Clarifying the relationship between total motile sperm counts and intrauterine insemination pregnancy rates.

OBJECTIVE: To study the relationship between postwash total motile sperm count (TMSC) and intrauterine insemination (IUI) outcomes. DESIGN: Retrospective review SETTING: Large fertility clinic PATIENT(S): A total of 92,471 insemination cycles from 37,553 patients were included in this study. INTERVENTION(S): All stimulated clomiphene citrate, letrozole, and/or injectable gonadotropin IUI cycles performed at a single institution from 2002 through 2018 were reviewed. Generalized estimating equations (GEE) analysis was used to account for multiple cycles by individual patients and to adjust for female partner age, body mass index, and stimulation protocol. MAIN OUTCOME MEASURE(S): Successful clinical pregnancy was defined as ultrasound confirmation of an intrauterine gestational sac with fetal cardiac activity. RESULT(S): A total of 92,471 insemination cycles were available to evaluate the relationship between postwash TMSC and clinical pregnancy. Pregnancy rates were highest with TMSC of ≥9 × 106 and declined gradually as TMSC decreased. Complete data for the adjusted GEE analysis were available for 62,758 cycles. Adjusted GEE analysis among cycles with TMSC of ≥9 × 106 (n = 46,557) confirmed that TMSC in this range was unrelated to pregnancy. Conversely, TMSC was highly predictive of pregnancy (Wald χ2 = 39.85) in adjusted GEE analysis among cycles with TMSC of <9 × 106 (n = 16,201), with a statistically significant decline. CONCLUSIONS: IUI pregnancy is optimized with TMSC of ≥9 × 106, below which the rates gradually decline. Although rare, pregnancies were achieved with TMSC of <0.25 × 106. Since the decline in pregnancy is gradual and continuous, there is no specific threshold above which IUI should be recommended. Rather, these more specific quantitative predictions can be used to provide personalized counseling and guide clinical decision making.

Factors associated with birth outcomes from cryopreserved blastocysts: experience from 4,597 autologous transfers of 7,597 cryopreserved blastocysts.

OBJECTIVE: To evaluate factors associated with cryopreserved blastocyst transfer birth outcomes, including age, expansion time, cryopreservation protocol, cryodamage, and number of embryos transferred. DESIGN: Retrospective cohort study. SETTING: Private infertility practice. PATIENT(S): Cryopreserved blastocyst transfer patients from January 2003 to April 2012. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Birth per transfer and children per embryo. RESULT(S): Overall live birth per transfer was 32%, with 17% twin births and 0.3% triplets. Live birth per transfer was significantly higher for vitrification compared with slow-freeze (day 5 cryopreservation: 47% vs. 35%; day 6 cryopreservation: 46% vs. 24%), as was live born children per transferred embryo (39% vs. 29% for day 5; 36% vs. 18% for day 6). Birth rates declined only slightly with increasing age at cryopreservation through 37 years, followed by an increasingly rapid decline in success with increasing age thereafter. Live birth rates declined rapidly (49%-18% for vitrification and 37%-10% for slow-freeze) as the percentage of intact cells after cryopreservation decreased from 95%-100% to 70%-79%, with almost no births when the percentage of intact cells was <70%. Increasing numbers of embryos per transfer were associated with significant increase in live birth per transfer but significant decrease in children per transferred embryo. Birth rates were much lower for blastocysts with delayed expansion on day 7 (10% per transfer). CONCLUSION(S): Birth outcomes from cryopreserved blastocyst transfer are influenced by age, timing of expansion, cryopreservation protocol, visible cryodamage, and the number of embryos transferred. Vitrification substantially improves outcomes versus slow freezing.

Interobserver and intraobserver variation in day 3 embryo grading.

OBJECTIVE: Variations in pregnancy rates (PR) between IVF programs are due to multiple factors, including embryo quality. Standardized embryo grading systems have been developed to improve communication between embryologists and clinicians. However, these grading systems have not been validated. We sought to quantify both interobserver and intraobserver variability using a standardized day 3 embryo grading system (Veeck scale). DESIGN: Prospective, sample-randomized, controlled, blinded study. SETTING: University hospital. PATIENT(S): Twenty-six practicing embryologists. INTERVENTION(S): Observation and grading of 35 video clips of day 3 embryos. MAIN OUTCOME MEASURE(S): Interobserver and intraobserver variability. Embryologists were also assessed by education level, years of experience, size of IVF program, and type of grading system used. Kappa scores and intraclass correlation coefficients were calculated. RESULT(S): Practicing embryologists differed from control (Lucinda Veeck) by as much as two grades, despite using the same grading system (Kappa = 0.24, interclass correlation coefficient = 0.98). There was also variability in grading the same embryo (Kappa = 0.69, interclass correlation coefficient = 0.88). Programs with higher cycle numbers per year had lower variability. CONCLUSION(S): There is substantial interobserver variability and moderate intraobserver variability among embryologists. Such variability could alter both the expected quality of embryos transferred, as well as the number transferred, both of which directly impact IVF program success.

Cryopreserved embryo transfers suggest that endometrial receptivity may contribute to reduced success rates of later developing embryos.

OBJECTIVE: To evaluate viability and implantation potential of cryopreserved blastocysts according to the day of blastocyst expansion and cryopreservation. DESIGN: Retrospective study. SETTING: Private ART center. PATIENT(S): Three hundred and seventy-five patients undergoing embryo transfer with cryopreserved blastocysts. INTERVENTION(S): Blastocyst cryopreservation on day 5, 6, or 7 after oocyte retrieval according to the day of blastocyst expansion and subsequent embryo transfer. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate (PR) per embryo transfer. RESULT(S): Clinical PRs were similar between blastocysts cryopreserved on day 5 and blastocysts cryopreserved on day 6 (32% vs. 28%). The clinical PR was lower for blastocysts cryopreserved on day 7 (15%), but this difference was not statistically significant after accounting for the number of embryos per transfer (P=.15). CONCLUSION(S): Viability and implantation potential are similar for day 5 and day 6 blastocyst cryopreservation. Viability may be reduced for blastocysts cryopreserved on day 7, but not to the extent suggested by reports of fresh transfers. These results suggest that reduced success rates associated with fresh transfers of later developing blastocysts may be the result of asynchrony with endometrial receptivity instead of poorer embryo quality.