Implantation Rates In Patients Research Articles

Mechanism Underlying the Low Implantation Rate in Patients with Thin Endometrium

Abstract: The aim of this study was to clarify the mechanism underlying the low implantation rate in patients with thin endometrium. Endometrial thickness during postovulation days 5–7 (mid-luteal phase) during a total of 1,035 natural cycles in 205 patients was analyzed retrospectively. We designated patients with endometrial thicknesses ≤ 6 mm as the thin group (n = 12) and those with endometrial thicknesses ≥ 7 mm as the normal group (n = 193), based on the markedly lower pregnancy rate in the thin group (thin: 8.3% vs. normal: 51.3%). Levels of steroid receptor, transforming growth factor α (TGFα) and oxidative stress were compared between the two groups. Oxidative stress was higher in the stroma of thin endometrium. In addition, expression of progesterone and estrogen receptors was higher, and TGF α expression was significantly lower in thin endometrium. Altered regulation of oxidative stress and levels of steroid receptors and TGF α appear to underlie the low implantation rate seen in patients with ...

Do circulating blood cells contribute to maternal tissue remodeling and embryo-maternal cross-talk around the implantation period?

In early pregnancy, human chorionic gonadotrophin (HCG) stimulates the corpus luteum (CL) of pregnancy to produce progesterone, which in turn maintains human embryo implantation in the uterus. In addition to this embryo-maternal cross-talk via the endocrine systems through blood circulation, accumulating evidence suggests that circulating blood cells also play an important role in embryo implantation. Peripheral blood mononuclear cells (PBMC) derived from pregnant women increased the progesterone production by luteal cells and promoted the invasion of embryos in vitro. Recombinant-HCG increased chemokine production by PBMC through lectin-glycan interaction and enhanced the effects of PBMC on embryo invasion. Later, it was shown that not only PBMC, but also circulating platelets were possible sources of these chemokines that promote extravillous trophoblast invasion to reconstruct maternal endometrial artery. Circulating platelets were also proposed to induce neovascularization during CL formation. Furthermore, intrauterine administration of autologous PBMC effectively improved live birth, pregnancy and implantation rates in patients with repeated (four or more) implantation failures during in vitro fertilization therapy. These findings suggest that circulating blood cells positively contribute to maternal tissue remodeling and embryo-maternal cross-talk around the implantation period in cooperation with the endocrine system.

Zygote Intrafallopian Transfer (ZIFT): A Viable Option for Women of Advanced Maternal Age

Background: Recurrent implantation failure and spontaneous abortion are more prevalent in women of advanced maternal age (AMA) primarily due to increased rates of gamete and embryonic aneuploidy. Murine models demonstrate lower live birth rates from in-vitro cultured embryos versus those developed in-vivo. It follows that in-vitro culture may contribute to abnormal human embryonic development leading to implantation failure. Zygote Intrafallopian Transfer (ZIFT) may improve implantation rates by providing optimal conditions for early embryonic development.Objective: To determine whether ZIFT improves implantation rate in patients of AMA who previously failed traditional in-vitro fertilization-embryo transfer (IVF-ET).Materials and Methods: All patients ≥36 years of age at the time of their first IVF-ET, who failed to achieve a clinical pregnancy and subsequently underwent a ZIFT procedure over a four year period from 2004-2008 were included. Cycles involving egg donation and frozen embryos were excluded. The primary endpoint of the study was implantation rate.Results: Seven patients who underwent 10 IVF-ET cycles (mean 1.4 failed IVF-ET cycles) and nine ZIFT cycles were included in the analysis. The mean age at the time of the first IVF-ET was 39.0 ± 1.2 (36-43) and at the time of the first ZIFT 39.7 ± 1.1 (36-43) (P>0.05). A total of 39 embryos (mean 3.9 ± 0.5 embryos per ET, range 1-6) were transferred in the IVF-ET group versus 43 zygotes (mean 4.8 ± 0.3) zygotes per ZIFT, range 3-6) in the ZIFT group (P>0.05). Both implantation rates, 14/43 (32.6%) and 0/39 (0%), and clinical pregnancy rate per transfer, 6/9 (66.7%) versus 0/10 (0%), were significantly higher in the ZIFT versus IVF-ET group respectively (P<0.05). The multiple pregnancy rate in the ZIFT group was 3/6 (50%). Overall, 4/7 (57.1%) of the patients undergoing ZIFT achieved a clinical pregnancy.Conclusions: ZIFT is a viable option for women of AMA with previous IVF-ET failure. These results suggest that the intra-fallopian environment may be superior to in-vitro conditions for patients with a higher tendency to embryonic aneuploidy. Larger, prospective crossover trials are needed to verify these favorable results. Background: Recurrent implantation failure and spontaneous abortion are more prevalent in women of advanced maternal age (AMA) primarily due to increased rates of gamete and embryonic aneuploidy. Murine models demonstrate lower live birth rates from in-vitro cultured embryos versus those developed in-vivo. It follows that in-vitro culture may contribute to abnormal human embryonic development leading to implantation failure. Zygote Intrafallopian Transfer (ZIFT) may improve implantation rates by providing optimal conditions for early embryonic development. Objective: To determine whether ZIFT improves implantation rate in patients of AMA who previously failed traditional in-vitro fertilization-embryo transfer (IVF-ET). Materials and Methods: All patients ≥36 years of age at the time of their first IVF-ET, who failed to achieve a clinical pregnancy and subsequently underwent a ZIFT procedure over a four year period from 2004-2008 were included. Cycles involving egg donation and frozen embryos were excluded. The primary endpoint of the study was implantation rate. Results: Seven patients who underwent 10 IVF-ET cycles (mean 1.4 failed IVF-ET cycles) and nine ZIFT cycles were included in the analysis. The mean age at the time of the first IVF-ET was 39.0 ± 1.2 (36-43) and at the time of the first ZIFT 39.7 ± 1.1 (36-43) (P>0.05). A total of 39 embryos (mean 3.9 ± 0.5 embryos per ET, range 1-6) were transferred in the IVF-ET group versus 43 zygotes (mean 4.8 ± 0.3) zygotes per ZIFT, range 3-6) in the ZIFT group (P>0.05). Both implantation rates, 14/43 (32.6%) and 0/39 (0%), and clinical pregnancy rate per transfer, 6/9 (66.7%) versus 0/10 (0%), were significantly higher in the ZIFT versus IVF-ET group respectively (P<0.05). The multiple pregnancy rate in the ZIFT group was 3/6 (50%). Overall, 4/7 (57.1%) of the patients undergoing ZIFT achieved a clinical pregnancy. Conclusions: ZIFT is a viable option for women of AMA with previous IVF-ET failure. These results suggest that the intra-fallopian environment may be superior to in-vitro conditions for patients with a higher tendency to embryonic aneuploidy. Larger, prospective crossover trials are needed to verify these favorable results.

The Effect of Intercourse around Embryo Transfer on Pregnancy Rate in Assisted Reproductive Technology Cycles

Background: Implantation failure is the most important cause of recurrent in vitro fertilization/intra cytoplasmic sperm injection (IVF/ICSI) failure. Several reports suggest that intercourse during the peritransfer period might improve pregnancy rates. This study is designed to determine whether intercourse during the peritransfer period will improve pregnancy and implantation rates in patients undergoing IVF or ICSI. Materials and Methods: In a randomized control trial study, 390 women with at least five years infertility were evaluated. In the study group, 195 patients had intercourse at least once 12 hours after embryo transfer. Implantation and clinical pregnancy rates were compared with 195 patients in the control group who had no intercourse for the entire assisted reproductive technology (ART) cycle. Results: Implantation rate in the study group was 6.5% in comparison with 5.5% for the control group. Clinical pregnancy rates were not significantly higher in study patients when compared to the control group (14.2% and 11.7% respectively). Conclusion: The results showed that intercourse during the peritransfer period can not increase pregnancy outcome.

The p53 codon 72 single nucleotide polymorphism lacks a significant effect on implantation rate in fresh in vitro fertilization cycles: an analysis of 1,056 patients

To determine whether the p53 codon 72 single nucleotide polymorphism, a change of the amino acid arginine (Arg) to proline (Pro) resulting from a single nucleotide mutation of guanine (G) to cytosine (C), has a clinically significant effect on implantation rate in fresh IVF cycles. Prospective cohort analysis. University-affiliated private IVF center. One thousand fifty-six female patients undergoing fresh nondonor IVF cycles. Embryo implantation rate. Of the 1,056 patients (2,600 total embryos transferred) undergoing their first IVF cycle, 289 had no implantation events and attempted a second cycle. Of the 289 patients in their second cycle, 72 had no implantation events and attempted a third cycle. The p53 codon 72 single nucleotide polymorphism frequencies in the first cycle (homozygous major allele Arg/Arg [G_G] = 45%, heterozygous allele Arg/Pro [G_C] = 44%, and homozygous minor allele Pro/Pro [C_C] = 11%) did not differ significantly across subsequent IVF cycles. There was no statistically significant difference in embryo implantation rate with respect to the single nucleotide polymorphism. The p53 codon 72 single nucleotide polymorphism lacks a clinically significant effect on embryo implantation rate in patients undergoing fresh nondonor IVF cycles.

A comparison of starting temperatures for slow freezing cryopreservation of blastocysts

OBJECTIVE: To compare starting temperature of 20 degrees C with -6.5 degrees C utilizing slow freezing and Menezo two step protocols for blastocyst cryopreservation by evaluating the resulting implantation rate at the time of thaw and transfer for each group. DESIGN: Retrospective study conducted in a University IVF program. MATERIALS AND METHODS: All patients between August 2006 and October 2007 with cryopreservation were randomized and included in this study. Data was analyzed on 258 blastocyts from 143 patients that were cryopreserved using Sage Blastocyst Freezing Media (RM-ART-8016). 146 blastocysts were cryopreserved using -6.5 degrees C as the starting temperature and 111 blastocysts were cyropreserved using 20 degrees C as the starting temperature. Thawing was performed using the two step Sage thaw protocol (RM-ART-8015). Survival and re-expansion were graded prior to transfer. The % survival is equal to the number of live cells. The % re-expansion reflects the size of the blastocele cavity. RESULTS: Using minitab anova one-way analysis, the following results were found: There was no significant difference in the number of embryos transferred, time in culture, % re-expansion or implantation rate. There was a significant difference between the two groups in average patient age, with the -6.5 degree C group exhibiting an older population. Interestingly, this same group exhibited higher % survival, but this was not significant. CONCLUSIONS: Changing the starting temperature to -6.5 degrees C for slow freezing of blastocyst did not impact implantation rate in patients and actually lead to a better survival rate, although not significant, in the slightly older group of patients. Blastocyst survival and re-expansion were not affected by the change in starting temperature. The change to -6.5 degrees C for slow freezing shortens the time necessary to complete this process saving personnel time without sacrificing frozen embryo quality.Table 1Starting Temp.no. embryosaverage patient ageaverage no. EThours in culture-6.5 degrees C14636.021.983.0120 degrees C11134.172.092.74P<0.010.2180.030 Open table in a new tab Table 2Starting Temp.% survival% re-expansionIR-6.5 degrees C88.2737.970.2120 degrees C80.6233.170.16P<0.010.3060.241 Open table in a new tab

Comparison of the Pregnancy Outcomes in Patients Receiving Hormone Replacement in the Luteal Phase after Transfer of Frozen-Thawed Embryos in the Natural Ovulatory Cycle

The aim of this study was to determine whether there is a difference in pregnancy outcomes dependent on the kind of hormone replacement treatment in the luteal phase after transfer of frozen-thawed embryos in the natural ovulation cycle. Two hundred and twenty-three cycles were examined in this study. The cycles were divided into three groups. In group A (40 cycles), the luteal phase was supported by human chorionic gonadotropin (hCG). In group B (83 cycles), the luteal phase was supported by hCG and vaginal suppository of progesterone. In group C (100 cycles), the luteal phase was supported by hCG, vaginal progesterone and transdermal estradiol. The pregnancy rate and implantation rate in group C (63.0% and 44.3%) were significantly and 28.0%) and group B (45.8% and 30.3%). In conclusion, administration of vaginal progesterone and transdermal estradiol in addition to hCG in the luteal phase in the natural ovulation cycle is effective for improving pregnancy and implantation rates in patients undergoing transfer of frozen-thawed embryos.

EMB-009 Implantation rates in patients with and without PGD

EMB-009 Implantation rates in patients with and without PGD

Beneficial effect of long zona dissection on frozen-thawed blastocysts at a young age.

Aim: To assess the appropriateness of assisted hatching using long zona dissection of human frozen-thawed blastocysts at the time of warming, especially in women over 35years of age or with repeated implantation failures. Methods: Of 177 frozen-thawed blastocyst transfer cycles, 89 control cycles had an intact zona and 88 cycles had assisted hatching using long zona dissection of human thawed blastocyst at the time of warming. These two groups were further subdivided by age to a total of four subgroups: ≤34years (assisted hatching, n=39; controls, n=39) and ≥35years (assisted hatching, n=49; controls, n=50). Twenty-seven cycles in the control group and 28 cycles in the assisted-hatching group had repeated implantation failures. The clinical and ongoing pregnancy rates and the implantation rate between the two groups were analyzed retrospectively. Results: The clinical pregnancy and implantation rates in women ≤34years were significantly higher after the application of assisted hatching compared with the control group (87.2% and 71.2%vs 56.4% and 46.6%, P<0.001). The clinical pregnancy and implantation rates of women with repeated implantation failures were higher after the application of assisted hatching compared with the control group (64.3% and 46.3%vs 48.1% and 34.1%), but this difference was not statistically significant. Conclusions: Routine assisted hatching using long zona dissection at the time of warming on frozen-thawed blastocysts is a safe and easy method to perform and is extremely beneficial for increasing the pregnancy rate in young women ≤34years of age, but not in women ≥35years of age. Despite increased pregnancy and implantation rates in patients with repeated implantation failures, statistical significance was not achieved. (Reprod Med Biol 2007; 6: 211-218).

The Effect of Uterine Fibroids on Embryo Implantation

Uterine fibroids are common but their role in infertility and effect on embryo implantation is unclear. There is evidence that submucosal fibroids are associated with poor reproductive outcome and that treatment with myomectomy is associated with an improvement in pregnancy rates. Various theories have been proposed to explain this relationship. Fibroids cause a mechanical distortion of the endometrial cavity-their presence may alter gamete and embryo transport (due to blockage of the tubal ostia or by altering uterine contractility and peristalsis) and subsequent embryo implantation (due to compression of the endometrium). They may lead to disruption of the junctional zone within the myometrial layer, affecting general uterine function in the initial stages of embryo invasion and later placentation. Altered vasculature due to the abnormal expression of angiogenic factors by uterine fibroids (such as basic fibroblast growth factor and platelet-derived growth factor) could play a role in a reduced implantation rate in patients with fibroids. Similarly, changes in the endometrium mediated by inflammation and factors involved in the process of fibrosis (such as transforming growth factor) could also have a detrimental effect. In addition, fibroids may affect gene expression pattern in the endometrium (such as HOXA10), disrupting the window of implantation. The supporting evidence for these theories is discussed in this review.

Effect of laser zona pellucida opening on clinical outcome of assisted reproduction technology in patients with advanced female age, recurrent implantation failure, or frozen–thawed embryos

To determine whether laser-assisted hatching can improve clinical outcome of assisted reproductive techniques in patients with advanced female age, with recurrent implantation failure, or who are using frozen-thawed embryos. A prospective randomized study. The infertility and IVF unit at a research facility in Iran. Four hundred ten patients with advanced female age (> or =37 y), 796 patients with recurrent implantation failure (for > or =2 cycles), and 180 patients with frozen-thawed embryos. Patients were divided equally into test and control groups. On the day of embryo transfer, the zona pellucida of the selected embryos in the test group were opened about 40 mum by using an infrared optical laser system, whereas in the control group they were all intact. Clinical pregnancy rates and implantation rates. In the patients with advanced female age or recurrent implantation failure, the clinical pregnancy and implantation rates were similar for the test and control groups. However, in the patients with frozen-thawed embryos, the rates were statistically significantly higher in the test group as compared with those of the control group (31.2% and 12.8% vs. 11.1% and 4.2%, respectively). The laser-assisted hatching improved the pregnancy and implantation rates in patients with frozen-thawed embryos but had no effect in patients with advanced female age or recurrent implantation failure.

Luteal estrogen supplementation in stimulated cycles may improve the pregnancy rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection–embryo transfer

Objective. To evaluate the effect of estradiol addition to progesterone supplementation during the luteal phase on pregnancy and implantation rates in patients undergoing in vitro fertilization/intracytoplasmic sperm injection–embryo transfer (IVF/ICSI-ET) cycles.Methods. In this prospective, randomized study, carried out in an IVF unit of a university hospital, we studied patients who were undergoing IVF/ICSI with controlled ovarian hyperstimulation using a gonadotropin-releasing hormone agonist/human recombinant gonadotropin long protocol. The main outcome measures were the pregnancy and implantation rates measured in the two groups.Results. Our results suggest higher pregnancy and implantation rates in IVF/ICSI-ET cycles that were supplemented with estradiol in the luteal phase.Conclusions. Estradiol supplementation during the luteal phase in women undergoing IVF/ICSI-ET has a beneficial effect on the outcome without (at least, as seems from this study) having any adverse effects.

Intrauterine administration of autologous peripheral blood mononuclear cells promotes implantation rates in patients with repeated failure of IVF–embryo transfer

There are few effective approaches to infertile patients with repeated failure in IVF-embryo transfer therapy. Since recent evidence suggests that some populations of maternal immune cells positively support embryo implantation, we have developed a new approach using peripheral blood mononuclear cells (PBMCs). Patients who had not experienced successful pregnancy despite four or more IVF-embryo transfer sessions were enrolled in this study (n = 35, 35 cycles). PBMCs were obtained from patients on the day of oocyte retrieval and were cultured with HCG for 48 h. Two days later, PBMCs were freshly isolated from patients again, combined with cultured PBMC and then administered to the intrauterine cavity of the patients. Blastocyst transfer was performed on day 5, and the success of implantation in the PBMC-treated group was compared with that in the non-treated group. Clinical pregnancy rate, implantation rate and live birth rate in the PBMC-treated group (41.2, 23.4 and 35.3%; n = 17, 47 and 16, respectively) were significantly higher than those in the non-treated group (11.1, 4.1 and 5.5%; n = 18, 49 and 18, respectively). Intrauterine administration of autologous PBMC may be an effective approach to improve embryo implantation in patients with repeated IVF failures.

P-298: Evaluation of the implantation and pregnancy rates by quality in single embryo transfer (SET) versus double embryo transfer (DET) when using frozen-thawed blastocysts: Are we improving the results when adding more embryos?

Excess embryos from a fresh cycle are often grown out to the blastocyst stage to determine developmental competence prior to freezing. At present, morphological evaluation is the most practical and simple method to classify embryos. The score assigned to the embryo is related to the presumed viability of the embryo and its capacity to implant and generate a pregnancy. The aim of this study was to determine if a difference exists in clinical pregnancy and implantation rates in patients that received one or two embryos with the same pre-freeze score.

Association between sperm autoantibodies and enhanced embryo implantation rates during in vitro fertilization

Previous investigations have demonstrated the propensity of strong IgA-class sperm autoantibodies to impede fertilization. However, because there has not been a general consensus on this issue, the aim of this retrospective analysis was to focus on the effects of different levels of IgA-class antibodies on each stage of the IVF procedure. This study has confirmed that high level IgA class antibodies significantly reduce fertilization rates but, unexpectedly, also has shown a very significant improvement in embryo implantation rates in patients with weak to moderate antibody levels. Interlaboratory prospective collaborative studies are being planned to test this preliminary observation more stringently.

Effects of recombinant human luteinizing hormone supplementation on ovarian stimulation and the implantation rate in down-regulated women of advanced reproductive age

To evaluate the effects of recombinant human luteinizing hormone (rhLH) supplementation on ovarian stimulation and implantation rate in down-regulated women of advanced reproductive age. Prospective randomized study. University teaching hospital. A total of 120 consecutive normogonadotropic infertile women > or = 35 years old undergoing their first cycle of IVF or intracytoplasmic sperm injection (ICSI) treatment. Ovarian stimulation in a long agonist protocol with a combination of recombinant human follicle-stimulating hormone (rhFSH) and rhLH (group 1, n = 60) starting on day 6 of FSH stimulation until hCG at a daily fixed dose of 150 IU of rhLH, or with rhFSH alone (group 2, n = 60). Ovarian stimulation characteristics, ovum retrieval, and IVF/ICSI outcome. The mean number of intermediate (10-14 mm) and large (> 14- < 18 mm) but not leading (> or = 18 mm) follicles was significantly lower in group 1 on the day of hCG injection. The oocyte yield and maturity as well as the number of oocytes fertilized were significantly higher in group 2 than in group 1. However, the number of patients having embryo transfer (n = 55 in both treatment groups), the number and quality of embryos replaced, the implantation rate (20.6% vs. 21.7%) and clinical pregnancy rates per embryo transfer (44% vs. 45%) were similar in groups 1 and 2. The rhLH supplementation does not increase ovarian response and implantation rates in patients of older reproductive age stimulated with rhFSH under pituitary suppression for assisted reproductive technologies (ARTs).

Oocyte quality does not deteriorate during repeated cycles of ovarian stimulation

Oocyte quality does not deteriorate during repeated cycles of ovarian stimulation

Post-implantation viability does not correlate with implantation rate in patients under 35 years of age

It has been demonstrated that patients with multiple gestations not only have higher implantation rates than patients with singleton gestation, but also have a lower rate of vanishing fetal sacs. Based on these observations the existence of the highly fertile individuals, whose embryos implant with higher efficiency than women with single gestation was postulated. We undertook a study to confirm these findings on a larger sample of patients and further investigate whether this phenomenon holds true for all patient age groups. Retrospective study We retrospectively analyzed 2 groups of IVF-ICSI patients: 1) 528 cycles resulting in multiple pregnancies and 2) 599 cycles resulting in singleton clinical pregnancies, defined as the presence of at least 1 gestational sac at a 5 weeks gestation transvaginal ultrasound. The groups were then subdivided into 3 subgroups: a) < 35 years old; b) 35–37 years old and c) > 37 years old. When the number of viable gestational sacs detected by a subsequent ultrasound exam was lower than the initial one, the number of vanishing embryos was registered. Mann-Whitney test, Fisher's exact test and unpaired t test were used as indicated for statistical analysis. Multiple pregnancies correlated strongly with higher implantation rates. Analyzing all the groups together, there was significant difference for both clinical miscarriage rates in the multiple pregnancy versus the single pregnancy group (10% vs 32.9%, p<0.0001, respectively) and the percentage of lost sacs (24.9% vs 32.9%, p=0.0003, respectively). For young patients (< 35 years old), however, in spite of significant difference in miscarriage rates between multiple vs singleton pregnancy groups (8.3% vs 25.4%, p<0.0001, respectively), interestingly, the percentage of lost sacs was virtually the same (22.9% vs 25.4%, p=0.364, respectively). This was not the case for older patients (group b and c), in whom there was significant difference for both clinical miscarriage rates and percentage of lost sacs between multiple and singleton pregnancies (data not shown). Our data clearly show that, for the younger group, patients with lower implantation rates present the same chance of spontaneous embryo reduction as do patients with high implantation rates. The lower miscarriage rate observed for multiple pregnancies (8.3%) in that group was thus a direct consequence of a higher initial number of implanted embryos. Therefore, intrinsic embryonic factors that could theoretically influence both implantation and post-implantation development potential are not a plausible explanation to our findings. Thus, we must consider that, at least for younger patients, there are other post-implantation factors, whether metabolic, immunological, hormonal or uterine, that certainly influence the development potential of a given embryo.

Does length of ovarian stimulation affect IVF pregnancy and implantation rates?

To determine if day of hCG administration following controlled gonadotropin stimulation affects pregnancy and implantation rates in patients undergoing fresh, non-donor IVF and day 3 embryo transfer. Retrospective analysis of 154 fresh non-donor IVF cycles during a 16 month period. All cycle starts that occurred on a Friday with subsequent day 3 transfer were included in the study. Three groups were compared; transfers occurring on a Thursday or Friday (9 or 10 day med protocol); transfers occurring on a Saturday or Sunday (11 or 12 day med protocol); and transfers occurring on a Monday, Tuesday or Wednesday (13, 14 or 15 day treatment). All retrievals initiated prior to day 9 and after 15 days of drug treatment were excluded from the study. Pregnancy and implantation rates were compared between the groups using Chi Square Analysis. Oocytes were retrieved in HTF (InVitrocare), hyaluronidased after 2 to 3 hours incubation and ICSI'ed following COC removal. Oocytes were placed in IVC-1 (IVC) after ICSI and cultured individually until Day 3. Embryos were placed into CCM (Vitrolife) on the morning of Day 3 for extended culture. The best embryos were identified and laser hatched (Zilos-Hamilton Thorne) prior to transfer. Morphologic assessment occurred on Day 2, 3, 5 and 6. Blastocysts were cryopreserved on Day 5, 6 or 7. All transfers occurred on Day 3 using a Wallace 23cm stylet (Irvine Scientific) and Cook Echotip Catheter (Cook OB/GYN) under abdominal ultrasound guidance and performed by the same physician (RFF). In the 148 cycles analyzed, 352 fresh embryos were AH and transferred (avg. 2.4 embryos/transfer), yielding a clinical implantation rate of 29% and PR of 54.7%. Significant differences in pregnancy and implantation rates were observed between the Sat/Sun and Mon/Tues/Wed transfer groups. The observed differences between groups might suggest that optimally timed drug stimulation regimes could yield significant improvements in IVF pregnancy and implantation rates. Although endocrine and ultrasonographic information are useful in the determination of optimal HCG administration, they may not necessarily reflect appropriate nuclear and cytoplasmic maturational synchrony of the oocytes retrieved. In poor and hyper-responders, abnormally short and long treatment regimes may upset the delicate equilibrium of nuclear and cytoplasmic events within an oocyte, i.e. nuclear mature oocytes with post mature granularity and vacuolation that ultimately results in poor embryo development. An 11 or 12-day ovarian stimulation regime may optimally strike a balance between immature, mature, and post mature nuclear and cytoplasmic events leading to optimized results in the form of better quality embryos. However, inherent patient variables (less stress on weekends, better patient compliance), reduced stress levels amongst clinical and laboratory staff, and practice philosophy cannot be ruled out as important prognostic factors.

Transfer of early-cleaved embryos increases implantation rate in patients undergoing ovarian stimulation and ICSI–embryo transfer

The hypothesis that inspection for early cleavage improves pregnancy rate by aiding selection of the best embryos for transfer was tested in this study. Inspection for early cleavage was performed randomly in women undergoing intracytoplasmic sperm injection (ICSI) cycles. No differences were observed between early cleavage-inspected and uninspected embryos. When the hypothesis that transfer of early-cleaved (EC) embryos yields a higher pregnancy rate than transfer of late-cleaved (LC) embryos was tested using early cleavage-inspected cycles, it was found that transfer of EC embryos resulted in a higher implantation rate than transfer of LC embryos. In transfers for which all embryos were EC (100% EC), transfer of fewer embryos yielded a higher implantation rate compared with LC and uninspected cycles. These results indicate that, when inspected, early cleavage increases the implantation rate in ICSI patients.