Parental experiences of uncertainty following an abnormal fetal anomaly scan: Insights using Han’s taxonomy of uncertainty

Abstract For a number of prospective parents, uncertainty during pregnancy starts when an anomaly is found during a routine fetal anomaly scan. This may be followed by numerous tests to determine the etiology and nature of the anomaly. In this study, we aimed to understand how prospective parents perceive and manage uncertainty after being confronted with a structural anomaly during their routine ultrasound. Han's taxonomy of uncertainty was used as a framework to identify and understand the different types of uncertainty experienced. Interviews were held in the UK (n = 8 women and n = 1 male partner) and in the Netherlands (n = 7 women) with participants who had experienced uncertainty in their pregnancy after a fetal scan. Data were analyzed using thematic analysis, and the uncertainties experienced by parents were mapped against the dimensions of the Han taxonomy (sources, issues, and locus). Participants' experience of uncertainty was relevant to all dimensions and subcategories of the Han taxonomy, showing its applicability in the prenatal setting. Sources of uncertainty included receiving probabilistic or ambiguous information about the anomaly, or information that was complex and challenging to understand. Issues of uncertainty included were those that were scientific—such as a probable diagnosis with no further information, personal—such as the emotional impact of uncertainty, and practical—such as limited information about medical procedures and practical aspects of care. Additionally, participants described what helped them to manage uncertainty. This included active coping strategies such as searching for information on the Internet, external coping resources such as seeking social support, and internal coping resources such as using positivity and hope. Several recommendations for the healthcare professional to minimize uncertainty and help the patient deal with uncertainty have been proposed based on these findings.


| INTRODUC TI ON
Antenatal screening for fetal structural anomalies has become part of routine pregnancy care in most Western countries since its introduction in the 1970s. Ultrasound scans play an important role in fetal surveillance during the course of pregnancy. These scans are also important in the monitoring and management of high-risk pregnancies, to reduce obstetric interventions and the risk of perinatal deaths (Alfirevic, Stampalija, & Dowswell, 2017;Edvardsson, Small, Persson, Lalos, & Mogren, 2014). In the majority of cases, routine ultrasound provides prospective parents with the opportunity for reassurance about the health and development of their baby (Garcia et al., 2002). However, in up to 5% of pregnancies, a structural anomaly will be detected (Best et al., 2017;Boyd et al., 2011).
While these diagnostic tests may lead to a clinical diagnosis, some parents will receive inconclusive results, variants of uncertain significance (VUS), or no diagnostic information.
Uncertainty can be described as a state of having 'imperfect or unknown information' (Gollust et al., 2012). Currently, the literature on uncertainty within the field of prenatal testing concentrates on uncertainty following ultrasound or diagnostic testing, where a lack of information can emotionally affect parents (Wou et al., 2018) and complicate pregnancy decision-making (Richardson & Ormond, 2017). In a prenatal testing setting, uncertainty may arise in a number of ways. For example, parents may be given a diagnosis with an uncertain prognosis; an unexpected diagnosis that may or may not have been related to the testing indication; a VUS for which no or limited prognostic information is available, or a result where 'no meaningful information is found' and a genetic cause of the fetal abnormality cannot be given (Richardson & Ormond, 2017). This can lead to many parents experiencing emotional turmoil as they do not have concrete information on which to base pregnancy-related decisions such as whether to undergo invasive testing, which can carry a small but significant risk of miscarriage (Quinlan-Jones, Hillman, Kilby, & Greenfield, 2017;Salomon, Sotiriadis, Wulff, Odibo, & Akolekar, 2019), and whether to continue the pregnancy or have a termination of pregnancy (Sommerseth & Sundby, 2010). Given that most parents have entered into prenatal testing expecting a diagnostic test that provides clarity, rather than uncertainty (Richardson & Ormond, 2017), this change in their expectations further complicates further decision-making. For those that continue with their pregnancy, anxiety can persist long after the birth if an explanation for the anomaly is not found, with concerns that history may repeat itself in future pregnancies (Garcia et al., 2002).
One approach to understanding uncertainty in healthcare settings is the conceptual taxonomy proposed by Han et al. which includes three major dimensions to describe medical uncertainty: source, issue, and locus (Han, Klein, & Arora, 2011) (Table 1). The value of the taxonomy is that it facilitates differentiation between the many types, sources, and manifestations of uncertainty within healthcare settings (Han et al., 2011), and furthermore, allows for the investigation of uncertainty from multiple perspectives (Makhnoon, Shirts, & Bowen, 2019). Han's taxonomy of uncertainty has been used in a number of different healthcare settings. For example, Pickles et al applied this taxonomy to outline the different sources of uncertainty General Practitioners described encountering in relation to prostate cancer screening in adults (Pickles, Carter, Rychetnik, McCaffery, & Entwistle, 2016). Han's taxonomy has also been applied in studies of clinical genomic sequencing, using a version of the taxonomy specifically developed for this purpose (Han et al., 2017). The three major dimensions (source, issue, and locus) remain the same, but additional layers further discriminate uncertainties relevant to variant findings in genomic sequencing.
Makhnoon et al used the taxonomy to describe the sources and issues of VUS-related uncertainty from the patient perspective (Makhnoon et al., 2019), and similarly, Park et al. applied the taxonomy to understand genetic counselors perceptions of uncertainty in pre-test counseling (Park, Zayhowski, Newson, & Ormond, 2019).
For many parents in the prenatal setting, their experience of uncertainty begins with the detection of an anomaly at a routine ultrasound examination. As far as we are aware, no study has applied Han's taxonomy to gain insight into the parent's experience of uncertainty following prenatal ultrasound examination, and how the uncertainty is managed. Using this taxonomy may lead to improved understanding of the different aspects of uncertainty and their impact in a prenatal setting and provide guidance for ways to support parents in managing their uncertainty. This may help both parents and clinicians establish realistic expectations of testing processes and outcomes. Here we describe qualitative interviews with parents from the United Kingdom (UK) and the Netherlands (NL) who have experienced uncertainty during their pregnancy and map these findings onto Han's taxonomy of uncertainty.

| Study design
This is a qualitative study using semi-structured interviews with parents who had experienced uncertainty during their pregnancy following a routine prenatal ultrasound examination. This work is part of a larger international study; the primary aim of the interviews was to inform the development of a discrete choice experiment to look at parents' preferences and tolerances for uncertainty in prenatal testing. During these interviews, parents discussed the experiences of receiving uncertain results and how they managed their uncertainty.
We undertook a qualitative analysis of the dataset focusing on the issue of uncertainty. We used the medical taxonomy of uncertainties by Han et al. (2011) to analyze the data through its three major dimensions (sources, issues, and locus).

| Study setting
Interviews were conducted in the UK and NL. These two countries routinely offer the fetal anomaly scan, with an uptake of over 90% (Gitsels-van der Wal et al., 2014;Ward & Soothill, 2011). In the UK, there is an agreed policy in place for screening fetal anomalies outlined by the Department of Health through the UK National Screening Committee (UK NSC) (Boyd et al., 2011). NICE guidelines state that ultrasound screening for fetal anomalies should be routinely offered normally between 18 weeks and 0 days and 20 weeks and 6 days (National Institute for Health & Care Excellence, 2008).
The NHS Fetal Anomaly Screening Programme (FASP) lists nine structural congenital anomalies or groups of anomalies and two chromosome anomalies that women should be screened for at the anomaly scan (Public Health England, 2018).
In the NL, patients are part of a compulsory health insurance scheme (Schäfer et al., 2010)

| Recruitment
To meet the inclusion criteria, participants had to be over 18 years of age and had a structural anomaly identified on ultrasound without a clear diagnosis and/or prognosis. Participants were excluded if the uncertainty was related to receiving a high-risk Down syndrome screening result, as this study was focused on rarer genetic anomalies. Participants had to be able to speak the local language where interviews were conducted. We did not stipulate a time limit for when the uncertainty was detected during the ultrasound scan, for example, more than 5 years ago, as we did not want to limit the number of potential participants.
In the UK, prospective participants were recruited through an advertisement placed on the Facebook page of Antenatal Results and Choices (ARC), a charity that supports parents through antenatal testing. Interested participants who fit the inclusion criteria were asked to contact the research team and provide more information about their uncertain result so that the research team could assess their suitability to take part in the study. Potential participants were emailed an information sheet, and a date and time to conduct a telephone interview was arranged with a researcher (JH or CL). Two participants (a couple) were invited to participate by the research team as they were participants in a separate interview study where a significant part of their experiences described in the interview was focused on uncertainty in the prenatal setting. They were invited to take part in this study via email and sent a participant information sheet. Three potential participants who contacted the research team were excluded due to a Down syndrome diagnosis obtained through amniocentesis, and two potential participants did not take part due to the recent loss of a baby and concerns regarding participant distress. In the NL, potential participants were recruited from a cohort of patients who had undergone prenatal ES following an abnormal fetal anomaly scan. After they received their ES results, potential participants were approached by telephone by their clinical geneticist at Erasmus Medical Centre to take part in an interview. Those that agreed to participate were then contacted by a researcher (JEK) at Erasmus Medical Centre to arrange a date and time to conduct the telephone interview and were sent a participant information letter.
Interviews in the UK and the NL were conducted between February and June 2019.

| Data collection
A topic guide (Supporting information S1) was developed in English in collaboration with an advisory team from the UK, the NL, Denmark, and the USA, comprising genetic counselors, social scientists, a patient advocate, a geneticist, and a health psychologist. As interviews were conducted as part of a larger international study to inform the development of a discrete choice experiment, we are only presenting data from the interviews that is relevant to this study which include the following: parents experience of receiving uncertain results; what was uncertain about the results, how the results were explained, the emotional and clinical impact of the uncertain results, how they managed the uncertainty, and decision-making based on uncertain results. The topic guide was translated into Dutch for interviews conducted in NL. All interviews in the UK and the NL were conducted via telephone. Consent for interviews in both countries was obtained prior to starting the interview. Participants were given the opportunity to ask questions before providing consent. In the UK, interviews were conducted by two female social scientists (CL and JH). In the NL, data were collected by a female researcher who was completing a Masters' degree at Erasmus University Rotterdam (JEK). Interviews took place between February and June 2019, and participants in the UK were offered a £10 gift voucher for their time. All interviews were recorded using a digital voice recorder and transcribed verbatim. Dutch recordings were transcribed by JEK. Dutch transcriptions were translated into English using Google Translate and were checked by JEK, who is a native Dutch speaker.

| Data analysis and validation
Data analysis was facilitated using NVivo version 12 (QSR International) and analyzed thematically (Braun & Clarke, 2006) using an abductive approach, which engages in a two-way dialogue between data and theory (Hiles, 2014). This approach was suitable for the qualitative analysis of this study, where we would be drawing together constructs from Han's taxonomy to explain and apply context and meaning to the data obtained (Hiles, 2014).
Data were collected and analyzed concurrently, and data collection ceased when content saturation had been reached and no new themes were identified from the interviews. The transcripts from UK and Dutch participants were treated as one dataset, with the sample considered too small and diverse for meaningful comparisons. Four UK transcripts were independently coded by JH and JEK to create a coding framework. Once an initial coding framework was developed, the Han taxonomy was applied and codes further refined to see how they mapped onto the three overarching dimensions of the taxonomy (source, issues, and locus). Three UK and three Dutch transcripts were then coded again following the dimensions of the taxonomy by JH and CL. As parents also spoke of how they managed the uncertainty, an additional theme focusing on management strategies was added to the coding framework. The application of the taxonomy to the dataset was discussed at various stages between JH, CL, and MH to make decisions about where individual codes and themes fit within the taxonomy, and at each stage, minor changes to the coding framework were made. Once a coding framework using the taxonomy had been finalized, the remaining transcripts were coded by JH and JEK. The findings of the analysis, including the application of the taxonomy to the dataset, were discussed by all members of the research team.

| Participants
Sixteen parents completed interviews; nine from the UK, and seven from the NL. All but one was female, and most were bachelor degree educated (15/16). Eleven women had undergone invasive testing following an ultrasound where an abnormality was found. Of these, seven Dutch women had ES. No UK women had ES. The types of uncertainty that were experienced at the ultrasound included structural anomalies such as a growth in the stomach, missing or malformed limbs, cardiac anomalies, fetal megacystis, or a smaller than expected fetus. In one case, a potential but unconfirmed diagnosis of Dandy-Walker syndrome and Joubert syndrome was given. Nine women reported choosing to have a termination of pregnancy (TOP) ( Table 2). Uncertainties had occurred between one and 11 years ago.
Interviews lasted between 35 and 61 min, with an average interview time of 49 min.

| Key themes
We identified three overarching themes. Two themes matched the dimensions of Han's taxonomy of uncertainty; primarily 'sources of uncertainty' and 'issues related to uncertainty'. The third theme focused on 'managing uncertainty'. Han's 'Locus' of uncertainty was not expanded on as a theme, as the locus in all cases here is the parent experiencing the uncertainty. The findings reflect parents' experience of an uncertain result identified during the fetal anomaly scan, including the experience of uncertainty as parents underwent further testing and/or made decisions about TOP.

Probability (a fundamental indeterminacy or randomness of future outcome)
Following the anomaly scan, some parents reported receiving information related to risk or chance of a particular prognosis, including whether the condition was genetic. For example, one Dutch parent, whose baby was found to have a thickened neck fold and proceeded with an amniocentesis, explained being told that she might have a '50% chance of a child with a [genetic] disorder and a 50% chance of a healthy child' (NL7, female, third child, pregnant at interview). In some cases, chance was described using verbal descriptors rather than numerical risks. For example, one UK parent, whose baby was found to have an abnormal growth in the stomach explained 'They said the baby could be disabled, it could be a chromosome problem'. (UK5, female, first child, continued pregnancy). Another example of probabilities that HCPs spoke about related to recurrence risk. One Dutch parent recalled being informed that there was a 25% chance of a possible recurrence of the defect detected (NL3, female, second child, chose TOP).
Probability was also used to present the chance of miscarriage following an invasive procedure. As one UK parent, whose ultrasound scan indicated that the baby's brain had not developed properly explained, 'my options at that time were to have a CVS [chorionic villus sampling] test the next day but with a 3% chance of miscarriage, and I just thought that was too high at that time'. (UK3, woman, first child, chose TOP). For some couples, any risk of miscarriage was considered too high, particularly in light of feeling protective toward the pregnancy.
Finally, probability was also used to discuss the likelihood of the baby surviving, which created uncertainty that was especially difficult for parents to process. Uncertainty about the baby's chances of survival could be a major source of anxiety during pregnancy. An example was given by one Dutch parent who described being informed that her unborn child had a '60% chance of survival'. This uncertainty over death and survival had such a profound effect on how she felt about her pregnancy, that she described focusing on the '40% [the baby] will not survive' rather than the higher figure associated with survival (NL4, female, second child, pregnant at interview).

Ambiguity (lack of reliability, credibility, or adequacy of risk estimates)
Parents described two types of ambiguity that they experienced.
The first related to a diagnosis or information about the condition itself being unavailable. For example, one Dutch parent explained that 'the obstetrician said that she had seen the abnormality and that she did not know what it meant' (NL3, female, second child, chose TOP). Additional diagnostic testing, such as CMA or ES did not always provide parents with further information or clarity. One UK parent, whose baby was found to have a larger than normal head and an extra digit on one of the hands, described how HCPs were not able to offer any further information other than a 'clinical suspicion that this was probably something genetic' (UK1, partner, first child, continued pregnancy).
A second type of ambiguity related to the 'imprecision' of the available information. Examples of this included the prognosis for the baby including whether the pregnancy would be viable and survive to full-term, and imprecision related to conditions associated with incomplete penetrance or variable expressivity. One Dutch parent, who was informed that the baby had a congenital heart defect, described being given a range of possible outcomes from 'very intense and which linger' to other children having 'better outcomes' (NL4, female, pregnant with first child at interview, continued with pregnancy).

Complexity (features of risk information that make it difficult to understand)
How the identified anomaly was explained could be difficult for parents to understand. This was articulated by one Dutch parent who Finally, complexity was also found to occur when more than one possible diagnosis was discussed at the same time, which could be overwhelming for parents to take in. This was highlighted by one partner who commented 'It was floated quite early on that this could be what it ended up turning out to be-Joubert's syndrome. There were some other things that were floated as well which is a lot more serious… So that was a bit overwhelming as well.' (UK1, partner, first child, continued pregnancy). Scientific (diagnostic, prognostic, causal, or therapeutic) Following the identification of an anomaly, some parents were given potential, unconfirmed diagnoses (diagnostic issue). For example, the UK parent whose baby was given a potential diagnosis of Joubert's syndrome, described this potential diagnosis was given with caveats such as '"mights," "buts" and "maybes"' (UK2, female, first child, continued pregnancy).

| Issues related to uncertainty
Additionally, there could be frustration that despite undergoing further diagnostic tests, the results did not necessarily provide any further clarity about potential treatments (therapeutic issue) as described by one partner who commented that there was 'not much that can be offered by way of intervention' for his unborn child (UK1, partner, first child, continued pregnancy). Finally, parents who underwent additional non-invasive procedures, such as further ultrasound scans or fetal MRI scans, also experienced prognostic issues related to uncertainty. For example, one UK parent explained that despite a possible diagnosis for her unborn child, there was no certainty that her baby would survive the delivery: 'There was still the 'but she's so small, how is she ever going to survive the delivery' (UK7, female, second child, continued pregnancy).

Personal (psychosocial and existential issues)
Discovering that their unborn child had a fetal anomaly came as a shock and affected parents emotionally. The uncertainty surrounding the etiology of the anomaly also caused concern for the potential recurrence in future pregnancies: 'There is another uncertainty in its place. That things may go wrong with a subsequent pregnancy and whether a new syndrome will arise or not during the next pregnancy' (NL8, woman, first child, chose TOP A number of parents also described procedural uncertainty related to the process and timelines of decision-making around TOP. One UK parent recounted not knowing how quickly she would have to make a decision about ending her pregnancy, being told by HCPs 'to ring us tomorrow morning with your decision because we've got to get you booked in to get it done' (UK6, female, first child, chose TOP).
Parents also experienced procedural uncertainties regarding the process following the birth of their child. In some cases, this could leave parents feeling apprehensive about the hospital they would be attending. This was explained by one Dutch parent who had planned a tour of the intensive care unit (ICU) during the last few weeks of her pregnancy to see where her baby would be transferred following the birth. However, when arriving at the unit, she found that the staff were unaware of their planned visit, explaining, 'we got there and they said 'oh, that was not passed on to us at all, that is really bad' and 'uhh…which unit then?' I didn't know and they didn't know' (NL4, female, pregnant at interview with first child, continued pregnancy).

Parent strategies
As it was not always possible for uncertainty to be resolved, parents adopted a range of strategies to help manage different aspects of uncertainty. There were examples of using positive reinterpretation and acceptance as a way to cope with uncertainty and decisions about TOP.
For example, one UK parent described that despite having to choose whether to end her pregnancy, she described herself as 'lucky' that the decision to have TOP was easy as 'there was not a single part of the child that is healthy' (UK9, female, first child, chose TOP).
Another UK parent described accepting that the physical features of the anomaly, despite a lack of diagnosis, were likely to indicate a poor prognosis. She went on to describe that she 'knew then within myself that I wanted to terminate the pregnancy because he was just so sick' (UK3, female, first child, chose TOP). Some parents also spoke positively about how their clinician prepared them for the upcoming birth, particularly if the birth was likely to be complicated. At a time when parents were often given limited information about the anomaly identified, this was one way of obtaining some certainty about the process of giving birth and what could happen after. One UK parent explained that her clinician prepared her for the possibility of a cesarean section if they felt that the baby's heart was 'under stress' (UK7, female, second child, continued pregnancy). Some clinicians also provided support by showing parents the ward that they and the baby would be staying in; 'The doctor made the effort to actually give us a tour of the ward that we'd be on, and like where she [baby] would be and where I might be, where the labor ward was'. (UK2, female, first child, continued pregnancy).

| D ISCUSS I ON
This is the first study to apply Han's taxonomy of medical uncertainty (Han et al., 2011) to a prenatal setting, specifically following the identification of a fetal anomaly after a routine ultrasound scan.
Understanding the different dimensions of uncertainty that may result as a consequence of prenatal screening and testing are useful to guide HCPs in how they can best care for parents. The application of Han's taxonomy provided a useful framework for understanding prospective parents' experience of uncertainty when faced with ultrasound anomalies and unclear findings from diagnostic tests. Our interviews with parents revealed examples of the different types of uncertainty described in the taxonomy regarding where uncertainty arises from (sources) and in relation to what the uncertainty was about (issues) ( Table 3). Detailed understanding of the different dimensions of uncertainty that may arise as a consequence of prenatal testing and screening is useful for supporting parents and a summary of good practice points for HCPs working with parents who face uncertainty is presented in Table 4.
Many of the experiences of uncertainty identified through this study are consistent with findings in the published literature (Harding, Hammond, Chitty, Hill, & Lewis, 2020). Regarding the 'sources' of uncertainty (probability, ambiguity, and complexity) we found, for example, that the uncertainty related to ambiguity included the limited information available to parents about the anomaly identified. In a study looking at pregnant women's experience after abnormal ultrasound findings, Asplin et al. found that the types or amount of information given to women contributed to feelings of uncertainty. This ambiguity subsequently led to women feeling that they had too little time for pregnancy-related decision-making (Asplin et al., 2012). In our study, uncertainty stemming from complexity included both the information itself and how it was communicated to parents, with the use of medicalized language seen as problematic. Similarly, Walser et al. found that parents receiving prenatal CMA results reported difficulties understanding some of the terminology used by the HCP (Walser, Werner-Lin, Russell, Wapner, & Bernhardt, 2016). Other studies have shown that patients, even with adequate literacy, may have difficulties understanding what they are being told due to medical terminology and jargon (Rubel, Werner-Lin, Barg, & Bernhardt, 2017 et al., 2016). We also found that anxiety resulting from uncertain findings from prenatal testing could continue after the birth. This is similar to research looking at mothers' anxiety after receiving false-positive results during new-born screening, and heightened anxiety related to potential chronic illness later on in the child's development (Hayeems et al., 2016;Price Dillard & Carson, 2005). Other studies have also found that parents who had received uncertain prenatal test results remained worried and uncertain about their child's development after the birth (Bernhardt et al., 2013;Desai et al., 2018). Werner-Lin et al.
noted heightened vigilance in mothers whose children were prenatally diagnosed with a copy number variant of uncertain significance . In our study, parents also reported experiences of procedural issues of uncertainty and expressed that there was ambiguity surrounding the information available to them for example, regarding timelines to make a decision about medical procedures, information about procedures such as termination, and other practical aspects of care such as where the baby would be born and which ward or unit they could be moved to. This is consistent with findings from other studies that have highlighted the importance of clear information regarding medical procedures, including next steps (Asplin et al., 2012;Black & Sandelowski, 2010). Limiting the ambiguity surrounding the diagnostic process and practical aspects of care could be beneficial in helping parents to cope with diagnostic uncertainty.

Dimension Examples of application in the prenatal testing context
Source Probability Likelihood that the anomaly on the scan could be a genetic issue There are a range of possible outcomes for the child Ambiguity Limited information is available about the anomaly Limited information regarding prognosis for the baby Complexity Complex information Complex explanations and use of medical jargon

Issue Scientific
Probable diagnoses with no further information (diagnostic) Further diagnostic tests unable to provide further information regarding potential treatment (therapeutic) Etiology of the anomaly (causal) Limited information regarding prognosis for the baby (prognostic)

Personal
Emotional impact of uncertainty-sadness, loneliness, self-blame, grief Concern for future pregnancies-repeat of 'history' Anxiety post-birth, waiting for 'signs' or 'symptoms' of anomaly to appear Practical Limited or unclear information about procedures, including where tests may take place and regarding termination of pregnancy. Limited information of what will happen following birth, for example, where the baby will be cared for

TA B L E 3 Summary of findings using the Han Taxonomy as an interpretive framework
When faced with hearing difficult and complex news, and what may happen going forwards, HCPs should be mindful about how information is delivered to parents, and establish what parents know and understand prior to starting a discussion (Biesecker et al., 2014).
Parents' desire and need for support to manage uncertainty in this setting is not uncommon (Bernhardt et al., 2013), and through this work, we were able to identify the strategies parents used for managing their uncertainty, many of which have been previously documented in the literature (Walser et al., 2016;Werner-Lin et al., 2016). Parents used practical strategies as well as internal and external coping strategies to manage different elements of uncertainty. For example, information seeking was a practical strategy to help try and bring clarity to complex or ambiguous information, such as those related to probable diagnoses or medicalized language (sources of uncertainty). Information seeking through Internet searches was a common approach used by parents to try and obtain information that has been seen in other studies (Denney-Koelsch, Côté-Arsenault, & Lemcke-Berno, 2015;Lotto, Smith, & Armstrong, 2018). Internal coping strategies used included 'remaining hopeful' and making a conscious decision not to worry or ruminate over the uncertainty, a coping mechanism also found in a recent study conducted with pregnant women receiving uncertain CMA results in Denmark (Lou et al., 2020). Some parents had also used 'positive reappraisal' as a method to cope with the difficulty of the decision to end their pregnancy. Such adaptive coping strategies to manage emotional distress are well illustrated in the literature to manage the grief that can be felt when ending a pregnancy due to a fetal anomaly (Lafarge, Mitchell, & Fox, 2013

| Strengths and limitations
A key strength of this study is that by applying the Han taxonomy to the uncertainties that follow on from receiving an abnormal fetal anomaly scan, we have been able to delineate the multiple forms of uncertainty that occur for parents. This in turn has provided a more nuanced understanding of the nature of uncertainty in the prenatal setting. Though the UK and the NL have different healthcare systems and differences in cultures, this study found that parents from both countries experienced similar types of uncertainty that mapped onto each dimension of the taxonomy.
While this could suggest that the experiences of parents remain similar regardless of the country they reside in and differences in prenatal care, this may have been influenced by the sample size and selective recruitment strategy for this study. Finally, applying this taxonomy to a population of parents from the UK and the NL demonstrates the generalizability of this taxonomy of uncertainty in health care. In agreement with Han and colleagues, this taxonomy facilitates an organized approach to understanding the issue of uncertainty in health care, its unique nuances and aids in suggesting appropriate strategies for its analysis and management (Han et al., 2011).
In future research, application of Han's taxonomy of genomic uncertainty (Han et al., 2017) may provide useful insights when specifically exploring patient's experiences of receiving prenatal ES results.
The study has a number of limitations. Due to the way parents were recruited, there were differences and biases between the populations. Only Dutch participants underwent ES and it is therefore possible that for Dutch parents, receiving ES results may have had a significant influence on their overall perceptions of uncertainty. All but two parents from the UK were recruited from a parent support group (ARC). It is possible that these parents had particularly negative experiences that led to them seeking support. The timeframe of uncertainty was anywhere from one to 11 years ago in the UK, with all Dutch parents experiencing uncertainty up to a year before they were interviewed. This may have affected recall of their experience, and additionally, health practices may have changed significantly in that time. Only one father volunteered to be interviewed, and the experience of uncertainty and the application of this to the taxonomy is largely based on female parents' experience of uncertainty. Therefore, these results are not transferable to fathers. Additionally, the small sample size, although does provide some insight, does make it difficult to draw general conclusions and provide an in-depth insight into parents' experiences of uncertainty. Finally, most of the parents in this sample were highly educated; participants with lower educational attainment may experience uncertainty differently.

| CON CLUS IONS
The findings from this study have provided novel insights into the way uncertainty is experienced in the prenatal setting, and the importance for parents of having clear information regarding the practical aspects of both medical procedures and care. Going forwards, we must be mindful of the likely increase in uncertain results that may arise from next-generation sequencing and how this may affect parents who are already in a state of uncertainty. By ensuring that communication is clear and parents are as prepared as possible, with adequate psychological support provided, we can try to minimize the negative impact of the experience of uncertainty in the prenatal setting.

AUTH O R S' CO NTR I B UTI O N S
CL conceived the study. All the authors inputted into study design and best practices for data acquisition. JH and JEK developed the codebook and coded the interviews. JH, JEK, MH, and CL analyzed the data. All the authors were involved in data interpretation. JH and JEK drafted the paper. All the authors revised the paper critically for important intellectual content and have approved the paper for publication.

CO M PLI A N CE WITH E TH I C A L S TA N DA R DS
In the UK, ethical approval for this study was obtained through London-Riverside Research Ethics Committee (18/LO/2120). In the Netherlands, ethical approval was obtained through the Erasmus Medical Centre Medical Ethics Review Committee.

C o nf lic t of inte re s t
The authors do not have a conflict of interest.

H u m a n s tu die s a n d info r m e d co ns e nt
This study was reviewed and approved by London-Riverside Research Ethics Committee (18/LO/2120). In the Netherlands, ethical approval was reviewed and obtained through the Erasmus Medical Centre Medical Ethics Review Committee. All procedures