P-593 Low dose clomiphene citrate does not reduce implantation rates - a cohort study based on modified Natural Cycle IVF

Study question

Does low dose clomiphene citrate (CC) reduce implantation and eventually pregnancy and live birth rates?

Summary answer

Low dose CC does not reduce implantation rate and pregnancy and live birth rates – based on the model of modified Natural Cycle IVF (NC-IVF).

What is known already

CC is commonly used for ovulation induction in the treatment of anovulation or idiopathic infertility. It is also added to NC-IVF cycles to mildly stimulate follicular growth and to inhibit LH surge. CC reduces endometrial thickness and affects endometrial function. Therefore it is assumed that CC negatively affects implantation and thereby reduced pregnancy and live birth per embryo. However, previous studies have shown inconsistent results as previous studies mainly calculated pregnancy rates per cycle but not implantation rate per embryo.

Study design, size, duration

This cohort study included embryos transferred in NC–IVF and CC-NC-IVF cycles. Women with a maximum age of 42 years were treated at a university hospital between 2011 and 2016. Clinical pregnancy rate and live birth rate per embryo transferred and miscarriage rate per amniotic sac were calculated.

Participants/materials, setting, methods

A daily dose of 25mg of CC starting on day 5-7 of the cycle until the day of ovulation trigger was applied. A modified mixed effect Poisson regression model was used to account for the number of cycles in the same women and the number of embryos in the same cycle to achieve rate ratios (RR). Adjustment for maternal age, parity, type of infertility, duration of subfertility and indication for IVF were made.

Main results and the role of chance

499 couples underwent a total of 1043 IVF cycles, 453 NC-IVF and 590 CC-NC-IVF cycles. Baseline characteristics of both groups were not different. The additional administration of CC did neither decrease clinical pregnancy rate (aRR 1.16; 95% CI: 0.90 – 1.50)[MV1] nor live birth rate per transferred embryo (aRR 1.20; 95% CI: 0.89 – 1.62). Miscarriage rate was also not different in CC-NC-IVF compared to NC-IVF (aRR 1.05; 95%: CI 0.63 – 1.76).

Limitations, reasons for caution

This study does not allow to draw any conclusions regarding the effect of higher CC dosages. As randomization was not performed, some bias regarding the choice of IVF treatment cannot be completely excluded.

Wider implications of the findings

As this study revealed for the first time that low dose CC does not affect implantation, low does CC can be used for many different treatments. However, further studies are required to evaluate if this also applies to higher CC dosages.

Trial registration number

not applicable

P-776 Maternal and neonatal outcomes of singletons and twins after frozen-thawed embryo transfer in different cycle regimes: Increased risks of hypertensive disorders in Hormone replacement cycles

Study question

What are the associations between cycle regime and maternal and neonatal outcomes after frozen-thawed embryo transfer leading to singleton or twin life birth?

Summary answer

Hormone replacement cycles are associated with higher and natural or low-dose stimulation with lower risks for bleeding, hypertension and preeclampsia in singleton and twin pregnancies.

What is known already

So far, there is no consensus on optimal cycle regimen for endometrial preparation: Frozen-thawed embryo transfers can be either performed in Natural Cycles (NC-FET), low-dose Stimulation Cycles (SC-FET) or Hormone Replacement Cycles (HRC-FET). In previous studies, HRC-FET was shown to be associated with an increase of serious maternal and neonatal complications, i.e. preeclampsia (doubled to tripled risk), postpartum hemorrhage (doubled risk), placenta accrete (sixfold risk), post-term birth (sixfold risk) and Caesarean section (doubled risk) compared to NC-FET or SC-FET. These results indicate that risks are increased in cycles in which the development of follicles and luteal bodies is medically inhibited.

Study design, size, duration

Retrospective cohort study analyzing a total of 4636 singletons and also 544 twins born after FET that were registered in the Swiss IVF Registry from 2014 to 2019.

Participants/materials, setting, methods

Women were divided into three groups according to the cycle regimes: NC-FET (n = 776), SC-FET (n = 758) and HRC-FET (n = 3646) leading to life birth. Maternal outcomes included pregnancy complications such as bleedings, isolated hypertension (>140/90 mmHg) and preeclampsia. Neonatal outcomes comprised gestational age and weight, mode of delivery and neonatal status.

Incidences were compared using Fisher exact or Chi-square tests. Multivariate mixed model analysis was performed for singleton and twin pregnancies.

Main results and the role of chance

In singleton pregnancies, the incidences of bleeding in first trimester (NC: 2.8%, SC: 2.6%, HRC: 7.0%; p<.001), isolated hypertension (NC: 0.9%, SC: 0.2%, HRC: 1.8%; p = <.001) and preeclampsia (NC: 1.7%, SC: 0.3%, HRC: 2.8%, p<.001) were significantly higher in HRC-FET. Gestational diabetes occurred most (NC: 4.6%, SC: 7.0%, HRC: 4.5%; p = 0.032) and intrauterine growth restriction least frequently (NC: 1.9%, SC: 0.2%, HRC: 1.3%; p = 0.004) in SC-FET. Highest spontaneous birth rates were reported in NC-FET (NC: 51.2%, SC: 45.0%, HRC: 33.8%; p<.001). Multivariate analysis revealed doubled odds ratio of bleeding in first trimester (aOR 2.01; 95% CI 1.20-3.37; p = 0.008%) and preeclampsia (aOR 2.13; 95% CI 1.12-4.05; p = 0.021) in HRC-FET vs. NC-FET and sixfold odds ratio of preeclampsia in HRC-FET vs. SC-FET (aOR 6.37; 95% CI 1.48-27.54; p = 0.013). Outcomes of SC-FET and NC-FET were comparable.

In twin pregnancies, the incidences of preeclampsia were significantly higher in HRC-FET (NC: 2.7%, SC: 1.0%, HRC: 7.2%, p = 0.026). There were no differences in delivery mode between cycle regime. Multivariate analysis revealed numerically higher odds ratio of preeclampsia in HRC-FET vs. NC-FET (aOR 2.57; 95% CI 0.55 - 12.07; p = 0.232) and in HRC-FET vs. SC-FET (aOR 4.07; 95% CI 0.47 - 34.91; p = 0.2) but without reaching significance.

Limitations, reasons for caution

The data were drawn from a registry analysis with limited information on patients’ characteristics. Data such as BMI were not available. As the study is based on a register analysis, some errors in data collection cannot be excluded.

Wider implications of the findings

This is the first large register study to demonstrate a clear association between the three different cycle regimes and pregnancy complications both in singleton and twin pregnancies. HRC-FET showed the highest maternal risks of hypertensive disorders, therefore, it should be avoided and replaced by SC-FET or NC-FET if medically possible.

Trial registration number

Not applicable.

P-391 Early pregnancy complications after frozen-thawed embryo transfer in different cycle regimes: Increased risks for miscarriages and bleedings in Hormone replacement cycles

Study question

What are the associations between cycle regime and early pregnancy complications after frozen-thawed embryo transfers and what are the respective life birth rates per pregnancy?

Summary answer

Hormone replacement cycles are associated with doubled odd ratios of bleedings and miscarriages <12 weeks leading to lowest life birth rates (LBR) per pregnancy (68.2%).

What is known already

So far, there are only few studies which analysed both, the associations between cycle regime and early pregnancy complications as well as life birth rates (LBR) per pregnancy after frozen-thawed embryo transfer (FET). In 2017, a Cochrane analysis did not find sufficient evidence to support the use of a specific cycle regimen in preference to another since there were only four direct comparisons. In 2021, a network meta-analysis including 26 RCTs and 113 cohort studies revealed lowest LBR in hormone replacement cycles compared with other endometrial preparation protocols but without stating the reasons for the lowest LBR.

Study design, size, duration

Retrospective cohort study analyzing a total of 7342 pregnancies after FET that were registered in the Swiss IVF Registry from 2014 to 2019.

Participants/materials, setting, methods

Women were divided into three groups according to the different cycle regimens: Natural Cycles (NC-FET, n = 998), low-dose Stimulation Cycles (SC-FET, n = 984) and Hormone Replacement Cycles (HRC-FET, n = 5360) leading to pregnancy. Outcomes included early pregnancy complications such as bleedings, miscarriages and ectopic pregnancies, deliveries (including intrauterine deaths) and LBR. Incidences were compared using Fisher exact and Chi-square tests. Multivariate mixed model analysis with pregnancy complications as outcome was performed.

Main results and the role of chance

The incidences of bleeding in first trimester (NC: 3.5%, SC: 4.3%, HRC: 8.4%; p<.001) and miscarriage <12 weeks (NC: 19.0%, SC: 19.7%, HRC: 29.1%; p<.001) were significantly higher in HRC-FET.

Multivariate analysis revealed doubled odds ratio of bleedings in first trimester (aOR 1.92; 95% CI 1.30-2.81; p<.001) and miscarriages <12 weeks (aOR 1.82; 95% CI 1.51-2.19; p<.001) in HRC-FET vs. NC-FET. There were comparable odds ratio in HRC-FET vs. SC-FET and no differences between NC-FET vs. SC-FET. Highest LBR per pregnancy (NC: 78.0%, SC: 77.2%, HRC: 68.2%%; p<.001) was reported in NC-FET.

Limitations, reasons for caution

The data were drawn from a registry analysis with limited information on patients’ characteristics. Data such as BMI were not available. As the study is based on a register analysis, some errors in data collection cannot be excluded.

Wider implications of the findings

This is the latest large European register study evaluating early pregnancy complications and LBR per pregnancy after FET by cycle regime. Miscarriage rate was highest in HRC-FET which can be translated into lower LBR. Thus, HRC-FET should be avoided if medically possible, to achieve better pregnancy outcomes.

Trial registration number

Non required

O-033 Ovarian tissue transplantations in 196 women by FertiPROTEKT– live birth rate of 26.5% per woman is associated with female age and first versus repeated transplantation

Study question

What is the live birth rate of ovarian tissue transplantation and which factors are associated with the success rate?

Summary answer

Live birth rate per transplanted woman is 26.5% and the success rate is associated with female age and first versus repeated transplantation.

What is known already

Live birth rates after tissue transplantations have been reported to be between around 24% and 41% per patient. Success rates seem to be negatively associated with increasing female age at the time of tissue cryopreservation and with pelvic radiation. Success rates are apparently not reduced after overnight transportation of tissue before freezing.

Study design, size, duration

Registry analysis of 244 transplantations in 196 women, performed by 26 centers of the FertiPROTEKT network from 2007 to 2019 with a follow up till 12/2020.

Participants/materials, setting, methods

Orthotopic transplantation was performed in 196 women, 191 with previous malignant and 5 with previous non-malignant diseases. Size of transplanting centers varied between 1 and 100 transplantations per center (average: 9.5 ± 19.6 transplantations). Factors possibly associated with success rate such as female age, first and repeated transplantation, experience of the transplanting center and overnight transportation of the tissue before freezing were analysed.

Main results and the role of chance

Average age of all transplanted 196 women was 31.3 years (SD, standard deviation, 5.2) at the time of cryopreservation (range 17-44y) and 35.9 years (SD 4.8, range 23-47) at the time of first transplantation. Overall pregnancy rate was 30.6% (95% CI, 24.2-37.6%) per first transplantation and 32.7% (95% CI, 26.1-39.7) per patient. Overall live birth rate per first transplantation was 25.0% (95% CI, 19.1-31.7%) and per patient 26.5% (95% CI, 20.5-33.3%). Pregnancy and live birth rates were calculated and graphically expressed as a continuous function of age to allow estimation of success rates per age group. Success rate decreased with increasing age at the time of tissue freezing. Pregnancy rate after first transplantation was 34.5% (95% CI, 26.7-42.9%) in women <35y and 20.4% (95% CI, 10.6-33.5%) in women ≥35y.

Pregnancy rate was higher after 1st transplantation (30.6% (95% CI, 24.2-37.6%)) compared to 2nd and more transplantations (11.8% (95% CI, 3.3-27.5%)).

Pregnancy rates after 1st transplantation was higher in centers with ≥10 transplantations (35.1%) compared to centers with <10 transplantation (25.4%) (p = 0.12). Corresponding live birth rates were 27.0% and 18.6%.

Success rates was not different in women with and without overnight transportation of tissue before cryopreservation.

Limitations, reasons for caution

The data were drawn from a registry analysis. Data such as ovarian reserve and premature ovarian insufficiency were not available for all women. Data might be influenced by different follow up policies of the centers.

Wider implications of the findings

The study reveals the high potential of ovarian tissue freezing and transplantation but only if freezing is performed in younger women. The study suggests to better focus on the first and not on repeated transplantations. It also opens the discussion if transplantation should rather be performed by experienced centres.

Trial registration number

Non

Clomiphene citrate stimulated cycles – additional gonadotrophin stimulation increases endometrium thickness without increasing implantation rate

It is known that Clomiphene citrate (CC) reduces endometrial thickness, but it is unknown if additional gonadotrophin stimulation increases endometrial thickness and if this has an effect on implantation rate in in vitro fertilization (IVF). The retrospective study included 263 minimal stimulation IVF-cycles stimulated with 25 mg CC per day (CC- IVF), and 161 IVF-cycles stimulated with CC plus 75IU hMG (human Menopausal Gonadotrophin) per day (CC/ hMG-IVF). Endometrial and oestradiol (E2) measurements were analysed between day -4 and 0 (0 = day of oocyte retrieval) and the association of endometrial thickness and treatment on implantation rates were studied after multiple adjustments. It was shown that on day 0, endometrium was significantly thicker in CC/hMG-IVF versus CC-IVF cycles (9.81 ±2.68 versus 9.06 ±2.54 mm, p = 0.005). However, increased endometrial thickness did not have an effect on implantation and live birth rates. In conclusion, gonadotrophins should not be added to low dose CC treated IVF cycles just to increase endometrial thickness as increased endometrial thickness does not increase implantation rate.

Follicular flushing leads to higher oocyte yield in monofollicular IVF: a randomized controlled trial

STUDY QUESTION

Does follicular flushing increase the number of mature oocytes in monofollicular IVF?

SUMMARY ANSWER

Follicular flushing increases the number of mature oocytes in monofollicular IVF.

WHAT IS KNOWN ALREADY

Flushing increases neither the oocyte yield nor the pregnancy rate in polyfollicular IVF or in poor responder patients. In monofollicular IVF, the effect of flushing has so far been addressed by two studies: (i) a prospective study with minimal stimulation IVF demonstrated an increased oocyte yield, and (ii) a retrospective study with natural cycle (NC)-IVF showed an increased oocyte yield and an increased transfer rate.

STUDY DESIGN, SIZE, DURATION

Randomized controlled trial including 164 women who were randomized for either aspiration with or without flushing from 2016 to 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Infertile women 18–42 years of age with an indication for IVF treatment at a university-based infertility unit. Women undergoing monofollicular IVF were randomized to either follicular aspiration only or follicular aspiration directly followed by five follicular flushes at a 1:1 ratio. The intervention was done without anaesthesia, using a gauge 19 single-lumen needle. Flushing volume was calculated (sphere formula) based on the size of the follicle.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 164 women were included; 81 were allocated to ‘aspiration only’ and 83 to additional ‘flushing’. Primary analysis was based on the intention-to-treat: oocyte yield, defined as the collected mature oocyte rate, was higher (n = 64/83, 77.1%) in the flushing group compared to the aspiration only group (n = 48/81, 59.3%, adjusted risk difference (RD): 18.2% (95% CI 3.9–31.7%), P-value = 0.02). In the flushing group, most oocytes were retrieved within the first three flushes (63/83, 75.8%). Fertilization rate was higher in the flushing group (n = 53/83, 63.9% vs n = 38/81, 46.9%; adjusted RD: 16.8% (96% CI 1.5–31.4%), P = 0.045). Transfer rate was also higher in the flushing group (n = 52/83, 62.7% vs n = 38/81, 46.9%; RD: 15.71 (95% CI 0.3–30.3%)), but the difference was not significant (P = 0.06). The clinical pregnancy rate n = 9/83 versus n = 9/81 (RD: −0.3% (95% CI −9.9% to 9.5%)) and live birth rate n = 7/83 versus n = 8/81 (RD: −1.5% (95% CI −10.4% to 7.1%)) were not significantly different between the flushing and the aspiration group. The median duration of the intervention was significantly longer with flushing (2.38 min; quartiles 2.0, 2.7) versus aspiration only (0.43 min; quartiles 0.3, 0.5) (P < 0.01). There was no significant difference in the mean (±SD) visual analogue scales pain score between the follicular flushing (3.4 ± 1.8) and the aspiration group (3.1 ± 1.89).

LIMITATIONS, REASONS FOR CAUTION

Blinding of the procedure was not possible.

WIDER IMPLICATIONS OF THE FINDINGS

Our study proved that flushing of single follicles in NC-IVF increases the oocyte yield. In contrast to polyfollicular IVF flushing seems to be beneficial in a monofollicular setting if the technique used in our study (single-lumen needle, 5 flushings with flushing volume adaptation) is applied.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the financial sources of the division and in part by a research grant provided by NMS Biomedical SA, Switzerland. The company did not have any roles in design or conduct of the study or in the preparation of the manuscript. The authors have no other conflicts of interest.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT 02641808.

TRIAL REGISTRATION DATE

29 December 2015

DATE OF FIRST PATIENT’S ENROLMENT

22 August 2016

Short-term application of ibuprofen before ovulation

AIM OF THE STUDY

The aim was to analyse if ibuprofen, as a non-selective cyclooxygenase (COX) inhibitor, has any negative effect on oocyte competence and embryo quality. COX- inhibitors are popular over-the-counter analgesics. Whereas selective COX inhibitors have been shown to impair female fertility, data on non-selective COX inhibitors are poor. Hence, they have not been recommended for women trying to conceive.

METHODS

This is an observational study comparing ibuprofen exposed and unexposed women from 18 to 42 years of age, using the model of natural cycle in vitro fertilisation (IVF) to determine oocyte and embryo quality. Follicular growth was monitored and if the follicle was mature (≥ 15mm size and estimated oestradiol level of ≥ 800pmol/l), ovulation was triggered. Women with luteinising hormone (LH) surge received 400mg ibuprofen every 8 hours to postpone ovulation, whereas women without LH surge received none (controls). Oocyte retrieval rate, oocyte maturity, fertilization rate, embryo development and embryo quality as well as implantation rate were analysed.

RESULTS

Of the 111 women included, 63 received ibuprofen, and 48 did not. Rates of mature oocytes and implantation rate did not differ. Logistic regression showed no significant association of ibuprofen intake, LH- level or reason for infertility on embryo quality.

CONCLUSION

Based on our results, we suggest that, particularly within natural cycle IVF, ibuprofen does no harm around ovulation as analgesic treatment.

Fertility preservation methods in young women with systemic lupus erythematosus prior to cytotoxic therapy: experiences from the FertiPROTEKT network

OBJECTIVES

Despite new treatment options, some patients with systemic lupus erythematosus (SLE) need to be treated with the cytotoxic agent cyclophosphamide (CYC). Unlike malignant disease, there are no recommendations for ovarian protection in SLE. The clinical experience of the FertiPROTEKT network as well as recommendations after literature review will be presented in this paper.

METHODS

Retrospective analyses of counselling and treatment data from the FertiPROTEKT register with special respect to SLE patients under 40 years prior to planned CYC treatment.

RESULTS

A total of 2836 patients were advised prior to cytotoxic treatment in one of the FertiPROTEKT centres during January 2007 to November 2011. Of those, 68 patients (mean age 25 +/- 6.07 years) were counselled for severe SLE. Only five women did not make use of a fertility preservation method. Sixty-three patients (92.6%) decided in favour of a fertility preservation method. The largest proportion (91.2%) opted for treatment with a GnRH analogue. Ovarian tissue removal for cryoconservation was performed in 16 patients (25%). Stimulation therapy for cryoconservation of fertilized egg cells was performed in three patients (4.4%).

CONCLUSIONS

When counselling patients with SLE for fertility preservation one has to be aware of the disease-specific risks. According to the literature, a safe and effective option in SLE up to now has been the use of a GnRH analogue. Cryoconservation of ovarian tissue must still be seen as an experimental treatment, but as data on removal, cryoconservation, retransplantation and pregnancies are steadily rising, this presents a promising option for young SLE patients. Cryoconservation of oocytes must be very critically evaluated due to the need for a stimulation therapy and should only be performed after particular consideration of the individual risks.