Minimal ovarian stimulation (mini-IVF) for IVF utilizing vitrification and cryopreserved embryo transfer

Effect of chronological age of patients with diminished ovarian reserve on in vitro fertilization outcome

The aim of this study was to evaluate the effect of chronological age on the in vitro fertilization (IVF) outcome in patients with diminished ovarian reserve (DOR). Four hundred and forty-nine women with DOR who underwent IVF cycles were enrolled in the study. There were only 296 patients who obtained available embryos. The patients with no available embryos had a significantly lower antral follicle count (AFC) and higher basal follicle-stimulating hormone (FSH) concentrations than those of women with available embryos, but chronological age in the two groups was comparable. However, patients aged >40 obtained a significantly lower ongoing pregnancy rate (OPR) than patients aged 35 - 40 or <35 (6.38% versus 26.15% versus 28.17%, respectively). Multivariate analysis also showed that chronological age was the only parameter associated with clinical results. It implied that patients with DOR still have reasonable chances of achieving a pregnancy, but their prognosis is significantly affected by chronological age.Impact statementWhat is already known on this subject? Diminished ovarian reserve DOR is a disappointing issue in reproductive medicine. Ovarian reserve, which represents ovarian biological age, is closely related to chronological age. However, ovarian biological age does not always match chronological age. Some studies suggest that biological age is more important than chronological age in predicting the outcome of in vitro fertilization (IVF). However, these conclusions are controversial.What do the results of this study add? We found DOR patients with no available embryos had significantly lower antral follicle count (AFC) and higher follicle-stimulating hormone (FSH) concentrations than that of patients with available embryos, but chronological age in the two groups was comparable. However, for patients with available embryos, chronological age is the only parameter associated with clinical results. For women aged >40 with DOR, chronological age was significantly negatively associated with clinical results.What are the implications of these findings for clinical practice and/or further research? Patients with DOR can obtain available embryos and still have a reasonable chance of becoming pregnant, but their prognosis is greatly affected by chronological age. Therefore, patients with DOR should seek medical help for pregnancy as soon as possible. When DOR patients over the age of 40 plan IVF treatment, the cost-effectiveness of healthcare should be considered.

Time associations between U.S. birth rates and add-Ons to IVF practice between 2005-2016

Until 2010, the National Assisted Reproductive Technology Surveillance System (NASS) report, published annually by the Center for Disease Control and Prevention (CDC), demonstrated almost constantly improving live birth rates following fresh non-donor (fnd) in vitro fertilization (IVF) cycles. Almost unnoticed by profession and public, by 2016 they, however, reached lows not seen since 1996-1997. We here attempted to understand underlying causes for this decline. This study used publicly available IVF outcome data, reported by the CDC annually under Congressional mandate, involving over 90% of U.S. IVF centers and over 95% of U.S. IVF cycles. Years 2005, 2010, 2015 and 2016 served as index years, representing respectively, 27,047, 30,425, 21,771 and 19,137 live births in fnd IVF cycles. Concomitantly, the study associated timelines for introduction of new add-ons to IVF practice with changes in outcomes of fnd IVF cycles. Median female age remained at 36.0 years during the study period and center participation was surprisingly stable, thereby confirming reasonable phenotype stability. Main outcome measures were associations of specific IVF practice changes with declines in live IVF birth rates. Time associations were observed with increased utilization of "all-freeze" cycles (embryo banking), mild ovarian stimulation protocols, preimplantation genetic testing for aneuploidy (PGT-A) and increasing utilization of elective single embryo transfer (eSET). Among all add-ons, PGT-A, likely, affected fndIVF most profoundly. Though associations cannot denote causation, they can be hypothesis-generating. Here presented time-associations are compelling, though some of observed pregnancy and live birth loss may have been compensated by increases in frozen-thawed cycles and consequential pregnancies and live births not shown here. Pregnancies in frozen-thawed cycles, however, represent additional treatment cycles, time delays and additional costs. IVF live birth rates not seen since 1996-1997, and a likely continuous downward trend in U.S. IVF outcomes, therefore, mandate a reversal of current outcome trends, whatever ultimately the causes.

Luteinizing hormone-independent rise of progesterone as the physiological trigger of the ovulatory gonadotropins surge in the human

The current ovarian cycle paradigm postulates that ovulation is triggered by a critically sustained elevation of estradiol. However, an in-depth look into the published data reveals considerable uncertainty about the relative roles of progesterone and estradiol in the ovulation process.This review provides compelling evidences that the role of estradiol in ovulation has been misinterpreted and that the true physiological trigger of ovulation is a luteinizing hormone-independent preovulatory progesterone surge in the circulation to approximately 0.5 ng/mL. Furthermore, the current work reconciles the ability of progesterone to trigger ovulation, with its well-established ability to block ovulation during pregnancy, or when administered in the form of a synthetic progestin in birth control formulations and with experimental data that estradiol benzoate triggers ovulation in the complete absence of progesterone.

predicting and improving the probability of live birth for women undergoing frozen-thawed embryo transfer: a data-driven estimation and simulation model

BACKGROUND AND OBJECTIVE

Frozen-thawed embryo transfer (FET) is now widely used for the treatment of infertility. For many couples and clinicians, concerns over the probability and how to increase the chance of a successful birth are very common. Currently, there is not a single model to predict the live birth outcomes for FET. To estimate the probability of live birth (PLB) in FET and to provide advice on potential treatment options by a data-driven predictive (DDP) model.

METHODS

2,189 FET cycles from Jan 2012 to Dec 2015 were recruited in a single center. 815 cycles of FET outcomes were live births and 1,374 cycles of FET outcomes failed. To verify the consistency of the DDP model, we carried out 10-fold cross-validation, and the mean and standard deviation of the accuracy were measured. Moreover, the performance of this model was evaluated by the mean and standard deviation of receiver operating characteristic curve and area under the curve (AUC).

RESULTS

Nine dominant factors, including age, BMI, HOMA-IR, basal follicle stimulating hormone, basal luteinizing hormone, basal estradiol, endometrial thickness, the number of embryo transfers and the total number of embryos, were automatically extracted from 28 candidate factors. The accuracy of our prediction model is 76.9%±1.6%, and the AUC is 0.83. Then, the PLB is estimated by the random forest algorithm. On this basis, the DDP model can comprehensively traverse and dynamically visualize the impact of several factors on live birth outcomes. Finally, optimal suggestions for the treatment of patients before FET are attempted to be made by the genetic algorithm.

CONCLUSION

The DDP model can not only provide satisfactory performance for predicting live birth outcomes in FET but also offer a visual estimation and simulation tool for clinicians to make treatment plans.

Use of Clomiphene Citrate in minimal stimulation in vitro fertilization negatively impacts endometrial thickness: an argument for a freeze-all approach

Objective

Minimal stimulation IVF is a treatment option that uses clomiphene citrate (CC). We sought to evaluate how CC impacts endometrial thickness during minimal stimulation IVF cycles.

Methods

We retrospectively analyzed a cohort of 230 cycles in 119 poor ovarian response patients. The IVF cycles were studied in three groups: 130 minimal stimulation cycles, 29 mild stimulation cycles, and 30 conventional high dose gonadotropin releasing hormone (GnRH) antagonist cycles. Thirty-three minimal stimulation IVF patients had 41 frozen embryo transfers (FET) which allowed us to study whether the CC effects were prolonged.

Results

Endometrial thickness in the minimal stimulation group was significantly lower than the mild and conventional stimulation groups (7.3±2.2mm versus 11.4±3.3mm versus 12.9±3.8mm, respectively, p<0.0001). In patients who underwent minimal stimulation IVF followed by FET, significantly thicker endometrial thickness was achieved during their FET cycles as compared to their minimal stimulation cycles (7.95±2.1mm versus 10.3±1.8mm, p<0.0001).

Conclusion

We concluded that endometrial thickness is impacted during minimal stimulation IVF cycles. Since negative effects on endometrial thickness are not observed in the patients’ subsequent FET cycle, a freeze-all approach is justified to mitigate adverse endometrial effects of CC in minimal stimulation IVF cycles.

Conventional versus minimal ovarian stimulation: an intra-patient comparison of ovarian response in poor-responder women according to Bologna Criteria

RESEARCH QUESTION

Is minimal ovarian stimulation (MOS) as effective as conventional ovarian stimulation (COS) in ovarian response and embryo quality in the same 46 poor-responder patients according to the Bologna criteria?

DESIGN

An intra-patient comparison of patients undergoing both protocols. Ovaries were stimulated with either a gonadotrophin-releasing hormone antagonist protocol and a combination of recombinant FSH and highly purified human menotrophin (HP-HMG) daily (COS), or with the use of clomiphene citrate 50 mg daily and 150 IU of HP-HMG or recombinant FSH every other day from simulation day 4 (MOS).

RESULTS

After MOS, significantly more good-quality embryos (1.0 ± 1.2 versus 0.3 ± 0.6) (P = 0.002), oocytes (3.2 ± 1.9 versus 2.0 ± 1.8) (P = 0.002), and mature (metaphase II) oocytes (2.6 ± 1.7 versus 1.6 ± 1.7) (P = 0.001) were obtained. In COS cycles, a significantly higher total gonadotrophin dose was needed per good-quality embryo (+2194 IU; 95% CI 618 to 3170).

CONCLUSIONS

In poor responder patients, MOS is a good alternative when COS has failed, or even as a first-line treatment. It offered a significantly greater number of good-quality embryos as well as a higher number of oocytes, using significantly lower doses of gonadotrophins per oocyte and embryo obtained.

Effectiveness of mild ovarian stimulation versus GnRH agonist protocol in women undergoing assisted reproductive technology: a meta-analysis

OBJECTIVE

our meta-analysis was conducted to evaluate the effectiveness of the mild ovulation induction protocol using CC/gonadotropin/GnRH antagonist compared to the conventional GnRH agonist protocol in women undergoing ART.

METHOD

Six electronic databases were searched from their date of establishment until August 2016. Outcomes in our analysis were calculated in terms of relative risk (RR) and weighted mean differences (WMD) and standard mean differences (SMD) with 95% confidence intervals (CI) using random effect models or fixed effect models.

RESULTS

Six prospective controlled clinical trials with 1543 women comparing the clinical impacts of the two protocols were included. The synthesized results suggested a significant reduction in the quantity of gonadotropins (SMD: -1.96, 95% CI: -2.28 to 1.64, I² = 78.5%), the incidence of OHSS (RR: 0.16, 95% CI 0.03-0.86, I² = 0%) and an increase in the cycle cancelation rate (RR: 1.46, 95% CI 1.05-2.03, I² = 89.4%). While no evidence of statistically significant differences between the groups existed in the other clinical outcomes.

CONCLUSION

This study suggested that the probable benefits of the mild protocol, including its less costs and safer process without reducing the overall IVF treatment success rates, seemed to make it a better treatment option. Larger sample prospective trials evaluating live birth, clinical pregnancy, OHSS, multiple pregnancy incidence and so on were desired to establish.

Efficiency of metaphase II oocytes following minimal/mild ovarian stimulation in vitro fertilization

BACKGROUND

An inverse relationship between oocyte efficiency and ovarian response was reported in conventional IVF. The purpose of this study was to report metaphase II (MII) oocyte efficiency according to oocyte yield in minimal/mild stimulation IVF (mIVF) and to assess whether oocyte yield affects live birth rate (LBR).

METHODS

Infertile women (n = 264) aged < 39 years old with normal ovarian reserve who had mIVF were recruited. All participants received the same protocol for ovarian stimulation. All the embryos were cultured to the blastocyst stage and vitrified using a freeze-all approach. This was followed by a single blastocyst transferred to each participant in subsequent cycles over a 6-month period. Ovarian response was categorized according to the number of MII oocyte yield (low: 1-2, intermediate: 3-6 and high ≥ 7 MII oocytes). MII oocyte utilization rate was calculated as the number of live births divided by the number of MII oocytes produced after only one oocyte retrieval and subsequent transfers of vitrified/warmed blastocysts. The main outcome measure was cumulative LBR over a 6-month period.

RESULTS

Among all the participants, 1173 total retrieved oocytes (4.4 ± 0.2 per patient) resulted in 1019 (3.9 ± 0.2 per patient) total MII oocytes, a clinical pregnancy rate of 48.1 % and a LBR of 41.2 %. Oocyte utilization rate was inversely related to ovarian response where it was 30.3 % in the "low" vs. 9.3 % in the "intermediate" vs. 4.3 % in the "high" oocyte yield groups (p < 0.05). Implantation rate significantly dropped as the number of MII oocytes increased and was highest in the "low" oocyte yield group (p < 0.0001). Cumulative LBR was similar in "low," "intermediate," and "high" oocyte yield groups (p > 0.05). The number of MII oocytes had poor sensitivity and specificity for predicting a live birth.

CONCLUSION

These data extend the hypothesis of oocyte efficiency reported in conventional IVF protocols to mIVF protocols.

TRIAL REGISTRATION

Registration clinicaltrials.gov: NCT00799929.

Systematic review of worldwide trends in assisted reproductive technology 2004-2013

BACKGROUND

Assisted Reproductive Technology (ART) has undergone considerable changes over the last decade, with consequences on ART outcomes in different regions of the world being unknown.

METHODS

We conducted a systematic review of published national and regional ART registry data to assess how changes in clinical practice between 2004 and 2013 have impacted outcomes in Australia and New Zealand, Canada, Continental Europe, the United Kingdom (U.K.), Japan, Latin America, and the United States (U.S.). The data reflect 7,079,145 total ART cycles utilizing both fresh and previously cryopreserved embryos from autologous oocytes that resulted in 1,454,724 live births. This review focused on the following measures: ART cycle volume, use of cryopreserved embryos, single embryo transfer (SET), live birth rates in fresh and frozen-thawed cycles, and perinatal outcomes in recent years.

RESULTS

SETs and utilization of frozen-thawed embryos increased worldwide over the study period. In 2012 SET utilization in all ART cycles was highest in Japan and Australia/New Zealand (82.6% and 76.3% respectively) and lowest in Latin America (16.0%). While gradual improvements in live birth rates were observed in most regions, some demonstrated declines. By 2012-2013, fresh cycle live birth rates were highest in the U.S. (29%) and lowest in Japan (5%). In Japan, the observed decline in fresh cycle live birth rate coincided with transition to minimal stimulation protocols, transfer of frozen-thawed rather than fresh embryos, and implementation of an SET policy. Similarly, implementation of an SET policy in parts of Canada was followed by a decline in fresh cycle live birth rate. Increasing live birth rates in frozen-thawed embryo cycles, seen all over the world, partially compensated for declines in fresh ART cycles. During 2012-2013 Australia/New Zealand and Japan reported the lowest multiple delivery rates of 5.6 and 4% respectively while the US had the highest of 27%. In recent years, preterm delivery rates in all regions ranged between 9.0 to 16.6% for singletons, 53.9 to 67.3% for twins, and 91.4 to 100% for triplets and higher order multiples. Inconsistencies in the way perinatal outcome data are presented by various registries, made comparison between regions difficult.

CONCLUSIONS

ART practices are characterized by outcome differences between regions. International consensus on the definition of ART success, which accounts for perinatal outcomes, may help to standardize worldwide ART practice and improve outcomes.

TRIAL REGISTRATION

PROSPERO ( CRD42016033011 ).

Getting Older Women Pregnant: Contemporary Thoughts

For women of advanced age with abnormally increased FSH levels, standardized hormonal stimulation often represents a cost-intensive procedure with a low success rate. It is well established now that with mild ovarian stimulation, there is a greater percentage of good-quality eggs (although a smaller number) than with higher-dose conventional stimulation. Mild stimulation protocols reduce the mean number of days of stimulation, the total amount of gonadotropins used and the mean number of oocytes retrieved. The proportion of high-quality and euploid embryos seems to be higher compared with conventional stimulation protocols, and the pregnancy rate per embryo transfer is comparable. Moreover, the reduced costs, the better tolerability for patients and the less time needed to complete an IVF cycle make mild approaches clinically and cost-effective over a given period of time. The low number of embryos available for transfer poses a great challenge in the management of older women going in for IVF. A potential management of these older women is to create a sufficient pool of embryos by accumulating vitrified good-grade embryos over several minimal stimulation and natural cycles. At the end of the accumulation process, these embryos can be subjected to a preimplantation genetic screening using next-generation sequencing and then the pool would have only chromosomal normal embryos with maximal chances of implantation. This would potentially make the chances of success for older women similar to normal responders. This management, however, is unthinkable without an outstanding vitrification program. The option of accumulating embryos has become a promising reality with the advent of vitrification technologies.

Resurgence of Minimal Stimulation In Vitro Fertilization with A Protocol Consisting of Gonadotropin Releasing Hormone-Agonist Trigger and Vitrified-Thawed Embryo Transfer

Minimal stimulation in vitro fertilization (mini-IVF) consists of a gentle controlled ovarian stimulation that aims to produce a maximum of five to six oocytes. There is a misbelief that mini-IVF severely compromises pregnancy and live birth rates. An appraisal of the literature pertaining to studies on mini-IVF protocols was performed. The advantages of minimal stimulation protocols are reported here with a focus on the use of clomiphene citrate (CC), gonadotropin releasing hormone (GnRH) ago- nist trigger for oocyte maturation, and freeze-all embryo strategy. Literature review and the author’s own center data suggest that minimal ovarian stimulation protocols with GnRH agonist trigger and freeze-all embryo strategy along with single embryo transfer produce a reasonable clinical pregnancy and live birth rates in both good and poor responders. Additionally, mini-IVF offers numerous advantages such as: i. Reduction in cost and stress with fewer office visits, needle sticks, and ultrasounds, and ii. Reduction in the incidence of ovarian hyperstimulation syndrome (OHSS). Mini-IVF is re-emerging as a solution for some of the problems associated with conventional IVF, such as OHSS, cost, and patient discomfort.

Shortened equilibration time can compromise clinical outcomes in human embryo vitrification

Vitrification is an important way to cryopreserve human embryos and the recommended time of embryo exposure to the vitrification solution is 1 min. However, practically speaking, the duration of embryos exposure to equilibration solution can vary from 5 to 15 min. The purpose of this study was to investigate the effect of different equilibration times on the outcomes of frozen-thawed embryo transfer cycles. The data were collected from our medical records from January 2012 to June 2013 and a total of 517 cycles were included. These cycles were divided into four groups according to the equilibration time: (i) 5-6 min; (ii) 7-8 min; (iii) 9-10 min and (iv) 11-12 min. The results show that there were no differences in terms of survival rate and fully intact embryo rate among the four groups. However, lower clinical pregnancy, embryo implantation and live birth rates were observed in the 5-6 min exposure group (54.6%, 31.9% and 48.2%, respectively) compared with the three other groups. The corresponding rates in the 9-10 min group (73.5%, 47.6% and 64.7%) were the highest. This study indicated that different equilibration times influenced the clinical outcomes of human embryo vitrification and vitrification with shortened equilibration time compromised the clinical outcomes. Appropriate prolongation of the equilibrium time would probably improve the clinical outcomes.

Time-lapse variables and embryo gender: a retrospective analysis of 81 live births obtained following minimal stimulation and single embryo transfer

PURPOSE

The purpose of this study was to determine which morphokinetic variables are related to embryo gender in a cohort of consecutive live births obtained through single blastocyst transfer following mild ovarian stimulation.

METHODS

Eighty-one live births (49 % of them females) from successfully treated, consecutive infertile patients (maternal age 36.9 ± 3.8 years, range 28-46) who underwent minimal ovarian stimulation, prolonged embryo culture in a time-lapse monitoring (TLM) incubator and elective single blastocyst transfers during 2012-2014. Early (PNf, t2-t9, cc2a, b, s2, s3) and late (tM, tSB, tfullB, texpB1, and texpB2) morphokinetic variables were scored according to published consensus criteria and were normalized to the time of pronuclear fading. For each variable, the ranges with the highest proportion of female embryos (optimal range) were determined by detailed examination of histograms.

RESULTS

Female embryo gender was associated both with late cleavage (t8), morula (tM), and blastocyst stage morphokinetic variables. The strongest associations (adjusted ORs, 7.0-7.8) were found for late, expanded stage blastocyst parameters; tfullB, texpB1, and texpB2. The proportion of female embryos was 69-71 and 25-26 % inside and outside of the optimal ranges, respectively. This allowed to predict 74-78 % of them, increasing their proportion by 57 % compared to the average.

CONCLUSIONS

Although the sample size of our cohort was limited, our findings suggest that several expanded blastocyst stage morphokinetic parameters are associated with female embryo gender. If confirmed on a larger sample these could be potentially used to increase the proportion of female embryos among non-invasively selected blastocysts following single embryo transfer.

Minimal stimulation IVF vs conventional IVF: a randomized controlled trial

BACKGROUND

Minimal stimulation in vitro fertilization (mini-in vitro fertilization) is an alternative in vitro fertilization treatment protocol that may reduce ovarian hyperstimulation syndrome, multiple pregnancy rates, and cost while retaining high live birth rates.

OBJECTIVE

We performed a randomized noninferiority controlled trial with a prespecified border of 10% that compared 1 cycle of mini-in vitro fertilization with single embryo transfer with 1 cycle of conventional in vitro fertilization with double embryo transfer.

STUDY DESIGN

Five hundred sixty-four infertile women (<39 years old) who were undergoing their first in vitro fertilization cycle were allocated randomly to either mini-in vitro fertilization or conventional in vitro fertilization. The primary outcome was cumulative live birth rate per woman over a 6-month period. Secondary outcomes included ovarian hyperstimulation syndrome, multiple pregnancy rates, and gonadotropin use. The primary outcome was cumulative live birth per randomized woman within a time horizon of 6 months.

RESULTS

Five hundred sixty-four couples were assigned randomly between February 2009 and August 2013 with 285 couples allocated to mini-in vitro fertilization and 279 couples allocated to conventional in vitro fertilization. The cumulative live birth rate was 49% (140/285) for mini-in vitro fertilization and 63% (176/279) for conventional in vitro fertilization (relative risk, 0.76; 95% confidence interval, 0.64-0.89). There were no cases of ovarian hyperstimulation syndrome after mini-in vitro fertilization compared with 16 moderate/severe ovarian hyperstimulation syndrome cases (5.7%) after conventional in vitro fertilization. The multiple pregnancy rates were 6.4% in mini-in vitro fertilization compared with 32% in conventional in vitro fertilization (relative risk, 0.25; 95% confidence interval, 0.14-0.46). Gonadotropin consumption was significantly lower with mini-in vitro fertilization compared with conventional in vitro fertilization (459 ± 131 vs 2079 ± 389 IU; P < .0001).

CONCLUSION

Compared with conventional in vitro fertilization with double embryo transfer, mini-in vitro fertilization with single embryo transfer lowers live birth rates, completely eliminates ovarian hyperstimulation syndrome, reduces multiple pregnancy rates, and reduces gonadotropin consumption.

Use of clomiphene-based stimulation protocol in oocyte donors: A comparative study

INTRODUCTION:

This study was undertaken to compare between clomiphene citrate (CC) and gonadotropin-releasing hormone antagonist-based protocols in donor-recipient cycles in terms of parameters of ovarian stimulation and obstetric outcome.

MATERIALS AND METHODS:

Two hundred and three fertile oocyte donors were stimulated using two different protocols: Clomiphene based (n = 103) and antagonist based (n = 100). Donors in the one group were stimulated from day 1 or 2 of spontaneous or withdrawal bleeds with CC (50 mg/day) and recombinant follicle-stimulating hormone (FSH) till the day of trigger while donors in the other group were stimulated using recombinant FSH from day 1 or 2, and the antagonist was added as per flexible antagonist protocol. When >3 follicles were >17 mm in diameter, trigger was given with 2 mg leuprolide intramuscular. Transvaginal oocyte retrieval was done after 34 h of trigger.

RESULTS:

There was no significant difference in between the two groups in terms of age, antral follicle count, starting dose of gonadotropins, total dose required, duration of stimulation, number of follicles retrieved, mature follicles, and fertilization rate. The serum estradiol levels were significantly raised in the clomiphene group (P < 0.001). Pregnancy rate was similar in both the groups. The clinical pregnancy rate was 65.94% in the clomiphene group and 57.46% in the antagonist group. The live birth rate per cycle started was 47.8% in the clomiphene group and 39.55% in the antagonist group. There was one case of ectopic pregnancy in the antagonist group.

CONCLUSION:

Controlled ovarian stimulation using clomiphene and gonadotropin is a viable option for donor oocyte cycles. The cost and number of injections used per cycle can be reduced by using the clomiphene-based protocols.

The association of serum estradiol level with outcomes of clomiphene citrate/human menopausal gonadotropin ovarian stimulation for in vitro fertilization and embryo transfer

BACKGROUND

The purpose of this study was to test the hypothesis that estradiol (E2) level on day 3 may be associated with in vitro fertilization (IVF) outcomes.

METHODS

The records of patients who received clomiphene citrate 100 mg/day plus human menopausal gonadotropin 150 IU/day from day 3 and received frozen-thawed embryo transfers were reviewed. Patients were divided into three groups: group A (E2 ≤30 pg/ml), group B (30< E2 ≤50 pg/ml), and group C (E2 >50 pg/ml). A total of 1080 cycles from 941 patients were included.

RESULTS

The number of eggs and MII oocytes were less in group C than group A (both, P = 0.001). The embryo implantation (P = 0.006) and clinical pregnancy rates (P = 0.036) were lower in group C than group B, and the rates were similar between group A and B.

CONCLUSION

Maintaining the serum E2 level from 30 to 50 pg/ml may result in a higher clinical pregnancy rate in IVF cycles.

Autologous oocyte cryopreservation in women aged 40 and older using minimal stimulation IVF

BACKGROUND

The value of oocyte cryopreservation in older women remains controversial. The aim of this study was to report the oocyte freezing experience in women aged 40 and older at a single fertility center.

FINDINGS

One hundred fifty eight women (mean age 43.9 ± 0.2) who underwent minimal ovarian stimulation IVF were enrolled. IVF protocol included the use of clomiphene citrate (50 mg/day) or letrozole (2.5 mg/day) with or without low dose gonadotropins (started at 75 IU/day and increased as needed to 150 IU/day). 584 retrieved oocytes (2.1 ± 0.15 per patient) yielded 532 mature MII oocytes that were frozen. After thawing and fertilization by ICSI, a total of 344 embryos (1.9 ± 0.1 per patient) were formed. A total of 57 relatively good embryos were transferred and yielded three live births (5.3 % per embryo transfer), three spontaneous abortions, and one chemical pregnancy.

CONCLUSIONS

These data are important in counseling older women who desire autologous oocyte freezing.

Comparison of different stimulation protocols used in in vitro fertilization: a review

Infertility is one of the major medical problems in the western world caused by genetic or epigenetic factors, or both, which has led to continuous research and advancements in the field of assisted reproductive technology (ART). Many stimulation protocols are available for controlled ovarian hyperstimulation (COH) in in vitro fertilization (IVF). This review compares the agonist long protocol, antagonist protocol and minimal stimulation protocol. Gonadotropin-releasing hormone (GnRH) antagonist and minimal stimulation protocol has shorter duration of treatment and less gonadotropin use. GnRH agonist long protocol is better in folliculogenesis and pregnancy rate, which is the imperative goal of COH. Despite its costly and lengthy approach, GnRH agonist long protocol has delivered satisfactory results in most women. On the other hand, patients with poor ovarian reserve may have greater advantage when considering minimal stimulation protocol. Evidently, it is crucial to have a larger scale studies with more focused comparisons, which take into account the differences in patients' response criteria and additional confounding variables (age, BMI, previous IVF outcomes etc.), in order to reach to a more definite conclusions.

Mild ovarian stimulation with clomiphene citrate launch is a realistic option for in vitro fertilization

OBJECTIVE

To validate the use of clomiphene citrate in IVF when mild stimulation approaches are chosen to reduce patient discomfort, risk, and cost.

DESIGN

Prospective cohort study.

SETTING

Private IVF clinic.

PATIENT(S)

A total of 163 patients undergoing IVF and with a good prognosis (defined as ≤38 years old with normal ovarian reserve and normovulatory cycles, body mass index <29 kg/m(2), no previous assisted reproductive technology cycles, no severe endometriosis, no history of recurrent miscarriage, no endocrine/autoimmune diseases, and no surgical semen extraction).

INTERVENTION(S)

Mild stimulation using a fixed protocol of clomiphene citrate (100 mg/d from cycle days 3 to 7) in combination with low doses of gonadotropins (150 IU of recombinant FSH on cycle days 5, 7, and 9) and GnRH antagonist.

MAIN OUTCOME MEASURE(S)

The cumulative delivery rate per patient after three fresh and/or frozen embryo transfers and time to pregnancy.

RESULT(S)

No dropouts were observed. The cumulative delivery rate was 70%, and the mean time to pregnancy was 2.4 months.

CONCLUSION(S)

Mild stimulation using clomiphene citrate in combination with low doses of gonadotropins can be considered a realistic option for good-prognosis patients undergoing IVF.

Obesity adversely impacts the number and maturity of oocytes in conventional IVF not in minimal stimulation IVF

OBJECTIVE

The objective of this study was to assess the relationship between BMI and oocyte number and maturity in participants who underwent minimal stimulation (mini-) or conventional IVF.

METHODS

Participants who underwent their first autologous cycle of either conventional (n = 219) or mini-IVF (n = 220) were divided according to their BMI to analyze IVF outcome parameters. The main outcome measure was the number of oocytes in metaphase II (MII). Secondary outcomes included the number of total oocytes retrieved, fertilized (2PN) oocytes, cleavage and blastocyst stage embryos, clinical pregnancy (CP), and live birth (LB) rates.

RESULTS

In conventional IVF, but not in mini-IVF, the number of total oocytes retrieved (14.5  ±  0.8 versus 8.8  ±  1.3) and MII oocytes (11.2 ± 0.7 versus 7.1 ± 1.1) were significantly lower in obese compared with normal BMI women. Multivariable linear regression adjusting for age, day 3 FSH, days of stimulation, and total gonadotropin dose demonstrated that BMI was an independent predictor of the number of MII oocytes in conventional IVF (p = 0.0004). Additionally, only in conventional IVF, BMI was negatively correlated with the total number of 2PN oocytes, as well as the number of cleavage stage embryos.

CONCLUSIONS

Female adiposity might impair oocyte number and maturity in conventional IVF but not in mini-IVF. These data suggest that mild ovarian stimulation might yield healthier oocytes in obese women.

Vitrification in human and domestic animal embryology: work in progress

According to the analysis of papers published in major international journals, rapidly increasing application of vitrification is one of the greatest achievements in domestic animal and especially human embryology during the first decade of our century. This review highlights factors supporting or hampering this progress, summarises results achieved with vitrification and outlines future tasks to fully exploit the benefits of this amazing approach that has changed or will change many aspects of laboratory (and also clinical) embryology. Supporting factors include the simplicity, cost efficiency and convincing success of vitrification compared with other approaches in all species and developmental stages in mammalian embryology, while causes that slow down the progress are mostly of human origin: inadequate tools and solutions, superficial teaching, improper application and unjustified concerns resulting in legal restrictions. Elimination of these hindrances seems to be a slower process and more demanding task than meeting the biological challenge. A key element of future progress will be to pass the pioneer age, establish a consensus regarding biosafety requirements, outline the indispensable features of a standard approach and design fully-automated vitrification machines executing all phases of the procedure, including equilibration, cooling, warming and dilution steps.

Follicle recruitment determines IVF productivity rate via the number of embryos frozen and subsequent transfers

IVF productivity rate is an index defined as the sum of all live births from either fresh or frozen embryo transfers arising from a single oocyte collection. This retrospective analysis over 9 continuous years used this index to understand the potential impact on pregnancy rates of milder stimulation regimens with associated reduced egg numbers. The productivity rate per collection increased in a linear and significant rate as more oocytes were recovered, more embryos frozen and more frozen embryo transfers contributed to pregnancy. This observation was true for women aged <35 years and less so for women aged 35-39 years but not for women aged 40 years and older. The contribution of frozen embryo transfer to the productivity rate rose in a linear manner, reaching over 40% of all live births with nine oocytes. The number of live births per oocyte, pronuclear embryos and thawed embryos decreased significantly but the number of live births per embryo transferred (fresh or frozen) rose with rising oocyte numbers, reflecting increasing opportunity for embryo selection. This study suggests that optimal benefits with minimal risks are gained from a model that includes both fresh and frozen transfers under stimulation generating between 8 and 12 eggs.

Low-intensity IVF: real progress?

A recent publication in this journal strongly advocated low-intensity IVF (LI-IVF) after presenting the authors' experience with minimal ovarian stimulation (mini-IVF). The data presented failed to support their conclusions. Therefore, presented here is a critique of their manuscript and of uncontrolled clinical use of LI-IVF, in general. In the absence of properly controlled studies, all forms of LI-IVF should be considered experimental and be offered only in well-controlled research settings and with appropriate informed consent.