Consecutive cycles in in vitro fertilization--embryo transfer

Embryo development and live birth in women with one previously failed full IVF/ICSI cycle

PURPOSE

To evaluate the embryological and pregnancy outcomes of women who failed in their first IVF treatment if they attempted a second cycle.

METHODS

For evaluating the embryological outcomes, the study cohort included 1,227 women who failed to obtain a live birth after the initial IVF cycle from September 2018 to August 2021 and returned for a second attempt. To evaluate reproductive outcomes including live birth rates (LBRs), 1227 women who returned for a second attempt were compared with 13,195 women undergoing their first oocyte retrieval with blastocyst culture attempted during the same study period.

RESULTS

In women who had a second cycle, the median number of oocyte retrieved (11 vs 9), fertilized oocytes (7 vs 5), usable embryos (6 vs 4) and blastocysts (3 vs 1) was higher in the second cycle compared to the first cycle (All p < 0.001). Blastocyst formation rates were significantly increased from 33% in the first cycle to 50% in the second cycle across the age group (p < 0.001). However, the primary transfer LBRs were significantly lower in the second cycle than that in the initial cycle (40.82% versus 51.79%, aOR: 0.74 [0.65, 0.84]). LBRs in the second cycle were 42.26%, 42.68%, 25.49% and 16.22% in women aged < 35, 35-37, 38-40, and > 40 years.

CONCLUSION

There was a notable enhancement in laboratory outcomes following the second attempt in women whose initial IVF cycles were unsuccessful. However, the uncertainty inherent in the successful implantation and the consequent progression to live birth remains a significant challenge.

Comparison of clinical outcomes among dual ovarian stimulation, mild stimulation and luteal phase stimulation protocols in women with poor ovarian response

This study aimed to determine whether consecutive ovarian stimulation in follicular and luteal phases within a single menstrual cycle (dual stimulation) is achievable and superior to conventional stimulation for poor ovarian responders (PORs). Data of 260 PORs were retrospectively collected and divided into three groups. Group A comprised of cycles with dual ovarian stimulation (n = 76), which were divided into two subgroups (follicular [group A-F] and luteal phase stimulation [group A-L]); group B comprised of cycles with ovarian stimulation that was performed only in the luteal phase (n = 52). Group C comprised of mild ovarian stimulation cycles (n = 132). Baseline parameters were not different among the three groups. The numbers of oocytes and embryo obtained were less in group A-F than group B and C, while group A overall had significantly more oocytes and viable embryo retrieved than did group B and C. Group A-L consumed significantly less gonadotropin than group B, without compromising the number of retrieved oocytes and embryo. The pregnancy outcomes of transfer of embryo from different stimulation phases were similar. We conclude that dual ovarian stimulation protocol is effective and potentially optimal for PORs.

The Effect of Dose Adjustments in a Subsequent Cycle of Women With Suboptimal Response Following Conventional Ovarian Stimulation

Several infertile patients, who may even represent around 40% of the infertile cohort, may respond "suboptimally" (4-9 oocytes retrieved) following IVF, despite being predicted as normal responders. The aim of our longitudinal study was to evaluate the ovarian response of suboptimal responders in terms of the number of oocytes retrieved, following their second IVF cycle, evaluating exclusively patients who had the same stimulation protocol and used the same or higher initial dose of the same type of gonadotropin compared to their previous failed IVF attempt. Overall, our analysis included 160 patients treated with a fixed antagonist protocol in their second cycle with the same [53 (33.1%)] or higher [107 (66.9%)] starting dose of rFSH. The number of oocytes retrieved was significantly higher in the second IVF cycle [6 (5-8) vs. 9 (6-12), p < 0.001]. According to our results, a dose increment of rFSH remained the only significant predictor of the number of oocytes retrieved in the subsequent IVF cycle (coefficient 0.02, p-value = 0.007) after conducting GEE multivariate regression, while adjusting for relevant confounders. A regression coefficient of 0.02 for the starting dose implies that an increase of 50 IU of the initial rFSH dose would lead to 1 more oocyte.

Molecular Mechanisms Responsible for Increased Vulnerability of the Ageing Oocyte to Oxidative Damage

In their midthirties, women experience a decline in fertility, coupled to a pronounced increase in the risk of aneuploidy, miscarriage, and birth defects. Although the aetiology of such pathologies are complex, a causative relationship between the age-related decline in oocyte quality and oxidative stress (OS) is now well established. What remains less certain are the molecular mechanisms governing the increased vulnerability of the aged oocyte to oxidative damage. In this review, we explore the reduced capacity of the ageing oocyte to mitigate macromolecular damage arising from oxidative insults and highlight the dramatic consequences for oocyte quality and female fertility. Indeed, while oocytes are typically endowed with a comprehensive suite of molecular mechanisms to moderate oxidative damage and thus ensure the fidelity of the germline, there is increasing recognition that the efficacy of such protective mechanisms undergoes an age-related decline. For instance, impaired reactive oxygen species metabolism, decreased DNA repair, reduced sensitivity of the spindle assembly checkpoint, and decreased capacity for protein repair and degradation collectively render the aged oocyte acutely vulnerable to OS and limits their capacity to recover from exposure to such insults. We also highlight the inadequacies of our current armoury of assisted reproductive technologies to combat age-related female infertility, emphasising the need for further research into mechanisms underpinning the functional deterioration of the ageing oocyte.

Intercycle variability of the ovarian response in patients undergoing repeated stimulation with corifollitropin alfa in a gonadotropin-releasing hormone antagonist protocol

OBJECTIVE

To determine whether individual subject variation in ovarian response between repeated cycles with the same ovarian stimulation protocol can be predicted.

DESIGN

Retrospective data analysis.

SETTING

Multicenter, open-label, uncontrolled clinical trial.

PATIENT(S)

Women aged 18-39 from a phase 3, open-label, uncontrolled trial with complete data across all cycles (n = 176).

INTERVENTION(S)

Up to three cycles of a single injection of 150 μg corifollitropin alfa for 7 days, then daily recombinant FSH/hMG until three follicles reached ≥17 mm. Gonadotropin-releasing hormone antagonist from stimulation day 5 until day of hCG administration.

MAIN OUTCOME MEASURE(S)

Numbers of follicles ≥11 mm on day of hCG in cycles 1-3, transition in ovarian response type between cycles from low (0-<6), normal (6-<18), and high (≥18), and serum FSH concentrations and antral follicle count (AFC) at each cycle start.

RESULT(S)

The mean (SD) numbers of follicles ≥11 mm on day of hCG were 13.4 (6.2), 13.3 (5.4), and 13.8 (6.4) in cycles 1, 2 and 3, respectively. Between cycles 1 and 2, 11.9% switched from normal to low or high response, and 12.5% switched from low or high to normal response; 75.6% remained in the same category. Between cycles 2 and 3, 15.9% switched from normal to low or high response, and 10.2% switched from low or high to normal response; 73.9% remained in the same category. These shifts are symmetrical in nature, in that the percentage of subjects who shift from normal to low or high response is comparable to the percentage of subjects who shift from low or high to normal response. Baseline FSH and AFC did not significantly predict transition in ovarian response.

CONCLUSION(S)

The variability in ovarian responses between repeated cycles using the same protocol was not explained by baseline FSH and AFC.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00696878 Protocol P05714.

The impact of the time interval on in-vitro fertilisation success after failure of the first attempt

The aim of this study was to identify the optimal time interval for in-vitro fertilisation that would increase treatment success after failure of the first attempt. This retrospective study evaluated 454 consecutive cycles of 227 infertile women who had two consecutive attempts within a 6-month period at an IVF centre. Data were collected on duration of stimulation, consumption of gonadotropin, numbers of retrieved oocytes, mature oocytes, fertilised eggs, good quality embryos on day 3/5 following oocyte retrieval and clinical and ongoing pregnancy. There were significant increases in clinical pregnancy rates at 2-, 3- and 4-month intervals. The maximum increase was after two menstrual cycles (p = 0.001). The highest rate of ongoing pregnancy was in women that had the second attempt after the next menstrual cycle following failure of IVF (27.2%). After IVF failure, initiating the next attempt within 2-4 months increases the clinical pregnancy rates.

Reproductive outcome of women 43 years and beyond undergoing ART treatment with their own oocytes in two Connecticut university programs

PURPOSE

The aim of this study was to analyze the outcomes of IVF/ICSI cycles in women aged 43 and beyond.

METHODS

Retrospective analysis of clinical pregnancy and live birth rates in 168 fresh, non donor, ART cycles performed in two Connecticut university IVF programs.

RESULTS

In women of 43 and 44 years the overall clinical pregnancy and live birth rates were 8.3% and 5.3% per initiated cycle, respectively. There were no clinical pregnancies in women ≥45 years old. First cycle characteristics were not different from repeated cycles in terms of duration of ovulation induction, number of collected oocytes and transferred embryos (p > 0.05).

CONCLUSIONS

Pregnancies can still be achieved with IVF/ICSI up to the age of 44. Since most pregnancies occurred within the first 3 cycles, another attempt may be a reasonable option before resorting to oocyte donation for patients who failed two previous cycles. Women 45 years and beyond do not benefit from ART procedures using their own oocytes.

The impact of ovarian stimulation for IVF on the developing embryo

The use of assisted reproductive technologies (ART) has been increasing over the past three decades, and, in developed countries, ART account for 1-3% of annual births. In an attempt to compensate for inefficiencies in IVF procedures, patients undergo ovarian stimulation using high doses of exogenous gonadotrophins to allow retrieval of multiple oocytes in a single cycle. Although ovarian stimulation has an important role in ART, it may also have detrimental effects on oogenesis, embryo quality, endometrial receptivity and perinatal outcomes. In this review, we consider the evidence for these effects and address possible underlying mechanisms. We conclude that such mechanisms are still poorly understood, and further knowledge is needed in order to increase the safety of ovarian stimulation and to reduce potential effects on embryo development and implantation, which will ultimately be translated into increased pregnancy rates and healthy offspring.

Cryopreservation of supernumerary high quality embryos predicts favorable outcomes for patients undergoing repeated cycles of in vitro fertilization

OBJECTIVE

To determine whether the decline in pregnancy and implantation rates in repeated fresh IVF cycles is associated with the availability of embryo cryopreservation.

DESIGN

Retrospective study.

SETTING

Assisted reproductive unit at an academic institution.

PATIENT(S)

Women <38 years old (1,037), undergoing nondonor fresh or frozen embryo transfer (FET) cycles between January 1, 2000 and December 31, 2005.

INTERVENTION(S)

In fresh cycles, women used either pituitary desensitization or GnRH antagonists in combination with gonadotropin stimulation protocols before oocyte retrieval. In FET cycles, endometrial development was achieved by oral E(2) and vaginal P after pituitary desensitization. Embryo transfer occurred either on day 3 or on day 5.

MAIN OUTCOME MEASURE(S)

Implantation and pregnancy rates (PR).

RESULT(S)

Excluding FET cycles, implantation rates and PRs declined significantly in repeated cycles compared to the initial one. However, women with supernumerary embryos for cryopreservation appeared to produce embryos with higher implantation potential but were excluded from the analysis. When FET cycles were included, there were no significant declines in PRs for at least three repeated cycles.

CONCLUSION(S)

Embryo cryopreservation stratifies women with high quality embryos from those with low quality embryos who require repeat fresh attempts, resulting in an accelerated decline in observed PRs and implantation rates.