Endocrine Abstracts

Introduction: Menarche is a late pubertal event that occurs at a mean age of 12.4 years and follows on an average of 2.5 years after the onset of thelarche. Some studies suggest an increase in precocious puberty (including early menarche) during the COVID-19 pandemic, potentially due to lifestyle changes and stress. However, this is an area of ongoing research, and the exact mechanisms are not fully understood. There is no published literature to suggest a similar increase in the incidence of isolated premature menarche.

Methods: We audited the clinical and laboratory data on girls referred to our service for early menarche. There were 11 referrals from primary care from Oct 2019 to April 2025 with an age range of 6.27-9.19 years. 1 patient is still being investigated and hence excluded from analysis.

Results and outcomes: The Tanner stage was B2, with advanced bone age in 3 girls and B1 in 7. The uterine length was pre-pubertal in 9 and borderline at 3.5 cm in 1 girl. Thyroid functions were checked in 8 girls and were normal. 4 girls were overweight based on BMI and 4 showed evidence of increased height velocity. 3 girls had recurrent vaginal bleed and had an MRI scan of brain (normal results), but only 1 required treatment with GnRH analogue. 8 girls have been discharged from the service as there were no ongoing concerns and 1 is still under follow-up.

Conclusions: We have noticed a sudden increase in referrals for isolated menarche since 2020. Although increased exposure to endocrine-disrupting chemicals through diet or environment could be contributing to this trend, the exact cause of this remains unknown at present.