Chapter 102

### Introduction

It is advisable that menstruation begin before the individual ceases to be a virgin.

Soramus of Ephesus (2nd century), text on diseases of women

Abnormal uterine bleeding is a common problem encountered in general practice. Heavy menstrual bleeding is the commonest cause of iron-deficiency anaemia in the Western world. A classification of abnormal uterine bleeding is presented in Table 102.1.

Table 102.1

Classification of abnormal uterine bleeding

Key facts and checkpoints

• Up to 20% of women in the reproductive age group complain of increased menstrual loss.1

• At least 4% of consultations in general practice deal with abnormal uterine bleeding.

• Up to 50% of patients who present with perceived menorrhagia (or excessive blood loss) have a normal blood loss when investigated.1 Their perception is unreliable.

• The possibility of pregnancy and its complications, such as ectopic pregnancy, abortion (threatened, complete or incomplete), hydatidiform mole or choriocarcinoma should be kept in mind.2

• A menstrual record is a useful way to calculate blood loss.

• The mean blood loss in a menstrual cycle is 30–40 mL.

• Blood loss is normally less than 80 mL.

• Heavy menstrual bleeding (menorrhagia)—HMB—is a menstrual loss of more than 80 mL per menstruation.

• HMB disposes women to iron-deficiency anaemia.

• Two common organic causes of HMB are fibroids and adenomyosis (presence of endometrium in the uterine myometrium).3

• Various drugs can alter menstrual bleeding (e.g. anticoagulants, cannabis, steroids).

### Defining what is normal and what is abnormal

This feature is based on a meticulous history, an understanding of the physiology and physiopathology of the menstrual cycle and a clear understanding of what is normal. Most girls reach menarche by the age of 13 (range 10–16 years).1 Dysfunctional bleeding is common in the first 2–3 years after menarche due to many anovulatory cycles resulting in irregular periods, heavy menses and probably dysmenorrhoea.

Once ovulation and regular menstruation are established the cycle usually follows a predictable pattern and any deviation can be considered as abnormal uterine bleeding (see Table 102.2). It is abnormal if the cycle is less than 21 days, the duration of loss is more than 7 days, or the volume of loss is such that menstrual pads of adequate absorbency cannot cope with the flow or clots.4

Table 102.2

Normal menstruation in the reproductive age group

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