Seasonality's Impact on Patients Receiving Intracytoplasmic Sperm Injections: A Reproductive Analysis.

Several studies indicated that seasonal variations may impact spontaneous conception or abortion.[ 1 ] A study has reported that among naturally conceived pregnancies in the USA, birth rates were higher during summer and early autumn than during spring, while in Northern Europe, birth rates were highest during spring but lowest during autumn.[ 2 ] Natural conception may be affected by several season-related factors, such as sperm quality, ovulation rate, or social parameters.[ 3 ] Sperm concentration and motility tend to be higher during certain seasons, with greater normal morphology observed during fall and winter compared to spring.[ 4 ] In sub-equatorial areas, Reiter et al .[ 5 ] reported that deterioration in sperm quality was observed during the summer, which is reflected by lower conception rates and, consequently, lower birth rates in the spring. Moreover, environmental light exposure on the female reproductive axis has been observed to affect, ovulation, and endometrial receptivity. Nakane and Yoshimura[ 6 ] stressed that hormone production and some physiological processes, including body temperature and rest-activity cycle have circadian rhythms that follow the daily light/dark cycle. Moreover, photoperiodism triggers melatonin secretion, which results in changes in the pituitary-ovarian axis hormones. In addition to the biological seasonal variation, social parameters, and patterns of sexual activity may also influence reproduction and birth rate in humans.[ 7 ] Considering the controversial results regarding the observed impact of seasonality on ART outcomes, the present study aimed to compare the outcomes of patients undergoing their first ICSI cycle, across four seasons in Aseer Region, Saudi Arabia.

Table 1 shows that the age of participants ranged from 25 to 42 years, with a mean age (±SD) of 34.7 ± 11.5 years. About one-fourth of the participants (25.7%) were ≤30 years old, 24% aged 31–35 years, 30% aged 36–40 years, and 20.3% were above 40 years old. Their duration of infertility ranged from 1 to 20 years, with a mean duration (±SD) of 6.0 ± 3.9 years. In about one-third of women (34.6%), the duration of infertility was 1–4 years, while it was 5-10 years in 46.3% and more than 10 years in 12.1%. A positive pregnancy test was the outcome of ICSI in 45.2% of women. However, live births occurred among 29.2% of women, while pregnancy loss (e.g., abortion, or chemical pregnancy) occurred in 16% of women. Characteristics of participants who underwent intracytoplasmic sperm injection (ICSI) Table 2 shows that the ICSI process did not differ significantly according to season. Characteristics of the intracytoplasmic sperm injection (ICSI) process according to season Table 3 shows that after ICSI, the live birth rate was highest during autumn (30.6%), while it was lowest during summer (27.3%). However, the outcome of ICSI did not differ significantly according to season. Outcome of intracytoplasmic sperm injection (ICSI) according to season P =0.658

Our analysis showed that seasonality does not have any impact on pregnancy outcomes. The live birth rate was highest during autumn and was lowest during summer. However, the outcome of ICSI did not differ significantly according to season. There are no conflicts of interest.

The age of participants ranged from 25 to 42 years, with a mean age of 34.7 ± 11.5 years. Approximately one-fourth (25.7%) were under 30 years old, 24% were aged 31–35 years, 30% were aged 36–40 years, and 20.3% were over 40 years old. The duration of infertility varied from 1 to 20 years, with a mean duration of 6.0 ± 3.9 years. For about one-third of the women (34.6%), the infertility lasted 1–4 years, while 46.3% experienced infertility for 5–10 years, and 12.1% for more than 10 years. The outcome of ICSI resulted in successful pregnancies for 45.2% of women, with live births occurring in 29.2%, while 16% experienced pregnancy loss. The study comparing outcomes of 2,194 women who underwent their first ICSI cycle in Aseer Region, Saudi Arabia, found no significant seasonal differences in ART treatment outcomes. This aligns with other studies, which reported no seasonal impact on fertilization or implantation rates in fresh embryo transfer cycles. Similarly many observed no seasonal effect on IVF outcomes.[ 2 3 4 5 6 ] Some studies have reported seasonal variations, and found higher pregnancy rates in Omsk during summer and autumn, while some, reported no seasonal variation in Alberta. Nakane and Yoshimura attributed seasonal effects on ICSI outcomes to melatonin’s influence on the reproductive tract, with Proctor et al . highlighting melatonin’s role in circadian rhythms and its higher secretion during winter.[ 6 ]

This study included 2,194 women undergoing their first intracytoplasmic sperm injection cycle at a private medical center in Abha City, Saudi Arabia, from January 1 st , 2017, to September 1 st , 2021. The participants were divided by the season of oocyte retrieval into spring (n = 515), summer (n = 583), autumn (n = 589), and winter (n = 503). Ethical approval was obtained from King Khalid University’s Research Ethics Committee (approval No. ECM#2024-407), and written informed consent was provided by all participants. The inclusion criteria required women to be between 20 and 44 years old with normal ovarian function, indicated by an antral follicle count greater than 7 and anti-Mullerian hormone levels higher than 1.1 ng/mL. They had to undergo their first fresh in vitro fertilization cycle using the follicular phase long-term protocol for ovulation induction, followed by a fresh embryo transfer after oocyte retrieval. Exclusion criteria included canceled embryo transfers due to liver or kidney dysfunction, genetic screening, personal reasons, and various medical conditions such as endometriosis, uterine abnormalities, endocrine diseases, and severe male factor infertility. For the downregulation regimen, patients received a subcutaneous injection of 3.75 mg of a short-acting gonadotropin-releasing hormone agonist on days 2–3 of their menstrual cycle to achieve pituitary downregulation. Pituitary suppression was confirmed by vaginal ultrasound and serum hormone levels after 30–42 days. Controlled ovarian hyperstimulation followed, with individualized dosages of gonadotropins based on the patient’s age, AMH level, AFC, BMI, and serum basal FSH level. Fresh embryo transfers were conducted based on embryo quality, endometrial status, and patient conditions.