What to do with a pregnant patient with a pituitary microadenoma who is on cabergoline (dopamine agonist)?

Management of Pituitary Microadenoma on Cabergoline During Pregnancy

Discontinue cabergoline immediately upon confirmation of pregnancy in patients with microadenomas, as the risk of tumor enlargement is only 1% and the drug should not be used during pregnancy unless absolutely necessary. 1, 2

Immediate Actions Upon Pregnancy Confirmation

• Stop cabergoline as soon as pregnancy is confirmed through a pregnancy test, as the FDA label explicitly states that patients should notify their physician if they suspect or become pregnant during therapy 1
• The risk of symptomatic microadenoma enlargement during pregnancy after discontinuing dopamine agonists is extremely low at approximately 1%, making discontinuation the safest approach 2
• Do not recommend therapeutic abortion if pregnancy occurred while on cabergoline, as preliminary evidence does not suggest increased adverse fetal outcomes 2

Clinical Monitoring Strategy During Pregnancy

• Perform clinical surveillance each trimester focusing on symptoms of tumor enlargement: severe headaches, visual changes (blurred vision, visual field defects), nausea, or vomiting 2, 3
• Formal ophthalmologic examination is not routinely indicated for microadenomas during pregnancy unless symptoms develop 4
• Reserve MRI for patients who develop concerning symptoms suggestive of tumor growth, as imaging is not needed for routine asymptomatic follow-up of microadenomas 4, 3

Management If Symptoms of Tumor Enlargement Develop

• If the patient develops headaches, visual symptoms, or other signs of adenoma expansion during pregnancy, restart dopamine agonist therapy immediately 5, 3
• Bromocriptine is the preferred agent if treatment reinitiation is needed during pregnancy, as it has more extensive safety data with over 6,000 reported pregnancies 2, 4
• If bromocriptine is not tolerated due to side effects (nausea, orthostatic hypotension), cabergoline can be used as an alternative throughout pregnancy, with case reports demonstrating safety and efficacy 6, 5, 3

Important Caveats and Pitfalls

• The FDA warns that dopamine agonists should generally not be used in patients with pregnancy-induced hypertension (preeclampsia, eclampsia) unless potential benefit outweighs risk 1
• Do not confuse microadenomas with macroadenomas: macroadenomas carry a 23% risk of symptomatic enlargement if dopamine agonists are discontinued, versus only 1% for microadenomas 2
• Breastfeeding after delivery does not increase the risk of tumor regrowth and should be encouraged 4
• Some microprolactinomas may undergo spontaneous regression during pregnancy, with complete resolution possible after delivery 3

Postpartum Management

• Recheck prolactin levels and consider repeat pituitary MRI 6-12 weeks postpartum to assess for any residual adenoma 3
• Many patients with microadenomas may not require resumption of cabergoline after pregnancy if prolactin levels normalize and regular menses return 3