Practice patterns and outcomes with the use of single embryo transfer in the United States

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.

Tubal Factor Infertility, In Vitro Fertilization, and Racial Disparities: A Retrospective Cohort in Two US Clinics

BACKGROUND

Nearly 14% of US women report any lifetime infertility which is associated with health care costs and psychosocial consequences. Tubal factor infertility (TFI) often occurs as a result of sexually transmitted diseases and subsequent pelvic inflammatory disease. We sought to evaluate for and describe potential racial disparities in TFI and in vitro fertilization (IVF) prevalence.

METHODS

Records of women aged 19 to 42 years in our retrospective cohort from 2 US infertility clinics were reviewed. We calculated TFI prevalence, IVF initiation prevalence, and prevalence ratios (PRs), with 95% confidence intervals (CIs) for each estimate, overall and by race.

RESULTS

Among 660 infertile women, 110 (16.7%; 95% CI, 13.8-19.5%) had TFI which was higher in Black compared with White women (30.3% [33/109] vs 13.9% [68/489]; PR, 2.2 [95% CI, 1.5-3.1]). For women with TFI, IVF was offered to similar proportions of women by race (51.5% [17/33] vs 52.9% [36/68] for Black vs White women); however, fewer Black than White women with TFI started IVF (6.7% [1/15] vs 31.0% [9/29]; PR, 0.2 [95% CI, 0-1.0]), although the difference was not statistically different.

CONCLUSIONS

Tubal factor infertility prevalence was 2-fold higher among Black than White women seeking care for infertility. Among women with TFI, data suggested a lower likelihood of Black women starting IVF than White women. Improved sexually transmitted disease prevention and treatment might ameliorate disparities in TFI.

Disparities in ART Live Birth and Cumulative Live Birth Outcomes for Hispanic and Asian Women Compared to White Non-Hispanic Women

BACKGROUND: Conflicting disparities have been seen in assisted reproductive technology (ART) outcomes for Hispanic and Asian women compared to white, non-Hispanic (WNH) women. We, therefore, sought to clarify these disparities and calculated cumulative live birth rates (CLBR) for these racial or ethnic groups using the SARTCORS database. METHODS: We performed an analysis of the 2014–2016 SARTCORS database for member clinics doing at least 50 cycles of ART each year. RESULTS: In comparison to cycles in WNH women, cycles in Hispanic and Asian patients were in older (p < 0.001), more nulliparous women, that were less likely to have a history of endometriosis compared WNH women regardless of prior ART status. ART cycles in Hispanic and Asian women, exhibited lower rates of live birth (LB) per cycle start (p < 0.001) compared to cycles in WNH women. Multivariate logistic regression demonstrated that cycles from Hispanic and Asian women were less likely to have a LB and CLBR than white women (OR 0.86; p = 0.004, OR 0.69; p < 0.001, respectively) independent of age, parity, BMI, etiology of infertility, use of ICSI or number of embryos transferred. CONCLUSIONS: Race or ethnicity continues to be an independent prognostic factor for LB and CLBR for ART. Additional analysis of trends among Hispanic and Asian women is warranted to enable addressing disparities in outcomes in ART treatment.

Applications of noninvasive prenatal testing in vanishing twin syndrome pregnancies after treatment of assisted reproductive technology in a single center

OBJECTIVE

The objective of the study is to assess the clinical application of noninvasive prenatal testing (NIPT) for VTS pregnancies after the treatment of assisted reproductive technology (ART).

METHOD

This was a retrospective study on VTS pregnancies through ART treatment. Participants underwent NIPT at 11 to 13 weeks gestation by sequencing. Resampling was recommended for both positive and testing failure cases. For NIPT positive results, participants were advised to have invasive testing. Clinical outcomes were obtained by telephone interview.

RESULTS

In total of 579 cases, testing failure rates after first sampling and resampling were 7.6% and 1.4%, respectively. Twelve positive results were reported by NIPT. But only one true positive was confirmed, giving a PPV of 8%. A total of 576 cases completed the follow-up (including 533 NIPT negative, 12 positive, and 31 testing failure) and three cases lost follow-up. Among the 536 cases with NIPT negative results, 504 (94.0%) resulted in live-birth and 29 (5.4%) resulted in miscarriage or stillbirths. No false-negative result was reported.

CONCLUSION

NIPT has the potential to be used in prenatal screening for VTS pregnancies. For the pregnant women who obtained positive and testing failure results, resampling after 15 weeks of gestation is recommended.

An Infertile Couple's Long and Expensive Path to Varicocele Repair

OBJECTIVE

To characterize the pathways to care that infertile couples requiring varicocele repair (VR) pursue prior to presenting to a male fertility clinic.

METHODS

An IRB-approved single center retrospective review of patients undergoing VR after presentation to an academic male fertility clinic was performed. Patients whose charts included partner histories were assessed for duration of attempting conception, prior workup, and assisted reproductive technology (ART) use.

RESULTS

A total of 405 couples were included. At presentation, mean age was 34.4 (SD ± 6.5) years for men and 31.1 (SD ± 4.3) years for women (P < .0001). A couple's first visit to a physician was a gynecologist in 59% (198/334) of couples, a reproductive endocrinologist (REI) in 25% (83/334) of cases, with 14% (47/334) presenting without a previous female workup and were self-referred, and 2% (6/334) seeing both a gynecologist and REI prior to presentation. On average, couples attempted pregnancy for 22.3 (SD ± 21.1, range 0-120) months prior to presentation. Eighteen percent of couples underwent ART prior to presentation. Couples who had undergone ART had lower pre-VR total motile sperm counts compared to couples not pursuing ART prior to presentation (P = 0.031). The majority (70.4%) of females had no abnormality in their workup, making varicocele the only correctable factor for infertility in the couple.

CONCLUSIONS

Our findings show a significant delay in referral of infertile men requiring VR. Eighteen percent of couples underwent costly ART prior to an inexpensive male workup. In an era of medical cost containment, early referral to a male infertility specialist is imperative.

Don't Give Up! A Cyber-ethnography and Discourse Analysis of an Online Infertility Patient Forum

Infertility affects women across the socioeconomic spectrum; however, it is by no means egalitarian in its distribution, nor uniform in its lived experience. Evidence shows striking disparities by income, race, and education in infertility prevalence, access to infertility services, and success rates after receiving infertility treatments. However, few studies so far have investigated disparities in patients' access to psychological support during the infertility journey. This paper undertakes a cyber-ethnography of the online patient forum, "Finding a Resolution for Infertility," hosted by RESOLVE: The National Infertility Association. It also draws from interviews with 54 infertility patients recruited from the forum. Our aim was to examine how social support operates within this virtual realm, by examining how the forum's language, norms, and values create and enforce categories of deserving and belonging among site users. We find that the forum's discourse privileges an infertility narrative we term the "persistent patient," in which a patient exhaustively researches treatment options, undergoes multiple cycles of treatment despite repeated failures, and ultimately achieves success (a healthy baby). Meanwhile, there is little to no discursive space for discussion of the financial and social resources necessary to act in accordance with this script. Thus, women without such resources can be alienated, silenced, and denied mental health support by this online community.

Embryo quality is the main factor affecting cumulative live birth rate after elective single embryo transfer in fresh stimulation cycles

OBJECTIVE

The study was aimed to evaluate which factors affect the cumulative live birth rate after elective single embryo transfer in women younger than 36 years. Additionally, number of children in women with more than one delivery per ovum pick-up after fresh elective single embryo transfer and subsequent frozen embryo transfers was assessed.

STUDY DESIGN

Retrospective cohort study analysing data of a university hospital's infertility clinic in 2001-2010. A total of 739 IVF/ICSI cycles with elective single embryo transfer were included. Analyses were made per ovum pick-up including fresh and subsequent frozen embryo transfers. Factors affecting cumulative live birth rates were examined in uni- and multivariate analyses. A secondary endpoint was the number of children born after all treatments.

RESULTS

In the fresh cycles, the live birth rate was 29.2% and the cumulative live birth rate was 51.3%, with a twin rate of 3.4%. In the multivariate analysis, having two (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.12-2.67) or ≥3 top embryos (OR 2.66; 95% CI 1.79-3.95) was associated with higher odds for live birth after fresh and frozen embryo cycles. Age, body mass index, duration of infertility, diagnosis or total gonadotropin dose were not associated with the cumulative live birth rate. In cycles with one top embryo, the cumulative live birth rate was 40.2%, whereas it was 64.1% in those with at least three top embryos. Of women who had a live birth in the fresh cycle, 20.4% had more than one child after all frozen embryo transfers. Among women with three or more top embryos after ovum pick-up, 16.1% gave birth to more than one child.

CONCLUSION

The cumulative live birth rate in this age group varies from 40% to 64% and is dependent on the quality of embryos. Women with three or more top embryos have good chance of having more than one child per ovum pick-up without elevated risk of multiple pregnancies.

Adverse pregnancy outcomes after in vitro fertilization: effect of number of embryos transferred and plurality at conception

OBJECTIVE

To evaluate risks for adverse pregnancy outcomes by number of embryos transferred (ET) and fetal heartbeats (FHB) in assisted reproductive technology-conceived singleton live births.

DESIGN

Longitudinal cohort using cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System between 2004 and 2008 among women who were treated and gave birth in Massachusetts.

SETTING

Not applicable.

PATIENT(S)

Assisted reproductive technology data on 6,073 births between 2004 and 2008 were linked to vital records and hospital data. Likelihood of ET ≥3 vs. 1-2, FHB >1 vs. 1, and risks of preterm birth (PTB, <37 weeks' gestation), low birth weight (LBW, <2,500 g), and small-for-gestational-age birth weight (SGA, <10th percentile) with FHB >1 were modeled with binary logistic regression using a backward-stepping algorithm, and presented as adjusted odds ratios (95% confidence intervals).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

ET ≥3, FHB >1, PTB, LBW, and SGA.

RESULT(S)

Higher ET was significantly more likely with older maternal age, intracytoplasmic sperm injection, assisted hatching, cleavage-stage embryos, and thawed embryos. The likelihood of FHB >1 with ≥3 ET vs. 1-2 ET was 2.04 (1.68-2.48). Risks of PTB and LBW with FHB >1 were 1.63 (1.27-2.09) and 1.81 (1.36-2.39), respectively; the risk of SGA was not significant. Nulliparity was associated with higher risks of PTB (1.34 [1.12-1.59]), LBW (1.48 [1.20-1.83]), and SGA (2.17 [1.69-2.78]).

CONCLUSION(S)

Number of embryos transferred was strongly associated with FHBs, with twice the risk of FHB >1 with ≥3 ET vs. 1-2 ET. Increasing FHBs were associated with significantly greater risks for PTB and LBW outcomes.

The presence of multiple gestational sacs confers a higher live birth rate in women with infertility who achieve a positive pregnancy test after fresh and frozen embryo transfer: a retrospective local cohort

BACKGROUND

After spontaneous conception, the rate of miscarriage is more common in multiple rather than singleton pregnancies. However, the incidence of miscarriage is lower in in-vitro fertilization twin versus singleton pregnancies. Most patients have little understanding of pregnancy outcomes once they achieve a positive pregnancy test. This study investigated the relationship between multiple pregnancy and miscarriage in women with infertility after fresh and frozen embryo transfer.

METHODS

Retrospective local cohort study of all consecutive patients undergoing in-vitro fertilization at our institution (n = 1130), fresh or frozen embryo transfer, between January 1, 2008 and December 31, 2012. Patient characteristics (age, body mass index, initial hCG, maximum follicle stimulating hormone levels) and in-vitro fertilization parameters (estradiol levels, eggs retrieved, and endometrial thickness) were collected and statistically analyzed using T-test and Chi-square test (Stata version 10). Linear and logistic regression were used when appropriate.

RESULTS

Overall, live birth rate for all cycles was 30.44% and total pregnancy loss was 6.55% - similar for fresh and frozen cycles despite a higher rate of biochemical pregnancies for frozen cycles. Among all pregnant patients, 62.48% had a live birth. Although clinical pregnancy rate was higher for fresh cycles, live birth rates were similar. In pregnancies where multiple sacs were demonstrated on ultrasound, live birth rates were higher despite 31% of patients losing at least one sac. This finding was comparable between fresh and frozen cycles. However, in patients under age 35 and using donor egg, no live birth advantage was seen in patients with multiple sacs. In fact, transferring more than one embryo did not increase live birth rate either.

CONCLUSIONS

Despite the many maternal and fetal risks of multiple pregnancies, patients who achieve a positive pregnancy test with fresh and frozen in-vitro fertilization and who have more than one pregnancy sac are more likely ultimately to deliver at least one baby. This finding is true of both fresh and frozen embryo transfer cycles. This pregnancy advantage is not seen in young patients and in patients using donor egg, and single embryo transfer maximizes birth outcomes.

Down syndrome screening in assisted conception twins: an iatrogenic medical challenge

OBJECTIVE

The objective of this study was to provide a critical analysis of the impact of assisted conception on prenatal screening for Down syndrome (DS) in twin pregnancies and the value of various screening modalities for early detection of anomalies.

METHODS

The literature was searched using PubMed and the Cochrane Library focusing on prenatal screening and antenatal care of assisted-conception twin pregnancies.

RESULTS

Serum screening alone is of limited value in detecting aneuploid twins, because the unaffected cotwin can "mask" the abnormal serum results of an affected one. In addition, this test can designate the pregnancy as at high risk but not identify the affected fetus. Nuchal translucency (NT) screening is the best available modality and a highly effective screening method for twin pregnancies. Among twins, NT alone has a 69% DS detection rate, first-trimester combined NT and serum biochemistry has a 72% DS detection rate, and an integrated screen will have an 80% DS detection rate at a 5% FPR. The data in the literature concerning the effect of assisted conception on maternal serum screening markers in twin pregnancies are scarce.

CONCLUSIONS

Down syndrome screening in assisted-conception twins presents clinical and technical challenges. Therefore, assisted-conception twins need close monitoring from conception to delivery, by a practitioner familiar with the available screening modalities and their relative accuracy.

Factors associated with monozygosity in assisted reproductive technology pregnancies and the risk of recurrence using linked cycles

OBJECTIVE

To evaluate factors associated with monozygosity (MZ) (number of fetal heartbeats on early ultrasound greater than the number of embryos transferred) and the risk of recurrence in subsequent pregnancies using a national assisted reproduction database.

DESIGN

Historical cohort study.

SETTING

Clinic-based data.

PATIENT(S)

197,327 pregnancies (including 2,824 with evidence of MZ) from cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) between 2004 and 2010.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Evidence of MZ, adjusted odds ratios and their 95% confidence intervals computed from logistic regression models.

RESULT(S)

In the univariate analysis, the risk of MZ was increased with ovulation disorders, donor oocytes, gonadotropin-releasing hormone agonist (GnRH-a) suppression, assisted hatching (AZH), and day 5-6 transfer, and was decreased with higher follicle-stimulating hormone (FSH) doses (≥3,000 IU). In the multivariate analysis, the risk of MZ was increased with GnRH-a suppression, AZH, and decreased with intracytoplasmic sperm injection (ICSI) and higher FSH dose. The interaction showed that although MZ was more likely with day 5-6 embryos, AZH had a minimal nonsignificant effect, whereas in day 2-3 embryos, AZH had a substantial statistically significant effect. Only one woman had a recurrence of MZ in a subsequent assisted reproduction pregnancy, which is consistent with randomness.

CONCLUSION(S)

The risk of MZ was higher with fresh day 5-6 embryos, donor oocytes, GnRH-a suppression, lower FSH doses, and AZH (particularly with day 2-3 embryos).

Pregnancy outcomes in a university hospital after legal requirement for single-embryo transfer

OBJECTIVE

To present our in vitro fertilization outcomes after implementation of the Turkish government policy limiting the number of transferred embryos to one, in women under the age of 35, and two, in women over age 35; and to demonstrate the feasibility of this policy.

STUDY DESIGN

We retrospectively reviewed the records of 423 patients who underwent ovarian stimulation, oocyte pick-up, intracytoplasmic sperm injection and embryo transfer due to primary or secondary infertility over a 22-month time interval. Clinical pregnancy was defined as a fetal heartbeat in the seventh gestational week. Embryo transfers were carried out on day 3 or 5. Descriptive statistics are given as the number of subjects and percentages.

RESULTS

A total of 353 embryo transfers were performed: 261 (73.9%) were single-embryo transfer (244 (69.1%) elective and 17 (4.8%) non-elective) and 92 (26.1%) were double-embryo transfer. Of the 244 elective single-embryo transfers, 6.6% (n=16) were performed using frozen-thawed embryos. The average patient age was 29.6±4.5 years in the single-embryo group and 36.5±2.4 years in the double-embryo group. The cumulative pregnancy rates per oocyte pick-up were similar in both groups: 41% (n=107) in the single-embryo group and 43.4% (n=40) in the double-embryo group (p=0.678). The cumulative live birth rate of the single-embryo group (32.1%) was not statistically different from the double-embryo group (35.8%) (p=0.518). The twin pregnancy rate after single-embro transfer was significantly lower than with double-embryo transfer (2.8% (n=3) vs. 32.5% (n=13); p<0.001) and 62.5% of the twin pregnancies occurred in women 35 years or older who underwent double-embryo transfer. No significant difference in the spontaneous abortion rates was recorded between the single- and double-embryo transfer groups (16 (6.1%) vs. 6 (6.5%); p=0.894).

CONCLUSION

Single-embryo transfer results in a pregnancy rate comparable to double-embryo transfer, with a significantly reduced multiple pregnancy rate. Double-embryo transfer in patients over age 35 should be reconsidered because of the resulting high rate of multiple pregnancy.

Elective single embryo transfer trends and predictors of a good perinatal outcome--United States, 1999 to 2010

OBJECTIVE

To assess trends in elective single ET and identify factors associated with a good perinatal outcome.

DESIGN

Retrospective cohort study.

SETTING

Clinic-based data.

PATIENT(S)

A total of 886,686 fresh, nondonor cycles reported to the National Assisted Reproductive Technology Surveillance System during 1999-2010, of which 17,166 met criteria for elective single ET.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rates of elective single ET and good perinatal outcome (term, singleton infant with normal birth weight).

RESULT(S)

In 2010, elective single ET comprised 5.6% of all fresh transfers, representing an eightfold increase since publication of first guidelines in 2004 recommending elective single ET. Compared with other ETs, elective single ETs were nearly twice as likely to result in a good perinatal outcome (37.1% vs. 18.9%, respectively). Among women using elective single ET, those aged <35 and 35-37 years had a good perinatal outcome (40.2% and 32.5%, respectively). In multivariable, log-binomial analyses, factors positively associated with a good perinatal outcome included male factor infertility, day 5 ET, and having ≥3 supernumerary embryos for cryopreservation.

CONCLUSION(S)

Between 1999 and 2010, national rates of elective single ET increased. Given the frequency of good perinatal outcomes among women aged 35-37 years, guidelines for elective single ET could be expanded to include patients in this age group with favorable prognoses.

Clinical factors associated with live birth after single embryo transfer

OBJECTIVE

To identify patient, cycle, and retrieval characteristics associated with embryo implantation and live birth in patients undergoing single embryo transfer (SET).

DESIGN

Analysis of prospectively collected IVF database.

SETTING

Academic IVF program.

PATIENT(S)

All patient cycles meeting criteria for SET between June 2004 and September 2010.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy and live birth.

RESULT(S)

Single embryo transfer was performed in 438 cycles, resulting in a clinical pregnancy rate of 76.2% and a live birth rate of 66.8% per transfer. Clinical pregnancy was associated with younger female age, ≥ 58% mature (metaphase II) oocytes at the time of retrieval, and increasing blastocyst expansion. Ongoing pregnancy was associated with younger female age and more advanced blastocysts. A diagnosis of uterine factor was negatively associated with live birth.

CONCLUSION(S)

Even in a favorable prognosis population, younger female age is associated with clinical pregnancy and live birth. Although all patients underwent blastocyst transfer, expanded and hatching blastocysts were strongly associated with pregnancy and live birth. A diagnosis of uterine factor was the only infertility diagnosis found to affect live birth after SET. Obesity did not negatively affect SET outcome. These findings may assist physicians in determining the best candidates for SET.

Endometrial expression of selected genes in patients achieving pregnancy spontaneously or after ICSI and patients failing at least two ICSI cycles

The objective of this study was to identify the endometrial gene expression profile in receptive phase, which could represent a useful prognostic tool for selecting IVF patients. Endometrial expression of 47 selected genes biopsied during the window of implantation in natural cycles was compared between patients who achieved a successful pregnancy spontaneously or after subsequent intracytoplasmic sperm injection (ICSI) cycles and patients who did not achieve a pregnancy after at least two failed ICSI cycles. The comparative analysis showed significantly different levels of expression in 19 genes, five implicated in apoptosis (CASP8, FADD, CASP10, APAF1, ANXA4), three in immunity (LIF, SPP1, C4BPA), five in transcriptional activity (MSX1, HOXA10, MSX2, HOXA11, GATA2), two in lipid metabolism (LEPR, APOD) and four in oxidative metabolism (AOX1, ALDH1A3, GPX3, NNMT). The evidence for these genes being differently expressed could represent the starting point of identifying the ideal receptive endometrial gene expression profile, which could be used in the future as a prognostic tool for IVF patients. Gene expression analysis technology has opened new important perspectives on the study of the physiological processes of different tissues and organs. Specifically for the endometrium, it would be really interesting to find out an endometrial gene expression profile of receptive phase, which could be used in future as a useful prognostic tool for selecting IVF patients. To achieve this aim, the objective of the present paper was the comparison of endometrial expression in natural cycles of 47 selected genes between the biopsies of patients who achieved a successful pregnancy, either spontaneously or after subsequent ICSI cycles, and those of patients who did not achieve a pregnancy after at least two failed ICSI cycles. The comparative analysis showed a significant different expression in 19 genes: five implicated in programmed cell death, known as apoptosis (CASP8, FADD, CASP10, APAF1, ANXA4), three in immunity (LIF, SPP1, C4BPA), five in transcriptional activity (MSX1, HOXA10, MSX2, HOXA11, GATA2), two in lipid metabolism (LEPR, APOD) and four in oxidative metabolism (AOX1, ALDH1A3, GPX3, NNMT). The evidence of these genes being differently expressed could represent the starting point of identifying the ideal receptive endometrial gene expression profile which could be used in the future as a prognostic tool for IVF patients.

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.

Cumulative birth rates with linked assisted reproductive technology cycles

BACKGROUND

Live-birth rates after treatment with assisted reproductive technology have traditionally been reported on a per-cycle basis. For women receiving continued treatment, cumulative success rates are a more important measure.

METHODS

We linked data from cycles of assisted reproductive technology in the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database for the period from 2004 through 2009 to individual women in order to estimate cumulative live-birth rates. Conservative estimates assumed that women who did not return for treatment would not have a live birth; optimal estimates assumed that these women would have live-birth rates similar to those for women continuing treatment.

RESULTS

The data were from 246,740 women, with 471,208 cycles and 140,859 live births. Live-birth rates declined with increasing maternal age and increasing cycle number with autologous, but not donor, oocytes. By the third cycle, the conservative and optimal estimates of live-birth rates with autologous oocytes had declined from 63.3% and 74.6%, respectively, for women younger than 31 years of age to 18.6% and 27.8% for those 41 or 42 years of age and to 6.6% and 11.3% for those 43 years of age or older. When donor oocytes were used, the rates were higher than 60% and 80%, respectively, for all ages. Rates were higher with blastocyst embryos (day of transfer, 5 or 6) than with cleavage embryos (day of transfer, 2 or 3). At the third cycle, the conservative and optimal estimates of cumulative live-birth rates were, respectively, 42.7% and 65.3% for transfer of cleavage embryos and 52.4% and 80.7% for transfer of blastocyst embryos when fresh autologous oocytes were used.

CONCLUSIONS

Our results indicate that live-birth rates approaching natural fecundity can be achieved by means of assisted reproductive technology when there are favorable patient and embryo characteristics. Live-birth rates among older women are lower than those among younger women when autologous oocytes are used but are similar to the rates among young women when donor oocytes are used. (Funded by the National Institutes of Health and the Society for Assisted Reproductive Technology.).

Race matters: a systematic review of racial/ethnic disparity in Society for Assisted Reproductive Technology reported outcomes

OBJECTIVE

To systematically review the reporting of race/ethnicity in Society for Assisted Reproductive Technology (SART) Clinic Outcome Reporting System (CORS) publications.

DESIGN

Systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology of literature published in PubMed on race/ethnicity that includes data from SART CORS.

SETTING

Not applicable.

PATIENT(S)

Not applicable.

INTERVENTION(S)

In vitro fertilization cycles reported to SART.

MAIN OUTCOME MEASURE(S)

Any outcomes reported in SART CORS.

RESULT(S)

Seven publications were identified that assessed racial/ethnic disparities in IVF outcomes using SART data. All reported a racial/ethnic disparity. However, more than 35% of cycles were excluded from analysis because of missing race/ethnicity data.

CONCLUSION(S)

Review of current publications of SART data suggests significant racial/ethnic disparities in IVF outcomes. However, the potential for selection bias limits confidence in these findings, given that fewer than 65% of SART reported cycles include race/ethnicity. Our understanding of how race/ethnicity influences ART outcome could be greatly improved if information on race/ethnicity was available for all reported cycles.

Predicting personalized multiple birth risks after in vitro fertilization-double embryo transfer

OBJECTIVE

To report and evaluate the performance and utility of an approach to predicting IVF-double embryo transfer (DET) multiple birth risks that is evidence-based, clinic-specific, and considers each patient's clinical profile.

DESIGN

Retrospective prediction modeling.

SETTING

An outpatient university-affiliated IVF clinic.

PATIENT(S)

We used boosted tree methods to analyze 2,413 independent IVF-DET treatment cycles that resulted in live births. The IVF cycles were retrieved from a database that comprised more than 33,000 IVF cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The performance of this prediction model, MBP-BIVF, was validated by an independent data set, to evaluate predictive power, discrimination, dynamic range, and reclassification.

RESULT(S)

Multiple birth probabilities ranging from 11.8% to 54.8% were predicted by the model and were significantly different from control predictions in more than half of the patients. The prediction model showed an improvement of 146% in predictive power and 16.0% in discrimination over control. The population standard error was 1.8%.

CONCLUSION(S)

We showed that IVF patients have inherently different risks of multiple birth, even when DET is specified, and this risk can be predicted before ET. The use of clinic-specific prediction models provides an evidence-based and personalized method to counsel patients.

Epidemiology of twinning in developed countries

Twin births contribute disproportionately to the overall burden of perinatal morbidity and mortality in developed countries. Twins constitute 2%-4% of all births, and the rate of twining has increased by 76% between 1980 and 2009. The rate of preterm birth (<37 weeks) among twins is about 60%. Of all twin preterm births in the United States, roughly half are indicated, a third are due to spontaneous onset of labor, and about 10% are due to preterm premature rupture of membranes. Mortality related to preterm birth is influenced by antecedent factors and is highest when preterm delivery is the consequence of preterm premature rupture of membranes, followed by those as a result of spontaneous preterm labor and lowest among indicated preterm births. There also appears to have been a recent decline in serious neonatal morbidity (one or more of 5-minute Apgar score <4, neonatal seizures or assisted ventilation for ≥ 30 minutes) among twin gestations. Compared with twins conceived naturally, those born of assisted reproduction methods are more likely to deliver at <37 weeks. Although perinatal mortality rates have declined among twin births, the effect of preterm delivery on trends in mortality and morbidity and other long-term consequences remain issues for major concern. With the rapid increase in the liberal use of assisted reproduction methods combined with women electing to postpone their pregnancies and increased likelihood of spontaneous twins with advancing maternal age, this review underscores the need to develop priorities to understand the peripartum and long-term consequences facing twin births.

Five-years of a mandatory single-embryo transfer (mSET) policy dramatically reduces twinning rate without lowering pregnancy rates

OBJECTIVE

To report the outcomes of a program policy instituted in 2004 mandating single-embryo transfer (mSET) for all women aged <38 years, with at least seven zygotes, no prior failed fresh cycle at our center, and at least one good-quality blastocyst.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

All women <38 years old undergoing a fresh cycle with autologous oocytes and all women undergoing a fresh cycle with donor oocytes from June 1, 1999, to May 31, 2004 (before mSET) and from June 1, 2004, to May 31, 2009 (after mSET).

INTERVENTION(S)

mSET policy implementation.

MAIN OUTCOME MEASURE(S)

Live-birth rate, multiple pregnancy rate, clinical volume, and outcomes of all mSET fresh IVF transfers were analyzed.

RESULT(S)

Clinical volume was unchanged between the two time groups. After implementation of mSET, live-birth rates improved from 51.1% to 55.9% and multiple-birth rates dropped from 34.8% to 17.5%. A total of 364 mSET fresh transfers were performed with a live-birth rate of 64.6% and a multiple-birth rate of 3.4%.

CONCLUSION(S)

A mandatory SET policy based on prognostic factors can be instituted with no drop in clinical volume and no negative effect on delivery rates. Multiple gestation rates can be dramatically lowered.

Experience with a patient-friendly, mandatory, single-blastocyst transfer policy: the power of one

OBJECTIVE

To determine whether a mandatory single-blastocyst transfer (mSBT) algorithm reduced multiple gestation rates without sacrificing clinical pregnancy rates.

DESIGN

Retrospective review.

SETTING

U.S. university-based assisted reproductive technology (ART) program.

PATIENT(S)

All women younger than 38 years undergoing their first ART cycle from 2009 to 2010 with ≥4 high-grade embryos on day 3 after oocyte retrieval (patients from 2009 were the "before" group, and patients completing ART under the mSBT policy in 2010 were the "after" group).

INTERVENTION(S)

mSBT algorithm.

MAIN OUTCOME MEASURE(S)

Multiple gestation and clinical pregnancy rates.

RESULT(S)

Of the qualified patients, 136 women met inclusion criteria (62 from 2009, 74 from 2010). The baseline demographics were similar between the groups. Statistically significantly fewer blastocysts were transferred per patient in 2010 compared with 2009 (1.5 vs. 1.9). The clinical pregnancy rates before (67.7%) or after (63.5%) the mSBT policy were not statistically significantly different. Multiple gestation rates were statistically significantly reduced, from 43.8% (2009) to 14.6% (2010) after the mSBT policy was instituted. More patients from 2010 had ≥1 blastocyst cryopreserved compared with 2009 (52.9% vs. 30.6%).

CONCLUSION(S)

A novel single-blastocyst transfer algorithm reduced multiple gestation rates and improved cryopreservation rates without compromising clinical pregnancy rates in good-prognosis patients.

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.