Normal menstruation is triggered by a fall in progesterone two weeks after ovulation, if the woman is not pregnant. The average menstruation lasts 4-5 days (n), and menstrual cycle 21-35 days(d). The equation for this is K = n/d, where K represents the menstrual cycle, n stands for the duration of bleeding, and d is the length of the cycle. Below represents normal values for the equation:
K = n/d K = 4-5/21-35
The normal volume of blood lost during menstruation is 30-40ml. Menorrhagia is defined as excessive menstrual blood loss, which exceeds 80ml. However, it is normally applied to a women experiencing heay menstrual bleeding which has an impact on her quality of life. This article will discuss the history, examination, causes, investigations and treatment options of menorrhagia.
One third of women will experience heavy menstrual bleeding at some point in their lives. It is important to rule out any conditions which could cause secondary menorrhagia and may be correctable. Due to the excessive blood loss, women are at increased risk of developing iron deficiency anaemia.
The aetiology of menorrhagia can be broadly divided into organic and non-organic. The single non-organic cause for menorrhagia is better known as Dsyfunctional Uterine Bleeding (DUB). DUB is a general term for abnormal vaginal bleeding where no cause is established, and accounts for 40-60% of presentations of menorrhagia. It is a diagnosis of exclusion. The organic causes are illustrated below. Although not an exhaustive list, it provides the important diagnoses not to miss when a woman presents with menorrhagia.
From the local causes of menorrhagia, the polyps and carcinomas, are mainly cervical and endometrial.
It also is important to highlight two diseases from this list - coagulopathy and hypothyroidism. The coagulopathic disease which can cause menorrhagia is von Willebrand's disease. These two disease are risk factors for menorrhagia, and it is important when undertaking the history and examination that the signs and symptoms for these are enquired about.
The history is vitally important, to distinguish between the different causes of menorrhagia. When taking a gynaecoloigcal history in general, there are four vital points to establish:
Specific for menorrhagia, here are questions you would want to include in the history:
- Duration of menstruation
- Duration of cycle
- How many tampons/pads the woman is using every day
- Intermenstrual/Post-coital bleeding
- Easy bruising/bleeding gums (vWB)
- Thyroid symtoms (hypothyroidism)
- Drug history (treatment related causes)
Flooding is a term women used to desribe heavy blood flow which goes through clothes and bedding. Understandably, this causes significant distress to women and some women will avoid outings in case of flooding. Clots are important to enquire about, as this represents heavy menstrual flow.
As shown, most of these questions relate to the different causes for menorrhagia, and having this information enables you to request the right investigations to further your understanding of the womans condition and arrange appropriate treatment.
The examination should be a confirmatory assessment, as most of the information you will need will be found from the history. Examination should include:
- Pelvic Examination - when history suggestive of local causes
- Assessment of thyroid signs - eg. weight gain/dry hair
- Evidence of bleeding - ie. bruising/bleeding gums (for von Willebrand's disease)
All women presenting with menorrhagia should have a full blood count done to assess for iron deficiency anaemia. After that, other investigations are performed only if there is clinical suspicion after history and examination. Relevant investigations may include:
1. Trans-vaginal Ultrasound Scan (TVUS) (first line diagnostic tool for structural abnomalities)
2. Endometrial biopsy (if TVUS reveals endometrial thickness of >5mm)
And if the history suggests, consider performing:
- Thyroid Function Tests
- Clotting studies
The most important diagnosis not to miss if a woman presents with menorrhagia is Endometrial Carcinoma. Red flags for this include:
- Age >45
- Persistent Intermenstrual Bleeding
- Medical Treatments failed
If the patient has these features, refer for endometrial biopsy urgently.
Management is directed at treating any secondary cause. After the initial cause is dealt with, several treatments can be used to decrease menstrual blood flow. In DUB, it is essential first of all to ressaure the woman there is no sinister pathology.
Management can be broadly divided into pharmaceutical and surgical treatments. Management is tailored to the individual as some are fertility conserving and other treatments are not appropriate until a womans family is complete.
These can be divided into hormonal and non-hormonal treatments.
- Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): The most commonly used agent is mefenamic acid. As a prostaglandin inhibitor, is reduces blood loss and dysmenorrhoea. It is given as the same dose for someone with pain.
- Anti-fibrinolytics: The agent used here is tranexamic acid, a plaminogen-activator inhibitor which can reduce blood loss by 60% as well as reducing pain.
- Levonorgestrel Intra-uterine System - Mirena: This is the first line treatment for menorrhagia, and should be in long term (12 months).
- Norethisterone (Oral Progestogen): This is third line treatment, which shows a significant reduction in menstrual blood loss.
The options are either endometrial resection or hysterectomy, and normally are an option for women when their family is complete.
- Endometrial resection: This operation involves removal of the endometrium, either by diathermy or laser ablation. Compared to hysterectomy, it reduces hospital stay and the time the women can commence daily life again. The complications of this procedure are uterine perforation and fluid overload.
- Hysterectomy: Hysterectomy means surgical removal of the uterus. It can be done several ways, laparoscopically, vaginally or abdominally. There are two types:
1. Total hysterectomy - uterus and cervix removed
2. Sub-total hysterectomy - cervix left intact
These may be done with or without oophrectomy (removal of the ovaries).
A summary of the management of a woman with menorrhagia is shown below.
- Hurskainen R et al. (2007) Diagnosis and treatment of menorrhagia. Acta Obstetrics Gynaecology Scan. 2007; 86(6): 749-57.
- Greer I, Cameron I, Kitchener H, Prentice A (2001) Mosby's Color Atlas and Text of Obstetrics and Gynaecology. London. Harcout: p 32-27
- Symonds M. E (2004) Essential Obstetrics and Gynaecology. Edinburgh. Churchill Livingston: p 45-54
- NICE Guidelines: CD44 Heavy Menstrual Bleeding