Morphological quality on Day 3 affects the pregnancy outcomes of low-quality euploid blastocysts: a retrospective cohort study.

STUDY QUESTION: Does the morphological quality on Day 3 influence the pregnancy outcomes of euploid blastocysts? SUMMARY ANSWER: The morphological quality on Day 3 affects the clinical pregnancy rate (CPR) and live birth rate (LBR) of low-quality euploid blastocysts. WHAT IS KNOWN ALREADY: The morphological grading of Day 3 embryos affects the pregnancy outcome of cleavage-stage embryos and is an excellent indicator to predict embryo development potential. However, it is still unclear whether morphological quality on Day 3 is associated with pregnancy outcomes of the euploid blastocyst. STUDY DESIGN, SIZE, DURATION: This retrospective cohort study comprised 1275 patients who received single euploid blastocyst transfer between January 2016 and August 2021 at a tertiary teaching hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients were grouped into two groups according to the morphological grading on Day 3 of transferred blastocysts: high-quality (HQ, including Grades I and II) Day 3 embryos and low-quality (LQ, Grade III) Day 3 embryos. The primary outcomes were CPR and LBR. Interactions of development days (Day 5 and Day 6) and morphological quality (high- and low-quality) of blastocysts with morphological quality of Day 3 embryos on pregnancy outcomes were tested in the stratified analysis and logistic regression models. The multivariate logistic regression analysis was conducted to investigate the independent effect of the morphological quality of Day 3 embryos on pregnancy outcomes after adjusting for potentially confounding factors. MAIN RESULTS AND THE ROLE OF CHANCE: The CPR and LBR of the HQ Day 3 embryos group were statistically higher than those of the LQ Day 3 embryos group (CPR: 59.73% versus 49.70%, respectively, P = 0.015; LBR: 49.73% versus 41.21%, respectively, P = 0.041). The development days of blastocysts did not exhibit a multiplicative interaction with the morphological quality of Day 3 embryos on the CPR (P for interaction = 0.648) and LBR (P for interaction = 0.925). The morphological quality of blastocysts exhibits a multiplicative interaction with the morphological quality of Day 3 embryos on the CPR (P for interaction = 0.020) and LBR (P for interaction = 0.012). After adjusting for potential confounders, the HQ Day 3 embryo group was positively associated with the CPR (adjusted odds ratio (aOR): 2.10, 95% CI: 1.31-3.36, P = 0.002) and LBR (aOR: 1.97, 95% CI: 1.20-3.25, P = 0.008) of LQ blastocysts. However, the morphological quality on Day 3 was not significantly associated with the CPR (aOR: 0.95, 95% CI: 0.58-1.55, P = 0.835) and LBR (aOR: 0.86, 95% CI: 0.53-1.40, P = 0.550) of HQ blastocysts. LIMITATIONS, REASONS FOR CAUTION: Selection and confounding bias introduced by the retrospective design cannot be completely eliminated in this study, although multivariable logistic analysis was conducted to adjust for potential confounders. Also, some subgroups had small sample sizes, which may reduce statistical power. Moreover, participants in our study only received single euploid blastocyst transfer, and whether the results could apply to blastocysts with unknown ploidy status is unclear. WIDER IMPLICATIONS OF THE FINDINGS: This study found that the morphological quality on Day 3 was significantly associated with the CPR and LBR of LQ blastocysts; Therefore, when only LQ euploid blastocysts are available for transfer, blastocysts derived from HQ Day 3 embryos are recommended. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

The optimal frozen embryo transfer strategy for the recurrent implantation failure patient without blastocyst freezing: thawing day 3 embryos and culturing to day 5 blastocysts.

This study aimed to investigate the optimal frozen embryo transfer (FET) strategy for recurrent implantation failure (RIF) patients with three consecutive failed cleaved embryo implantations and no blastocyst preservation. This retrospective analysis was divided into three groups based on the FET strategy: thawed day 3 embryo transfer (D3 FET group); and extended culture of frozen-thawed day 3 embryos to day 5 blastocysts transfer (D3-D5 FET group); thawed blastocyst transfer (D5 FET group). Transplant cycle data were compared between the three groups. In total, 43.8% of vitrified-thawed cleavage embryos developed into blastocysts. Analysis of the three transplantation strategies showed that, compared with the D3 FET group, D3-D5 had a significantly better hCG-positivity rate and live-birth rate (P < 0.05). Pregnancy outcomes in the D3-D5 FET group and D5 FET group were similar regarding hCG-positivity rate, implantation rate, clinical pregnancy rate, and live-birth rate. Our findings propose two potentially valuable transfer strategies for patients experiencing repeated implantation failures. The D3-D5 FET approach presents a greater potential for selecting promising embryos in cases without blastocyst preservation; however, this strategy does entail the risk of cycle cancellation. Conversely, in instances where blastocyst preservation is an option, prioritizing consideration of the D5 FET strategy is recommended.

Day-3 vs. Day-5 fresh embryo transfer.

OBJECTIVE: Embryo transfer on day-5 has been associated with higher success rates, therefore our IVF clinics started to extend embryo culture until blastocyst stage. This study aimed to compare the success rates of day-3 vs. day-5 embryo transfers. METHODS: We had 266 patients included, all having undergone ICSI, with 221 patients having undergone day-3 embryo transfers, and 45 patients having undergone day-5 embryo transfers. Patients with more than five good quality embryos on day-3 were chosen to prolong the culture of embryos into day-5. RESULTS: There were no significant differences in patient characteristics, including baseline LH, FSH, Prolactin and Estradiol hormone levels. In addition, there were also no significant differences in rFSH total dosage and duration of stimulation day. Final estradiol levels, number of follicles, retrieved oocytes, matured oocytes, fertilized oocytes and number of embryos were significantly higher in day-5 compared to day-3 embryo transfer groups. Number of embryos transferred on day-3, were significantly higher compared to day-5. Neither group showed any significant differences in clinical pregnancy, implantation, multiple pregnancy or living birth rates. There were no differences in birth weights and lengths, head circumstances and Apgar Scores between both groups either in singleton or twin group. CONCLUSIONS: Transferring embryos at day-3 may provide the same benefits as day-5 embryo transfers to patients. However, more embryos were required to be transferred to achieve these comparable results.

Developmental potential of different embryos on day 3: a retrospective study.

To investigate how different quality of day 3 (D3) embryos affect blastocyst formation and clinical outcomes. This retrospective study analysed 699 patients undergoing assisted reproductive technology (ART) between January 2017 and February 2021. A total of 2517 D3 embryos were transferred to blastocyst medium for extended culture. D3 embryos were divided into five groups. Grade A, 6-10 cells, symmetrical blastomeres and <20% fragmentation; grade B, 6-10 cells, uneven blastomeres and ≥20% fragmentation; grade C, >10 cells, symmetrical blastomeres and <20% fragmentation; grade D, >10 cells, uneven blastomeres and ≥20% fragmentation; grade E, <6 cells. Status of day 5 (D5) and day 6 (D6) blastocysts and the clinical outcomes (blastocyst transfer) of each D3 embryo were recorded. The grade C group showed a higher D5 blastocyst formation rate and a high-quality blastocyst rate than other groups (p<.05). However, the clinical pregnancy rates in the grade A group were higher than other groups (p<.05). Embryos with low speed of development (grade E group) showed considerable clinical outcomes that were still worth investigating. D3 embryos with less fragmentation and ≥6 symmetrical blastomeres revealed a higher developmental potential, while embryos with 6-10 blastomeres showed the ideal clinical outcomes.Impact StatementWhat is already known on this subject? Accurate embryo evaluation can effectively reflect the developmental potential of different embryos. The number of blastomeres, proportion of fragmentation, and blastomere symmetry are three important and popular morphologic parameters used for evaluating day 3 (D3) embryos. However, in existing reports, combining these three parameters for embryo evaluation often results in different results. This is because different researchers have chosen different criteria for these three parameters.What do the results of this study add? In this retrospective study, we summarised the medical records of our reproductive centre in the past three years, redefined the evaluation method of the D3 embryos, and analysed the corresponding developmental potential and clinical outcomes. We conclude that although the embryonic development potential of grade C embryos (>10 cells, symmetrical blastomeres and/or <20% fragmentation) is relatively good, the results of grade A embryos (6-10 cells, symmetrical blastomeres and/or <20% fragmentation) are better in terms of clinical outcomes.What are the implications of these findings for clinical practice and/or further research? We believe this is meaningful for embryologists to choose embryos for transfer and predict the clinical outcome of IVF cycles.

Day 3 time lapse selection is beneficial for the patients with no good-quality embryos.

We aimed to evaluate whether or not time lapse selection was beneficial for the cleavage-stage embryo transfers. The study included 838 infertile women with good ovarian reserve (obtaining more than 8 oocytes) from January 2018 to August 2019. Based on the transferred embryos with different grades (grade I, II and III), the patients were divided into day 3 selection with conventional morphology (CM) and day 3 selection with time lapse (TL) groups. For the grade I and II embryos, we observed that CM and TL had similar implantation, clinical pregnancy and ongoing pregnancy (p > .05) rates. For the grade III embryos, we observed that CM group showed slightly lower implantation (36.74 versus 41.03%, p = .261) and clinical pregnancy (56.82 versus 64.10%, p = .182) rates than TL group. CM group showed significantly lower ongoing pregnancy (47.35 versus 59.83%, p = .025) rate than TL group. And we observed that CM group had significantly higher blastulation (38.93 versus 26.61%, p = .019) rate than TL group. We concluded that TL selection was beneficial to the patients with no good-quality embryos in the first cleavage-stage embryo transfers.

The influence of oxygen concentration during embryo culture on obstetric and neonatal outcomes: a secondary analysis of a randomized controlled trial.

STUDY QUESTION: Does oxygen concentration during 3-day embryo culture affect obstetric and neonatal outcomes? SUMMARY ANSWER: Oxygen concentration during 3-day embryo culture does not seem to affect the obstetric and neonatal outcomes measured. WHAT IS KNOWN ALREADY: Atmospheric oxygen appears to be harmful during extended embryo culture. Embryo culture conditions might therefore be a potential risk factor for subsequent fetal development and the health of future children. No data are available concerning the obstetrics and neonatal outcomes after Day 3 transfer of embryos cultured under reduced and atmospheric oxygen tensions. STUDY DESIGN, SIZE, DURATION: A secondary analysis of a previous randomized controlled trial assessing clinical pregnancy outcomes was carried out. This analysis included 1125 consecutive oocyte donation cycles utilizing ICSI or IVF and Day 3 embryo transfers between November 2009 and April 2012. The whole cohort of donated oocytes from patients who agreed to participate in the study were randomly allocated (1:1 ratio) to a reduced O2 tension group (6% O2) or an air-exposed group (20% O2) based on a computer-generated randomization list. Fresh and vitrified oocytes were used for oocyte donation. Only those pregnancies with a live birth at or beyond 24 weeks of gestation were included. PARTICIPANTS/MATERIALS, SETTING, METHODS: Day 3 embryos were cultured in an atmosphere of 5.5% CO2, 6% O2, 88.5% N2 versus a dual gas system in air. MAIN RESULTS AND THE ROLE OF CHANCE: From the eligible 1125 cycles, 564 were allocated to the 6% O2 group and 561 cycles to the 20% O2 group. However, 50 and 62 cycles did not reach embryo transfer in the 6% and 20% O2 groups, respectively. No differences were found between 6% O2 and atmospheric O2 tension in the number of livebirths per embryo transfer (mean ± SD, 0.5 ± 0.7 versus 0.5 ± 0.7), pregnancy complications or neonatal outcomes. Both groups (6% and atmospheric O2) had similar single and twin delivery rates (40.8% versus 38.1% and 10.7% versus 12.3%, respectively). Preterm delivery rates and very preterm delivery rates (10.80% versus 13.24% and 1.25% versus 2.94%, respectively), birthweight (3229 ± 561 g versus 3154 ± 731 g), low birthweight (2.92% versus 2.45%), birth height (50.18 ± 2.41 cm versus 49.7 ± 3.59 cm), head circumference (34.16 ± 1.87 cm versus 33.09 ± 1.85 cm) and 1 min Apgar scores (8.96 ± 0.87 versus 8.89 ± 0.96) were also similar between 6% and atmospheric O2 groups, respectively. LIMITATIONS, REASONS FOR CAUTION: The number of liveborns finally analyzed is still small and not all obstetric and neonatal variables could be evaluated. Furthermore, a small proportion of the obstetric and neonatal data was obtained through a questionnaire filled out by the patients themselves. One reason for the lack of effect of oxygen concentration on pregnancy outcome could be the absence of trophectoderm cells at cleavage stage, which may make Day 3 embryos less susceptible to hypoxic conditions. WIDER IMPLICATIONS OF THE FINDINGS: Nowadays many IVF laboratories use a more physiological oxygen concentration for embryo culture. However, the benefits of using low oxygen concentration on both laboratory and clinical outcomes during embryo culture are still under debate. Furthermore, long-term studies investigating the effect of using atmospheric O2 are also needed. Gathering these type of clinical data is indeed, quite relevant from the safety perspective. The present data show that, at least in egg donation cycles undergoing Day 3 embryo transfers, culturing embryos under atmospheric oxygen concentration seems not to affect perinatal outcomes. STUDY FUNDING/COMPETING INTEREST(S): The present project was supported by the R + D program of the Regional Valencian Government, Spain (IMPIVA IMDTF/2011/214). The authors declare that they have no conflict of interest with respect to the content of this manuscript. TRIAL REGISTRATION NUMBER: NCT01532193.

The sequential embryo transfer compared to blastocyst embryo transfer in in vitro fertilization (IVF) cycle in patients with the three repeated consecutive IVF. A randomized controlled trial.

The purpose of this study was to determine the pregnancy rate in the double sequential transfer of embryos on both day 3 and day 5 compared to day 5 alone, in in vitro fertilization-embryo transfer (IVF/ET) in patients with the three repeated consecutive IVF failures. In this controlled trial, women scheduled for IVF/ET with the three repeated consecutive IVF failures were randomized to either sequential transfer of embryos on day 2 and on day 5 after ovum pick-up (group 1, n = 60) or blastocyst ET on day 5 (group 2, n = 60) as a control group. The primary outcome measures were the chemical and clinical pregnancy rate. Baseline and cycle characteristics were comparable in both groups. Chemical and clinical pregnancy rate was similar in the sequential ET group (40%) compared to the day 5 of ET group (38.3%) (p value = .85). It seems that the double ET does not increase the chance of pregnancy rate compared to blastocyst ET on day 5 in the patients with the three repeated IVF-ET failures.

Over Ten-Cell Good Embryo Transfers on Day Three have Equivalent Clinical Outcomes with Those of Eight-Cell Embryos in Female Patients Aged ≤35 Years: A Retrospective Cohort Study.

BACKGROUND/AIM: To compare the clinical outcomes between > 10- and 8-cell good quality embryos on day 3. METHODS: A retrospective study of a cohort of 459 patients was included in the fresh embryo transfer (ET) cycle group from January 2009 to April 2016. In this group, 2 good quality embryos on day 3, were transferred on corresponding dates, in 75 patients (> 10-cell embryos), and in 384 patients (8-cell embryos). Seven hundred and forty four patients, with 1 blastocyst transferred derived from > 10-cell (n = 183) or 8-cell (n = 561) good quality embryos on day 3, were assigned in the frozen ET (FET) group. RESULTS: In the ET group, the clinical pregnancy and live birth rates of the > 10-cell transfer patients were comparable with those of the 8-cell transfer group (62.67 vs. 69.27%, 60.00 vs. 59.90%, respectively); however, the miscarriage rate of > 10-cell transfers was significantly lower than that of 8-cell transfers (4.26 vs. 13.53%, p < 0.05). In the FET group, there were no statistically significant differences found in the clinical pregnancy, live birth, and miscarriage rates between one > 10-cell-derived and one 8-cell-derived blastocyst transfers (71.04 vs. 65.78%, 59.02 vs. 54.19%, and 16.92 vs. 17.62%, respectively). CONCLUSIONS: The results suggested that > 10- and 8-cell, good quality embryos on day 3, had comparable viability and clinical outcomes.

Detection of early cleavage embryos improves pregnancy and delivery rates of Day 3 embryo transfer during in vitro fertilization.

OBJECTIVE: This study established a simple criterion for improving the pregnancy and delivery rates of Day 3 embryo transfer for in vitro fertilization (IVF) by assessing the early cleavage of two-cell stage embryos. MATERIALS AND METHODS: In total, 258 cycle patients undergoing an IVF and Day 3 embryo transfer program were recruited. All cycles were divided into four groups containing viable Day 3 embryos and those (A) with distinct early cleavage (equal-sized blastomeres and ≤10% fragmentation: ECA grade); (B) with indistinct early cleavage (equal sized blastomeres, >2 blastomeres, or >10% fragmentation: ECB grade); (C) without early cleavage [no early cleavage (NEC grade)]; or (D) without early cleavage being assessed (control) at 25-27 after insemination. RESULTS: The percentage of viable Day 3 embryos from ECA grade (75.1%, 507/675) was significantly higher than that from ECB grade (19.2%, 151/403) or NEC grade (27.1%, 127/469) embryos (p < 0.01). The pregnancy and delivery rates in the ECA group [65.7% (65/990) and 48.5% (48/990), respectively] were significantly higher than those in the ECB group [30.8% (4/13) and 7.7% (1/13), respectively] or NEC group [36.8% (14/38) and 23.7% (9/38), respectively; all p < 0.01]. The implantation rate in the ECA group (32.3%, 129/400) was higher than those in the ECB (6.8%, 4/59) and NEC (13.0%, 18/136) groups (p < 0.01). CONCLUSION: Simple selection using the early cleavage morphology may improve the pregnancy and delivery rates of Day 3 embryo transfer programs.

Neonatal health including congenital malformation risk of 1072 children born after vitrified embryo transfer.

STUDY QUESTION: Does vitrification of Day 3 and Day 5 embryos adversely affect birth outcomes of singletons and twins in comparison with peers born after fresh embryo transfer? SUMMARY ANSWER: Neonatal health parameters, including the prevalence of congenital malformations, in singletons and twins born after embryo vitrification are similar to or slightly better than after fresh embryo transfer. WHAT IS ALREADY KNOWN: Although vitrification, rather than slow-freezing, of embryos is routine practice nowadays, convincing evidence regarding the safety for the offspring is sparse. Literature data comprise results from mostly small-sized studies or studies including only Day 3 or only Day 5 vitrified embryo transfers. Overall, better or comparable perinatal outcomes, in terms of higher birthweight and lower risk for small-for-gestational age or for low birthweight, have been reported for singletons born after vitrified embryo transfer compared with fresh embryo transfer. According to the single available study with sufficient sample size, the congenital malformation rate was found to be comparable after vitrified and fresh embryo transfers. STUDY DESIGN, SIZE, DURATION: Data were collected from 960 cycles after transfer of embryos vitrified on Day 3 (n = 457) or Day 5 (n = 503) and from 1644 cycles after fresh embryo transfer on Day 3 (n = 853) or Day 5 (n = 791), performed between 2008 and 2013 at the Centre for Reproductive Medicine of the university hospital UZ Brussel. Outcome measures were neonatal health in terms of birthweight, small-for-gestational age, prematurity rate, perinatal death and major/minor/total malformation rate. PARTICIPANTS/MATERIALS, SETTING, METHODS: Perinatal health parameters of 11 stillborns and 1061 live borns (827 singletons and 234 twins) in the vitrified group and of 28 stillborns and 1838 live borns (1374 singletons and 464 twins) in the fresh embryo group are reported. Within 3 months after birth, children in the two study groups were assessed clinically with special attention to congenital malformations by a paediatrician blinded to the type of embryo transfer. Data were analysed by multiple linear and logistic regression, adjusted for treatment variables and maternal characteristics. MAIN RESULTS AND THE ROLE OF CHANCE: Mothers to infants in the vitrified group were on average slightly older and more often suffering from pregnancy-related hypertensive disorders than mothers to infants in the fresh transfer group. Singletons born after vitrification showed a higher birthweight standard deviation score (SDS) (-0.4 versus -0.7; 95% confidence interval (CI): 0.0-0.3, P = 0.001) and a lower small-for-gestational age rate (AOR: 0.55; 95% CI: 0.34-0.90) in comparison with peers born after fresh embryo transfer. Preterm birth rate and perinatal death rate were comparable between the two groups (AOR: 0.91; 95% CI: 0.57-1.43 and AOR: 0.97; 95% CI: 0.40-2.36). In twins, neonatal outcomes including birthweight SDS, small-for-gestational age and prematurity rates were comparable in the vitrified and the fresh groups, when adjusted for confounders. Furthermore, the rate of major congenital malformations in live borns was comparable between the vitrified group and the fresh group, both in singletons (2.6 versus 2.8%; AOR: 0.91; 95% CI: 0.47-1.78) and in twins (2.4 versus 2.7%; AOR: 0.51; 95% CI: 0.05-5.72). Also, the total malformation rate in the vitrified group (3.4%; 95% CI: 2.4-4.8) did not differ from the rate in the fresh embryo group (3.9%; 95% CI: 3.1-5.0). The embryonic stage at vitrification or fresh transfer (cleavage-stage embryo or blastocyst) did not influence the birth characteristics or malformation rate. LIMITATIONS, REASONS FOR CAUTION: The main limitation of this study is the rather small twin group. Therefore, the outcome results for twins should be interpreted cautiously. WIDER IMPLICATIONS OF THE FINDINGS: This study provides evidence that transfer of vitrified Day 3 and Day 5 embryos does not adversely affect the neonatal health of the offspring in comparison with transfer of fresh embryos. Furthermore, neonatal outcomes were not different after transfer of vitrified blastocysts compared with transfer of vitrified cleavage-stage embryos. STUDY FUNDING/COMPETING INTERESTS: Educational grants for establishing and organizing the data collection have come from IBSA, Ferring, Organon, Shering-Plough and Merck. Merck Belgium funded the data collection for outcomes after vitrification between 2012 and 2015. All co-authors, except M.B., declared no conflict of interest. M.B. has received consultancy fees from Organon, Serono Symposia and Merck.

Risk of ectopic pregnancy following day-5 embryo transfer compared with day-3 transfer.

The incidence of ectopic pregnancy after IVF is increased approximately 2.5-5-fold compared with natural conceptions; however, the aetiology for this increased risk remains unclear. One proposed practice change to decrease the incidence of ectopic pregnancy is blastocyst embryo transfer on day 5 rather than cleavage-stage embryo transfer on day 3. A retrospective cohort study was conducted to compare the risk of ectopic pregnancy following fresh day-5 embryo transfer with day-3 embryo transfer among women who underwent IVF and achieved pregnancy from 1998 to 2011. There were 13,654 eligible pregnancies; 277 were ectopic. The incidence of ectopic pregnancy was 2.1% among day-3 pregnancies and 1.6% among day-5 pregnancies. The adjusted risk ratio for ectopic pregnancy from day-5 compared with day-3 transfer was 0.71 (95% confidence interval 0.46-1.10). Although this analysis included 13,654 cycles, with a two-sided significance level of 0.05, it had only 21.9% power to detect a difference between the low incidence of ectopic pregnancy among both day-3 and day-5 transfers. In conclusion, this study was not able to demonstrate a difference in the risk of ectopic pregnancy among day-3 compared with day-5 transfers.

Comparative study of pregnancy outcomes between day 3 embryo transfer and day 5 blastocyst transfer in patients with progesterone elevation.

OBJECTIVE: To explore the effects of progesterone (P) elevation on pregnancy outcomes of day 3 embryo and day 5 blastocyst transfer. METHODS: Clinical outcomes (pregnancy and ectopic pregnancy rates) following day 3 embryo and day 5 blastocyst transfer cycles were retrospectively analysed. Day 3 embryo and day 5 blastocyst transfer cycles were divided into normal P level (P ≤ 1.5 ng/ml) and P elevation group (P > 1.5 ng/ml), based on the serum P level on the day of human chorionic gonadotropin (hCG) administration. RESULTS: A total of 2868 cycles were analysed. In day 3 embryo transfer cycles (n = 2345), the clinical pregnancy rate was significantly higher in the normal P level group compared with the P elevation group (55.4% versus 46.7%, respectively) and the ectopic pregnancy rate was significantly lower in the normal P level group compared with the P elevation group (2.8% versus 7.9%, respectively). In day 5 blastocyst transfer cycles (n = 523), there were no significant differences in the clinical pregnancy and ectopic pregnancy rates between the two groups, based on the P level. CONCLUSION: These preliminary findings suggest that day 5 blastocyst transfer should be adopted for patients with P elevation on the day of hCG administration.

Application of two different synthetic sequential media for the human IVF-ET program: a prospective, randomized, and comparative study.

OBJECTIVE: Since IVF program was first established, various types of media and culture systems have been developed either in-house or commercially. The aim of this study was to compare the efficacy of in-house Maria Research Center (MRC) media to that of commercially available Sydney IVF media in human day 3 embryo transfer cycles. METHODS: Three hundred sixty nine couples were included in this prospective, randomized, and comparative study. All couples undergoing IVF treatment at the Maria Fertility Hospital were randomly assigned to either Sydney IVF (n=178) or MRC (n=191) media. RESULTS: No difference was observed between the MRC media and Sydney IVF media groups with respect to fertilization rate (74.4% vs. 75.5%). The clinical pregnancy and implantation rates of MRC media (47.1% and 20.0%, respectively) were also similar to those of Sydney IVF media (44.4% and 19.4%, respectively). However, the proportion of embryos with good quality on day 3 was significantly higher in the MRC media group than the Sydney IVF media group (50.2% vs. 43.2%) (p<0.05). CONCLUSION: MRC media were as effective as Sydney IVF media for sustaining embryo development and pregnancy rates. The present study implies that MRC media can be a suitable alternative to commercially available media for human IVF-ET program.