Infertility, defined as the failure to achieve a clinical pregnancy after at least 12 months of regular unprotected sexual intercourse, occurs in 1 in 10 couples [1-3]. Approximately half of these couples undergo fertility treatment, such as in vitro fertilization (IVF), with the ultimate goal of conceiving a healthy child [3]. Infertility and its treatments can be emotionally and financially burdensome to couples and society. An important research priority is to find modifiable factors that can improve the chance of conceiving a healthy child from IVF [4]. Increasing evidence shows that lifestyle is such a potential modifiable factor. IVF success rates are positively associated with a healthy diet, a normal BMI, and moderate physical activity levels [5-12]. Furthermore, a healthy preconception lifestyle benefits offsprings’ health [13]. Several international guidelines recommend addressing unhealthy lifestyles before conception, specifically in people with infertility [14-16]. In contrast, a Cochrane review indicated a lack of clear guidance on the content and format of lifestyle programs for improving conception chances [17]. Health care providers also recognize the need for such guidance [18,19].

Evidence from other fields shows that mobile health (mHealth)—defined as the use of mobile and wireless technologies for health—is a promising format to promote healthy lifestyle behavior [20]. mHealth is widely scalable, relatively cheap, and adaptable according to the needs of patients [21]. Using mHealth among people with infertility may counter identified barriers such as lack of time and personnel and is easy to implement in daily life [20,22]. Recent studies on lifestyle apps for people with infertility have shown an improvement in secondary lifestyle outcomes (eg, food intake) but were not effective for the primary clinical outcomes, such as pregnancy rate or live birth [11,23-25]. Adherence is a challenge in traditional lifestyle studies. Therefore, in-depth analyses of use data of mHealth interventions is crucial to identifying factors that enhance use and engagement by participants and effectiveness of mobile preconception lifestyle interventions. In 2016, the World Health Organization mHealth Technical Evidence Review Group developed a guideline for the reporting of mHealth interventions. This guideline emphasized the need for detailed reporting on use [26]. Despite these existing guidelines, a review of mobile lifestyle interventions emphasized the need for improved reporting on the use of such interventions to evaluate their effectiveness more accurately [27].

To gain better insights into the effectiveness of a preconception lifestyle app for couples undergoing IVF (PreLiFe study) [22,25], a process evaluation focusing on use and user experiences was conducted with the aim of identifying factors that may lead to higher use and engagement, ultimately enhancing the effectiveness of mobile lifestyle apps.

This process evaluation (Table 1) of the PreLiFe app, a mobile lifestyle app for couples undergoing IVF, included stakeholder interviews, quantitative observation, and data monitoring. More specifically, an objective quantitative study (data monitoring) using a tracking-based system assessed the actual use of the PreLiFe app over time in relation to partner use and in relation to the specific fertility treatment. A subjective quantitative study using online questionnaires assessed acceptability and partner support experienced while using the PreLiFe app. A qualitative study (stakeholder interviews) using semistructured interviews evaluated the user experiences with the PreLiFe app in depth in the context of the users’ daily lives and in relation to their fertility treatment.

The effectiveness of the PreLiFe program was evaluated in the PreLiFe study [25]. The protocol for this multicenter, single-blind randomized controlled trial has been registered (ClinicalTrials.gov identifier NCT03790449) and published previously [28]. A detailed description of the PreLiFe program has been published previously [22]. Briefly, eligible couples starting IVF were randomized (1:1 allocation ratio) to an attention control arm or an intervention arm receiving the PreLiFe program. The PreLiFe program is a systematically developed complex preconception lifestyle intervention acting on a combination of lifestyle topics (diet, physical activity, and emotional distress) and offered in a blended care format. It was developed according to the Medical Research Council framework, and patients were involved in the development of this app from the earliest phases of design [22]. The program includes a mobile app (PreLiFe app) with on-demand tailored advice and skill training on diet (food literacy), physical activity, and mindfulness in combination with SMS text messages. In addition, patients receive telephone interaction every 3 months with a health care provider trained in motivational interviewing (Figure S1 in Multimedia Appendix 1). Participants were followed for 12 months or until an ongoing pregnancy was confirmed via ultrasound at 12 weeks of gestational age. Changes in lifestyle and in reproductive outcomes were observed. The study started in January 2019 and was prematurely stopped on March 13, 2020, as, due to the COVID-19 pandemic, all Belgian fertility clinics were closed for an undefined period. As the primary outcome was time to ongoing pregnancy, recruitment was stopped as of March 13, 2020. In addition, couples who had been randomized and were still participating in the trial at that time needed to be censored. The PreLiFe study period varied from 2 to 365 days. Table S1 in Multimedia Appendix 1 provides an overview of the number of couples in the study at each time point and reasons for ending the PreLiFe study. During the PreLiFe study period, all participating couples received standard medical treatment (ie, IVF with or without intracytoplasmic sperm injection) according to the local protocol of the participating fertility clinic. Both partners in couples randomized to the intervention arm additionally received the PreLiFe program.

This study was approved by the Ethics Committee Research of the University Hospitals Leuven and the local ethics committees of the participating clinics (approval s61202 for the qualitative evaluation and s61596 for the quantitative evaluation). Written informed consent was obtained from all participants. Interviews were audio-recorded and transcribed verbatim. All identifying information was removed from the transcripts to ensure anonymity.

This paper describes the quantitative and qualitative evaluation of the use and user experience of the PreLiFe app, as well as the app’s acceptability and the partner support experienced.

Overall, patients were positive about the PreLiFe app, often felt supported by their partners while using the app, and were willing to use it, as revealed by our quantitative and qualitative subjective evaluations. However, our objective use data revealed that actual app use was low, particularly among men. We observed that PreLiFe app use was related to partner app use and to the stage of fertility treatment (higher app use during the start of IVF treatment). Furthermore, we observed that the module that had the highest number of interactions and highest level of tailoring (the diet module) had the highest use.

One of the most remarkable findings of this study was the paradox between the high scores for acceptability and subjective use and the low actual objective use, highlighting the importance of objective measurement methods for app use. In the context of behavior change, these findings could be explained by the fact that the participants were in a phase of being aware of the health benefit (contemplation phase) but not yet having enough motivation or awareness to proceed to action for behavior change (in this case, regular app use and follow-up goals). Focusing on intrinsic motivation and possibly external motivation (intermediate follow-up by a physician or health care professional) could potentially have a synergistic effect. Compliance and acceptability do not reflect the actual use of lifestyle apps. Comparing our results with those of other studies remains difficult. A recent systematic review of lifestyle apps indicated substantial variability in intervention characteristics and inconsistent reporting of use outcomes [27]. Future research should work with core outcome sets on use to address this inconsistency in selecting and reporting of use outcomes [32]. Although previous research has shown that patients undergoing IVF need support in lifestyle modification and prefer a mobile app as a time-efficient format [22], the actual use of our PreLiFe app was low, especially among men. A possible reason may be found in a recent study by Robertson et al [33], who showed that patients undergoing IVF might prefer focusing on their treatment instead of other factors such as emotional management or their lifestyle. Another potential explanation for the low use among men is that we did not consider gender-specific differences when developing our app. Previous studies have shown that men may have different perceptions of lifestyle relevance to the fertility trajectory or different coping strategies to handle infertility [34,35]. Furthermore, lifestyle behavior and motivation to improve their lifestyle might differ between partners. Further characterizing the current needs of both partners and tailoring lifestyle apps to their personalized needs and motivations can contribute to the engagement of both partners in such interventions.

A recent systematic review identified several factors that positively influence adherence to lifestyle apps: personal support, content personalization, individualized push notifications, and user-friendly design [36]. In our study, we observed that PreLiFe app use was higher when the partner used the app as well and that patients felt supported by their partners. This is in line with previous studies showing that involving both partners in lifestyle interventions can facilitate mutual support, behavior change, and compliance at little additional cost [23,37]. A recent Dutch study providing tailored coaching on vegetable, fruit, and folic acid intake; smoking; and alcohol consumption in a blended approach to couples trying to conceive reported improved lifestyle behavior, which was more robust when both partners participated [38]. These findings suggest that partner-based interventions may offer a comparative advantage over individual-focused apps. Future studies on lifestyle apps for people with infertility should further consider this partner interaction.

PreLiFe app use also increased during fertility treatment, when participants were in contact with health care providers. This supports the idea that blended care models combining digital tools with professional support may enhance engagement. Determining the optimal balance between digital autonomy and health care provider interaction remains a key question [39].

Identifying the balance between time investment and personalization is also key for future research on this topic. Participants indicated lack of time as the most important reason for not using the PreLiFe app. In contrast, we observed the highest use for the diet module, which was the module with the highest level of time investment, interaction (2 push messages per week), and tailoring (personalized goals based on a questionnaire).

Another improvement area defined was the lack of interaction with other data systems such as wearables. Integration of wearables could enhance personalization and efficiency, as observed in other health apps [40]. However, further research on this topic in this specific population is warranted.

The main strength of this study is that we combined qualitative and quantitative data on the use and user experiences of both partners, allowing for an in-depth understanding of participants’ use and experiences with a preconception lifestyle app. Furthermore, to our knowledge, we are the first to provide objective insights into the actual use of a lifestyle app among both partners. We did so using app-based tracking, an objective measure not prone to social desirability bias. In-depth analysis of such use data can contribute to identifying and improving factors that lead to higher use and engagement, ultimately enhancing the effectiveness of lifestyle apps [41,42].

The limitations of this study should also be considered. First, all participants were asked about their rationale for not using the PreLiFe app, but fewer than 1 in 3 women and men replied, potentially not reflecting the views of all nonusers. In general, self-selection of the participants might have played a role throughout the PreLiFe study. Our study population had a higher physical activity level and lower rates of overweight and obesity than the general Belgian population [43,44]. Selection bias could have been present in our study, resulting in participants with a high interest in lifestyle and health. Furthermore, most patients were of European origin and highly educated, limiting the generalizability of our results. Finally, to avoid burdening the participants, the final results of the qualitative study were not returned to them for validation. This decision could potentially lead to misinterpretations of their true thoughts.

In conclusion, our findings show good acceptability and user experiences but low actual objective use of a preconception lifestyle app for couples undergoing IVF. Lifestyle apps can empower patients to feel more in control and supported regarding their reproductive health. However, to increase use and potential effectiveness, future research on lifestyle apps for people with infertility should further focus on the personalization of such apps to individual needs and on the interaction with partners, health care providers, and other patient data systems such as wearables.