Reproductive Technology Clinic Outcome Reporting Research Articles

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

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. 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. Not applicable. 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, <37weeks' gestation), low birth weight (LBW, <2,500g), 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). None. ET ≥3, FHB >1, PTB, LBW, and SGA. 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]). 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.

Use of assisted reproductive technology treatment as reported by mothers in comparison with registry data: the Upstate KIDS Study

To assess the validity of maternally reported assisted reproductive technologies (ART) use and to identify predictors of reporting errors. Linkage study. Not applicable. A total of 5,034 (27%) mothers enrolled, from whom 4,886 (97%) self-reported information about use of infertility treatment, including ART, for the index birth. None. Four measures of validity (sensitivity, specificity, positive and negative predictive values) and use of net reclassification improvement (NRI) methods to identify predictors associated with concordant/discordant maternal reporting. The Upstate New York Infant Development Screening Program (Update KIDS Study) was linked with the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) using a defined algorithm for 2008-2010. The sensitivity, specificity, positive and negative predictive values were high (0.93, 0.99, 0.80, and 1.00, respectively). The validity of maternal report was high, reflecting few differences by participant characteristics except for maternal age dichotomized at 29 years as identified with NRI methods. Maternally reported ART is valid, with little variation across various characteristics. No strong predictors of discordant reporting were found, supporting the utility of population-based research with SART CORS linkage.

Adverse pregnancy and birth outcomes associated with underlying diagnosis with and without assisted reproductive technology treatment

To compare the risks for adverse pregnancy and birth outcomes by diagnoses with and without assisted reproductive technology (ART) treatment to non-ART pregnancies in fertile women. Historical cohort of Massachusetts vital records linked to ART clinic data from Society for Assisted Reproductive Technology Clinic Outcome Reporting System. Not applicable. Diagnoses included male factor (ART only), endometriosis, ovulation disorders, tubal (ART only), and reproductive inflammatory disorders (non-ART only). Pregnancies resulting in singleton and twin live births from 2004 to 2008 were linked to hospital discharges in women who had ART treatment (n = 3,689), women with no ART treatment in the current pregnancy (n = 4,098), and non-ART pregnancies in fertile women (n = 297,987). None. Risks of gestational diabetes, prenatal hospitalizations, prematurity, low birth weight, and small for gestational age were modeled using multivariate logistic regression with fertile deliveries as the reference group adjusted for maternal age, race/ethnicity, education, chronic hypertension, diabetes mellitus, and plurality (adjusted odds ratios [AORs] and 95% confidence intervals [CIs]). Risk of prenatal hospital admissions was increased for endometriosis (ART: 1.97, 1.38-2.80; non-ART: 3.34, 2.59-4.31), ovulation disorders (ART: 2.31, 1.81-2.96; non-ART: 2.56, 2.05-3.21), tubal factor (ART: 1.51, 1.14-2.01), and reproductive inflammation (non-ART: 2.79, 2.47-3.15). Gestational diabetes was increased for women with ovulation disorders (ART: 2.17, 1.72-2.73; non-ART: 1.94, 1.52-2.48). Preterm delivery (AORs, 1.24-1.93) and low birth weight (AORs, 1.27-1.60) were increased in all groups except in endometriosis with ART. The findings indicate substantial excess perinatal morbidities associated with underlying infertility-related diagnoses in both ART-treated and non-ART-treated women.

The need to improve patient care through discriminate use of intracytoplasmic sperm injection (ICSI) and improved understanding of spermatozoa, oocyte and embryo biology

D. T. Carrell, A. Nyboe Andersen and D. J. Lamb Departments of Surgery (Urology), Obstetrics and Gynecology, and Human Genetics, University of Utah School of Medicine, Salt Lake City, UT, USA, The Fertility Clinic, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark, and The Center for Reproductive Medicine, Scott Department of Urology and the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA

Application of a validated prediction model for in vitro fertilization: comparison of live birth rates and multiple birth rates with 1 embryo transferred over 2 cycles vs 2 embryos in 1 cycle

The purpose of this study was to use a validated prediction model to examine whether single embryo transfer (SET) over 2 cycles results in live birth rates (LBR) comparable with 2 embryos transferred (DET) in 1 cycle and reduces the probability of a multiple birth (ie, multiple birth rate [MBR]). Prediction models of LBR and MBR for a woman considering assisted reproductive technology developed from linked cycles from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System for 2006-2012 were used to compare SET over 2 cycles with DET in 1 cycle. The prediction model was based on a woman's age, body mass index (BMI), gravidity, previous full-term births, infertility diagnoses, embryo state, number of embryos transferred, and number of cycles. To demonstrate the effect of the number of embryos transferred (1 or 2), the LBRs and MBRs were estimated for women with a single infertility diagnosis (male factor, ovulation disorders, diminished ovarian reserve, and unexplained); nulligravid; BMI of 20, 25, 30, and 35 kg/m2; and ages 25, 35, and 40 years old by cycle (first or second). The cumulative LBR over 2 cycles with SET was similar to or better than the LBR with DET in a single cycle (for example, for women with the diagnosis of ovulation disorders: 35 years old; BMI, 30 kg/m2; 54.4% vs 46.5%; and for women who are 40 years old: BMI, 30 kg/m(2); 31.3% vs 28.9%). The MBR with DET in 1 cycle was 32.8% for women 35 years old and 20.9% for women 40 years old; with SET, the cumulative MBR was 2.7% and 1.6%, respectively. The application of this validated predictive model demonstrated that the cumulative LBR is as good as or better with SET over 2 cycles than with DET in 1 cycle, while greatly reducing the probability of a multiple birth.

Using the Society for Assisted Reproductive Technology Clinic Outcome System morphological measures to predict live birth after assisted reproductive technology

To model morphological assessments of embryo quality that are predictive of live birth. Longitudinal cohort using cycles reported in the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS) between 2007 and2011. Clinic-based data. Fresh autologous assisted reproductive technology (ART) cycles with ETs on day 3 or day 5 and morphological assessments reported (25,409 cycles with one embryo transferred and 96,093 cycles with two embryos transferred). Live-birth rates were modeled by morphological assessments using backward-stepping logistic regression for cycle 1 and over five cycles, separately for day 3 and day 5 transfers and number of embryos transferred (1 or 2). Additional models for each day of transfer also included the number of oocytes retrieved and the number of embryos cryopreserved. None. Live births. Morphological assessments of grade, stage, fragmentation, and symmetry were significant for the day 3 models; grade, stage, and trophectoderm were significant in the day 5 model; inner-cell mass was significant in the models when two embryos were transferred. Number of oocytes retrieved and number of embryos cryopreserved were significant for both day 3 and day 5 models. These findings confirm the significant association between embryo quality parameters reported to SART CORS and live-birth rate after ART.

The effect of father's age in fertile, subfertile, and assisted reproductive technology pregnancies: a population based cohort study.

To compare ages of mothers and of fathers at delivery in couples who are fertile, subfertile, and subfertile treated with assisted reproductive technology (ART) and to characterize birth outcomes in the ART population according to paternal age. Live birth deliveries in Massachusetts between July, 2004 and December, 2008 were identified from vital records and categorized by maternal fertility status and treatment as ART, subfertile or fertile. The ART births were linked to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) database to obtain cycle-specific treatment data. Parental ages were obtained from birth certificates. Age of mothers and fathers were compared using ANOVA for continuous measures and χ (2) for categories. Risks of prematurity (<37 weeks), low birthweight (<2,500 g), and low birthweight z-score (small for gestatational age, SGA) were modeled using logistic regression by categories of paternal age as adjusted odds ratios and 95 % CI. The study population included 9,092 ART, 6,238 subfertile, and 318,816 fertile deliveries. Paternal ages in the ART and subfertile groups were similar and differed significantly from those of the fertile group. Maternal age in the ART and subfertile groups averaged 5-6 years older than their fertile counterparts and fathers averaged 4-5 years older with twice as many being older than 37. The risks for prematurity, low birthweight and SGA did not increase with increasing paternal age. Fathers in ART- treated and subfertile couples are older than in their fertile counterparts. Older paternal age was not assoicated with increased risk for prematurity, low birthweight, or SGA.

Assisted hatching and intracytoplasmic sperm injection are not associated with improved outcomes in assisted reproduction cycles for diminished ovarian reserve: an analysis of cycles in the United States from 2004 to 2011

To investigate the impact of intracytoplasmic sperm injection (ICSI) and assisted hatching (AH) on assisted reproductive technology (ART) outcomes in initial cycles with diminished ovarian reserve (DOR) as the primary diagnosis. Retrospective cohort study of cycles from the Society for Assisted Reproductive Technology (SART) Clinic Outcome Reporting System database. Not applicable. A total of 422,949 fresh, nondonor, initial ART cycles of which 8,597 were diagnosed with only elevated FSH and 38,926 were diagnosed with only DOR according to the SART DOR categorization. None. Live birth and clinical pregnancy rates. ICSI and AH were associated with diminished odds of live birth in SART DOR-only cycles (adjusted odds ratio [AOR] 0.88, 95% confidence interval [CI] 0.81-0.96 for ICSI; AOR 0.77, 95% CI 0.71-0.84 for AH). No association between odds of live birth andeither ICSI or AH in elevated FSH-only cycles was observed. The combination of ICSI and AH was associated with significantly lower odds of live birth in SART DOR-only cycles but not in elevated FSH-only cycles. In initial ART cycles for which the only indication relates to a diagnosis of DOR, AH and ICSI are not associated with improved live birth rates.

A prediction model for live birth and multiple births within the first three cycles of assisted reproductive technology

To develop a model predictive of live-birth rates (LBR) and multiple birth rates (MBR) for an individual considering assisted reproduction technology (ART) using linked cycles from Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) for 2004-2011. Longitudinal cohort. Clinic-based data. 288,161 women with an initial autologous cycle, of whom 89,855 did not become pregnant and had a second autologous cycle and 39,334 did not become pregnant in the first and second cycles and had a third autologous cycle, with an additional 33,598 women who had a cycle using donor oocytes (first donor cycle). None. LBRs and MBRs modeled by woman's age, body mass index, gravidity, prior full-term births, infertility diagnoses by oocyte source, fresh embryos transferred, and cycle, using backward-stepping logistic regression with results presented as adjusted odds ratios (AORs) and 95% confidence intervals. The LBRs increased in all models with prior full-term births, number of embryos transferred; in autologous cycles also with gravidity, diagnoses of male factor, and ovulation disorders; and in donor cycles also with the diagnosis of diminished ovarian reserve. The MBR increased in all models with number of embryos transferred and in donor cycles also with prior full-term births. For both autologous and donor cycles, transferring two versus one embryo greatly increased the probability of a multiple birth (AOR 27.25 and 38.90, respectively). This validated predictive model will be implemented on the Society for Assisted Reproductive Technology Web site (www.sart.org) so that patients considering initiating a course of ART can input their data on the Web site to generate their expected outcomes.

Calculating length of gestation from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) database versus vital records may alter reported rates of prematurity

To compare length of gestation after assisted reproductive technology (ART) as calculated by three methods from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) and vital records (birth and fetal death) in the Massachusetts Pregnancy to Early Life Longitudinal Data System (PELL). Historical cohort study. Database linkage analysis. Live or stillborn deliveries. None. ART deliveries were linked to live birth or fetal death certificates. Length of gestation in 7,171 deliveries from fresh autologous ART cycles (2004-2008) was calculated and compared with that of SART CORS with the use of methods: M1 = outcome date - cycle start date; M2 = outcome date - transfer date + 17 days; and M3 = outcome date - transfer date + 14 days + day of transfer. Generalized estimating equation models were used to compare methods. Singleton and multiple deliveries were included. Overall prematurity (delivery <37 weeks) varied by method of calculation: M1 29.1%; M2 25.6%; M3 25.2%; and PELL 27.2%. The SART methods, M1-M3, varied from those of PELL by ≥ 3 days in >45% of deliveries and by more than 1 week in >22% of deliveries. Each method differed from each other. Estimates of preterm birth in ART vary depending on source of data and method of calculation. Some estimates may overestimate preterm birth rates for ART conceptions.

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

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. Historical cohort study. Clinic-based data. 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. None. Evidence of MZ, adjusted odds ratios and their 95% confidence intervals computed from logistic regression models. 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. 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).

Impact of monozygotic twinning on multiple births resulting from in vitro fertilization in the United States, 2006–2010

To determine the contribution of monozygotic twining to in vitro fertilization multiple births. We performed a retrospective analysis of the incidence of monozygotic twining in multiple births resulting from fresh embryo transfers using 2006-2010 data from the Society for Reproductive Technology Clinic Outcome Reporting System. The number of embryos transferred were fewer than the number of births in 0.5% (223/40950) of twin, 29% (659/2289) of triplet, and 64% (43/67) of quadruplet births resulting from transfer of fresh embryos from 2006 to 2010. In 2010, 37% of triplets and 100% of quadruplet births occurred when fewer than 3 and fewer than 4 embryos respectively were transferred. Monozygotic twinning plays a key role in the development of triplet and quadruplet pregnancies achieved through in vitro fertilization.

Live birth rates and birth outcomes by diagnosis using linked cycles from the SART CORS database

This study uses linked cycles of assisted reproductive technology (ART) to examine cumulative live birth rates, birthweight, and length of gestation by diagnostic category. We studied 145,660 women with 235,985 ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System during 2004-2010. ART cycles were linked to individual women by name, date of birth, social security number, partner's name, and sequence of ART treatments. The study population included the first four autologous oocyte cycles for women with a single diagnosis of male factor, endometriosis, ovulation disorders, diminished ovarian reserve, or unexplained infertility. Live birth rates were calculated per cycle, per cycle number (1-4), and cumulatively. Birthweight and length of gestation were calculated for singleton births. Within each diagnosis, live birth rates were highest in the first cycle and declined with successive cycles. Women with diminished ovarian reserve had the lowest live birth rate (cumulative rate of 28.3 %); the live birth rate for the other diagnoses were very similar (cumulative rates from 62.1 % to 65.7 %). Singleton birthweights and lengths of gestation did not differ substantially across diagnoses, ranging from 3,112 to 3,286 g and 265 to 270 days, respectively. These outcomes were comparable with national averages for singleton births in the United States (3,296 g and 271 days). Women with the diagnosis of diminished ovarian reserve had substantially lower live birth rates. However, singleton birthweights and lengths of gestation outcomes were similar across all other diagnoses.

Second try: who returns for additional assisted reproductive technology treatment and the effect of a prior assisted reproductive technology birth

To evaluate the effect of a prior assisted reproductive technology (ART) live birth on subsequent live-birth rates. Historical cohort study. Clinic-based data. The study population included 297,635 women with 549,278 cycles from 2004 to 2010 from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. Try 1 refers to ART cycles up to and including the first live birth, try 2 to ART cycles after a first live birth. None. Live-birth rates by cycle number, try number, and oocyte source. Younger women at try 1 are more likely to return for try 2. Women returning for try 2 were more likely to have had an ART singleton versus multiple birth (33.2% after a try 1 singleton versus 8.1% after twins and 4.9% after triplets) and were less likely to have a diagnosis of diminished ovarian reserve or tubal factors. Live-birth rates were significantly higher for try 2 compared with try 1 for autologous fresh cycles, averaging 7.7 percentage points higher over five cycles. Live-birth rates were not significantly different for try 2 versus try 1 with thawed autologous cycles or either fresh or thawed donor cycles. These results indicate that when fresh autologous oocytes can be used, live-birth rates per cycle are significantly greater after a prior history of an ART live birth.

Effect of maternal height and weight on risk for preterm singleton and twin births resulting from IVF in the United States, 2008–2010

To analyze the effects of preconception maternal height and weight on the risk of preterm singleton and twin births resulting from invitro fertilization (IVF). We performed a retrospective cohort analysis of the incidence of very early preterm birth (VEPTB), early preterm birth (EPTB), and preterm birth (PTB), before 28, 32, and 37 completed weeks, respectively, in 60,232 singleton and 24,111 twin live births using 2008-2010 live birth outcome data from the Society for Reproductive Technology Clinic Outcome Reporting System. Maternal obesity is associated with significantly increased risk of VEPTB, EPTB, and PTB in pregnancies conceived by IVF. For morbidly obese women (body mass index ≥35) with singletons, rates of VEPTB, EPTB, and PTB were 1.7%, 3.6%, and 16.4%, with adjusted risk ratios (aRRs) and 95% confidence levels (CIs) of 2.6 (1.8-3.6), 2.2 (1.8-2.6), and 1.5 (1.4-1.7) using corresponding rates for normal body mass index (95% CI, 18.6-24.9) as referent. For morbidly obese women with twins, rate of VEPTB and EPTB were 6.5% and 12.5%, with aRRs and 95% CIs of 2.4 (1.8-3.0) and 1.5 (1.3-1.8). For singletons, the rate of PTB for short stature women (<150 cm) was 14.2%, as compared with 11.8% in those women with height ranging between 160-167 cm (referent), with aRRs and 95% CIs of 1.2 (1.0-1.4). Preconception maternal obesity and short stature are associated with significantly increased risk of VEPTB and early preterm singleton and twin births in pregnancies resulting from IVF.

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 w...

Comparison of measures in SART database and Massachusetts vital statistics

To utilize a linked database to examine the concordance of key demographic and clinical measures in the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) and state vital statistics data.

Alternate methods of estimating gestational age from national databases may overestimate rates of preterm birth following ART

To compare gestational age (GA) and preterm birth among ART births, as calculated by three methods from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) and from birth records in the Massachusetts (MA) Pregnancy to Early Life Longitudinal Data System (PELL).

Cumulative Birth Rates with Linked Assisted Reproductive Technology Cycles

BackgroundLive-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.MethodsWe 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.ResultsThe 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.ConclusionsOur 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

To systematically review the reporting of race/ethnicity in Society for Assisted Reproductive Technology (SART) Clinic Outcome Reporting System (CORS) publications. 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. Not applicable. Not applicable. In vitro fertilization cycles reported to SART. Any outcomes reported in SART CORS. 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. 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.