Uterine Fibroids for Undergraduates Max Brinsmead MB BS PhD September 2012

Uterine Fibroids Benign tumours (leiomyomata) of uterine smooth muscle Common – 25% of women in a lifetime Usually multiple Various sizes Genetic predisposition more common in black races More common in the obese Less common in smokers More common in nulliparas Accounts for ~30% of hysterectomies

Fibroid Locations Subserous Submucous (~5% of all fibroids) Intramural Project from the uterus into the peritoneal cavity Sometimes pedunculated Least likely to cause symptoms Submucous (~5% of all fibroids) Project into the uterine cavity Most likely to cause symptoms Intramural Most common Usually multiple

Intramural & Submucous Fibroids

Subserous Fibroid at Laparoscopy

Fibroid Symptoms Mostly asymptomatic Menorrhagia Pressure effects Heavy regular periods Iron deficiency anaemia Pressure effects Urine frequency Pelvic tumour awareness Difficulty initiating micturition Pain, Infertility & Irregular vaginal bleeding May be due to other pathology

Fibroids’ Natural History Oestrogen-dependent tumours that grow slowly: Whilst cycling premenopausal Probably whilst on COC When taking E2 HRT Will regress with menopause Response to progestin-only contraception is uncertain Malignant change rare <1:1000

Investigation of Fibroids Ultrasound Frequently misdiagnosed with this modality “Multiple small fibroids” is usually irrelevant Heterogenous echolucency is normal in a parous uterus Adenomyosis can look the same Size and location important Can be a “contraction wave” in pregnancy MRI better than CT Imaging Laparoscopy and Hysteroscopy Saline hysterography Useful for pedunculated submucous fibroids

Treatment Options for Fibroids Hysterectomy If the uterus is >10w size Or symptoms that are due to the fibroids Rapid growth Abdominal or vaginal Myomectomy Best for single fibroid in a young woman ~50% come to hysterectomy within 5 years? Hysteroscopic resection Uterine artery embolisation (UAE) Medical options GnRH analogue Mirena

Fibroids and Infertility In most women the association is result and not cause It is said that ≈3% of infertility is due to fibroids Most infertility specialists will recommend removal of any fibroid with >50% of its surface in the uterine cavity The results from removal of a single submucous fibroid can be dramatic And there is evidence that removal of intramural fibroids >5 cm diam will enhance fertility with IVF

Fibroids and Pregnancy In most women there is no effect 80% remain unchanged in size Rarely rapid growth and red degeneration Increased risk of bleeding and threatened preterm delivery But most deliver at term Fibroid in the lower segment can interfere with vaginal birth Myomectomy at the time of Caesarean is not wise 30% require emergency hysterectomy

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