Is cabergoline (dopamine receptor agonist) safe to use during pregnancy?

Cabergoline in Pregnancy

Cabergoline can be used during pregnancy when clinically necessary, though it should ideally be discontinued once pregnancy is confirmed unless the benefits clearly outweigh the risks, particularly in cases of large prolactinomas requiring continued treatment. 1

FDA Classification and Official Warnings

The FDA label explicitly states that dopamine agonists in general should not be used in patients with pregnancy-induced hypertension (preeclampsia, eclampsia, postpartum hypertension) unless potential benefits outweigh risks. 1 However, the label acknowledges that "there are no adequate and well-controlled studies in pregnant women" and states the drug "should be used during pregnancy only if clearly needed." 1

Evidence-Based Safety Profile

The accumulated observational data from over 2,000 pregnancies exposed to cabergoline shows reassuring safety outcomes:

• A systematic review of 1,662 pregnancies found no increased risk of major malformations or spontaneous abortions compared to other comparators or no treatment. 2

• The largest single observational study of 380 pregnancies (329 with follow-up data) demonstrated a spontaneous miscarriage rate of 42% among abortions, with 97% live delivery rate among completed pregnancies, and only 9% neonatal abnormalities with no apparent pattern. 3

• A multicenter study of 103 pregnancies with fetal exposure ranging from 3-25 weeks (96.9% during first trimester) found spontaneous abortion rate of 7.2%, preterm delivery rate of 8.8%, and only 3.6% neonatal abnormalities (1 major, 2 minor). 4

Clinical Management Algorithm

For microadenomas (most common scenario):

• Discontinue cabergoline 4-6 weeks after conception confirmation, as the risk of tumor enlargement during pregnancy is only 1%. 5
• Follow symptomatically each trimester without routine imaging. 5

For macroadenomas (higher risk scenario):

• Three management options exist: 5
  1. Discontinue cabergoline after pregnancy diagnosis (23% risk of tumor enlargement) with monthly visual field testing
  2. Continue cabergoline throughout pregnancy with monthly visual field testing 6
  3. Prepregnancy surgical debulking followed by discontinuation (2.8% risk of tumor enlargement)

If pregnancy occurs unexpectedly during cabergoline treatment:

• Therapeutic abortion is not warranted based on drug exposure alone. 5
• The drug can be continued if clinically indicated, particularly for symptomatic macroadenomas. 6

Comparison to Bromocriptine

While bromocriptine has more extensive pregnancy safety data and is often considered first-line, cabergoline offers important advantages: 5

• Cabergoline is more effective at normalizing prolactin levels and restoring ovulation
• Preliminary evidence does not suggest increased adverse fetal outcomes compared to bromocriptine 5
• Switching from cabergoline to bromocriptine upon pregnancy confirmation may be unnecessary given the reassuring safety data 2

Critical Monitoring Requirements

Patients must be counseled to: 1

• Notify their physician immediately if pregnancy is suspected
• Undergo pregnancy testing if there is any suspicion
• Report shortness of breath, persistent cough, difficulty breathing when lying down, or extremity swelling (signs of valvulopathy)

Cardiac surveillance is essential: 1

• Baseline echocardiogram before treatment initiation
• Echocardiographic monitoring every 6-12 months or as clinically indicated
• Discontinue if new valvular regurgitation, restriction, or leaflet thickening develops

Common Pitfalls to Avoid

• Do not automatically switch to bromocriptine upon pregnancy confirmation if cabergoline is well-tolerated and clinically necessary, as this may cause disease flare and bromocriptine is poorly tolerated by many patients. 2

• Do not withhold cabergoline in symptomatic macroadenomas during pregnancy, as uncontrolled tumor growth poses greater maternal and fetal risks than continued medication exposure. 6

• Do not use cabergoline for lactation suppression postpartum, as this is not a recommended indication and interferes with breastfeeding. 1

• Do not combine with D2-antagonists (phenothiazines, butyrophenones, metoclopramide) as these counteract cabergoline's effects. 1

Breastfeeding Considerations

Cabergoline should not be given to women postpartum who are breastfeeding or planning to breastfeed, as its prolactin-lowering action directly interferes with lactation. 1 The drug's excretion in human milk is unknown, but the mechanism of action makes it incompatible with nursing. 1