The preovulatory serum estradiol pattern in natural IVF/ICSI cycles

Optimal Timing of Ovulation Triggering to Achieve Highest Success Rates in Natural Cycles-An Analysis Based on Follicle Size and Oestradiol Concentration in Natural Cycle IVF

INTRODUCTION

Timing of ovulation triggering is essential in infertility treatments including treatments based on natural menstrual cycles. However, data on follicle size and oestradiol (E2) concentration are limited. Therefore, the model of natural cycle IVF (NC-IVF) was applied to provide more detailed information on these parameters to better schedule the optimal time for triggering ovulation.

MATERIALS AND METHODS

A retrospective cross-sectional analysis of 606 monofollicular NC-IVF cycles was performed at a university-based IVF centre from 2016 to 2019. Follicle size and E2 and LH serum concentrations were evaluated on day -5 to 0 (day 0 = day of oocyte retrieval). Ovulation was triggered if follicle size was 14-22 mm. Patients with irregular cycles, endometriosis >II°, cycles with azoospermia or cryptozoospermia and cycles with inconsistent data were excluded. All parameters were analysed inter- and intraindividually, and associations of the parameters were evaluated. Associations were adjusted for age, cause of infertility and number of previous transfers.

RESULTS

The mean age of women undergoing NC-IVF was 35.8 ± 4.0 years. Follicle size increased by 1.04 ± 0.03 mm, and E2 concentration by 167 ± 11.0 pmol/l per day.Based on a multivariate adjusted mixed model with follicle size, E2 and their interaction, the number of retrieved oocytes was associated with E2 concentration (aOR 1.91, 95% CI: 1.03-3.56; p = 0.040). Maturity of oocytes was associated not only with E2 concentration (aOR 2.01, 95% CI: 1.17-3.45; p = 0.011) but also with follicle size (aOR 1.27, 95% CI: 1.01-1.60; p = 0.039), as was the interaction of both parameters (aOR 0.96, 95% CI: 0.93-0.99; p = 0.017).LH surge was calculated to start in 25% of cases at an E2 level of 637 pmol/l, in 50% of cases at 911 pmol/l and in 75% of cases at an E2 level of 1,480 pmol/l.The live birth rate per follicle aspiration cycle was (non-significantly) higher in cycles with follicles sizes at the time of oocyte retrieval of 18-22 mm (7.7%-12.5%) versus in cycles with follicles sizes of 14-17 mm (1.6%-4.3%).

CONCLUSION

The study contributes to an optimization of infertility treatments involving natural cycles. The study gives guidance about the number of days required after follicle monitoring to schedule the optimal time for triggering ovulation.

Decrease in preovulatory serum estradiol is a valuable marker for predicting premature ovulation in natural/unstimulated in vitro fertilization cycle

Background

Premature ovulation occurs at a high rate in natural-cycle in vitro fertilization (IVF), and cycle cancellation further hampers the overall efficiency of the procedure. While lower levels of estradiol (E2) are observed in preovulatory follicles, it is unclear whether declines in E2 can be used as an effective marker of premature ovulation.

Methods

This retrospective analysis includes 801 natural/unstimulated IVF/ICSI cycles undergoing scheduled ovum pick-up (OPU) and 153 natural/unstimulated IVF/ICSI cycles undergoing emergency OPU at a university IVF center from May 2014 to February 2017.

Results

Among the 801 IVF/ICSI cycles undergoing scheduled OPU, preovulatory E2 levels increased by more than 10% in 403 (50.31%) cycles of the sample (Group A), while 192 (23.97%) cycles experienced a plateau (increased or decreased by 10%; Group B), and 206 (25.72%) cycles decreased by more than 10% (Group C). Group C had more patients who experienced premature LH surges, premature ovulation, as well as the fewest oocytes retrieved, frozen embryos, and top-quality embryos. A multivariate logistic regression analysis indicated that premature ovulation was associated with preovulatory E2/−1E2 ratio and premature LH surge. Moreover, preovulatory E2/−1E2 ratio served as a valuable marker for differentiating premature ovulation, with an AUC (area under the receiver operating curve) of 0.708 and 0.772 in cycles with premature LH surges and cycles without premature LH surges, respectively. Emergency OPU resulted in a significantly decreased rate of premature ovulation and increased number of frozen embryos.

Conclusion

Decreases in preovulatory serum E2 was a valuable marker for premature ovulation in natural/unstimulated IVF cycle. Emergency OPU based on the preovulatory E2/−1E2 ratio decreased the rate of premature ovulation in cycles that experienced E2 decreases.

Electronic supplementary material

The online version of this article (10.1186/s13048-018-0469-x) contains supplementary material, which is available to authorized users.

Serum estradiol level change after human chorionic gonadotropin administration had no correlation with live birth rate in IVF cycles

OBJECTIVE

To investigate the correlation between the estradiol (E2) level change after hCG administration and the live birth rate in GnRH agonist long or short protocols, and to explore the possible factors related to E2 dynamics after hCG administration during controlled ovarian hyperstimulation (COH).

STUDY DESIGN

A retrospective analysis was performed on 2868 patients who received IVF/intracytoplasmic sperm injection (ICSI) treatment with GnRH agonist long or short protocol. The patients were divided into three groups according to their serum E2 changes after hCG administration, and the live birth rates were compared among groups. The area under the receiver operating characteristic (ROC) curve was calculated to assess the predictive value of E2 change for the probability of live birth. Logistic regression analysis was also applied to exclude interference from various confounding factors. Finally, multivariate regression analysis was conducted to assess factors related to the E2 change after hCG administration.

RESULTS

No significant difference was observed in live birth rates (4.26%, 36.38% or 30.81% in long protocol (P=0.697); 25.81%, 26.71% or 30.81% in short protocol (P=0.697)) among patients with increasing, plateauing or decreasing E2 responses after hCG administration. The area under the ROC curve for the E2 change in prediction of live birth rate was 0.506 in long protocol, or 0.524 in short protocol. Logistic regression analysis showed that the serum E2 change after hCG administration had no correlation with live birth rate. Multivariate regression analysis showed that the percentage of mature follicles (larger than 14mm) and the duration of stimulation negatively correlated with the E2 change after hCG administration.

CONCLUSIONS

In GnRH agonist cycles, the serum E2 change after hCG administration had no correlation with live birth rate in fresh embryo transfer cycles, and this change negatively correlated with the percentage of mature follicles on the day of hCG administration.

Embryo transfer and luteal support in natural cycles

Embryo transfer policy and luteal supplementation was reviewed, comparing literature data and the results from the Maribor IVF Centre. A retrospective analysis of 1024 cycles in patients undergoing IVF, intracytoplasmic sperm injection (ICSI) or testicular sperm aspiration in unstimulated cycles was carried out using four different approaches for cycle monitoring. This showed that the most successful protocol for monitoring was administration of human chorionic gonadotrophin (HCG) when serum oestradiol was >0.49 nmol/l and follicle diameter was at least 15 mm. The implantation rate per transferred embryo was higher when a blastocyst was transferred (42.8%) rather than a day-2 embryo (23.5%) in the same monitoring protocol. Analysis of the influence of patient age on the success of oocyte retrieval, oocyte fertilization, embryo transfer rate and delivery rate demonstrates that patient age does not influence the rate of positive oocyte retrieval or fertilization rate as much as it influences pregnancy rate per embryo transfer. The delivery rate per cycle was dramatically influenced by age in patients over 38 years. There is no clear evidence in the literature as to whether luteal phase support is necessary in natural cycles for IVF/ICSI. Comparing the data, a higher pregnancy rate was observed if HCG was administered after embryo transfer.

Ovarian follicular concentration of IL-12, IL-15, IL-18 and p40 subunit of IL-12 and IL-23

BACKGROUND

The aim of the study was to determine the presence of interleukin (IL)-12, IL-15, IL-18 and p40 subunit of IL-12/IL-23 in follicular fluid from spontaneous cycles and the relation between the concentration of selected cytokines and IVF-embryo transfer outcome.

METHODS

IVF-embryo transfer and enzyme immunoassay (EIA) (R&D Systems, Minneapolis, MN, USA and MBL, Nagoya, Japan) were used.

RESULTS

Follicular fluid of women included in the IVF-embryo transfer procedure contained common p40 subunit of IL-12/IL-23 (median 70.1 pg/ml), IL-15 (median 1.3 pg/ml) and IL-18 (median 38.2 pg/ml). There was a significant negative correlation between follicular fluid concentrations of IL-15 and IL-18 (R=-0.392, P=0.003). Significantly higher concentrations of common p40 subunit of IL-12/IL-23 (median 79.8 pg/ml) were found in the follicular fluid taken from follicles containing oocytes, when compared with those without an oocyte (median 44.5 pg/ml, P=0.006). Patients who achieved clinical pregnancy had significantly decreased concentration of IL-15 (median 0.8 pg/ml) compared with patients without successful IVF-embryo transfer outcome (median 1.4 pg/ml, P=0.047).

CONCLUSION

Follicular fluid collected from spontaneous cycles contains detectable levels of p40 subunit of IL-12/IL-23, IL-15 and IL-18. Increased concentrations of p40 subunit of IL-12/IL-23 in follicles containing oocytes suggest an important role of this cytokine in reproduction. Possible negative value of IL-15 as a predictor of IVF-embryo transfer success remains to be determined.

Minimal stimulation IVF with late follicular phase administration of the GnRH antagonist cetrorelix and concomitant substitution with recombinant FSH: a pilot study

BACKGROUND

The use of the natural cycle for IVF offers the advantage of a patient-friendly and low-risk protocol. Its effectiveness is limited, but may be improved by using a GnRH antagonist to prevent untimely LH surges.

METHODS

In this pilot study, minimal stimulation IVF with late follicular phase administration of the GnRH antagonist cetrorelix and simultaneous substitution with recombinant FSH was applied for a maximum of three cycles per patient. Main outcome measures were pregnancy rates per started cycle and cumulative pregnancy rates after three cycles.

RESULTS

A total of 50 patients completed 119 cycles (2.4 per patient). Fifty-two embryo transfers resulted in 17 ongoing pregnancies [14.3% per started cycle; 32.7% per embryo transfer; 95% confidence interval (CI) 7.9-20.7% and 19.7-45.7%, respectively]. One dizygotic twin pregnancy occurred after transfer of two embryos, the other pregnancies were singletons. The cumulative ongoing pregnancy rate after three cycles was 34% (95% CI 20.6-47.4%). Live birth rate was 32% per patient (95% CI 18.8-45.2%).

CONCLUSIONS

Pregnancy rates after IVF with minimal, late follicular phase stimulation are encouraging. Considering the low-risk and patient-friendly nature of this protocol, it may be a feasible alternative to IVF with ovarian hyperstimulation.

Measurement of perifollicular blood flow of the dominant preovulatory follicle using three-dimensional power Doppler

OBJECTIVE

To establish whether we might predict the outcome of unstimulated in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles with quantitative indices of perifollicular blood flow assessed with three-dimensional (3D) reconstruction of power Doppler images.

METHODS

This prospective study included an analysis of 52 unstimulated cycles. Color and power Doppler ultrasound examinations of a single dominant preovulatory follicle were performed on the day of oocyte pick-up. With 3D reconstruction and processing, quantitative indices were obtained i.e. the percentage of volume showing a flow signal (VFS) inside a 5-mm capsule of perifollicular tissue and the percentage of VFS of each of the three largest vessels in this capsule. These indices as well as pulsed Doppler indices were compared between the groups of cycles with different outcomes using a one-way ANOVA test.

RESULTS

In nine cycles no oocyte was retrieved (Group A), in seven cycles no fertilization occurred (Group B) and in 30 cycles no implantation occurred (Group C). Six cycles resulted in pregnancy (Group D). There were no statistically significant differences in pulsed and power Doppler indices between these groups. However, the percentage of VFS in the capsule was higher than average in cycles with implantation (19.22 +/- 16.82 vs. 12.42 +/- 8.89, NS) and the percentage of VFS in the main vessel exhibited lower than average values in cycles with implantation (20.66 +/- 10.05 vs. 39.84 +/- 20.15), but only reached borderline statistical significance (F = 2.457, P = 0.074).

CONCLUSION

It can be hypothesized that the follicles containing oocytes able to produce a pregnancy have a distinctive and more uniform perifollicular vascular network.

Results of intracytoplasmic sperm injection of single oocyte in 362 unstimulated cycles

PURPOSE

The purpose was to test the adequacy of unstimulated cycles for intracytoplasmic sperm injection (ICSI) and to evaluate implantation and pregnancy rates in three different age groups.

METHODS

ICSI was performed in 362 unstimulated cycles in women up to 45 years old. All cycles were monitored by serum estradiol, urinary LH, and ultrasound.

RESULTS

The delivery rate per started cycle was higher in patients younger than 36 (9.4%) than in cycles with patient's age between 36 and 39 years (4.8%) or older than 40 (4.6%) but the difference was not statistically significant. In all groups, the fertilization rate was similar (70.4, 77.6, and 84.8%, respectively). The pregnancy rate per cycle and the pregnancy rate per puncture was similar in the group of patients in age between 36 and 39 years (8.3 and 9.7%) and those older than 40 (7.7 and 9.3%).

CONCLUSIONS

Unstimulated cycles monitored by serum estradiol, urinary LH, and ultrasound can produce an acceptable pregnancy rate after ICSI procedure only in patients younger than 36.

Is there any benefit from the culture of a single oocyte to a blastocyst-stage embryo in unstimulated cycles?

BACKGROUND

The aim of the study was to test the influence of 2- and 5-day cultivation of a single oocyte on the pregnancy rate in a non-stimulated cycle.

METHODS

A retrospective chart review of 391 consecutive patients undergoing IVF and intracytoplasmic sperm injection in unstimulated cycles was performed. The embryos were kept in MediCult universal IVF medium for day 2 transfers and in BlastAssist System for day 5 transfers.

RESULTS

The oocyte recovery rate in the group for 2-day cultivation and in the group for 5-day cultivation was similar, being 79.4 (162/204) and 83.6% (154/187) respectively. The same is true of the fertilization rate (73.8 versus 77.7%). The blastulation rate was 52.8%. The embryo transfer rate per cycle was higher when day 2 embryos were transferred: 64.8% (105/162) compared with 35.7% (55/154) if blastocyst-stage embryos were transferred. The pregnancy rate per transferred embryo was higher when a blastocyst was transferred (40.0%) instead of a day 2 embryo (23.8%).

CONCLUSION

The expected pregnancy rate calculated per embryo available on day 2 of cultivation was similar in both groups (23.8 versus 22.2%) and it was not affected by oocyte culture to the blastocyst stage.

Value of the serum estradiol level on the day of human chorionic gonadotropin injection and on the day after in predicting the outcome in natural in vitro fertilization/intracytoplasmic sperm injection cycles

OBJECTIVE

To predict the risk of premature ovulation and possibility of pregnancy in natural IVF/ICSI cycles on the basis of the estradiol (E2) level on the day of hCG injection and on the day after.

DESIGN

A prospective study.

SETTING

Hospital research program.

PATIENT(S)

One hundred sixty-four women undergoing 305 IVF/ICSI natural cycles.

INTERVENTION(S)

Serum E2 levels were measured approximately 12 h before (day 0) and 12-17 h after hCG administration (day 1).

MAIN OUTCOME MEASURE(S)

E2 levels on day 0 and day 1, the ratio of the day 1 to day 0 levels, and cycle outcome.

RESULT(S)

In cycles with premature ovulation and in conception cycles, the average E2 level on day 0 was statistically significantly higher than in other cycles, whereas the E2 ratio was statistically significantly lower. Multiple logistic regression was used to determine the connection of the E2 level on day 0 (B0 = -0.742, B = 2.147, P =.01) and the E2 ratio (B0 = -0.742, B = -3.135, P<.001) with premature ovulation. Only the E2 ratio (B0 = 0.659, B = -2.209, P =.0068) was significantly connected with conception.

CONCLUSION(S)

In predicting the outcome of natural IVF/ICSI cycles, the importance lies not in the E2 level on the day of hCG administration or on the day after, but rather in the E2 ratio.