Endometrial preparation for frozen-thawed embryo transfer in an artificial cycle: transdermal versus vaginal estrogen

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.

Preparation of the endometrium for frozen embryo transfer: an update on clinical practices

Over the past decade, the application of frozen-thawed embryo transfer treatment cycles has increased substantially. Hormone replacement therapy and the natural cycle are two popular methods for preparing the endometrium. Hormone replacement therapy is now used at the discretion of the doctors because it is easy to coordinate the timing of embryo thawing and transfer with the schedules of the in-vitro fertilization lab, the treating doctors, and the patient. However, current results suggest that establishing a pregnancy in the absence of a corpus luteum as a result of anovulation may pose significant maternal and fetal risks. Therefore, a 'back to nature' approach that advocates an expanded use of natural cycle FET in ovulatory women has been suggested. Currently, there is increasing interest in how the method of endometrial preparation may influence frozen embryo transfer outcomes specifically, especially when it comes to details such as different types of ovulation monitoring and different luteal support in natural cycles, and the ideal exogenous hormone administration route as well as the endocrine monitoring in hormone replacement cycles. In addition to improving implantation rates and ensuring the safety of the fetus, addressing these points will allow for individualized endometrial preparation, also as few cycles as possible would be canceled.

Association between serum estradiol level on day of progesterone start and outcomes from frozen blastocyst transfer cycles utilizing oral estradiol

PURPOSE

Supraphysiologic serum estradiol levels may negatively impact the likelihood of conception and live birth following IVF. The purpose of this study is to determine if there is an association between serum estradiol level on the day of progesterone start and clinical outcomes following programmed frozen blastocyst transfer cycles utilizing oral estradiol.

METHODS

This is a retrospective cohort study at an academic fertility center analyzing 363 patients who underwent their first autologous single (SET) or double frozen embryo transfer (DET) utilizing oral estradiol and resulting in blastocyst transfer from June 1, 2012, to June 30, 2018. Main outcome measures included implantation, clinical pregnancy, live birth, and miscarriage rates. Cycles were stratified by quartile of serum estradiol on the day of progesterone start and separately analyzed for SET cycles only. Poisson and Log binomial regression were used to calculate relative risks (RR) with 95% confidence intervals (CI) for implantation, clinical pregnancy, live birth, and miscarriage with adjustments made for age and BMI.

RESULTS

Cycles with the highest quartile of estradiol (mean 528 pg/mL) were associated with lower risks of implantation (RR 0.66, CI 0.50-0.86), ongoing pregnancy (RR 0.66, CI 0.49-0.88), and live birth (RR 0.70, CI 0.52-0.94) compared with those with the lowest estradiol quartile (mean 212 pg/mL). Similar findings were seen for analyses limited to SETs. There was no significant difference in miscarriage rate or endometrial thickness between groups.

CONCLUSION

High levels of serum estradiol on the day of progesterone start may be detrimental to implantation, pregnancy, and live birth following frozen blastocyst transfer.

Analysis of Relevant Factors Affecting the Pregnancy Rate of Frozen-Thawed Embryo Transfer Cycle

Objective

The aim of this study is to explore the relevant factors affecting the pregnancy rate of frozen-thawed embryo transfer cycle.

Methods

The clinical data of 931 patients who underwent artificial cycle preparation for endometrial FET from April 2017 to November 2020 in the reproductive center of our hospital were retrospectively analyzed.

Results

According to the pregnancy situation, the patients were divided into 450 cases of pregnancy and 481 cases of biochemical pregnancy. The univariate analysis of FET biochemical pregnancy showed that there were statistically significant differences between pregnancy and biochemical pregnancy in terms of years of infertility, age, endometrial thickness, P level, E2/P, and the number of high-quality embryos (P < 0.05). Multivariate analysis of pregnancy showed that age <30 years was a protective factor for biochemical pregnancy and endometrial thickness <8 mm and E2/P < 0.3 were risk factors (P < 0.05).

Conclusion

The regulation of endometrial thickness and E2/P serves as the key of treatment for patients undergoing FET using artificial cycle preparation for endometrial transfer, and it contributes to improve the pregnancy rate; also, the patient's age is an important indicator influencing the pregnancy rate.

Short (seven days) versus standard (fourteen days) oestrogen administration in a programmed frozen embryo transfer cycle: a retrospective cohort study

Research question

What influence does seven days of oestrogen administration versus fourteen days have on the reproductive outcomes of frozen-thawed embryo transfer (FET) in programmed endometrial preparation cycles?

Design

In a retrospective study, conducted at a university-affiliated tertiary hospital, a total of 2628 infertile patients (4142 FET cycles) were divided into one of two groups between January 2014 and December 2020: group A (n = 1406, seven days of oestrogen before progesterone (P4) supplementation) and group B (n = 2716, fourteen days of oestrogen before P4 supplementation). The primary outcome was cumulative live birth rate (CLBR). Secondary outcomes were other pregnancy-related outcomes, maternal and neonatal complications.

Results

No significant difference in CLBR was observed when comparing seven versus fourteen days of oestrogen administration before starting P4 supplementation (47.6% vs. 48.8%, P = 0.537). Furthermore, multivariable logistic regression analysis revealed that oestrogen administration in programmed FET cycles (7 days vs. 14 days) was not significantly associated with CLBR (OR 1.04, 95% CI 0.89–1.23). The risks of maternal and neonatal complications were comparable between the two groups.

Conclusions

Variation in the duration of oestradiol supplementation before P4 initiation does not impact FET reproductive outcomes. For infertile women who desire to conceive as soon as feasible, short (seven days) oestrogen administration in a programmed FET cycle may be a suitable alternative.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00967-5.

Luteal-phase support in assisted reproductive technology: An ongoing challenge

It has been shown that in controlled ovarian hyper stimulation cycles, defective luteal phase is common. There are many protocols for improving pregnancy outcomes in women undergoing fresh and frozen in vitro fertilization cycles. These approaches include progesterone supplements, human chorionic gonadotropin, estradiol, gonadotropin-releasing hormone agonist, and recombinant luteinizing hormone. The main challenge is luteal-phase support (LPS) in cycles with gonadotropin-releasing hormone agonist triggering. There is still controversy about the optimal component and time for starting LPS in assisted reproductive technology cycles. This review aims to summarize the various protocols suggested for LPS in in vitro fertilization cycles.

A comprehensive evaluation of progestin-primed ovarian stimulation protocol in patients with or without PCOS undergoing in vitro fertilization

Progestin-primed ovarian stimulation (PPOS) regimen was established for assisted reproduction. However, its feasibility and outcomes in polycystic ovary syndrome (PCOS) patients need further evaluation. The outcomes of infertile patients with PCOS (study group) and normal ovaries (control group with unexplained infertility and tubal factor infertility) who underwent PPOS and IVF/ICSI protocol were retrospectively studied. The baseline information, primary, and secondary outcomes of patients were collected. The dynamic changes of hormones were closely monitored. 198 PCOS patients and 374 controls were included in this study. After controlled ovarian hyperstimulation (COH), 15 oocytes were retrieved from PCOS patients on average, which was more than those from the controls (p < 0.001). The oocytes and embryos obtained from the PCOS patients exhibited better developmental potential as the number of fertilized oocytes, cleaved embryos, top-quality embryos, viable embryos, cryopreserved embryos, the rate of fertilization, and viable embryo per oocyte retrieved in PCOS patients were significantly higher than those in the controls (all p < 0.001). No significant difference between the two groups was identified regarding the primary outcome, ongoing pregnancy, and other secondary outcomes. No moderate to severe ovarian hyperstimulation syndrome (OHSS) was diagnosed in either group. With the proposed PPOS protocol, the quantity, quality, developmental potential of oocytes, and embryos obtained from PCOS patients were superior to those from controls. The protocol was efficient and safe in terms of pregnancy, obstetric, and perinatal outcomes. OHSS was effectively mitigated in the patients, with or without PCOS, who underwent COH.

Impact of the type of endometrial oestrogen preparation for frozen-thawed embryo (vaginal or transdermal) on perinatal outcomes in an artificial cycle

INTRODUCTION

Serum oestradiol concentration at the time of frozen embryo transfer (FET) in artificial cycle are lower when using transdermal administration of oestrogen for endometrial preparation compared to the vaginal route. This difference could have consequences for placentation and establishment of maternal-foetal circulation. The aim of our study was to compare the birth weight of newborns and the perinatal issues after FET in an artificial cycle with regard to the route of administration of oestrogens.

METHODS

Retrospective monocentric cohort study in the medically assisted reproduction department of the University Hospital of Angers, France, between January 2017 and October 2020. Inclusion criteria were age >18 years old and one live birth after FET in an artificial cycle. The main outcome was the birth weight of the newborns. The choice of oestrogens administration (transdermal or vaginal) was left to the patient.

RESULTS

804 FET in artificial cycle were included in our study. Oestrogens were administrated in 356/804(36.6%) patients using transdermal route and in 448/804(45.9%) patients using vaginal route. There were 68/345 (19.1%) live births in the transdermal group and 85/448 (19%) in the vaginal group. There was no difference in the birth weight of the newborns (3320[2100-4165] grams in the transdermal group vs 3327.5[915-4650] grams in the vaginal group, p=0.72). All the other perinatal issues were comparable between the two groups.

CONCLUSION

Birth weights and perinatal issues were comparable with regard to the route of administration of oestrogens (vaginal or transdermal) in the context of endometrial preparation before FET in an artificial cycle.

A prospective study of oral estrogen versus transdermal estrogen (gel) for hormone replacement frozen embryo transfer cycles

AIM

This study was done to compare the efficacy of transdermal estrogen (gel) to oral estradiol in hormone replacement frozen embryo transfer cycles (HR- FET).

MATERIALS AND METHODS

This was a prospective study conducted between March 2019 and December 2019. We included 294 HR FET cycles: 156 cycles using oral estrogen tablets (oral group) and 138 cycles using transdermal gel (17 beta estradiol 0.06% w/w) (gel group). Primary objective of this study was to compare endometrial thickness (ET) on the day of progesterone start between the two groups. Our secondary objective was to compare implantation rates (IR), clinical pregnancy rates (CPR), miscarriage rates (MR), duration of estrogen administration, estradiol (E2) levels before the start of progesterone, cycle cancellation rates, patient satisfaction score and undesirable side effects between both the groups.

RESULTS

There was no significant difference in the ET, IR, CPR, MR and duration of E2 administration and cycle cancellation rates between both the groups. Patient satisfaction score was significantly higher (8.02 ± 1.07 vs 6.96 ± 0.99 p < .01) and side effects were significantly lower (18.1% vs 55.1%, p≤.01), in the gel group compared to the oral group.

CONCLUSION

This study concluded that transdermal estrogen (gel) is equally efficacious as oral estrogen in HR FET cycles with transdermal gel having an added benefit of better patient comfort with less side effects and better safety profile.

Endometrial thickness measurements among Asherman syndrome patients prior to embryo transfer

STUDY QUESTION

Is there an association between endometrial thickness (EMT) measurement and clinical pregnancy rate among Asherman syndrome (AS) patients utilizing IVF and embryo transfer (ET)?

SUMMARY ANSWER

EMT measurements may not be associated with successful clinical pregnancy among AS patients undergoing IVF.

WHAT IS KNOWN ALREADY

Clinical pregnancy rate after IVF is significantly lower in patients with a thin endometrium, defined as a maximum EMT of <7 mm. However, AS patients often have a thin EMT measurement due to intrauterine scarring, with a paucity of data and no guidance on what EMT cutoff is appropriate when planning an ET among these patients.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study of 45 AS patients treated at a specialized advanced hysteroscopic clinic from 1 January 2015, to 1 March 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Review of EMT measurements prior to a total of 90 ETs, among 45 AS patients. The impact of the maximum EMT measurement prior to ET on clinical pregnancy rate was analyzed.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 25/45 (55.6%) AS patients ultimately went on to have ≥1 clinical pregnancy following a mean ± SD of 2.00 ± 1.26 ET attempts. There was a total of 90 ETs among the 45 AS patients, with 29/90 (32.2%) ETs resulting in a clinical pregnancy. Younger patient age (P = 0.05) and oocyte donation (P = 0.01) were the only variables identified to be significant predictors for a positive clinical pregnancy outcome on bivariate analysis. The mean EMT measurement prior to all ETs among AS patients was 7.5 ± 1.6 mm. EMT measurement prior to ET did not predict a positive clinical pregnancy on either bivariate (P = 0.84) or multivariable analysis (odds ratio 0.91, P = 0.60). 31.8% of EMT measurements measured <7.0 mm. In this small cohort, no difference in the clinical pregnancy rate was detected when comparing ETs with EMT measurements of <7.0 mm versus ≥7.0 mm (P = 0.83). The mean EMT measurement decreased with increasing AS disease severity; 8.0 ± 1.6 mm for mild disease, 7.0 ± 1.4 mm for moderate disease and 5.4 ± 0.1 mm for severe disease.

LIMITATIONS, REASONS FOR CAUTION

Our small sample size limits our ability to draw any definitive conclusions. In addition, patients utilized various infertility clinics. This limits our ability to evaluate the consistency of EMT measurements and the IVF care that was received.

WIDER IMPLICATIONS OF THE FINDINGS

EMT measurement cutoff values should be used with caution if canceling a scheduled ET in AS patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was not funded. K.I. reports personal fees from Karl Stroz and personal fees from Medtronics outside the submitted work. The other authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Effect of transdermal estrogen dose regimen for endometrial preparation of frozen-thawed embryo transfer on reproductive and obstetric outcomes

PURPOSE

Previous studies have reported different methods of estrogen administration during endometrial preparation for frozen-thawed embryo transfer (FET). This study aimed to investigate a beneficial regimen of transdermal estrogen administration for FET.

METHODS

We investigated the reproductive and obstetric outcomes of FET by comparing the increasing dose (ID) group that mimics changes in serum estradiol during the menstrual cycle and the constant dose (CD) group. Transdermal patches were used for estrogen administration in both groups. In our hospital, we targeted 315 cycles of the ID group in which FET was performed in 2017 and 324 cycles of the CD group in which FET was performed in 2018. In all cases, single embryo transfer was performed.

RESULTS

All were singleton pregnancies. There was no difference in clinical pregnancy rate (28.9% vs 28.2%, P =.837) and live birth rate (17.3% vs 21.4%, P =.201) between the ID and CD groups. Spontaneous abortion rate was significantly lower in the CD group than in the ID group (37.2% vs 23.0%, P =.041). There was no difference in obstetrical outcomes.

CONCLUSIONS

It was considered that the simple CD regimen may be more beneficial than the complicated ID regimen.

Neurophysiology of cognitive behavioural therapy, deep breathing and progressive muscle relaxation used in conjunction with ART treatments: a narrative review

BACKGROUND

Infertility is defined as the failure to achieve clinical pregnancy after 12 months of regular unprotected intercourse. It could be due to male or female factors, each requiring different treatment options. ART treatment exposes couples to numerous psychological stressors. Therefore, it has been recommended by the ESHRE Psychology and Counselling Guideline Development Group recently that psychosocial support should be offered as a complementary therapy during infertility treatments. In this context, the efficiency of different psychological interventions, such as cognitive behaviour therapy (CBT), deep breathing (DB), and progressive muscle relaxation (PMR), was evaluated in several clinical trials in terms of couples' mental health and pregnancy outcomes.

OBJECTIVE AND RATIONALE

The neurophysiology of CBT, DB and PMR, which are used in interventional studies, in both men and women undergoing ART, has not yet been fully elucidated. This review represents a comprehensive report, aiming to collate novel insights into the neurobiological processes and physiological mechanisms that occur during the practice of CBT, DB and PMR.

SEARCH METHODS

PubMed, Google Scholar and Cochrane Library were interrogated to conduct this comprehensive literature review. The search was carried out using combinations of MeSH terms and keywords: infertility, assisted reproductive techniques, IVF, ICSI, emotions, psychological stress, cognitive behavioural therapy, mind-body therapies and relaxation. Relevant information related to the mechanism of action of stress management techniques were obtained from original articles and reviews published in English without taking into consideration the time of publication. Moreover, as it was not the major focus of the review, only recent systematic reviews (2015-2019) pinpointing the effects of psychological interventions on infertility treatment outcomes were also retrieved from the above-mentioned databases.

OUTCOMES

CBT, DB and PMR may modify the activity of stress-related brain regions such as the prefrontal cortex, amygdala, hypothalamus and hippocampus, as demonstrated by functional MRI and electroencephalogram studies. Furthermore, applying these techniques was associated with mood improvements and a decline in stress biomarkers, and, hypothetically, reducing stress biomarkers attenuates the stress-induced effects on ART outcomes.

WIDER IMPLICATIONS

Increasing the knowledge of fertility staff, researchers and physicians regarding the mechanisms of action of these stress management techniques has several advantages. For instance, understanding the underlying neurophysiological pathways would assist practitioners to engage ART couples in the practice of these techniques. Also, it may enhance the quality of the support programmes and psychological research. Accordingly, this will ensure that these interventions reach their full potential and therefore improve clinical outcomes.

Is there a critical LH level for hCG trigger after the detection of LH surge in modified natural frozen-thawed single blastocyst transfer cycles?

Purpose

There is no consensus yet in the literature on an optimal luteinizing hormone (LH) level for human chorionic gonadotrophin (hCG) trigger timing in patients undergoing frozen-thawed embryo transfer (FET) with modified natural cycles (mNC). The objective of our study was to compare the clinical results of hCG trigger at different LH levels in mNC-FET cases.

Methods

This retrospective study was conducted in Istanbul Memorial Hospital ART and Genetics Center. A total of 1076 cases with 1163 mNC-FET cycles were evaluated. LH levels between the start of LH rise (15 IU/L) and LH peak level (> 40 IU/L) were evaluated. Cycles were analyzed in four groups: group A (n = 287) LH level on the day prior to the day of hCG; groups B, C and D, LH levels on the day of hCG: group B (n = 245) LH 15–24.9; group C (n = 253), LH 25–39.9; group D (n = 383) LH ≥ 40. Cycle outcomes in the four groups were compared.

Results

Subgroup analyses of mNC-FET groups showed that implantation, clinical and ongoing pregnancy rates, and pregnancy losses were not significantly different in patients with different LH levels on the day of hCG trigger.

Conclusion

Our study suggests that hCG can be administered at any time between the start of LH rise (≥ 15 IU/L) and LH peak level (≥ 40 IU/L) without a detrimental effect on clinical outcome.