Lifestyle Factors Boosting IVF Success: New Study Findings

In a recent publication in the journal Frontiers in Endocrinology, researchers explored the impact of lifestyle factors and the quality of life specific to IVF on outcomes associated with assisted reproductive technology (ART).

Background The issue of infertility affects approximately 48.5 million couples worldwide, leading to a surge in ART procedures, with 2.5-3 million cycles performed annually globally and nearly 450,000 in Japan alone. Notably, 1 in every 13.9 Japanese babies is born through ART, underscoring the importance of factors such as age, ovarian reserve, and lifestyle choices—including diet, smoking, exercise, and sleep—on the success of these treatments. The World Health Organization (WHO) emphasizes the assessment of quality of life (QOL), including fertility-specific QOL, using tools like the Fertility Quality of Life tool (FertiQoL). However, further investigation is needed to fully comprehend the intricate relationship between fertility-specific QOL and ART outcomes.

About the Study The study focused on infertile couples in Japan undergoing their initial in vitro fertilization (IVF) treatment, selecting participants based on specific health and demographic criteria. Initially, participants provided information on their dietary patterns, inspired by the Mediterranean diet but adapted to Japanese preferences, and lifestyle choices, including sleep patterns, work routines, computer usage, smoking habits, and physical activity levels, quantified using metabolic equivalent tasks (METs). Additionally, fertility-specific quality of life was evaluated using the Japanese version of the FertiQoL questionnaire to assess its impact on treatment results.

The study detailed protocols for controlled ovarian stimulation, laboratory procedures, and embryo transfer (ET), specifying medication dosages and administration schedules tailored to individual patient profiles. Selection of high-quality blastocysts for transfer was based on the Gardner classification, with a required wash-out period between stimulation and ET. The outcomes of IVF/intracytoplasmic sperm injection (ICSI) were meticulously recorded, including hormone levels, fertilization rates, embryo development, and confirmation of pregnancy via serum Human Chorionic Gonadotropin (hCG) tests and transvaginal ultrasound to detect gestational sacs (GS).

Statistical analysis aimed to elucidate the relationship between patient characteristics, dietary and exercise habits, FertiQoL scores, and IVF outcomes, utilizing a multivariable approach to identify significant factors. The study sought to enroll 286 patients to detect clinically relevant differences in the primary outcome—the rate of high-quality blastocysts—employing comprehensive statistical analysis with SAS software.

Study Results Between May 2019 and March 2022, 291 women seeking their initial IVF treatment at clinics affiliated with the IVF Japan Group and the University of Tokyo Hospital were initially considered for participation. After excluding individuals who discontinued treatment, achieved spontaneous pregnancy, or met exclusion criteria, 281 women underwent controlled ovarian stimulation and oocyte retrieval. Various factors, including failure of fertilization, absence of high-quality embryos, and loss to follow-up, resulted in 260 participants proceeding with ET, of whom 200 underwent single blastocyst embryo transfers (blast-SETs). Among these, 139 women displayed positive hCG levels indicative of pregnancy, with 121 women demonstrating a single GS detected without multiple GS occurrences.

The research investigated the incidence of high-quality blastocysts per oocyte retrieval, revealing that women aged over 36 or those with Hashimoto’s disease exhibited notably diminished rates. Additionally, frequent consumption of fish was tentatively associated with reduced rates. Examination of all embryo transfer (ET) cycles demonstrated that older women faced diminished prospects of a positive pregnancy test, whereas sufficient sleep, extended computer use, and non-smoking partners were correlated with enhanced prospects. Detection of gestational sacs (GS) following ET was more likely with the use of olive oil, extended computer use, and a body mass index (BMI) of 20.8 kg/m² or higher, although advanced age decreased the likelihood.

Specifically focusing on blastocyst single embryo transfer (blast-SET) cycles, computer usage for four or more hours daily significantly elevated the likelihood of a positive pregnancy test and GS detection. Increasing age tended to reduce the likelihood of a positive pregnancy test, while a higher FertiQoL Total scaled treatment score and a specific BMI threshold appeared to favor GS detection, albeit with a trend toward significance rather than conclusive evidence.

Conclusions In summary, the study delved into the impact of lifestyle, dietary habits, and fertility-specific quality of life (QoL) on assisted reproductive technology (ART) outcomes among Eastern Asian women. Key discoveries include the adverse effects of advanced age and Hashimoto’s disease on blastocyst quality, as well as the positive associations between adequate sleep, computer use, and pregnancy success. Consumption of olive oil emerged as beneficial for gestational sac detection, challenging presumptions about dietary influences on fertility. Notably, male smoking detrimentally affected outcomes, underscoring the significance of lifestyle factors in reproductive success.

For more information: Lifestyle and fertility-specific quality of life affect reproductive outcomes in couples undergoing in vitro fertilization, Frontiers in Endocrinology, https://doi.org/10.3389/fendo.2024.1346084