Changing ovarian stimulation parameters in a subsequent cycle does not increase the number of euploid embryos

Dual Trigger with hCG Plus GnRHa for Final Oocyte Maturation in PGT-A Cycles Results in Similar Euploidy Rates when Compared to hCG-Only Trigger

Factors that may have an effect on euploidy rate of blastocysts have been investigated thoroughly in the literature. We aimed to assess whether dual trigger alters the ploidy chance of a blastocyst in preimplantation genetic screening for aneuploidy (PGT-A) cycles. This retrospective cohort study was conducted in a total of 385 PGT-A cycles at a single tertiary center for various indications. Final oocyte maturation was triggered using human chorionic gonadotropin (hCG) or the combination of hCG and gonadotropin-releasing hormone agonists (GnRHa) (dual trigger). Participants were divided based on triggering method and all demographic and clinical characteristics of the patients were compared. Final oocyte maturation was triggered in 143 cycles with hCG (37.1%), and in 242 cycles with dual trigger (62.9%). The duration of stimulation was shorter in the dual trigger arm compared to the hCG trigger group (10.0 ± 1.6 vs. 9.4 ± 1.4 days, p ≤ .001). Euploidy rates per blastocyst tested were 23.4% and 26.1% respectively for hCG and dual trigger groups without significance. Similar rates of euploidy were noted, even after age stratification. There was no significant difference between the groups regarding positive pregnancy result and ongoing pregnancy rates (p = .779 vs. p = .188). Although dual triggering, compared to hCG triggering, does not provide an additional superiority on blastocyst euploidy rate, further studies in women with different infertility etiology are needed to specifically evaluate the impact of triggering method on ploidy rates.

Leave the past behind: women's reproductive history shows no association with blastocysts' euploidy and limited association with live birth rates after euploid embryo transfers

STUDY QUESTION

Is there an association between patients' reproductive history and the mean euploidy rates per biopsied blastocysts (m-ER) or the live birth rates (LBRs) per first single vitrified-warmed euploid blastocyst transfers?

SUMMARY ANSWER

Patients' reproductive history (as annotated during counselling) showed no association with the m-ER, but a lower LBR was reported after euploid blastocyst transfer in women with a history of repeated implantation failure (RIF).

WHAT IS KNOWN ALREADY

Several studies have investigated the association between the m-ER and (i) patients' basal characteristics, (ii) ovarian stimulation strategy and dosage, (iii) culture media and conditions, and (iv) embryo morphology and day of full blastocyst development. Conversely, the expected m-ER due to women's reproductive history (previous live births (LBs), miscarriages, failed IVF cycles and transfers, and lack of euploid blastocysts among prior cohorts of biopsied embryos) still needs investigations. Yet, this information is critical to counsel new patients about a first cycle with preimplantation genetic testing for aneuploidy (PGT-A), but even more so after former adverse outcomes to prevent treatment drop-out.

STUDY DESIGN, SIZE, DURATION

This observational study included all patients undergoing a comprehensive chromosome testing (CCT)-based PGT-A cycle with at least one biopsied blastocyst in the period April 2013-December 2019 at a private IVF clinic (n = 2676 patients undergoing 2676 treatments and producing and 8151 blastocysts). m-ER were investigated according to women's reproductive history of LBs: no/≥1, miscarriages: no/1/>1; failed IVF cycles: no/1/2/>2, and implantation failures after previous transfers: no/1/2/>2. Among the 2676 patients included in this study, 440 (16%) had already undergone PGT-A before the study period; the data from these patients were further clustered according to the presence or absence of euploid embryo(s) in their previous cohort of biopsied blastocysts. The clinical outcomes per first single vitrified-warmed euploid blastocyst transfers (n =1580) were investigated according to the number of patients' previous miscarriages and implantation failures.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy without hatching in Day 3, CCT-based PGT-A without reporting segmental and/or putative mitotic (or mosaic) aneuploidies and single vitrified-warmed euploid blastocyst transfer. For statistical analysis, Mann-Whitney U or Kruskal-Wallis tests, as well as linear regressions and generalised linear models among ranges of maternal age at oocyte retrieval were performed to identify significant differences for continuous variables. Fisher's exact tests and multivariate logistic regression analyses were instead used for categorical variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Maternal age at oocyte retrieval was the only variable significantly associated with the m-ER. We defined five clusters (<35 years: 66 ± 31%; 35-37 years: 58 ± 33%; 38-40 years: 43 ± 35%; 40-42 years: 28 ± 34%; and >42 years: 17 ± 31%) and all analyses were conducted among them. The m-ER did not show any association with the number of previous LBs, miscarriages, failed IVF cycles or implantation failures. Among patients who had already undergone PGT-A before the study period, the m-ER did not associate with the absence (or presence) of euploid blastocysts in their former cohort of biopsied embryos. Regarding clinical outcomes of the first single vitrified-warmed euploid blastocyst transfer, the implantation rate was 51%, the miscarriage rate was 14% and the LBR was 44%. This LBR was independent of the number of previous miscarriages, but showed a decreasing trend depending on the number of previous implantation failures, reaching statistical significance when comparing patients with >2 failures and patients with no prior failure (36% versus 47%, P < 0.01; multivariate-OR adjusted for embryo quality and day of full blastocyst development: 0.64, 95% CI 0.48-0.86, P < 0.01). No such differences were shown for previous miscarriage rates.

LIMITATIONS, REASONS FOR CAUTION

The sample size for treatments following a former completed PGT-A cycle should be larger in future studies. The data should be confirmed from a multicentre perspective. The analysis should be performed also in non-PGT cycles and/or including patients who did not produce blastocysts, in order to investigate a putative association between women's reproductive history with outcomes other than euploidy and LBRs.

WIDER IMPLICATIONS OF THE FINDINGS

These data are critical to counsel infertile couples before, during and after a PGT-A cycle, especially to prevent treatment discontinuation due to previous adverse reproductive events. Beyond the 'maternal age effect', the causes of idiopathic recurrent pregnancy loss (RPL) and RIF are likely to be endometrial receptivity and selectivity issues; transferring euploid blastocysts might reduce the risk of a further miscarriage, but more information beyond euploidy are required to improve the prognosis in case of RIF.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The risk of poor ovarian response during repeat IVF

RESEARCH QUESTION

What are the incidence and risk factors for poor ovarian response (POR) during repeat IVF?

DESIGN

A retrospective analysis of 1224 consecutive patients who underwent at least two IVF stimulations in a single centre over a 6-year period. Risk factors from the initial treatment were assessed for association with POR during repeat IVF using logistic regression analysis. A simple, practical predictive model was constructed and evaluated for accuracy and calibration, based on the factors that demonstrated significant association with subsequent POR. POR during repeat IVF was defined as ≤3 retrieved oocytes or cancellation before retrieval following recruitment of ≤3 mature follicles.

RESULTS

The risk of POR during repeat IVF was approximately 11.5%. A higher POR risk during repeat IVF is associated with a reduced oocyte yield during the initial treatment (≤3 oocytes: odds ratio [OR] 14, 95% confidence interval [CI] 6.42-30.24; 4-9 oocytes: OR 4.13, 95% CI 2.00-8.54; 10-15 oocytes: OR 1) and low ovarian reserve (anti-Müllerian hormone [AMH] <5.4 pmol/l: OR 3.54, 95% CI 2.24-5.59; AMH 5.4-25 pmol/l: OR 1). Women with low ovarian reserve who experience POR during the initial IVF have the highest risk of suffering POR again during repeat IVF (57% within 1 year). Other groups, such as women with unexpected POR or expected poor responders with suboptimal ovarian response during the initial IVF, are also at risk of exhibiting POR during a subsequent treatment (28% within 1 year).

CONCLUSIONS

As there is a clear association between POR and lower live birth rates, this practical model may help manage patients' expectations during repeat IVF treatment.