Dear patient, while considering a patient of prolactin secreting pituitary microadenoma (microprolactinoma) on dopaminergic agonist drugs like
bromocriptine or cabbergolin , becomming pregnant , two issues need to be addressed
1. effect of pregnancy on prolactinoma
2. safety of the dopaminergic agonist drug during pregnancy
Regarding the first one i.e effect of pregnancy on prolactinoma , it is known that pregnancy causes an increase in the size of normal
pituitary gland by about 30% and this increase in size occurs in all directions, gland height may increase up to 12 mm but it usually never crosses 26mm. However chances of clinically significant enlargement of a
pituitary microprolactinoma during pregnancy are only 1.3% if dopamine agonists are discontinued and the chances are lesser especially if the tumour has regressed with prior dopamine agonistic therapy. Therefore patients with microprolactinomas are not diccouraged from becomming pregnant .
Regarding the second issue i.e safety of dopamine agonists during pregnancy on foetal well being, cabbergolin being a newer drug ,its safety profile is not clearly established regarding its propensity to cause
spontaneous abortion ,ectopic pregnancy,
trophoblastic disease, multiple pregnancies or foetal malformations, where as the safety profile of bromocriptine is well established during pregnancy except for first 3 to 4 weeks. There fore bromocriptine is considered the therpy of choice for microprolactinoma during pregnany.
The standard approach for a patient of microprolactinoma who wants to become pregnant is to start the patient on bromocriptine to allow the ovulation to occur,encourage unprotacted contact with the husband, and watch for the pregnancy to occur, once pregnancy is confirmed, hold bromocriptine and keep the patient under observation for any symptoms of tumour enlargement like headache,blurring of vision ,excessive urination due to
diabetes insipidus and if these symptoms occur,bromocriptine should be immediately reinstituted and MRI brain with out contrast should be done to access the pituitary gland. Generally regression occurs with bromocriptine reinstitution with improvement of symptoms except in few rare cases where trans nasal trans sphenoidal hypophysectomy may be required but the surgery carries the risk of foetal loss There fore i feel that you can go ahead and plan for pregnancy becoz you had a microprolactinoma that had regressed with dopamine agonistic drug (cabbergoline) but for this challange you need to be under close monitaring and supervision of your
endocrinologist , lets hope for the best and be prepared for the worst .