Case 19: Absent periods

 

Case 19: Absent periods

CASE 19: ABSENT PERIODS

History

An 18-year-old woman presents with an absence of periods for 6 months. This has occurred

twice before in the past but on both occasions menstruation returned so she was not too

concerned. Her periods started at the age of 12 years and were initially regular. She has

no medical history of note and denies any medication. She is currently in her first year at

university. She runs most days and reports a ‘healthy’ diet avoiding carbohydrate foods

and meat. She is the oldest of three siblings and her parents separated when she was 12

years. She has minimal contact with her father and lives mainly with her mother who she

says she gets on well with. She has had a boyfriend in the past but has veered away from

any sexual relationships.

Examination

The woman is tall and thin with a body mass index (BMI) of 15.5 kg/m2. There is evidence of

fine downy hair growth on her arms. Heart rate is 86/min and blood pressure 100/65 mmHg.

Abdominal examination reveals no scars or masses, and genital examination is not performed.

INVESTIGATIONS

Normal range

Follicle-stimulating hormone 1.0 IU/L Day 2–5

1–11 IU/L

Luteinizing hormone 0.8 IU/L Day 2–5

0.5–14.5 IU/L

Oestradiol 52 pmol/L 70–600 pmol/L

Prolactin 630 mu/L 90–520 mu/L

Testosterone 1.6 nmol/L 0.8–3.1 nmol/L

Transabdominal ultrasound report: the uterus is anteverted and measures 41×33×19

mm. The endometrium appears thin and regular measuring 2.3 mm.

The right ovary contains a few tiny follicles and the ovarian volume is 4.3 cm3. The left

ovary has no visible follicles and measures 3.8 cm3. No dominant follicle or corpus luteum

is visualized on either ovary.

Questions

• What is the diagnosis?

• How would you further investigate and manage this woman?100 Cases in Obstetrics and Gynaecology

46

ANSWER 19

The woman has evidence of hypogonadotrophic hypogonadism – she has low oestradiol

levels associated with low gonadotrophin stimulation from the anterior pituitary. This may

be due to various pituitary or hypothalamic causes, but in this case clearly relates to anorexia

nervosa and possibly excessive exercise. The raised prolactin is consistent with stress and

does not need to be investigated further. At a BMI below 18 kg/m2, menstruation tends to

cease, returning once the BMI increases again.

The ultrasound shows a small uterus, very thin inactive endometrium and immature ovaries

with minimal follicular activity, all of which are typical findings in anorexia nervosa.

The previous episodes of amenorrhoea probably occurred when her dietary intake was very

low and it may be that starting at university may have increased her stress levels with the

consequence of worsening her anorexia.

Further investigation

• Full blood count, liver and renal function should all be monitored as these are

affected in severe disease.

• A bone scan should be arranged to check for bone density – hypo-oestrogenism as a

result of anorexia is likely to induce early-onset osteoporosis and fractures.

• Psychological assessment is also important to guide appropriate treatment.

Management

Encouraging the woman to eat a more normal diet and to avoid exercising is the ideal management, but anorexia is a chronic disease that is often refractory to treatment. Explanation that

her periods will return if she increases her BMI may possibly encourage her to put on weight.

The combined oral contraceptive pill should be prescribed in the meantime, which will prevent osteoporosis and bring on periods, albeit pharmacologically induced.

Referral to a specialist eating disorders unit is vital in addressing the long-term problem for

this woman. Commonly, eating disorders arise out of childhood difficulties and family or

group therapy should be considered.

If the investigations suggest renal or hepatic impairment then inpatient management is likely

to be necessary.

KEY POINTS

• Menstruation usually ceases when BMI is less than 18 kg/m2.

• Amenorrhoiec anorexic women need oestrogen replacement to protect them

from osteoporosis.

• Anorexia is often refractory to treatment.