Preparation of cycles for cryopreservation transfers using estradiol patches and Crinone 8% vaginal gel is effective and does not need any monitoring

Effect of estrogen exposure on pregnancy outcomes in artificial frozen-thawed embryo transfer cycles

In contemporary times, the employment of vitrification freezing technology has led to the widespread adoption of frozen-thawed embryo transfer (FET) worldwide. Meanwhile, hormone replacement therapy (HRT) is a crucial protocol for priming the endometrium during FET cycles. Estrogen is required in HRT cycles for the induction of progesterone receptors and to promote endometrial thickness. However, there is no universal consensus on the treatment duration, dosage regimen, administration route, and target serum estrogen levels. Therefore, this study aimed to offer a comprehensive review of these topics. A shorter duration of estrogen exposure may elevate the risk of early miscarriage, while prolonged exposure to estrogen does not seem to confer advantages to general population and may be attempted in individuals with thin endometrium. Moreover, excessive estrogen levels on the day of progesterone administration may be associated with higher miscarriage rates and lower live birth rates (LBR). To offer more comprehensive guidance for clinical practice, extensive and prospective studies involving a large sample size are warranted to determine the optimal concentration and duration of estrogen exposure.

Elevated estradiol levels in frozen embryo transfer have different effects on pregnancy outcomes depending on the stage of transferred embryos

Supplementation with estradiol (E2) is routinely used in frozen embryo transfer (FET) cycles and embryo age plays an important role in conceiving. This study was to compare the effects of serum E2 levels on pregnancy outcomes between cleavage- and blastocyst-stage FET cycles using hormone replacement therapy. A total of 776 FET cycles (669 couples) performed from January 2016 to December 2019 were included in the present retrospective cohort study. Regarding cleavage-stage embryo transfers, E2 levels on progesterone initiation day were significantly lower in the ongoing pregnancy/live birth (OP/LB) group than in the non-OP/LB group (214.75 ± 173.47 vs. 253.20 ± 203.30 pg/ml; P = 0.023). In addition, there were downward trends in implantation, clinical pregnancy and OP/LB rates with increasing E2 levels. However, in blastocyst-stage embryo transfers, such trends were not observed, and E2 levels were not significant difference between the OP/LB group and the non-OP/LB group (201.66 ± 182.14 vs. 197.89 ± 212.83 pg/ml; P = 0.884). The results suggests that elevated progesterone-initiation-day E2 levels may negatively affect pregnancy outcomes during artificial cleavage-stage embryo transfers. However, it is not necessary to monitor E2 levels when transferring blastocysts in artificial FET cycles.

Does high estrogen level negatively affect pregnancy success in frozen embryo transfer?

Introduction

High estrogen levels could reduce pregnancy rates by disrupting the implantation of the embryo into the endometrium in patients treated with fresh cycles of in vitro fertilization. The aim of the present study was to investigate the effect of estrogen levels on the pregnancy and abortion rate in autologous frozen embryo transfer with hormone replacement therapy (HRT).

Material and methods

A historical cohort study was conducted in an academic setting to investigate the effect of estrogen levels on the pregnancy and abortion rates for all autologous artificial frozen embryo transfer cycles performed from January 2016 to January 2018. Serum estradiol levels recorded on day 2 or 3 of the cycle were stated as e1, and levels recorded on the day of progesterone were indicated as e2. Human chorionic gonadotropin (β-hCG) positivity, which was examined 14 days after the transfer, was used to evaluate biochemical pregnancy. Abortion was defined as the termination of pregnancy before the 20th gestational week.

Results

There were 130 patients with unexplained infertility, 20 patients with poor ovarian reserve, and 54 patients with male factor. Of the patients with unexplained infertility, poor ovarian reserve, and male factor, 58, 4, and 27 of them were pregnant, respectively. No statistically significant difference was found between the e1 and e2 levels of the pregnant and non-pregnant groups (p = 0.273, p = 0.219). In addition, there was no statistically significant difference between e2 levels in terms of the abortion rate (p = 0.722).

Conclusions

In autologous frozen embryo transfer with HRT, estrogen levels did not have a significant effect on the pregnancy or abortion rate. Therefore, estrogen levels do not need to be monitored in frozen embryo transfer with HRT.

Impact of Serum Estradiol Levels Prior to Progesterone Administration in Artificially Prepared Frozen Embryo Transfer Cycles

Background: The need for endocrine monitoring in artificial cycles for frozen embryo transfer (FET) remains unclear and, more specifically, the value of the late-proliferative phase serum estradiol (E2) levels is with conflicting evidence in current literature. Objective: To investigate whether artificial FET cycles require endocrine monitoring for the serum E2 level prior to initiation of exogenous progesterone administration after an endometrial thickness of 6.5 mm has been reached. Design: One thousand two hundred and twenty-two (n = 1,222) artificial FETs performed in a tertiary center between 2010 and 2015 were subdivided into 3 groups according to the following late-proliferative serum E2 level percentiles: ≤p10 (E2 ≤144 pg/ml; n = 124), p11-p90 (E2 from 145 to 438 pg/ml; n = 977) and >p90 (E2 >439 pg/ml; n = 121). A mixed-effects multilevel multivariable regression analysis was performed to assess the potential effect of the late-proliferative E2 level on the live birth rate (LBR). Results: The level of late-proliferative circulating E2 showed no significant difference in terms of LBR after FET. Specifically, the multivariable regression model demonstrated a LBR of 19.5% for the p11-p90 reference group, compared to 24.4% for the ≤p10 (p = 0.251) and 19.5% for the >p90 group (p = 0.989). Conclusion: In this large retrospective dataset, no association was observed between late-proliferative phase serum E2 levels and LBR following FET in artificially prepared cycles. Although, caution is warranted due to the retrospective nature of the analysis and the potential for unmeasured confounding, we argue that monitoring of the late-proliferative serum E2 levels and using them to guide clinical decision-making (e.g., medication step-up, cycle prolongation or cancelation) may be of questionable value.

Frozen embryo transfer: a review on the optimal endometrial preparation and timing

STUDY QUESTION

What is the optimal endometrial preparation protocol for a frozen embryo transfer (FET)?

SUMMARY ANSWER

Although the optimal endometrial preparation protocol for FET needs further research and is yet to be determined, we propose a standardized timing strategy based on the current available evidence which could assist in the harmonization and comparability of clinic practice and future trials.

WHAT IS KNOWN ALREADY

Amid a continuous increase in the number of FET cycles, determining the optimal endometrial preparation protocol has become paramount to maximize ART success. In current daily practice, different FET preparation methods and timing strategies are used.

STUDY DESIGN, SIZE, DURATION

This is a review of the current literature on FET preparation methods, with special attention to the timing of the embryo transfer.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Literature on the topic was retrieved in PubMed and references from relevant articles were investigated until June 2017.

MAIN RESULTS AND THE ROLE OF CHANCE

The number of high quality randomized controlled trials (RCTs) is scarce and, hence, the evidence for the best protocol for FET is poor. Future research should compare both the pregnancy and neonatal outcomes between HRT and true natural cycle (NC) FET. In terms of embryo transfer timing, we propose to start progesterone intake on the theoretical day of oocyte retrieval in HRT and to perform blastocyst transfer at hCG + 7 or LH + 6 in modified or true NC, respectively.

LIMITATIONS REASONS FOR CAUTION

As only a few high quality RCTs on the optimal preparation for FET are available in the existing literature, no definitive conclusion for benefit of one protocol over the other can be drawn so far.

WIDER IMPLICATIONS OF THE FINDINGS

Caution when using HRT for FET is warranted since the rate of early pregnancy loss is alarmingly high in some reports.

STUDY FUNDING/COMPETING INTEREST(S)

S.M. is funded by the Research Fund of Flanders (FWO). H.T. and C.B. report grants from Merck, Goodlife, Besins and Abbott during the conduct of the study.

TRIAL REGISTRATION NUMBER

Not applicable.

Determining the Optimal Duration of Progesterone Supplementation prior to Transfer of Cryopreserved Embryos and Its Impact on Implantation and Pregnancy Rates: A Pilot Study

Objective. To determine the optimal duration of progesterone supplementation prior to transfer of cryopreserved embryos and its impact on implantation and pregnancy rates. Study Design. Prospective randomised study. Materials and Methods. In an IVF unit of a tertiary centre, sixty-six patients undergoing cryopreserved embryo transfer cycles were included. Endometrial preparation was done with estradiol valerate. Once it reached a minimum of 7 mm, patients were allocated randomly into group I (n = 39) and group II (n = 27). Injectable progesterone 100 mg daily was then started for 3 and 4 days, respectively. This was followed by transfer of at least one thawed cleavage stage day 2 embryo of good quality. Groups I and II were compared in terms of clinical pregnancy and implantation rates. Results. In group I (3-day progesterone) and group II (4-day progesterone) the pregnancy rates were 41.02% (16/39) and 18.51% (5/27), respectively. On the other hand, the implantation rates were 16.82% (18/107) and 7.69% (6/78), respectively. The difference was statistically significant (p values 0.0172 and 0.0386, resp.). Conclusion. Progesterone supplementation for three days before the transfer of cleavage stage (day 2) cryopreserved embryos has significantly higher pregnancy and implantation rates, as compared to four-day supplementation.

Efficacy of micronised vaginal progesterone versus oral dydrogestrone in the treatment of irregular dysfunctional uterine bleeding: a pilot randomised controlled trial

BACKGROUND

The vaginal route is more effective than the other drug delivery routes for some specific indications.

AIM

To compare the efficacy of a vaginal progesterone preparation with that of oral dydrogesterone.

METHODS

A total of 69 women with irregular dysfunctional uterine bleeding were randomly assigned into one of two groups: oral dydrogesterone group (n = 35) and vaginal progesterone group (n = 34). At the end of a three-month treatment period, the women were re-evaluated. The endometrial histology findings and menstrual cycle characteristics were used as primary outcome measures. Pearson chi-square and Fisher's exact test were used for data analysis.

RESULTS

Findings from 54 eligible women were evaluated. There was no statistically significant difference in both menstrual recordings and endometrial histology results between the groups.

CONCLUSIONS

Vaginal micronised progesterone could be an alternative to oral preparations in the treatment of dysfunctional uterine bleeding. This needs to be further evaluated in adequately controlled randomised trials against other effective treatments.

Estrogen level monitoring in artificial frozen-thawed embryo transfer cycles using step-up regime without pituitary suppression: is it necessary?

Background

To discuss the meaning of serum oestradiol monitoring in frozen embryo transfer cycle using hormone replacement without pretreatment with gonadotropin hormone (GnRH) agonist.

Methods

The data from two hundred twelve women undergoing two hundred seventy-four frozen-thawed embryo transfer (FET) cycles was included in this retrospective cohort study. They were detected of serum oestradiol levels and endometrium thicknesses during hormone supplement FET cycles and compared their pregnancy outcomes according to their oestradiol level on progesterone initiation day.

Results

Patients with different levels of serum oestradiol (percentile 0–25^th, 25^th–75^th and 75^th–100^th) on progesterone initiation day yielded the endometrium thickness of 9.3 ± 0.12, 8.9 ± 0.07 and 9.1 ± 0.11 mm(P > 0.05) and the pregnancy rate of 32.2%, 38.4% and 36.3% (P > 0.05) respectively.

Conclusion

The serum estradiol level did not predict pregnancy success in hormone replacement FET cycles, suggesting that oestradiol monitoring in this method of endometrial preparation is unnecessary.

What is the ‘ideal’ duration of progesterone supplementation before the transfer of cryopreserved–thawed embryos in estrogen/progesterone replacement protocols?

Different studies dealing with the start of progesterone supplementation in assisted reproduction treatment cycles have shown that the problem apparently is the correct timing. We therefore would like to discuss the data on: (i) the start of progesterone replacement in oocyte donation programmes; (ii) the start of progesterone replacement in frozen-thawed hormone-supplemented cycles; (ii) the problem of too early a rise of progesterone in fresh IVF cycles as a model of too early an administration of progesterone; and (iv) the benefit of high progesterone levels on the day of embryo transfer in fresh IVF cycles. From the data reviewed in this paper it seems to be appropriate to start progesterone administration before transfer in oocyte donation programmes as well as transfer of cryopreserved/thawed cells as soon as the endometrium is developed sufficiently (> or =8 mm, trilaminar pattern), and to perform the embryo transfer not before day 3-4 of progesterone treatment, i.e. embryo development on day 2-3. Studies dealing with the influence of too early a rise of progesterone in fresh IVF cycles have shown different results. In fact high progesterone levels seem to reflect a high response but not a lower probability of conception. Furthermore, high progesterone levels on the day of embryo transfer in fresh IVF cycles could lower myometrial contractility and therefore increase implantation rates. Since the experience from oocyte donation programes shows the benefit of a longer preparation time using progesterone, and high progesterone levels seem to have a benefit during embryo transfer, this would suggest extending progesterone administration before transfer. However, we have to find the optimal individual transfer protocol after mock cycles, for example with pinopode detection or other methods applicable in routine IVF programmes. We need more studies to be sure whether reproductive outcome after transfer of cryopreserved-thawed cells in estrogen/progesterone supplement cycles is influenced by the duration of progesterone pretreatment. If this is so, we must look for practicable methods to modify the protocols according to the individual patient, the embryonic developmental stage during transfer and other variables.

Counselling on cryopreservation of pronucleated oocytes

The German Embryo Protection Law permits only the cryopreservation of supernumerary pronuclear stage eggs. Data are needed to counsel patients about their individual benefits from this procedure. All fresh embryo transfer cycles performed from January 1994 until December 1998 in which supernumerary pronucleate eggs were cryopreserved (n = 557) were analysed retrospectively, together with data from all subsequent cycles involving transfers of frozen-thawed pronucleate eggs (n = 420) from January 1994 until June 2001. The additional cumulative pregnancy rate per fresh cycle was 11.5%. This rate depended on the number of embryos per transfer, i.e. 1.9, 8.2 and 13.0% respectively when one, two or three embryos were transferred (P < 0.05). A strong correlation was found between the numbers of cryopreserved pronucleate eggs and pregnancy rates, of 9.3, 10.5 and 17.1% when 1-3, 4-6, or at least 7 pronucleate eggs were available respectively. Additional benefit in terms of this rate from cryopreservation for a patient with and without a pregnancy in the fresh embryo transfer cycles was 5.3 and 12.7% respectively. It is concluded that higher pregnancy rates in cycles involving cryopreserved eggs for patients who did not become pregnant in fresh transfer cycles reveals the disadvantage of the German Embryo Protection Law, which does not allow embryo selection. Therefore, cryopreservation of pronucleate eggs with a higher developmental potential is possible. The total pregnancy rate could be raised from 28.0 to 35.5% per fresh transfer cycle.