.

RESULTS

Both in patients under 35 years (n = 776) and those aged 35 to 39 years (n = 169), the transfer of two versus three multicellular embryos results in similar clinical pregnancy rates (CPR), implantation rates (IR) and live birth rates (LBR). In both age groups, the multiple pregnancy rate (MPR) was significantly higher in the three-embryo groups. Among women over 40 years of age (n = 35), there were no differences in the CPR, IR, MBR or LBR between the two groups

CONCLUSIONS

Transferring two instead of three multicellular embryos in patients under 40 years old significantly decreases the risk of MPR without compromising PR, IR and LBR. In the age group above 40, transferring two instead of three multicellular embryos did not decrease PR, IR, MBR or LBR. Transferring more embryos when a patient had more unsuccessful cycles was not warranted in all patients.