Estimating the relationship between hair relaxer use and uterine leiomyoma occurrence in Nigerian women

Background: Uterine fibroids remain one of the most common pelvic benign tumors of the female reproductive tract, affecting up to 70% of women before menopause. While established risk factors such as age, ethnicity and hormonal influences are well documented, recent years have seen growing concerns regarding the relationship between uterine fibroids and prolonged chemical exposure. In this study, we investigate the relationship between the use of hair relaxers and the prevalence of uterine fibroids among women presenting for pelvic ultrasound.
Methods: A cross-sectional study was conducted among 354 women ≥ 18 years who presented for ultrasound scanning at various diagnostic centers in Nigeria. Data was collected using structured questionnaires administered with the assistance of radiologists and sonographers, alongside ultrasound findings. Sociodemographic, obstetric, anthropometric, and hair care practices were also assessed. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS) version 26.0 to evaluate associations between variables and fibroid presence.
Results: Participants had a mean age of 37.5 ± 8.6 years, with most being multiparous (73.2%) and of low socioeconomic status (61.9%). Uterine fibroids were detected in 90.1% of participants, with a mean fibroid count of 2.19 ± 1.56. The use of hair relaxers was common (83.3%). Although most users applied relaxers fewer than five times per year (63.3%), they had also used them for long durations exceeding 16 years (63.3%). Both frequency (χ² = 194.201, p < 0.001) and duration (p < 0.001) of relaxer use showed strong associations with fibroid presence. Notably, fibroids were not observed among women with no history of relaxer use. Tribe (p < 0.001) and socioeconomic status (p = 0.035) were also significantly associated with fibroid prevalence, with the Benin and Yoruba tribes having the highest number of women with fibroids and no fibroids, respectively. Conversely, age and parity were not associated with fibroid prevalence.
Conclusion: In conclusion, this study demonstrates a strong association between hair relaxer use and uterine fibroids, particularly with prolonged and frequent exposure. These findings highlight the need for increased awareness and further research into modifiable risk factors contributing to fibroid development.