Endocrine Abstracts

Introduction: Phytoestrogens are derived from plants that are structurally and functionally similar to oestrogens. Their health benefits are widely extolled, although excessive consumption in children may cause adverse effects.

Case 1: A 5.7-year old female presented with a one-month history of breast development and a 3-day history of vaginal bleeding. Prior to presentation, she was taking a health drink containing fennel and sesame seeds, in addition to eating a vegetarian diet high in soya. Examination was B4, P1, A1 with no cliteromegaly, and her height was above her mid-parental target range. Baseline gonadotrophins were suppressed (LH <0.1 IU/L, FSH 0.1 IU/L, oestradiol <92 pmol/L). GnRH stimulation test indicated gonadotrophin independent puberty. Tumour markers were normal, as was her urine steroid profile (USP) and brain MRI. Pelvic ultrasound scan (USS) reported a peri-pubertal uterus with an endometrial stripe and marginally increased ovarian volumes with small follicles. Bone age was advanced by 2.5 years. A diagnosis of pseudo-precocious puberty secondary to high dietary phytoestrogen was proposed. Advice was given to remove the seeds and soya products from her diet. Three months later her pubertal features had regressed.

Case 2: A 3-year old Malaysian female presented with a 1-month history of breast development and 1-week history of vaginal bleeding. Examination was B3, P1, A1, with oestrogenisation of the labia and clitoromegaly, but no cutaneous lesions. Baseline gonadotrophins were suppressed with an elevated oestrogen of 493pmol. USP and tumour markers were normal. GnRH test excluded central puberty. USS showed a pubertal uterus, and bone age was advanced by 18 months. MRI of head and adrenals were normal. On further questioning, the gonadotrophin-independent precocious puberty was thought to be secondary to her parents’ phytoestrogen containing herbal extract (Kacip Fatimah) which she had been intermittently taking. Once this was stopped, all pubertal features regressed.

Conclusions: Phytoestrogens are widely available and their increased consumption may play a role in earlier pubertal development. These cases highlight the importance of a thorough history of diet and non-prescription supplements when assessing premature pubertal changes.