The true natural cycle frozen embryo transfer - impact of patient and follicular phase characteristics on serum progesterone levels one day prior to warmed blastocyst transfer.

BACKGROUND: In a true-natural cycle (t-NC), optimal progesterone (P4) output from the corpus luteum is crucial for establishing and maintaining an intrauterine pregnancy. In a previous retrospective study, low P4 levels (< 10 ng/mL) measured one day before warmed blastocyst transfer in t-NC were associated with significantly lower live-birth rates. In the current study, we aim to examine the relationship between patient, follicular-phase endocrine and ultrasonographic characteristics, and serum P4 levels one day prior to warmed blastocyst transfer in t-NC. METHOD: 178 consecutive women undergoing their first t-NC frozen embryo transfer (FET) between July 2017-August 2022 were included. Following serial ultrasonographic and endocrine monitoring, ovulation was documented by follicular collapse. Luteinized unruptured follicle (LUF) was diagnosed when there was no follicular collapse despite luteinizing-hormone surge (> 17 IU/L) and increased serum P4 (> 1.5 ng/mL). FET was scheduled on follicular collapse + 5 or LH surge + 6 in LUF cycles. Primary outcome was serum P4 on FET - 1. RESULTS: Among the 178 patients, 86% (n = 153) experienced follicular collapse, while 14% (n = 25) had LUF. On FET-1, the median serum luteal P4 level was 12.9 ng/mL (IQR: 9.3-17.2), ranging from 1.8 to 34.4 ng/mL. Linear stepwise regression revealed a negative correlation between body mass index (BMI) and LUF, and a positive correlation between follicular phase peak-E2 and peak-P4 levels with P4 levels on FET-1. The ROC curve analyses to predict < 9.3 ng/mL (< 25th percentile) P4 levels on FET-1 day showed AUC of 0.70 (95%CI 0.61-0.79) for BMI (cut-off: 23.85 kg/m2), 0.71 (95%CI 0.61-0.80) for follicular phase peak-P4 levels (cut-off: 0.87 ng/mL), and 0.68 (95%CI 0.59-0.77) for follicular phase peak-E2 levels (cut-off: 290.5 pg/mL). Combining all four independent parameters yielded an AUC of 0.80 (95%CI 0.72-0.88). The adjusted-odds ratio for having < 9.3 ng/mL P4 levels on FET-1 day for patients with LUF compared to those with follicle collapse was 4.97 (95%CI 1.66-14.94). CONCLUSION: The BMI, LUF, peak-E2, and peak-P4 levels are independent predictors of low serum P4 levels on FET-1 (< 25th percentile; <9.3 ng/ml) in t-NC FET cycles. Recognition of risk factors for low serum P4 on FET-1 may permit a personalized approach for LPS in t-NC FET to maximize reproductive outcomes.

Comparison of the efficacy of subcutaneous versus vaginal progesterone using a rescue protocol in vitrified blastocyst transfer cycles.

RESEARCH QUESTION: Does administration of subcutaneous (s.c.) progesterone support ongoing pregnancy rates (OPR) similar to vaginal progesterone using a rescue protocol in hormone replacement therapy frozen embryo transfer cycles? DESIGN: Retrospective cohort study. Two sequential cohorts - vaginal progesterone gel (December 2019-October 2021; n=474) and s.c. progesterone (November 2021-November 2022; n=249) -were compared. Following oestrogen priming, s.c. progesterone 25 mg twice daily (b.d.) or vaginal progesterone gel 90 mg b.d. was administered. Serum progesterone was measured 1 day prior to warmed blastocyst transfer (i.e. day 5 of progesterone administration). In patients with serum progesterone concentrations <8.75 ng/ml, additional s.c. progesterone (rescue protocol; 25 mg) was provided. RESULTS: In the vaginal progesterone gel group, 15.8% of patients had serum progesterone <8.75 ng/ml and received the rescue protocol, whereas no patients in the s.c. progesterone group received the rescue protocol. OPR, along with positive pregnancy and clinical pregnancy rates, were comparable between the s.c. progesterone group without the rescue protocol and the vaginal progesterone gel group with the rescue protocol. After the rescue protocol, the route of progesterone administration was not a significant predictor of ongoing pregnancy. The impact of different serum progesterone concentrations on reproductive outcomes was evaluated by percentile (<10th, 10-49th, 50-90th and >90th percentiles), taking the >90th percentile as the reference subgroup. In both the vaginal progesterone gel group and the s.c. progesterone group, all serum progesterone percentile subgroups had similar OPR. CONCLUSIONS: Subcutaneous progesterone 25 mg b.d. secures serum progesterone >8.75 ng/ml, whereas additional exogenous progesterone (rescue protocol) was needed in 15.8% of patients who received vaginal progesterone. The s.c. and vaginal progesterone routes, with the rescue protocol if needed, yield comparable OPR.

Vitrified-warmed blastocyst transfer timing related to LH surge in true natural cycle and its impact on ongoing pregnancy rates.

RESEARCH QUESTION: Does the timing of warmed blastocyst transfer in true natural cycle (tNC) differ according to six different commonly used definitions of LH surge, and do differences in timing have any impact on ongoing pregnancy rate (OPR)? DESIGN: Prospective monitoring, including repeated blood sampling and ultrasound analyses of 115 warmed blastocyst transfer cycles performed using tNC between January 2017 and October 2021. RESULTS: The reference timing of follicular collapse +5 days would be equivalent to LH surge +6 days in only 5.2-41.2% of the cycles employing the six different definitions of the LH surge. In contrast, the reference timing was equivalent to LH surge +7 days in the majority of cycles (46.1-69.5%) and less commonly to LH surge +8 days (1.8-38.3%) and +9 days (0-10.4%). For each definition of the LH surge, the OPR were comparable among the different warmed blastocyst transfer timings related to the LH surge (LH surge +6/+7/+8/+9 days). When logistic regression analysis was performed to evaluate the independent effect of variation of warmed blastocyst transfer timing (LH surge +6/+7/+8/+9 days) on OPR and taking LH surge +6 days as the reference, change in timing was not an independent predictor of OPR for any of the definitions of the LH surge. CONCLUSIONS: Employing a policy of performing warmed blastocyst transfer on follicular collapse +5 days and using six different definitions of the LH surge, vitrified-warmed embryo transfer timing is indeed equivalent to LH surge +7/+8 and even +9 days in a significant proportion of tNC with comparable reproductive outcomes.

Comparison of single euploid blastocyst transfer cycle outcome derived from embryos with normal or abnormal cleavage patterns.

RESEARCH QUESTION: To assess incidence of abnormal cleavage among biopsied blastocysts; to compare euploidy rates of the blastocysts with abnormal and normal cleavage; and to compare single euploid blastocyst transfer (SEBT) outcome derived from embryos with normal or abnormal cleavage. DESIGN: Retrospective analysis of prospectively collected data in a private IVF clinic. Consecutive 554 patients (749 cycles) undergoing preimplantation genetic testing for aneuploidy (n = 497; 671 cycles) or monogenic diseases (n = 57; 78 cycles) were included. All assessments for abnormal cleavage were carried out retrospectively; presence of abnormal cleavage was not a factor in deciding which euploid embryo to transfer. A total of 1015 blastocysts were biopsied and 295 SEBT procedures were carried out. Main outcome measure was live birth rate (LBR). RESULTS: Incidence of reverse cleavage, direct cleavage, and reverse plus direct cleavage, were 7.7%, 6.4% and 2.3%, respectively. Of the 1015 biopsied blastocysts, 35.0% were euploid. Blastocysts with abnormal cleavage, in total, had a significantly higher euploidy rate compared with blastocysts with normal cleavage (44.6% [74/166] versus 33.1% [281/849]; P = 0.017). The LBR after SEBT with normal, reverse and direct cleavage, and direct cleavage plus reverse cleavage, was 133/238 (55.9%), 6/26 (23.1%), 8/24 (33.3%) and 0/3 (0.0%) (P < 0.001). Generalized estimating equation analysis showed that the presence of abnormal cleavage pattern was the only independent predictor of LBR (OR 0.316; 95% CI 0.115 to 0.867; P = 0.013). CONCLUSIONS: Blastocysts with direct or reverse cleavage should be biopsied in preimplantation genetic testing cycles if they are morphologically eligible. Euploid blastocysts with abnormal cleavage, however, have approximately half the LBR of those euploid blastocyst with normal cleavage, hence, blastocysts with abnormal cleavage should have lower priority for transfer.

Subcutaneous luteal phase progesterone rescue rectifies ongoing pregnancy rates in hormone replacement therapy vitrified-warmed blastocyst transfer cycles.

RESEARCH QUESTION: Will luteal phase rescue with additional progesterone increase serum progesterone concentrations and improve reproductive outcomes in patients with low serum progesterone concentrations undergoing hormone replacement therapy (HRT) cycles? DESIGN: Case-control study including 40 consecutive patients with serum progesterone concentrations <8.75 ng/ml on the 5th day of progesterone supplementation who underwent rescue with a daily bolus of 25 mg s.c. progesterone, starting on the afternoon of the 5th day of progesterone administration. For every patient who underwent progesterone rescue, three patients matched by age, body mass index, number of previous attempts and number of blastocysts transferred, with serum progesterone concentration >8.75 ng/ml on the 5th day of progesterone administration served as controls (n = 120). The main outcome measure was ongoing pregnancy rate (OPR). RESULTS: Baseline demographic features and embryological data of the rescue and control groups were comparable. As expected, the mean serum progesterone concentration was lower in the rescue group on the 5th day of progesterone administration (7.84 ± 0.92 versus 15.32 ± 5.02 ng/ml; P < 0.001). Following rescue, the mean serum progesterone concentration on the day of vitrified-warmed embryo transfer (6th day of progesterone administration) was 33.43 ± 10.83 ng/ml (range 14.61-82.64 ng/ml), and the OPR of the rescue and control groups were comparable. CONCLUSIONS: In patients undergoing HRT vitrified-warmed blastocyst transfer with serum progesterone concentrations lower than 8.75 ng/ml 1 day prior to the scheduled embryo transfer (6th day of progesterone administration), additional supplementation with a 25 mg s.c. daily progesterone dose seems to rescue the cycle, resulting in OPR comparable to those of patients with serum progesterone >8.75 ng/ml.

Addition of intramuscular progesterone to vaginal progesterone in hormone replacement therapy in vitrified-warmed blastocyst transfer cycles.

RESEARCH QUESTION: Does intramuscular progesterone supplementation ensure ongoing pregnancy rates (OPR) comparable with vaginal progesterone only in hormone replacement therapy cycles for vitrified-warmed embryo transfer; and is there a window of serum progesterone concentration out of which reproductive outcomes may be negatively affected? DESIGN: Retrospective longitudinal cohort study carried out at a single IVF clinic. In total, 475 consecutive, day-5 to day-6 vitrified-warmed embryo transfer cycles using hormone replacement therapy regimen were included. Vaginal progesterone only was given to 143 patients; supplementation of vaginal progesterone only with intramuscular progesterone supplementation every third day was given to 332 patients. On the sixth day of progesterone administration, immediately before frozen-thawed embryo transfer, circulating progesterone levels were measured. Main outcome measure was OPR. RESULTS: The baseline demographic features and embryological data of the vaginal progesterone only and intramuscular progesterone supplementation groups were comparable. The OPR were 48.3% and 51.8%, respectively (P = 0.477). Neither the circulating progesterone level nor the type of progesterone administration were independent predictors of OPR. The effect of serum progesterone levels on OPR was evaluated by percentiles (<10%, 10-49%, 50-90% and >90%), taking 50-90% as the reference sub-group. All percentiles in the intramuscular progesterone supplementation group and in the vaginal progesterone only group had similar OPR. CONCLUSIONS: Intramuscular progesterone supplementation every third day, overall, does not enhance OPR compared with vaginal progesterone only.

PGT for aneuploidy does not affect three-cycle cumulative IVF discontinuation rate in women of advanced maternal age.

RESEARCH QUESTION: Does preimplantation genetic testing for aneuploidy (PGT-A) influence the discontinuation rate in women with advanced maternal age (AMA) undergoing IVF? DESIGN: Retrospective longitudinal cohort study carried out at a single IVF clinic in Turkey. In total, 401 consecutive AMA cases were included. Discontinuation rates of pre-intervention (conventional IVF; June 2013 to October 2014; 203 couples; 270 cycles) and post-intervention (PGT-A; April 2015 to June 2016; 198 couples; 285 cycles) periods were compared. To delineate the reason for discontinuation, a telephone survey was conducted. Primary outcome measure was cumulative discontinuation rate before completing three cycles of IVF treatment without achieving an ongoing pregnancy. RESULTS: The discontinuation rates after the first and second failed cycles were comparable between the two arms as were the cumulative discontinuation rates before completing three cycles. The cumulative ongoing pregnancy rate per embryo transfer was significantly higher in the PGT-A arm (43.2% versus 16.8%; P < 0.001). The cumulative ongoing pregnancy rate per patient was comparable between the two arms (20.7% versus 16.3%, respectively). Female age was the only significant contributor to treatment discontinuation (hazard ratio [HR] 1.07; 95% CI 1.09 to 1.13). Of the 296 couples discontinuing treatment in both arms, 179 (179/296 [60.5%]) participated in the survey; overall, psychological burden was the main reason for treatment discontinuation (37/179 [20.7%]). CONCLUSIONS: About 90% of AMA cases not achieving an ongoing pregnancy discontinue IVF treatment before completing three cycles. Discontinuation rate is not reduced by carrying out PGT-A. Female ageing is the only significant contributor, with a hazard of discontinuing further IVF treatment of 7% with female ageing of 1-year.

The effect of ≤6 cm sized noncavity-distorting intramural fibroids on in vitro fertilization outcomes: a systematic review and meta-analysis.

IMPORTANCE: The potential detrimental effects of fibroids on natural fecundity and in vitro fertilization (IVF) outcomes may be influenced by their size, location, and number. The impact of small noncavity-distorting intramural fibroids on reproductive outcomes in IVF is still controversial, with conflicting results. OBJECTIVE(S): To determine whether women with noncavity-distorting intramural fibroids of ≤6 cm size have lower live birth rates (LBRs) in IVF than female age-matched controls with no fibroids. DATA SOURCES: MEDLINE, Embase, Global Health, and Cochrane Library databases were searched from inception until July 1, 2022. STUDY SELECTION AND SYNTHESIS: Women undergoing IVF with noncavity-distorting intramural fibroids ≤6 cm constituted the study group (n = 520), whereas women with no fibroid formed the controls (n = 1392). Female age-matched subgroup analyses were performed to evaluate the impact of different cut-offs for size (≤6, ≤4, and ≤2 cm), location (the International Federation of Gynecology and Obstetrics [FIGO] type-3), and the number of fibroids on reproductive outcomes. Mantel-Haenszel odds ratios (ORs) with 95% confidence intervals (CIs) were used for outcome measures. All statistical analyses were performed using RevMan 5.4.1 MAIN OUTCOME MEASURE(S): The primary outcome measure was LBR. Secondary outcome measures were clinical pregnancy, implantation, and miscarriage rates. RESULT(S): After adopting the eligibility criteria, 5 studies were included in the final analysis. Women with ≤6 cm noncavity-distorting intramural fibroids had significantly lower LBRs (OR: 0.48, 95% CI: 0.36-0.65, 3 studies, I2=0; low-certainty evidence) compared with women with no fibroids. A significant reduction in LBRs was noted in ≤4 cm but not in the ≤2 cm subgroups. The FIGO type-3 fibroids of 2-6 cm size were associated with significantly lower LBRs. Owing to a lack of studies, the impact of the number of noncavity-distorting intramural fibroids (single vs. multiple) on IVF outcomes could not be assessed. CONCLUSION(S): We conclude that 2-6 cm sized noncavity-distorting intramural fibroids have a deleterious effect on LBRs in IVF. The presence of FIGO type-3 fibroids of 2-6 cm size is associated with significantly lower LBRs. Conclusive evidence from high-quality randomized controlled trials, the reference standard study design for studies of health care interventions, is needed before myomectomy might be offered in daily clinical practice to women with such small fibroids before undergoing IVF treatment.

Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review.

Despite the worldwide increase in frozen embryo transfer, the search for the best protocol to prime endometrium continues. Well-designed trials comparing various frozen embryo transfer protocols in terms of live birth rates, maternal, obstetric and neonatal outcome are urgently required. Currently, low-quality evidence indicates that, natural cycle, either true natural cycle or modified natural cycle, is superior to hormone replacement treatment protocol. Regarding warmed blastocyst transfer and frozen embryo transfer timing, the evidence suggests the 6th day of progesterone start, LH surge+6 day and hCG+7 day in hormone replacement treatment, true natural cycle and modified natural cycle protocols, respectively. Time corrections, due to inter-personal differences in the window of implantation or day of vitrification (day 5 or 6), should be explored further. Recently available evidence clearly indicates that, in hormone replacement treatment and natural cycles, there might be marked inter-personal variation in serum progesterone levels with an impact on reproductive outcomes, despite the use of the same dose and route of progesterone administration. The place of progesterone rescue protocols in patients with low serum progesterone levels one day prior to warmed blastocyst transfer in hormone replacement treatment and natural cycles is likely to be intensively explored in near future.