IVF Success Rates Research Articles

Trigger of oocyte maturation with low-dose human chorionic gonadotropin (hCG) reduces the risk of ovarian hyperstimulation syndrome (OHSS) and improves IVF outcome

10,000 IU hCG has been routinely used for the induction of oocyte maturation in the IVF treatment, but there is no solid scientific evidence to support whether 10,000 IU hCG is really needed to induce oocyte maturation. In this study, we compared the risk of OHSS development, oocyte maturation rate and IVF success rate in the high-risk patients after 5,000 IU hCG vs 10,000 IU hCG triggers in donor or non-donor IVF cycles.

Accrual of euploid blastocysts after comprehensive chromosome screening (CCS) is a novel strategy to improve transfer outcomes and set expectations in poor prognosis patients

Poor responders have lower per ET delivery rates and higher miscarriage rates than normal responders, perhaps resulting in discontinuation of care. Extensive validation of CCS has demonstrated improved sustained implantation rates (SIR) of euploid embryos, but have principally focused on normal responders. Whether the benefit applies to patients at high risk of poor outcomes has not been evaluated. This study seeks to evaluate IVF success rates in poor prognosis patients using a strategy of extended culture, trophectoderm (TE) biopsy for CCS, vitrification and frozen ET (FET) of euploid blastocysts.

Individualized decision-making in IVF: calculating the chances of pregnancy

Are we able to develop a model to calculate the chances of pregnancy prior to the start of the first IVF cycle as well as after one or more failed cycles? Our prediction model enables the accurate individualized calculation of the probability of an ongoing pregnancy with IVF. To improve counselling, patient selection and clinical decision-making in IVF, a number of prediction models have been developed. These models are of limited use as they were developed before current clinical and laboratory protocols were established. This was a cohort study. The development set included 2621 cycles in 1326 couples who had been treated with IVF or ICSI between January 2001 and July 2009. The validation set included additional data from 515 cycles in 440 couples treated between August 2009 and April 2011. The outcome of interest was an ongoing pregnancy after transfer of fresh or frozen-thawed embryos from the same stimulated IVF cycle. If a couple became pregnant after an IVF/ICSI cycle, the follow-up was at a gestational age of at least 11 weeks. Women treated with IVF or ICSI between January 2001 and April 2011 in a university hospital. IVF/ICSI cycles were excluded in the case of oocyte or embryo donation, surgically retrieved spermatozoa, patients positive for human immunodeficiency virus, modified natural IVF and cycles cancelled owing to poor ovarian stimulation, ovarian hyperstimulation syndrome or other unexpected medical or non-medical reasons. Thirteen variables were included in the final prediction model. For all cycles, these were female age, duration of subfertility, previous ongoing pregnancy, male subfertility, diminished ovarian reserve, endometriosis, basal FSH and number of failed IVF cycles. After the first cycle: fertilization, number of embryos, mean morphological score per Day 3 embryo, presence of 8-cell embryos on Day 3 and presence of morulae on Day 3 were also included. In validation, the model had moderate discriminative capacity (c-statistic 0.68, 95% confidence interval: 0.63-0.73) but calibrated well, with a range from 0.01 to 0.56 in calculated probabilities. In our study, the outcome of interest was ongoing pregnancy. Live birth may have been a more appropriate outcome, although only 1-2% of all ongoing pregnancies result in late miscarriage or stillbirth. The model was based on data from a single centre. The IVF model presented here is the first to calculate the chances of an ongoing pregnancy with IVF, both for the first cycle and after any number of failed cycles. The generalizability of the model to other clinics has to be evaluated more extensively in future studies (geographical validation). Centres with higher or lower success rates could use the model, after recalibration, by adjusting the intercept to reflect the IVF success rates in their centre. This project was funded by the NutsOhra foundation (Grant 1004-179). The NutsOhra foundation had no role in the development of our study, in the collection, analysis and interpretation of data; in writing of the manuscript, and in the decision to submit the manuscript for publication. There were no competing interests.

Impact of gonadotropins on oocyte maturation, fertilisation and developmental competence in vitro

The aim of the present study was to evaluate the dose-dependent effects of gonadotropins, either singly (Bravelle (B), Luveris (L), Menupur (M), Repronex (R), Gonal-F (G), Follism (F) and Norvarel (N)) or in combination (Menupur+Bravelle; Repronext+Bravelle; and Bravelle+Norvarel), on rates of oocyte maturation, fertilisation and early embryo development in vitro in an animal model. Bovine cumulus-oocyte complexes (COCs) were purchased commercially and cultured in TCM-199 with 10% fetal bovine serum supplemented with varying concentrations of gonadotropin (0, 5, 10, 20, 40IU or United States Pharmacopoeia (USP) mL-1) for 24 and 48h according to current IVF clinical stimulation protocols. All gonadotropins enhanced oocyte maturation in vitro in a dose-dependent manner. Individually, Gonal-F (Merck KGaA, Darmstadt, Germany), Follism (Merck Co, Whitehouse Station, NJ, USA) and Repronext (Ferring, Parsippany, NJ, USA) promoted oocyte maturation; in combination, they effectively enhanced COC expansion and increased the maturation competence of MII oocytes. However, high concentrations of gonadotropins may result in maturation arrest. Specific combinations of gonadotropins may change the rate of early embryonic development (8-16-cells) and morula-blastocyst formation. These data provide support for the responsiveness of bovine oocytes to gonadotropins in vitro and the need to consider variations in the relative concentrations and ratio of combinations (FSH/LH or human chorionic gonadotropin) for optimisation of oocyte developmental competence. The results of the present study could be applied to therapeutic clinical stimulation protocols and help improve IVF success rates.

Current trends and progress in clinical applications of oocyte cryopreservation.

To delineate the current trends in the clinical application of oocyte cryopreservation. Although the first live birth from oocyte cryopreservation was reported approximately three decades ago, significant improvement in the clinical application of oocyte cryopreservation took place only over the past decade. On the basis of the available evidence suggesting that success rates with donor oocyte vitrification are similar to that of IVF with fresh donor oocytes, the American Society of Reproductive Medicine has recently stated that oocyte cryopreservation should no longer be considered experimental for medical indications, outlying elective oocyte cryopreservation. Meanwhile, a few surveys on the attitudes toward oocyte cryopreservation revealed that elective use for the postponement of fertility is currently the most common indication for oocyte cryopreservation. Most recently, a randomized controlled trial revealed important evidence on the safety of nondonor oocyte cryopreservation, and confirmed that the clinical success of vitrification is comparable to that of IVF with fresh oocytes. The evidence suggesting similar IVF success rates with both donor and nondonor cryopreserved oocytes compared with fresh oocytes will increase the utilization of elective oocyte cryopreservation. Appropriate counseling of women for oocyte cryopreservation requires the establishment of age-based clinical success rates with cryopreserved oocytes for various indications.

Low oxygen concentrations for embryo culture in assisted reproductive technologies

Background During IVF and ICSI procedures, human preimplantation embryos are cultured in the laboratory. While some laboratories culture in an atmospheric oxygen concentration (20%), others use a lower concentration (5%) as this resembles more closely the oxygen concentration observed in the oviduct and the uterus. Animal studies have shown that atmospheric oxygen concentrations could have a negative impact on embryo quality via reactive oxygen species causing oxidative stress. In humans, it is currently unknown which oxygen concentration provides the best success rates of IVF/ ICSI procedures resulting in the highest birth rate of healthy newborns. This is a summary of a meta-analysis recently published in the Cochrane Library (Bontekoe et al., 2012) evaluating whether embryo culture at low oxygen concentrations improves the treatment outcome when compared with embryo culture at atmospheric oxygen concentrations.

Acute dietary zinc deficiency before conception compromises oocyte epigenetic programming and disrupts embryonic development

Recent findings show that zinc is an important factor necessary for regulating the meiotic cell cycle and ovulation. However, the role of zinc in promoting oocyte quality and developmental potential is not known. Using an in vivo model of acute dietary zinc deficiency, we show that feeding a zinc deficient diet (ZDD) for 3–5 days before ovulation (preconception) dramatically disrupts oocyte chromatin methylation and preimplantation development. There was a dramatic decrease in histone H3K4 trimethylation and global DNA methylation in zinc deficient oocytes. Moreover, there was a 3–20 fold increase in transcript abundance of repetitive elements (Iap, Line1, Sineb1, Sineb2), but a decrease in Gdf9, Zp3 and Figla mRNA. Only 53% and 8% of mature eggs reached the 2-cell stage after IVF in animals receiving a 3 and 5 days ZDD, respectively, while a 5 day ZDD in vivo reduced the proportion of 2-cells to 49%. In vivo fertilized 2-cell embryos cultured in vitro formed fewer (38%) blastocysts compared to control embryos (74%). Likewise, fewer blastocyst and expanded blastocyst were collected from the reproductive tract of zinc deficient animals on day 3.5 of pregnancy. This could be due to a decrease in Igf2 and H19 mRNA in ZDD blastocyst. Supplementation with a methyl donor (SAM) during IVM restored histone H3K4me3 and doubled the IVF success rate from 17% to 43% in oocytes from zinc deficient animals. Thus, the terminal period of oocyte development is extremely sensitive to perturbation in dietary zinc availability.

An update on the role of prokineticins in human reproduction-potential therapeutic implications

Objective: Prokineticin-1 (PROK1) is a recently described protein with a wide range of functions including tissue specific angiogenesis, modulation of inflammatory responses and regulation of haematopoiesis. PROK1 has been found in the steroidogenic organs like ovary, testis, adrenal and specially placenta and they have been found to have a role in development of the olfactory system and GnRH system. The aim was to update the role of PROK1 and PROK2 inhuman reproduction since the review was provided by Maldono-Perez (2007) on the potentials of prokineticins in reproduction. Design: A review of international scientific literature by a search of Pubmed and the authors files was done for citation of articles relevant to prokineticins in reproduction, be it its role in ovary, testis, uterus with special emphasis on implantation, normal pregnancy, in labour, pathophysiological states like tubal pregnancy, pcos, various genital tumours, and cases of isolated hypogonadotropic hypogonadism with mutations with PROK2/ PROKR2 and studies detailing functional mechanisms. Results: In the normal cycle, PROK1 has been found to have important roles in implantation, regulating several genes like COX-2, IL-8, IL-11, CTGF related to implantation. Initially murine studies revealed a critical role of PROK2 pathway on olfactory bulb morphogenesis and GnRH secretion which was accidentally discovered and since then several studies on mutations in PROK2/PROKR2 showed that they underlie some case of KS in humans. Although in mouse heterozygote state is not associated with clinical phenotype, most of human mutations are heterozygous. Conclusions: Role of PROK-1 in the process of implantation, with a deeper understanding of the process success rates in IVF and ART can be improved, besides understanding the pathophysiology of tubal pregnancy. Further presence in ovarian follicles of PROK1 can be used to plan a strategy for treating pcos. Development of antagonism of PROK’S may be a helpful strategy in treating preterm labour.

Multiple Pregnancies After ART and How to Minimize their Occurrence

In the past few decades, the number of multiple pregnancies has increased significantly. Advanced maternal age, use of ovarian stimulation and use of IVF are all responsible for this. A multiple pregnancy carries excess maternal and neonatal risks and is associated with undesired extra health care expenses as well. Up to 1/3 of the pregnancies following IVF are multiple gestations; most being twins. The best way to minimize the risk of twins is to transfer a single embryo only. The majority of the embryos do not implant however and most clinics routinely transfer 2 or even more embryos to maintain high IVF success rates (pregnancy rates). A high success rate despite the transfer of fewer, preferably a single embryo could be maintained if we had better tools to identify the embryo with the highest implantation potential. Current selection criteria based on the cleavage rate and morphology of the embryo are not particularly effective for this. The past decade has seen a lot of research aiming to screen the embryos based on various properties. This review will discuss the perinatal outcome of IVF multiples, available screening tools for embryo selection and the current status of the development of new tools.

Hysteroscopic findings in women with recurrent IVF failures and the effect of correction of hysteroscopic findings on subsequent pregnancy rates

Our aim is to evaluate the incidence of unrecognized uterine abnormalities in cases with recurrent IVF failure by screening office hysteroscopy (OH), and impacts of treatment of hysteroscopic findings on the success rate of IVF. The retrospective and descriptive study was conducted at assisted reproduction unit in a tertiary medical center. One hundred and fifty-seven patients with a history of recurrent IVF failures underwent hysteroscopy between May 2009 and March 2012. Hysteroscopy (diagnostic or operative, as appropriate) was performed to evaluate the endometrial cavity in patients with two or more IVF failures and Incidence of abnormal hysteroscopic findings and the clinical pregnancy rate (CPR) in subsequent IVF cycles were assessed. In all, 44.9 % of the patients included in this study had abnormal hysteroscopic findings and 75 women (48.1 %) became pregnant following hysteroscopy. Of these pregnancies, 36 occurred in women with corrected endometrial pathology, the majority of which was identified as endometrial polyps. Implantation rate and clinical pregnancy rate were statistically significant increased after polipectomy. Abnormal findings on hysteroscopy are significantly higher in patients with previous ART failure and hysteroscopy could be seen as a positive prognostic factor for achieving pregnancy in subsequent IVF procedure in women with a history of RIF.

Sequential comprehensive chromosome analysis on polar bodies, blastomeres and trophoblast: insights into female meiotic errors and chromosomal segregation in the preimplantation window of embryo development

What is the optimal stage from oocyte through preimplantation embryo development for biopsy and preimplantation genetic screening (PGS) to detect abnormal chromosome segregation patterns in eggs or embryos from advanced maternal age (AMA) patients? Testing at the polar body (PB) stage was the least accurate mainly due to the high incidence of post-zygotic events. This suggests that postponing the time of biopsy to the blastocyst stage of preimplantation embryo development may provide the most reliable results for PGS. In the PGS field there is an ongoing debate about the optimal biopsy stage for PGS. This is a result of the lack of understanding of how aneuploidy arises in the human embryo. To date, most of the cytogenetic data obtained during PGS investigations have been derived through the analysis of cells at isolated points in the preimplantation window, thus potentially missing critical information on chromosomal segregation. Understanding the chromosome segregation patterns during preimplantation development holds the potential to significantly increase the success rates of IVF. In this study, a sequential comprehensive chromosome analysis of both the PBs and the corresponding embryos at both the cleavage and the blastocyst stages is presented. This is a prospective longitudinal cohort study performed between October 2009 and August 2011 involving 9 infertile couples and 21 sets of complete comprehensive chromosomal screening data, including PB1, PB2, corresponding blastomeres and trophectoderm (TE) samples. Infertile couples undergoing IVF cycles with PGS where the female partner was older than 40 years and with a good response to controlled ovarian stimulation (>10 MII oocytes retrieved) were enrolled into the study. The exclusion criteria were (i) patients presenting with abnormal karyotype; (ii) specific ovarian pathologies including polycystic ovary syndrome, endometriosis grade III or higher and premature ovarian failure and (iii) severe male factor infertility (motile sperm count of <500 000/ml after preparation of a fresh ejaculate). The PBs, blastomere and TE samples were sequentially biopsied and analyzed by array comparative genomic hybridization (aCGH). The analysis of chromosome segregation patterns was performed to infer the origin of aneuploidy and to investigate the diagnostic accuracy of both PB and cleavage-stage PGS strategies. Twenty-one sets of complete data (PB1/PB2/blastomere/TE) including 84 aCGH experiments showed a pattern of multiple meiotic errors typically caused by sister chromatid separation errors and predominantly arising in the second meiotic division. Twenty-two of the 24 (91.7%) errors in the first meiotic division arose as a consequence of premature sister chromatid predivision. In half of these cases, the second meiotic division resulted in a balancing chromosome segregation event producing a normal female complement for that chromosome in the resulting embryo. Overall, only 62 out of 78 (79.5%) of the abnormal meiotic segregations had errors in the either one or both PBs consistent with the aneuploidies observed in their resulting embryos. Ten of the 21 (47.6%) embryos had aneuploidies other than female meiotic-derived ones, most of which detected on Day 3 and confirmed on Day 5 or 6 of embryo development (20/25) with chromosomal loss being three times more frequent than gains. Notably, as high as 20% of female-derived aneuploidies detected on PBs and confirmed on Day 3 were rescued at the blastocyst stage, mainly as a result of diploidization of trisomic chromosomes. On a per chromosome basis, the sensitivity in predicting blastocyst chromosomal complement was significantly lower for PB approach, 61.7%, compared with blastomeres analysis, 86.4% (P < 0.01). The study was limited to the analysis of oocytes and embryos from AMA patients. Thus, these findings apply only to this patient group. Comparisons with other patient populations including patients with different indications for PGS should be made in future research. In addition, higher resolution and/or more accurate chromosomal screening tests could be used in future studies to corroborate the current findings. These findings provide critical insights into the mechanisms causing errors during female meiosis and the preimplantation embryo development period to improve the design and treatment outcome of PGS.

Ultrasound diagnosed adenomyosis has a negative impact on successful implantation following GnRH antagonist IVF treatment

Does the presence of ultrasound diagnosed adenomyosis interfere with successful implantation in patients undergoing IVF treatment with GnRH antagonist ovarian stimulation? The presence of ultrasound diagnosed adenomyosis was associated with a significant reduction in successful implantation of good quality embryos in patients undergoing GnRH antagonist stimulation for IVF treatment (viable clinical pregnancy rate 23.6% versus 44.6%, P= 0.017). There is currently no consensus regarding the impact of adenomyosis on implantation potential. Although some studies have identified alterations in the endometrial milieu in adenomyosis patients that may impact implantation, several papers have reported no associated reproductive deficit. However, these pregnancy outcome studies have primarily investigated patients undergoing long down-regulation IVF protocols, where low levels of serum estrogen (before commencing the ovarian stimulation) may inactivate the adenomyosis and potentially negate its effect on implantation. Given that the majority of fertility clinics are now moving towards the more 'patient-friendly' antagonist protocol, where patients are not placed in a hypo-estrogen state before commencing ovarian stimulation, the question of whether adenomyosis has an impact on IVF success rates in GnRH antagonist-stimulated IVF treatment needs to be examined. This is a retrospective cohort study of 748 patients who, between April 2010 and March 2012, underwent a screening transvaginal ultrasound to identify possible pelvic pathology before commencing their IVF treatment. From this screening group, 213 patients were eligible to be included in the study as they had no obvious underlying uterine or embryonic factors that could have interfered with successful implantation (aged ≤39 years, good quality Day 4/5 embryo for single-embryo transfer, no uterine fibroids/hydrosalpinx or endometrial polyps). There were 213 patients in a private IVF unit eligible to be included in the study, with 38 patients (17.84%) having ultrasound diagnosed adenomyosis and 175 patients having no adenomyosis on the scan. Only the first treatment cycle for each patient was included. The adenomyosis group had a viable clinical pregnancy rate of 23.6% compared with 44.6% in the non-adenomyosis group (P =0.017). However, the median maternal age and duration of infertility of the adenomyosis group was 2 years older and 4 months greater, respectively, than that of the non-adenomyosis group. A logistic regression analysis was performed to account for these differences between the two groups, with the adjusted results still showing a statistically significant decline in viable pregnancy rate in the adenomyosis group (OR = 0.408, CI = 0.181-0.922, P =0.031 when adjusting for maternal age; OR = 0.417, CI = 0.175-0.989, P =0.047 when adjusting for duration of infertility) Given the retrospective nature of this study, there is risk of bias. This risk was minimized by having subjective variables such as embryo quality assessed by individuals not involved in the study, while strictly applying the pre-determined inclusion/exclusion criteria to all study participants. Furthermore, it is acknowledged that ultrasound is not a perfect test for the diagnosis of adenomyosis and, therefore, may underestimate the incidence of adenomyosis by misclassifying some patients with mild adenomyosis as not affected. The results of this study should be representative of outcomes for any patient undergoing a GnRH antagonist ovarian stimulation cycle for IVF since standard IVF treatment protocols were used. MSD Australia have provided us with a small amount of funding to cover our costs (including a travel grant for Dr Thalluri to present this work at a conference).

Impact of number of oocytes thawed and the day of embryo transfer on ivf success rates with vitrified donor oocytes: an individual patient data meta-analysis from 508 thaw cycles

Impact of number of oocytes thawed and the day of embryo transfer on ivf success rates with vitrified donor oocytes: an individual patient data meta-analysis from 508 thaw cycles

Increasing FSH dosage beyond physiological range fails to upregulate estradiol production by granulosa cells in vitro

It is generally accepted that IVF success rate depends on the number of oocytes retrieved, and thus patients are categorized as poor or good responders. In order to achieve maximal ovarian stimulation, patients receive large doses of exogenous FSH. However, in certain patients high FSH may compromise the quality of the oocytes produced. In granulosa cells, the main downstream effect of FSH signaling is the upregulation of the aromatase gene (CYP19) and estradiol (E2) production. We are particularly interested to detect whether in vitro there is a sustained dose-response to higher doses FSH or if the response reaches a plateau or even diminishes.

Characterizing the influence of vitamin D levels on IVF outcomes

Vitamin D plays a role in reproductive capacity. Recently, several investigators have demonstrated higher IVF pregnancy rates in vitamin D replete women. The objective of this study was to validate these findings and to further elucidate the role of vitamin D in reproduction among a diverse group of women. This was a retrospective cohort study in an academic tertiary care center of 188 infertile women undergoing IVF. Serum levels of vitamin D (25OH-D) were measured in previously frozen serum samples. The main outcome measure was clinical pregnancy, defined as sonographic presence of a heartbeat following IVF. The relationship between vitamin D status and pregnancy rates differed by race (P < 0.01). Among non-Hispanic whites, pregnancy rates declined with progressively lower levels of vitamin D, while in Asians, the reverse was true. Adjusting for age and number and quality of embryos transferred among non-Hispanic whites, the odds of pregnancy were four times higher in vitamin D replete versus deficient patients. Live birth rates mirrored pregnancy rates. Vitamin D status was not associated with ovarian stimulation parameters or with markers of embryo quality. Vitamin D deficiency is associated with lower pregnancy rates in non-Hispanic whites, but not in Asians, possibly due to their lower IVF success rates. Vitamin D deficiency was not correlated with ovarian stimulation parameters or with markers of embryo quality, suggesting its effect may be mediated through the endometrium.

Die‐Off Ratio Correlates with IncreasedTNF‐α:IL‐10 Ratio and DecreasedIVFSuccess Rates Correctable withHumira

Human embryos develop at varying rates in culture, with only a fraction of the eggs retrieved developing to 'transfer quality' embryos. We investigated whether the ratios between the number of eggs retrieved or the number of pro-nucleate embryos formed and the number of Day 3 embryos with ≥5 cells [oocyte 'die-off ratios' (DOR)] were correlated with the chance of IVF success, independent of other factors such as embryo grade score and patient's age. We also investigated what factors may be correlated with this ratio. 608 IVF fresh cycles in subfertile women were retrospectively evaluated. For each cycle, an oocyte DOR number was calculated as follows: Number of eggs retrieved divided by the number of Day 3 embryos with ≥5 cells. This number was correlated with the subsequent success rates for the index cycles. A 'post-fertilization' or 'embryo' die-off ratio (EDOR; the number of pro-nucleate embryos/the number of day 3 embryos ≥5 cells) was also calculated. The oocyte DOR showed a reverse linear correlation with IVF live birth rate. Live birth rate = (-5.75; DOR) +71.6 (with DOR > 1; P ≤ 0.005; R = -0.87). In addition, the oocyte DOR continued to show an inverse correlation with success rates even when embryo quality and patient's age were held constant. The post-fertilization or EDOR also continued to show a statistically significant negative correlation with live birth rate (R = -0.91; P ≤ 0.01). The preconception TNF-α:IL-10 ratio, an immmunologic marker (drawn 3.3 ± 2.6 months preconception), was more strongly correlated with high oocyte DOR than either age or number of eggs retrieved (P = 0.04, 0.14, 0.72, respectively). When anti-TNF-α therapy (Humira) was given preconception, the oocyte DOR's negative effect on live birth rate was nearly eliminated (correlation coefficient between oocyte DOR and live birth rate: cycles using no Humira, R = -0.90, P ≤ 0.006; cycles using Humira, R = 0.25, P ≤ 0.55). In subfertile women undergoing IVF, the oocyte DOR may help predict IVF success rates. This factor may offer an additional tool to help improve implantation rate, clinical pregnancy rate, live birth rate, and live birth rate per embryo transferred for an upcoming IVF cycle. Although many mechanisms may contribute to the oocyte DOR's negative effect on IVF success rates, its correlation with elevated preconception TNF-α:IL-10 ratio and correction with Humira suggests a strong immunologic component that may be treatable.

United Kingdom - Cardiff and Oxford research aims to improve IVF success rates

United Kingdom - Cardiff and Oxford research aims to improve IVF success rates

Recurrent IVF failure: other factors

IVF failure is a problem for a couple in the singular but can be a tragedy in the plural. Recurrent IVF failure has multiple known causes but many which are not routinely considered as part of the posttreatment analysis. The reason is there are several causes associated with lifestyle and other causes related to pre-existing conditions that have only a tenuous or no apparent connection to fertility. This article examines the impact of obesity, cigarette smoke, uterine anatomy, body mass index, thyroid dysfunction, immune factors, the hereditary and acquired thrombophilias, and embryo transfer technique on recurrent IVF failure.

In vitro fertilization is a successful treatment in endometriosis-associated infertility

To assess success rates of IVF and intracytoplasmic sperm injection in women with various stages of endometriosis. Retrospective cohort study. Reproductive medicine unit in a university hospital. Infertile women (n = 2,245) with various stages of endometriosis or tubal factor infertility. IVF or intracytoplasmic sperm injection. Dose of FSH, number of oocytes retrieved, fertilization rate, implantation rate, pregnancy rate (PR), live birth/ongoing PR. Women with endometriosis had similar pregnancy and live birth/ongoing PR as did women with tubal factor infertility, but the American Society for Reproductive Medicine (ASRM) stage I and II endometriosis patients had a lower fertilization rate, and stage III and IV patients required more FSH and had fewer oocytes retrieved. Splitting the stage III and IV groups into patients with and without endometriomas showed that the endometrioma group required more FSH and had a significantly lower pregnancy and live birth/ongoing PR. With the exception of patients with endometrioma, infertile women with various stages of endometriosis have the same success rates with IVF and intracytoplasmic sperm injection as patients with tubal factor. This contrasts with the systematic review on which the European Society of Human Reproduction and Embryology bases its recommendations.

Endometrial receptivity defects during IVF cycles with and without letrozole.

Our aim was to study ways to improve IVF success rates in women with suspected endometrial receptivity defects. We conducted a retrospective cohort study examining the effect of letrozole (aromatase inhibitor) on integrin expression as a marker of endometrial receptivity. We compared IVF outcomes in 97 infertile women who had undergone ανβ3 integrin assessment by immunohistochemistry in mid-luteal endometrial biopsies. Of 79 women undergoing standard IVF, 29 (36.7%) lacked normal integrin expression. Eighteen other women with low integrin were studied after receiving letrozole during early IVF stimulation. An independent set of ανβ3 integrin-negative patients (n = 15) who had undergone repeat endometrial biopsy for integrin testing while taking letrozole were re-evaluated. Clinical pregnancy and delivery rates were higher in women with normal ανβ3 integrin expression compared with those who were integrin negative [20/50 (40%) versus 4/29 (13.8%); P = 0.02 and 19/50 (38%) versus 2/29 (7%); P < 0.01, respectively]. In 18 women who received letrozole early in IVF, 11 conceived (61.1%; P < 0.001) compared with integrin-negative patients who did not receive letrozole. In integrin-negative women who were rebiopsied on letrozole, 66.7% reverted to normal integrin expression. Positive endometrial aromatase immunostaining using a polyclonal antibody was a common finding in infertile patients compared with controls. Lack of endometrial ανβ3 integrin expression is associated with a poor prognosis for IVF that might be improved with letrozole co-treatment. Prospective studies are needed to confirm and extend these findings but the data suggest that aromatase expression may contribute to implantation failure in some women.