History
A
31-year-old woman has been trying to conceive for nearly 3 years without
success. Her last period started 7 months ago and she has been having periods
sporadically for about 5 years. She bleeds for 2–7 days and the periods occur
with an interval of 2–9 months. There is no dysmenorrhoea but occasionally the
bleeding is heavy.
She
was pregnant once before at the age of 19 years and had a termination of
pregnancy.
She had a laparoscopy
several years ago for pelvic pain, which showed a normal pelvis.
Cervical
smears have always been normal and there is no history of sexually transmitted infection.
The
woman was diagnosed with irritable bowel syndrome when she was 25, after thorough
investigation for other bowel conditions. She currently uses metoclopramide to increase
gut motility, and antispasmodics.
Her
partner is fit and well, and has two children by a previous relationship.
Neither partner drinks alcohol or smokes.
Questions
What
is the diagnosis and its aetiology?
How
would you further investigate and manage this couple?
Answer
The
infertility is secondary to anovulation as shown by the day 21 progesterone (30
nmol/L suggests ovulation has occurred). Normal testosterone and gonadotrophins
and high prolactin suggest the likely case of anovulation is
hyperprolactinaemia. Hyperprolactinaemia may be physiological in
breast-feeding, pregnancy and stress. The commonest causes of pathological
hyperprolactinaemia are tumours and idiopathic hypersecretion, but it may also
be due to drugs, hypothyroidism, ectopic prolactin secretion or chronic renal
failure. In this case the metoclopramide is the cause, as it is a dopamine antagonist
(dopamine usually acts via the hypothalamus to cause inhibition of prolactin secretion,
and if this is interrupted, prolactin is excreted to excess). Galactorrhoea is
not a common symptom of hyperprolactinaemia, occurring in less than half of
affected women.
Drugs
associated with hyperprolactinaemia (due to dopamine antagonist effects)
Metoclopramide
Phenothiazines (e.g. chlorpromazine, prochlorperazine,
thioridazine)
Reserpine
Methyldopa
Omeprazole,
ranitidine, bendrofluazide (rare associations)
The
metoclopramide should be stopped and the woman reviewed after 4–6 weeks to ensure
that the periods have restarted and that the prolactin level has returned to
normal. If this does not occur, then further investigation is needed to exclude
other causes of hyperprolactinaemia such as a pituitary micro- or
macro-adenoma. It would be advisable to repeat the day 21 progesterone level to
confirm ovulatory cycles. The woman should have her rubella immunity checked
and should be advised to take preconceptual folic acid until 12 weeks of
pregnancy.
If the woman fails to
conceive then a full fertility investigation should be planned with semen
analysis and tubal patency testing (hysterosalpingogram or laparoscopy and dye test).
KEY
POINTS
A full drug history should be elicited in women with
amenorrhoea or infertility.
Galactorrhoea occurs in less than half of women with
hyperprolactinaemia.
Day 21 progesterone over 30 nmol/L is suggestive of
ovulation.
No comments:
Post a Comment