Do patient factors influence embryologists’ decisions to freeze borderline blastocysts?

Abstract

Research question

To investigate whether patient factors influence the decision to freeze a blastocyst with low implantation potential.

Design

This experimental study assessed 170 practicing embryologists from a variety of countries who were recruited via an online survey. Participants were currently practicing embryologists, who grade blastocysts as part of this role. The survey presented decision-making ‘vignettes’ to participants. These included specific patient information, as well as an image of an expanded blastocyst that was of borderline quality for inner cell mass and trophectoderm, for which the embryologist selected whether or not to freeze. High/low maternal age, the presence/absence of other top quality blastocysts, and the presence/absence of previously unsuccessful IVF cycles were systematically varied within the patient information in a 2 × 2 × 2 design. Participants reported how likely they would be to freeze a particular blastocyst on a scale of 1 (Extremely Unlikely) to 7 (Extremely Likely), and whether or not they would ultimately freeze each blastocyst (Yes or No).

Results

Lower maternal age, no other high-quality blastocysts within the cohort, and multiple unsuccessful IVF cycles were associated with greater likelihood of recommending to freeze (P < .001). Furthermore, significant interactions among all three patient factors were noted.

Conclusion

This study provides evidence suggesting that when faced with an uncertain blastocyst, factors pertaining to the patient (maternal age, the presence/absence of other top quality blastocysts, and the presence/absence of previously unsuccessful IVF cycles) influence the decision to freeze.

Introduction

Blastocyst grading is a critical step during the IVF process, providing an estimate of blastocyst viability in order to rank for transfer, and determining blastocyst usability and therefore suitability for freezing or transfer. Although there is a consistent correlation between higher blastocyst grade and higher pregnancy rates reflecting developmental potential [8, 21, 22], the absolute minimal useable blastocyst grade and how to proceed with these ‘borderline’ blastocysts is unknown. Typically, a threshold of grade B for the inner cell mass (ICM) and trophectoderm (TE) is the standard for whether a blastocyst is suitable for freezing [11]. Recently, the minimal useable blastocyst grade has come into question as blastocysts with few cells (typically grade C) for their inner cell mass (ICM) or trophectoderm (TE) have been reported to maintain modest live birth rates [9, 14, 15, 24]. With borderline blastocysts, the decision to freeze becomes uncertain, leading to a difficult decision for the embryologist.

Blastocyst grading is prone to significant inter-embryologist and intra-embryologist variability. Studies involving assessment of blastocyst morphology have indicated between fair to moderate agreement [13, 17, 19]. Specifically, agreement has been reported to be fair when assigning ICM and TE grade, but moderate when assigning expansion stage, reflecting the fact that assigning ICM and TE grade is more subjective compared to expansion stage [19]. While agreement of which is best when deciding which blastocyst to transfer is relatively good, little is known about the agreement value for the decision to freeze a blastocyst, especially when the grade is associated with low implantation potential. Although the odds may be smaller, recent evidence suggests that ‘low’-quality embryos can still lead to live births [3, 5, 9, 15, 24] and normal perinatal outcomes [2]. Grading subjectivity can lead to uncertainty and make it unclear whether a blastocyst is suitable for freezing or whether it has little developmental potential and instead should be discarded—as there is no objective test for viability using blastocyst morphology alone.

Research in other clinical areas suggests that when making important decisions, medical professionals search for information, which will guide their decision-making process [18, 21, 22], critically appraising such information to ascertain whether it answers the particular clinical question. This is an active process including reflection on and appraisal of the information relevant to the decision [20, 23]. The patient-centred focus of assisted reproduction means that embryologists often function as health-care workers, with an associated emotional involvement in their work [6]. Viewed in this light, when the morphological basis necessary for a decision such as a ‘freeze’ recommendation is unclear or missing, theory suggests embryologists will begin to search for new information that might allow a decision to be made, for example the patient factors and their clinical history.

How the decisions to freeze borderline embryos are made, and the extent to which patient information regarding reproductive history is incorporated into decisions is currently unknown. As such, the primary objective of this study was to investigate how three patient factors (maternal age, the presence of other high-quality blastocysts, and the number of prior failed IVF cycles a patient had undergone) influenced the decision to freeze blastocysts specifically selected for morphology associated with low implantation potential.

Materials and methods

Study design

To test whether patient factors (higher/lower maternal age, multiple/no prior IVF cycles, and multiple/no other top quality blastocysts present) influenced the decision to freeze, 170 embryologists were recruited to an online experimental study between January and July 2018. The primary aim of the study was to experimentally assess whether three patient factors—maternal age 35 or 40 years, the presence or absence of prior IVF cycles, and the presence or absence of other high-quality blastocysts being available in the cohort—independently and/or interactively impacted the decision to freeze a series of eight blastocysts of borderline quality.

Study participants

A convenience sample of 170 currently practicing embryologists was recruited between January and July of 2018. The sample was predominantly female (74.7%), with an average age of 39.29 years (SD = 10.44 years). Most participants held a Master’s Degree or higher, identified their current role as either an embryologist or senior embryologist, and reported using the Gardner system to grade blastocysts. Participant characteristics are summarized in Table 1 below. Prior studies have not investigated the effect of patient factors on the decision to freeze, and as such, a priori power analysis was impossible.

Table 1.

Characteristics of participants in a study on embryologist’s decision making

		Participants (n = 170)
Age (years)		39.29 (10.44)
Experience (years)		13.24 (8.90)
% Female		74.7
Education	Bachelor’s %	21.8
	Master’s %	48.8
	PhD %	24.1
	MD %	1.2
	Other %	4.1
Current position	Embryologist %	25.3
	Senior embryologist %	41.8
	Supervisor %	18.8
	Other %	14.1
Grading system	Gardner system %	71.8
	UK/ACE scheme %	5.9
	SART %	2.9
	ALPHA/ESHRE %	4.1
	Other %	15.3
Clinic cycles per year	Less than 500%	38.2
	Between 500 and 1000%	38.8
	Over 1000%	23
% reporting interaction with patients		68.2

Participants who selected ‘Other’ as their job title confirmed that they were involved in blastocyst grading regularly as part of their role

Survey design

Participants responded to advertising on messaging boards and mailing lists (e.g. EmbryoMail and IVF.net). Study advertising provided a link to consent and the study. After providing informed consent and recording professional background information, participants read and rated eight ‘decisional scenarios’. Several aspects of normal IVF practice were standardized in the instructions, which stated that patients had all been previously unsuccessful at achieving live birth following natural cycles or treatment and have no children, that all cases were ‘freeze-all’ cycles, and that no Pre-implantation Genetic Testing (PGT) was carried out.

Each scenario began with describing each patient’s clinical background, including the three details that were experimentally manipulated to indicate (a) whether the female patient providing the oocytes was 35 or 40 years old, (b) the presence or absence of prior IVF cycles (4 prior cycles vs. no prior cycles), and (c) the presence or absence of other high-quality blastocysts within the cohort (five high-quality blastocysts vs. no other blastocysts). This information was followed by the presentation of eight embryos in one of two layouts according to detail (c) above, where there were either (1) five high-quality expanded blastocysts (for example Gardner grade A for ICM and TE), two cleavage stage arrested embryos, and one expanded blastocyst of borderline quality (between Gardner grades B and C for ICM and TE) or (2) seven cleavage stage arrested embryos and one expanded blastocyst of borderline quality. It was specified that each series of images was presented as the last day of culture (day 6). Participants made two ratings about each scenario: (1) the likelihood that they would freeze and (2) whether they would freeze the borderline blastocyst indicated. Data were recorded anonymously by the survey platform (Qualtrics, Provo UT).

Primary measures

After each scenario, participants were asked ‘Given the clinical context, what is the likelihood you would freeze the blastocyst indicated here?’ making a 1 (extremely unlikely) to 7 (extremely likely) rating. This odd-numbered Likert scale was used to generate variance and to allow participants to indicate the degree of likelihood. They were then asked ‘If you had to choose, would you freeze this embryo? (Yes/No)’.

Decisional scenarios

As noted, the eight patient clinical backgrounds were manipulated such that the three patient factors systematically varied in a factorial 2 × 2 × 2 within persons design. An example scenario with accompanying image is provided in Appendix.

Selection of embryo and blastocyst images

Embryoscope (Vitrolife, Goteborg, Sweden) time-lapse images of cleavage stage embryos, high-quality expanded blastocysts, and expanded blastocysts of borderline quality were included in the decisional scenarios. Cleavage stage embryos were between the 6 to 12 cell stages and showed no evidence of compaction. High-quality blastocysts were of transferable quality (for example Gardner grade A for ICM and TE) and were at expansion stage 4 [7]. Blastocysts of borderline quality were between Gardner grades B and C for ICM and TE and were at expansion stage 4. Blastocysts of borderline quality were defined in the current study as having few cells with a poorly distinguished mass for ICM and few TE cells, with some large cells, or ‘gaps’ in the TE network. The images of the borderline blastocysts were validated as being uncertain or borderline by qualified embryologists practicing a minimum grading threshold of usability of Gardner grade 3BB. All images received recommendations to freeze and discard by different embryologists (i.e., generating a range of responses), indicating that they were of borderline quality and thus difficult to classify by practicing embryologists. Each borderline blastocyst image was randomly assigned to a decisional scenario, irrespective of the decisional context.

Statistical analysis

All statistical analysis was performed using SPSS Version 23. Data regarding the outcomes of the decisions are presented as mean likelihood of freezing and percentage Yes responders. To assess whether the patient factors (maternal age, the presence/absence of prior cycles, and the presence/absence of other high-quality blastocysts) independently or concurrently impacted freeze decisions (as well as whether gender or dichotomized clinical experience impacted freeze ratings), mixed model ANOVAs were conducted. However, because (a) there were no main or interaction effects associated with clinical experience and (b) the key patient factor effects were essentially identical across the models, only the results from the 2 (maternal age) × 2 (the presence/absence of prior cycles) × 2 (the presence/absence of other high-quality blastocysts) model are presented. Given negative skew in some of the likelihood ratings, these data were transformed using a standard square root transformation.

Ethical permission

Permission to conduct the study was obtained from the Human Participants Ethics Committee (Ref: 020515).

Results

Decisional outcomes

Consistent with a view of the decisional scenarios and images being highly uncertain, freeze decisions varied between 10 and 60% across the scenarios (Fig. 1). Ratings on the 1–7 scale ranged from 4.22 (maternal age = 35, no prior cycles, no other high-quality blastocysts present) to 1.93 (maternal age = 40, no prior cycles, other high-quality blastocysts present). When pressed for a decision, Yes/No responses followed a similar trend, with the highest proportion of Yes responses (64.4%) observed in the ‘low age, no prior cycles, no other high-quality blastocysts’ scenario, while the lowest proportion (10.4%) was observed in the ‘high age, no prior cycles, other high-quality blastocysts present’ scenario. It was noted that seven participants scored all 8 blastocysts with the same likelihood of freezing (both yes and no). Survey results for these participants were excluded from the analyses because they may represent clinics that have a strong policy for or against freezing borderline blastocysts, where embryologist decision making is not required.

Fig. 1.

Percentage of ‘Yes’ responses and mean likelihood of freezing a blastocyst under different patient scenarios

The primary ANOVA-based analysis revealed significant main effects for all three patient factors. Likelihood of recommending freezing was greater with lower maternal age (P < .001), the absence of other high-quality blastocysts in the cohort (P < .001), and the presence of multiple prior cycles (P < .001).

Significant two- and three-way interactions between the patient factors were also evident. Specifically, maternal age and the presence of prior IVF cycles interacted (P < .001), indicating that in patients of decreased maternal age, not having undergone a prior cycle was associated with lower likelihood ratings, while in patients of more advanced maternal age this was associated with higher likelihood of freezing ratings (Fig. 2). Furthermore, maternal age and the presence of multiple high-quality blastocysts within the cohort interacted (P = .003), suggesting that while the overall likelihood of freezing was higher when there were no other viable blastocysts in the cohort, this difference was significantly greater in younger intending mothers than in older intending mothers (Fig. 3).

Fig. 2.

Two-way interaction between maternal age and the presence or absence of prior IVF cycles and its effects on the likelihood of freezing a borderline blastocyst. Asterisk denotes a difference at P < .001

Fig. 3.

Two-way interaction between maternal age and the presence or absence of other top quality blastocysts within the same cohort, and its effect on the likelihood of freezing a borderline blastocyst. Asterisk denotes a difference at P ≤ .001

Furthermore, a three-way interaction was found to be significant (P < .001). This interaction demonstrates that while in the two-way interaction, the difference in freezing likelihood with the presence or absence of other blastocysts was greater in patients of lower maternal age (Fig. 3), when prior IVF cycles were included in the model, there was no longer a significant difference between the presence/absence of other viable blastocysts in younger intending mothers, while this difference remained in older intending mothers. Similarly, while the two-way model suggested that multiple prior IVF cycles were associated with higher likelihood ratings in patients with advanced maternal age, this difference was altered in the three way model. Specifically, the absence of other viable blastocysts reversed this relationship in older intending mothers so that prior IVF cycles corresponded to higher likelihood of freezing ratings, and no prior cycles was associated with lower ratings. Likewise, in patients of decreased maternal age, when there were no other viable blastocysts, the difference between likelihood ratings based on prior IVF cycles reduced the difference between the two ratings to the point of statistical non-significance (see Fig. 4).

Fig. 4.

Three-way interaction between maternal age, prior IVF cycles, the presence of other viable blastocysts, and likelihood of freezing ratings

Discussion

The factors influencing the decision of whether or not to freeze low-quality blastocysts are complex. In contributing to this nascent area of work, the current report is clear in demonstrating that decisions are profoundly influenced by factors beyond blastocyst morphology and the grading systems. Specifically, analyses showed that a decision to freeze a low-quality blastocyst was more likely when maternal age was lower, where patients had multiple failed prior IVF cycles, or in the absence of other viable blastocysts within the cohort. The causal influence of these factors was further complicated by interactions among the predictor variables. Embryologists likely consider a multitude of factors when deciding whether or not to freeze borderline blastocysts, including maximizing the odds of reproductive success; avoiding patient disappointments, financial and emotional consequences; and minimizing the risk of complications. The patient-centred focus of assisted reproduction means that embryologists often function as health-care workers, with an associated emotional involvement in their work [6], and in light of this, it is perhaps unsurprising that different decisions are made when routine guidance is uncertain.

Most importantly, these data suggest that where the morphology of the blastocyst is inconclusive in terms of grading and/or guidance for possible freezing, embryologists incorporate patient/clinical information into the decision-making process. Exactly how this works is unclear, although a combination of (a) treating some patient factors as indicators of increased risk, or the likelihood of treatment failure or adverse complications, and (b) using patient data to gauge the possibility of future reproductive efforts seems likely.

Of the factors tested here, it is well established that increased maternal age predicts a host of negative outcomes in IVF [1, 9, 12] and appeared to broadly reduce the likelihood of freeze recommendations. Similarly, the likelihood of freezing a borderline blastocyst when other high-quality blastocysts were available was lower: a response that may reflect a desire to minimize additional treatment burden when the decision is less likely to alter cumulative treatment outcome. The embryologist may consider it unlikely that a patient with many high-quality blastocysts will need to utilize one that is of borderline quality in the future. Taken together, these findings tend to suggest that embryologists are using at least some patient information as proxy indicators of the likelihood of treatment failure or adverse complications. However, findings regarding the presence of prior cycles as well as some of the interactions among the patient variables suggest such an interpretation is incomplete.

Analyses showed that scenarios in which the patients had failed multiple IVF cycles received greater freeze recommendations, even though repeated implantation failure is associated with a greater risk of a negative outcomes [16]. If minimizing the chances of adverse complications/treatment failure was the sole focus of decision-making, it might be expected that embryologists would choose to not freeze a borderline blastocyst for a patient with multiple failed past IVF cycles since success is unlikely. On the contrary, it may also be that borderline embryos from patients with prior failed cycles are seen as ‘last chance’ opportunities by some embryologists. Although the motivations of our sample are unknown, it seems clear that risk minimization is only a part of what drives these crucial clinical decisions and that embryologists may also consider whether the patient will have future reproductive opportunities via IVF.

Such an interpretation is consistent with some of the interactions among the patient factors. In one scenario, a 40-year-old patient with five unsuccessful attempts at IVF was evaluated. In such a scenario, a risk-minimization perspective might suggest that this patient is unlikely to achieve a pregnancy and that a borderline blastocyst is unlikely to succeed and increases patient’s risk of treatment failure, meaning it should not be frozen. However, embryologists in the current study were, in fact, more likely to freeze in this situation. Such a pattern suggests that clinical information about the patient may be interpreted in a different way by the embryologist, depending on the patient’s specific context. Having had multiple attempts at IVF may be seen as reflecting an ongoing commitment to parenthood, while, rather than indexing greater risk, being over 40 may indicate that ‘time is running out’ for the patient. In such cases, it may be that a borderline blastocyst is seen as reflecting the patient’s last chance to achieve a pregnancy and a freeze recommendation ensues. Understanding how situational contexts cause information about the patient to be interpreted in one way versus another is complex but will be important in future studies testing the factors that influence decisions with marginal blastocysts.

This study is the first to experimentally test factors that might be involved in the decision to freeze a borderline blastocyst, and we acknowledge some limitations. Firstly, to preserve anonymity, information about where the participants practised was not collected. Therefore, there may be differences in freezing criteria based on geographical reason. However, the information provided to participants focused on basic information (e.g. maternal age, whether other blastocysts from that cohort are being frozen), which all embryologists would have access to regardless of the region or nature of clinic (e.g. public vs private funding). Secondly, as an experimental online study, participants had incomplete (manipulated) information about the hypothetical patients and therefore made their decisions without being able to zoom or focus on blastocyst images. While the images used were standardized by only including blastocysts that were fully expanded, had few cells in the TE, and had an ICM that was ‘poorly distinguished’, other, unmeasured differences in images may have contributed to our findings (e.g. having fewer number of cells in their TE or ICM than other embryos). As has been noted however, all images were validated as borderline through testing by 8 currently practicing embryologists using a minimal useable grade of BB [7, 11]. In this validation study, all 8 images used generated both ‘Yes’ and ‘No’ responses for decision to freeze in the absence of patient contextual factors suggesting the images were sufficiently uncertain, and therefore of borderline quality. Similarly, in the primary study itself, all images again received both ‘Yes’ and ‘No’ responses for decision to freeze. Taken together, this supports the notion that the images used in the study were uncertain and the decision to freeze could not be made consistently and reliably based on morphology alone. As an added measure to limit the potential impact of clinical policies that either require freezing all blastocysts or restrict freezing to grade BB or better, seven participants who scored all 8 blastocysts the same likelihood of freezing were removed from the sample set.

Clearly more research is needed in this area to standardize the decision-making process for borderline blastocysts. The current study focused on one influencer of this decision—patient contextual factors. This study can be replicated with ‘real’ patient cases and associated blastocyst images rather than vignettes to apply the findings in a real-world setting. Furthermore, future research should assess whether or not other possibly relevant patient information, such as ethnicity, marital status, socio-economic status, or private versus public/insurance funding, impacts the decision to freeze. Future researchers may also wish to investigate whether patient factors still influence decisions in cases where there is less uncertainty, and blastocyst morphology is more conclusive. Lastly, artificial intelligence (AI) holds potential to provide additional information on blastocysts with borderline morphology and thus provide objective measures of viability, thus reducing the role of patient factors in deciding whether or not to freeze [4, 10].

In conclusion, evidence from this large study of practicing embryologists shows that in situations where the viability and suitability for freezing an embryo based on blastocyst morphology are uncertain, information regarding the patient influences the decisions embryologists make. Importantly, the same piece of patient information may be differentially weighted in these decisions, meaning that clinical care in terms of blastocyst use varies among embryologists, likely even in the same clinic. This variation merits further research and standardization.

Appendix. Survey vignettes and images presented to embryologists for decision making

You have been assigned to grade and freeze blastocysts for the day. You have a reasonable number of cases to check, and systematically work your way through the case load before you start performing ICSI later in the day. The following cases are presented. All couples have been previously unsuccessful at achieving a live birth following either natural cycles or treatment and have no children. For various reasons, all cases presented here are ‘freeze all’ cycles, but none are undergoing either pre-implantation genetic screening (PGS) or pre-implantation genetic diagnosis (PGD). Each vignette outlines the relevant medical history of each couple and focuses on blastocyst development during the current cycle. Each vignette asks whether each embryo presented should be frozen given its morphological appearance on the last day of culture (day 6).

Vignette 1

Laura, aged 35 years, has recently been diagnosed with tubal infertility after a hysterosalpingography (HSG) showed occlusion of both fallopian tubes. Laura also undergoes high-intensity exercise 4–5 times per week but has maintained a body mass index (BMI) of 21. Laura’s partner David, who is 38 years, presented with a normal semen analysis. The total number of motile sperm seen in David’s ejaculate was 94 million, and overall, a high percentage of rapidly moving sperm were recorded (34%). Following Laura’s diagnosis, Laura and David came through for their first cycle of IVF. Laura showed a normal ovarian response to her stimulation regimen and was triggered when her three largest follicles were ≥ 18 mm. The pick-up procedure was straightforward, and a final number of 10 eggs were collected. The couple had good fertilization where all but two eggs fertilized. Following 5 days of culture, the embryos were checked for development to the blastocyst stage. Although there were 3 expanding morulas, no embryo had reached a suitable stage for freezing on day 5. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. Five blastocysts are suitable for freezing, where these have all expanded and have a high grade for their inner cell mass (ICM) and trophectoderm (TE). Would you freeze the remaining embryo indicated here?

Vignette 2

Luke (35 years) has congenital bilateral absence of the vas deferens (CBAVD) due to a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, resulting in obstructive azoospermia. Stacey, also 35 years, has been tested and is not a carrier of the mutation. Stacey has a family history of polycystic ovarian syndrome (PCOS) but has no symptoms herself. She has a normal AMH for her age and has regular cycles. Following Luke’s diagnosis, he had a testicular sperm extraction (TESE) procedure, resulting in motile sperm being frozen. Altogether, Luke and Stacey have had 4 previous cycles of ICSI using the frozen TESE sperm. During each cycle, Stacy had a good response to ovarian stimulation, but so far no transfer has resulted in a live birth. This current cycle resulted in 11 eggs being collected; however, 2 of the eggs had not fully matured to metaphase II by the time the eggs were injected using ICSI. Eight of the 9 mature eggs fertilized normally following ICSI. After 5 days of culture the embryos were checked for their development, where there was one morula, one expanding morula, and one very early blastocyst present, all of which did not reach the criteria for freezing following observation. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. Five top quality blastocysts are ready to be frozen. Would you freeze the remaining embryo indicated here?

Vignette 3

Mike, 34 years, was recently diagnosed with azoospermia after his first semen analysis. He subsequently had a second semen analysis, confirming that no motile sperm could be found following ejaculation. Six months after the initial diagnosis, Mike had a testicular sperm extraction, but motile sperm could not be found in the extracted tissue. This was confirmed following histology on a section of the tubule tissue. Two years after the diagnosis Mike, now 36, and his partner Lucy, 35 years, are coming through for their first cycle of ICSI using Mike’s younger brother Sam (33 years) as a personal sperm donor. Lucy is fit and healthy and has regular cycles. Lucy showed an adequate response to her stimulation protocol, producing a cohort of 13 eggs ≥ 14 mm at the time of trigger. Of the 11 eggs collected at pick-up, 9 were injected, and 8 fertilized successfully using the donor sperm. On day 5 of embryo development, it was noted that there was one very early blastocyst, but none were ready to be frozen on this day. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. From the cohort of embryos, 7 have not passed the cleavage stage and are therefore not suitable for freezing. Would you freeze the remaining embryo indicated here?

Vignette 4

Andrew (age 35) has male factor infertility, characterized by low sperm concentration (3 million sperm per ml), and reduced motility (22%). Of note, Andrew also has few rapidly motile sperm (2%). Andrew’s partner Marlena (age 40) has a normal ovarian reserve, but due to her maternal age is expected to have a high rate of aneuploidy in her eggs. Marlena and Andrew have elected not to undergo PGS testing on their embryos but may consider noninvasive prenatal testing (NIPT) during a pregnancy. Andrew and Marlena are currently undergoing their first cycle of ICSI treatment. Marlena experienced steady follicle growth following 9 days of follicle stimulating hormone (FSH) stimulation and was triggered when her 4 largest follicles were ≥ 18 mm. At pick-up, 9 mature eggs were collected, and one empty zona pellucida was noted at the time of hyase denudation. Following ICSI of the 9 mature eggs, 8 fertilized following ICSI. The embryos were checked for their development on day 5; two embryos remained at the cleavage stage of development, but the remaining embryos had shown some progression on from the cleavage stage, with 3 morulas, one expanding morula, and two low grade blastocysts (low number of cells in the ICM and TE), which were not suitable for freezing after assessment. Following 6 days of culture, further blastocyst development had been observed, and 5 blastocysts were suitable for freezing. Would you freeze the remaining embryo indicated here?

Vignette 5

Thomas (age 44) has retrograde ejaculation. Following processing of a retrograde sample, an adequate number of sperm were frozen for use during ICSI (1 million motile sperm per straw). Kelly (age 40) has a BMI of 27, mild submucosal fibroids, and an adequate ovarian reserve for her age. During Thomas and Kelly’s first cycle of ICSI, Kelly had a poor response to stimulation, with slow follicle growth, and only 3 mature eggs collected. Following a change in stimulation regimen in her second cycle, Kelly’s response to stimulation was improved and 10 mature eggs were collected. In total, Thomas and Kelly have now had 4 previous ICSI cycles, each resulting in a fresh blastocyst transfer, but without success. In the current cycle, there were 11 mature eggs collected, and 8 of these fertilized following ICSI. The 3 eggs that did not fertilize all contained only 1 pro-nuclei (1PN). On day 5, 4 of the embryos showed early signs of blastocyst development, but no embryo had reached a suitable level of expansion for adequate assessment of the ICM and TE. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. Five good quality blastocysts are suitable for freezing. Would you freeze the remaining embryo indicated here?

Vignette 6

Alice is a single 40-year-old women with mild endometriosis and a normal ovarian reserve for her age. Alice has always wanted to have children and has decided to use a sperm donor as she is not in a long-term relationship and is concerned about her ticking biological clock. Alice initially enrolled a personal friend to be her sperm donor, but his first semen analysis showed azoospermia, and he was therefore unsuitable for further testing. She has now chosen a clinic sperm donor and is coming through for her first cycle of ICSI. Alice had a good response to her stimulation regimen, with 14 follicles seen on her first scan. Alice was triggered after all 14 follicles showed optimal growth. In total, 12 eggs were collected, and 9 of these were mature. Following ICSI with the donor sperm, 1 of the eggs lysed, but the remaining 8 fertilized successfully. When the embryos were checked on day 5, there were 7 that had not developed past the 12-cell stage indicating that they had arrested, but one remaining embryo was still showing signs of development, although it was not at a suitable stage for freezing. Following 6 days of culture, the embryos are checked again for development to the blastocyst stage. There is no developmental change for the 7 arrested embryos, and they are therefore not suitable for freezing. Would you freeze the remaining embryo indicated here?

Vignette 7

Nicole and Brian are both 40 years old and have unexplained infertility. Nicole has ovulatory cycles, tubal patency, an AMH of 16, and a BMI of 23. Brian’s initial semen analysis showed a good number of motile sperm (44 million motile) and IVF insemination was indicated. Their first cycle of IVF however resulted in fertilization failure, with sperm bound to the zona, and adequate sperm motility at the time of the fertilization check. All eggs were mature, so the cause of the fertilization failure was unknown. Their subsequent 3 cycles of ICSI gave successful fertilization, but no pregnancy. In their most recent cycle, Nicole and Brian requested to have two blastocysts replaced, but this did not result in a live birth. In the current cycle, Nicole had a good response to stimulation, and 11 eggs collected, which was similar to her previous cycles. Following ICSI, 8 eggs fertilized normally out of the 9 mature, where the remaining egg was noted to contain 3 pro-nuclei (3PN). No embryos could be frozen when they were checked for blastocysts development on the morning of day 5 (116 h of development), where it was recorded that 7 embryos had only developed to the day 3 stage, and the remaining embryo had begun the process of compaction. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. There is no developmental change for the 7 arrested embryos, and they are therefore not able to be frozen. Would you freeze the remaining embryo indicated here?

Vignette 8

Hannah, 35 years, has Asherman’s syndrome and requires a surrogate. Hannah’s partner Harry, 41 years, has semen parameters which are below the normal range, and poor morphology was noted on his most recent semen analysis. Specifically, a high number of sperm with elongated heads were recorded. Hannah’s sister Penny, 33 years, with two children of her own, has been a surrogate for Hannah and Harry during their past 4 cycles of ICSI. Hannah’s first cycle was characterized by a high number of immature eggs, but her subsequent cycles resulted in up to 10 mature eggs each time. Penny had a fresh blastocyst transfer, but no live birth, following Hannah and Harry’s last three cycles. In the current cycle, Hannah had 13 eggs collected, and 5 of these were immature. All of the mature 8 eggs fertilized following ICSI. After being checked on day 5, it was noted that 7 embryos had stopped developing at the cleavage stage and there was one blastocyst, but it was too early to tell whether it had a suitable ICM and trophectoderm, and this was therefore not frozen. Following 6 days of culture, the embryos are checked for development to the blastocyst stage. All 7 arrested embryos show no further progression and are not suitable for freezing. Would you freeze the remaining embryo indicated here?