Does cleavage- versus blastocyst-stage embryo transfer improve fertility rates in women over 38 years of age undergoing assisted reproductive technology?

OBJECTIVE: To evaluate whether extending embryo culture to day 5 (D5) affects pregnancy rates in women older than 38 years undergoing in vitro fertilization (IVF). METHODS: This retrospective, observational cohort study included data from fresh IVF cycles of women over 38 years, during 2011-2021. The cohort was divided according to day 3 (D3) versus D5 embryo transfer (ET). RESULTS: A total of 346 patients (ages 38-45 years) who underwent 496 IVF cycles were included, each yielding one to six embryos. A total of 374 (75%) fresh D3 ETs were compared with 122 (25%) D5 ETs. Demographically, there were more nulliparas in the D3 group (189 [50.9%] vs 47 [38.8%], P = 0.021). Higher gonadotropin dosage was used (3512 ± 1346 vs 3233 ± 1212 IU, P = 0.045) and lower maximum estradiol levels were reached in the D3 group (1129 ± 685 vs 1432 ± 708 pg/mL, P = 0.002). Thirty-three (27%) of the D5 cycles resulted in transfer cancelation due to failure of blastocyst formation (P = 0.001). However, clinical pregnancy rates (P = 0.958), live birth rates (P = 0.988), and miscarriage rates (P = 0.710) did not differ between D3 and D5 ETs. Multivariable logistic regression for clinical pregnancy rate showed that day of transfer did not have a significant effect on the odds (P = 0.376), but maternal age (P = 0.001) and number of retrieved oocytes (P = 0.009) were significant variables. CONCLUSIONS: In older women, culturing embryos to blastocyst stage can decrease invalid ETs without reducing pregnancy rates. Cancelation rates are higher but it may avoid interventions and conserve valuable time.

Two types of cleavage, from zygote to three cells, result in different clinical outcomes and should be treated differently.

Research Question: What is the utilization rate of embryos that exert inadequate zygote cleavage into three daughter cells? Design: This study used a retrospective dataset from a single IVF Unit. A total of 3,060 embryos from 1,811 fresh IVF cycles were analyzed. The cleavage pattern, morphokinetics, and outcome were recorded. Only 2pn embryos, fertilized by ejaculated sperm, and cultured in a time-lapse system for at least 5 days were included. We generated three study groups according to the embryo's cleavage pattern: (I) Control, normal cleavage (n = 551); (II) fast cleavage, zygote to three cells within 5 h (n = 1,587); and (III) instant direct tripolar cleavage (IDC) from zygote to three cells (n = 922). Results: The rate of usable fast cleavage blastocysts was 108/1,587 (6.81%) and usable control blastocysts was 180/551 (32.67%). The time of PN fading and from fading to first cleavage differed significantly between the three groups. Although the pregnancy rate of control and fast cleavage blastocysts were comparable (40.35% and 42.55%, respectively), the amount of instant direct cleavage embryos that reached blastocyst stage was neglectable (only four embryos out of 922 analyzed IDC embryos) and unsuitable for statistical comparison of pregnancy rates. Conclusion: Our results indicate the need to culture instant direct cleavage embryos for 5 days, up to the blastocyst stage, and avoid transfer of embryos that are fated to arrest even when their morphological grade on day 3 is acceptable, whereas fast cleavage embryos could be transferred on day 3 when there is no alternative.

Stain-Free Sperm Analysis and Selection for Intracytoplasmic Sperm Injection Complying with WHO Strict Normal Criteria.

This multi-center study evaluated a novel microscope system capable of quantitative phase microscopy (QPM) for label-free sperm-cell selection for intracytoplasmic sperm injection (ICSI). Seventy-three patients were enrolled in four in vitro fertilization (IVF) units, where senior embryologists were asked to select 11 apparently normal and 11 overtly abnormal sperm cells, in accordance with current clinical practice, using a micromanipulator and 60× bright field microscopy. Following sperm selection and imaging via QPM, the individual sperm cell was chemically stained per World Health Organization (WHO) 2021 protocols and imaged via bright field microscopy for subsequent manual measurements by embryologists who were blinded to the QPM measurements. A comparison of the two modalities resulted in mean differences of 0.18 µm (CI -0.442-0.808 µm, 95%, STD-0.32 µm) for head length, -0.26 µm (CI -0.86-0.33 µm, 95%, STD-0.29 µm) for head width, 0.17 (CI -0.12-0.478, 95%, STD-0.15) for length-width ratio and 5.7 for acrosome-head area ratio (CI -12.81-24.33, 95%, STD-9.6). The repeatability of the measurements was significantly higher in the QPM modality. Surprisingly, only 19% of the subjectively pre-selected normal cells were found to be normal according to the WHO2021 criteria. The measurements of cells imaged stain-free through QPM were found to be in good agreement with the measurements performed on the reference method of stained cells imaged through bright field microscopy. QPM is non-toxic and non-invasive and can improve the clinical effectiveness of ICSI by choosing sperm cells that meet the strict criteria of the WHO2021.

Standardization of Post-Vitrification Human Blastocyst Expansion as a Tool for Implantation Prediction.

The increased use of vitrified blastocysts has encouraged the development of various criteria for selecting the embryo most likely to implant. Post-thaw assessment methods and timetables vary among investigators. We investigated the predictive value of well-defined measurements of human blastocyst re-expansion, following a fixed incubation period. Post-thaw measurements were taken exactly at 0 and 120 ± 15 min. Minimum and maximum cross-sectional axes were measured. Three groups were defined: Group 1: embryos that continued to shrink by 10 µm or more; group 2: embryos that ranged from -9 to +9 µm; and group 3: re-expansion of 10 µm or more. Patient and morphokinetic data were collected and integrated into the analysis. A total of 115 cases were included. The clinical pregnancy rate for group 1 was 18.9%; group 2, 27%; and group 3, 51.2% (p = 0.007). Pre-thaw morphologic grading and morphokinetic scores of the study groups did not reveal differences. p-values were 0.17 for the pre-thaw morphologic score, 0.54 for KID3, and 0.37 for KID5. The patients' demographic and clinical data were similar. The clinical pregnancy rate correlated with the degree of thawed blastocyst re-expansion measured 2 h after incubation. This standardized measure is suggested as a tool to predict the potential of treatment success before embryo transfer.

Gonadotropin releasing hormone agonist triggering for in vitro maturation cycles.

The objective was to evaluate the outcomes of in vitro maturation (IVM) cycles using gonadotropin releasing hormone agonist (GnRH-ag) triggering. A retrospective cohort of IVM cycles from January 2015 to December 2019 in a single university-affiliated centre was examined. Main outcome measures were: (i) IVM maturation rate; and (ii) IVM maturation result. Secondary outcome measures were: (i) metaphase II (MII) rate on the day of egg retrieval; (ii) final MII maturation rate; and (iii) pregnancy rates. A total of 98 IVM cycles were performed during the study period: 50 (51%) were triggered with GnRH-ag (17 received FSH priming and 33 did not) and 48 cycles (49%) were triggered by hCG (37 with FSH priming and 11 without). A significant (p = 0.01) difference was noticed in maturation rate on egg retrieval day, in favour of the GnRH-ag group, although not in the final maturation rate achieved. Pregnancy rates were comparable between treatment sub-groups. GnRH-ag triggering in IVM cycles is an optional triggering mode and can be considered an acceptable option, especially when fertility preservation is a concern. GnRH agonists resulted in higher maturation rate on day of oocyte retrieval, but no difference in the total maturation rate.

A prospective study of C-reactive protein in patients with obesity during IVF.

This prospective cohort pilot study investigated the physiology of C-reactive protein (CRP) during in vitro fertilization (IVF) cycles and its effect on outcomes in women with and without obesity. The study was conducted from April to August 2014, in the IVF Unit of a university-affiliated hospital. Women aged 18-42 years were enrolled. Those with chronic inflammatory diseases or acute illness were excluded. A total of 31 patients were included: 17 with BMI < 30 kg/m2 and 14 with BMI ≥ 30 kg/m2. Serum CRP levels were measured: (i) before starting ovarian stimulation; (ii) on the day of ß-HCG administration; and (iii) on day of ovum pick-up (OPU), in both serum and follicular fluid. Serum CRP levels were significantly higher in women with obesity at all time points. For the entire cohort, a positive correlation was found between basal oestradiol (E2) and basal CRP (r = 0.71, p < 0.05). A specific pattern of CRP levels was not detected during the IVF cycle. High serum CRP levels on OPU day had a negative effect on embryo quality (p = 0.056). CRP ≥ 0.5 mg/dL was associated with lower quality embryos (2.6 ± 0.3 vs. 3.3 ± 0.3; p = 0.04). High serum CRP level on OPU day negatively affects embryo quality.

Does stress affect IVF outcomes? A prospective study of physiological and psychological stress in women undergoing IVF.

RESEARCH QUESTION: What are the effects of physiological and psychological stress on fertility outcomes for women undergoing IVF? DESIGN: A prospective cohort study of 72 patients undergoing IVF in 2017 and 2018. Physiological stress was assessed by salivary cortisol measurements: (i) pretreatment, when the patient received the IVF protocol; (ii) before oocyte retrieval (follicular cortisol was also measured); and (iii) before embryo transfer. Emotional stress was evaluated at each assessment with the State-Trait Anxiety Inventory and a 1-10 Visual Analogue Scale (VAS, referred to as the 'Stress Scale'. Correlations between cortisol concentrations, psychological stress and IVF outcome were assessed. RESULTS: Salivary cortisol concentrations increased by 28% from pretreatment phase (0.46 ± 0.28 µg/dl) to maximum concentration on oocyte retrieval day (0.59 ± 0.29 µg/dl, P = 0.029) and then decreased by 29% on embryo transfer day (0.42 ± 0.23 µg/dl, P = 0.0162). On embryo transfer day, cortisol among women in their first cycle was higher than women who underwent more than one treatment (P = 0.024). Stress Scale score increased by 39% from pretreatment to a maximum score on oocyte retrieval day and then decreased by 12% on embryo transfer day. Salivary cortisol and Stress Scale were not related to subsequent embryo transfer, fertilization rate, embryo quality or clinical pregnancy rate. Follicular cortisol concentration was positively correlated with fertilization rate (r = 0.4, P = 0.004). CONCLUSION: It can be cautiously concluded that physiological and psychological stress do not negatively affect IVF outcomes. Moreover, high follicular cortisol concentrations might have positive effects on pregnancy rates.

Number of Oocytes Retrieved as a Criterion for "Freeze-All" Strategy versus a Single "Rescue" Bolus of Low-Dose Human Chorionic Gonadotropin Following GnRH Agonist for Ovulation Triggering: A Pilot Study.

AIM: To evaluate the number of oocytes retrieved as a criterion - when to use a "freeze-all" or low-dose "rescue human chorionic gonadotropin (hCG)" strategy. METHODS: A retrospective study. Instead of the classic hCG trigger, an E2 level of ≥3,000 pg/mL was used to trigger ovulation with GnRH agonist. The decision whether to "freeze all" or perform fresh embryo transfer (ET) with a bolus of hCG was made based on a maximum number of 20 oocytes retrieved. Beyond this cut off, a "freeze-all" strategy was implemented. Below this cut-off value, a fresh ET using a single bolus of 62.5 µg hCG on day 3 following oocyte pick-up was performed. The main outcome measures were clinical pregnancy rates and ovarian hyperstimulation syndrome (OHSS). RESULTS: E2 and progesterone levels increased after the rescue hCG bolus administration (E2 from 643.4 ± 311.1 to 1,086.1 ± 574.7 pg/mL, p = 0.003 and progesterone from 13.1 ± 4.8 to 39.2 ± 28.7 ng/mL, p < 0.0001). The clinical pregnancy rates were 25% in the freeze-all group and 32% in the rescue hCG group (p = 0.57). OHSS was not reported in either group. CONCLUSIONS: Both strategies seem to be efficacious and safe. An upper limit of 20 retrieved oocytes appears to be safe for applying a rescue hCG strategy.

What we learned from extended culture of 'rejected' day-3 cleavage stage embryos: a prospective cohort study.

BACKGROUND: To test whether poor quality day-3 embryos can undergo successful blastulation and implantation. METHODS: A prospective cohort study was conducted. Whether or not a good quality embryo was transferred on day-3, poor quality (rejected) embryos were further cultured and followed. The clinical outcome of each embryo was assessed. RESULTS: A total of 694 rejected embryos (from 205 patients) were included, with a blastulation rate of 21.2% (147 embryos) compared to 64.2% general blastulation rate reported by our laboratory (P < 0.01). In a multivariate logistic regression model, only their grade on day-3 significantly affected blastulation (P = 0.01). A total of 97 embryos attained eligibility for fresh transfer or cryopreservation, only 6 of which resulted from a day-3 embryo scored < 2. Of these, 52 were transferred, resulting in 21 pregnancies (16 clinical and 5 chemical). In summary, 694 cultured embryos yielded 16 clinical pregnancies; a 2.3% clinical pregnancy rate. CONCLUSIONS: Low score day-3 embryos can result in successful blastulation and clinical pregnancies. However, the normal blastulation rate is poor.

Does the transfer of a poor quality embryo together with a good quality embryo affect the In Vitro Fertilization (IVF) outcome?

BACKGROUND: IVF cycles which result in only one good quality embryo, and a second poor quality embryo present a dilemma when the decision involves transferring two embryos. The aim of this study was to evaluate whether a poor quality embryo has a negative effect on a good quality embryo when transferred along with a good quality embryo. METHODS: We retrospectively evaluated in vitro fertilization (IVF) cycles involving single embryo transfers (SET) and double embryo transfers (DET). Embryo quality was divided into poor "P" and good "G" quality. The main outcome measures were: live birth, implantation rate, miscarriage rate, clinical pregnancy rate and multiple pregnancy ratio. RESULTS: Six hundred three women were included. The study group consisted of 180 (29.9%) patients who had a double embryo transfer (DET) with one poor quality embryo and one good quality embryo (P + G). Control 1 group included 303 (50.2%) patients who had DET with two good quality embryos (G + G), and control 2 group consisted of 120 (19.9%) patients who had a single embryo transfer (SET) with one good quality embryo (G). Live birth rates were not significantly different when compared between study groups: 30.8% in the SET group (G), 27.2% in the (G + P) group and 33.7% in the (G + G) group. The SET group had the highest implantation rate (33.9%) compared to the DET groups (21.8% (G + P), 25.4% (G + G)) (P =0.022). The clinical pregnancy rate was 33.3% in the SET group (G), 33.3% in the (G + P) group, and 39.3% in the (G + G) group (P =0.39). The miscarriage rate was comparable in all groups. CONCLUSION: A poor quality embryo does not negatively affect a good quality embryo, when transferred together in a double embryo transfer.

Time lapse microscopy is useful for elective single-embryo transfer.

The aim of our study was to evaluate time lapse microscopy (TLM) as a selection tool for single-embryo transfer (SET) on day 5, blastocyst stage. An observational cohort study was conducted. Patients who had SET were compared to patients who had double embryo transfer (DET). A total of 108 patients were included in analysis, 83 had SET, and 25 underwent DET. Embryos were incubated and evaluated using TLM. The pregnancy rates were similar between the groups (42.2% in SET and 48.0% in DET). However, the multiple pregnancy rate was significantly higher in the DET group compared to the SET group (41.7% versus 2.9%, respectively; p < 0.001). This study concludes that SET with TLM do not decrease pregnancy rates compared to DET. However, transfers of two embryos increase the rate of multiple pregnancies.

What are the best predictors for successful GnRH antagonist protocol in in vitro fertilization (IVF) treatment?

OBJECTIVE: To determine factors that affect the success rate of GnRH antagonist protocol in in vitro fertilization (IVF) treatment. DESIGN: Retrospective cohort study. PATIENTS: Patients who underwent IVF cycle with their first GnRH antagonist protocol. INTERVENTION: Antagonist protocol during IVF treatment. The main outcome measurements were; Number of retrieved oocytes, embryo quality and pregnancy rate. RESULTS: Gravidity was negatively correlated with number of eggs (p = 0.017), while total follicle number ≥15 (p = 0.044) and E(2) on day of human chorionic gonadotropin (HCG) (p = 0.000) had a positive correlation with number of eggs. Maximum follicle size at HCG administration showed a trend toward an inverse correlation (p = 0.053). Addition of LH to drug stimulation was negatively correlated with number of eggs in comparison to rFSH only (p = 0.013 and 0.0000, respectively). Age and number of frozen eggs were negatively correlated with successful pregnancy (p = 0.025 and 0.004, respectively), while embryo quality, gravidity and number of embryos were positive (p = 0.011 and 0.014, respectively). CONCLUSION: Controlled parameters like timing of antagonist start, duration of antagonist and the optimal leading follicle diameter for HCG triggering had no effect on treatment outcomes.

GnRH-antagonist programming versus GnRH agonist protocol: a randomized trial.

OBJECTIVE: Testing the ability to program IVF GnRH-antagonist cycles to avoid weekend oocyte retrieval. STUDY DESIGN: Preliminary randomized clinical trial. Patients presenting an indication for IVF or IVF-ICSI were assigned into either the Treatment Group - GnRH antagonist protocol, programmed to start stimulatory agents on a Friday, with oral 2mg estradiol valerate twice a day from the 2nd day of cycle until the first Friday to follow, or to the Control Group - long luteal GnRH agonist protocol. RESULTS: The performance of 27 Treatment Group patients and 24 Control Group patients was analyzed. Cycle dynamics were not clinically or statistically different except for a significant difference in the number of follicles measuring ≥18 mm on hCG administration day. There were no differences in the number of aspirated ova, fertilization rates, embryo quality or number of embryos to be transferred. Pregnancy rate was 41.7% in the Treatment Group and 50% in the Control Group (P>0.5). Only one patient assigned to the Treatment Group had a weekend retrieval. CONCLUSIONS: Preliminary results demonstrate no compromise related to follicular estrogen programming in a GnRH antagonist protocol and provide reassurance regarding the ability to achieve programming goals.

Embryo quality and implantation rates are not influenced by total motile count values in an ICSI programme: a novel point of view.

Total motile count (TMC) is a useful tool for sperm evaluation, comprising both quantitative and motility parameters. Although frequently used, TMC has not yet been evaluated as a contributory variable for intracytoplasmic sperm injection (ICSI) cycles. In this study we evaluate the possible role of TMC as a prognostic parameter in cycles designated for ICSI. We also test the existence of a possible TMC-threshold value that might be predictive for ICSI cycle outcome in the everyday practice. This is a retrospective cohort study in which the research question is addressed by a locally weighted regression (LOESS) analysis. Primary outcome measures are fertilization rate, good quality embryos rate and implantation rate. A total of 666 patients were included, contributing 1456 cycles. The effect of TMC over the fertilization rate was significant, depicting an inverted U-shaped curve: with up to approximately 10 million motile sperm, fertilization rates increased as TMC increased, but from this point on decreased. A slight increment in the rate of good embryo formation with increasing value of TMC was noted, but this did not reach a statistical significance. TMC values demonstrated no effect in the case of implantation rates. ICSI may offer an advantage related to fertilization rates for the sub-fertile male population, with a motile sperm count up to 10 million.

Human oocyte cryopreservation and the fate of cortical granules.

OBJECTIVE: To examine the effect of the commonly used oocyte cryopreservation protocol on the cortical granules (CGs) of human immature germinal vesicle (GV) and mature metaphase II (MII) oocytes. DESIGN: Laboratory study. SETTING: IVF unit. INTERVENTION(S): Unfertilized, intracytoplasmic sperm injected (ICSI) oocytes, and immature oocytes were cryopreserved using a slow freezing-rapid thawing program with 1,2-propanediol (PROH) as a cryoprotectant. MAIN OUTCOME MEASURE(S): Cortical granule exocytosis (CGE) was assessed by either confocal microscopy or transmission electron microscopy (TEM). RESULT(S): The survival rates of frozen-thawed oocytes (mature and immature) were significantly lower compared with zygotes. Both mature and immature oocytes exhibited increased fluorescence after cryopreservation, indicating the occurrence of CGE. Mere exposure of oocytes to cryoprotectants induced CGE of 70% the value of control zygotes. The TEM revealed a drastic reduction in the amount of CGs at the cortex of frozen-thawed GV and MII oocytes, as well as appearance of vesicles in the ooplasm. CONCLUSION(S): The commonly used PROH freezing protocol for human oocytes resulted in extensive CGE. This finding explains why ICSI is needed to achieve fertilization of frozen-thawed human oocytes.

The effect of chilling on membrane lipid phase transition in human oocytes and zygotes.

BACKGROUND: Chilling injury occurs when the cell membrane undergoes a transition from the liquid state to the gel state. Human oocytes and single-cell zygotes are of similar shape and size but the post-thawing survival rate of oocytes is poorer. We set out to investigate the possible difference in membrane lipid phase transition (LPT) temperature between the two cell types. METHODS: The LPT temperature was measured with a Fourier Transform Infrared analyser, which detects the change in the vibration frequency of the CH2 bond stretches of the membrane lipid molecules during temperature change. The LPT temperatures of unfertilized human oocytes, in vitro-matured oocytes, and immature germinal vesicle (GV) stage oocytes were compared with that of abnormally fertilized human zygotes. RESULTS: The LPT temperatures of zygotes and of mature and immature GV oocytes differ significantly from each other (10.0 +/- 1.2, 16.9 +/- 0.9 and 24.4 +/- 1.6 degrees C respectively; P < 0.05). CONCLUSIONS: Zygotes show a higher resistance to chilling injury compared to oocytes at different developmental stages; this might explain the relatively poor survival rates of cryopreserved human oocytes and indicates the necessity to adjust the cryopreservation protocols in order to minimize cryoinjury.