How do you determine elevated prolactin levels in a breastfeeding woman with a history of prolactinoma microadenoma after stopping dopamine agonist medication, such as bromocriptine (bromocriptine) or cabergoline (cabergoline), during pregnancy?

From the Guidelines

To determine elevated prolactin levels in a breastfeeding woman with a history of prolactinoma microadenoma after stopping dopamine agonist medication during pregnancy, serial prolactin measurements should be obtained while considering the normal physiologic hyperprolactinemia of lactation, with the first measurement taken 6-8 weeks postpartum and follow-up levels every 2-3 months during breastfeeding, as suggested by the most recent guidelines 1. The interpretation of these values requires comparing them to the expected range for lactating women, which is typically between 100-300 ng/mL, rather than non-lactating reference ranges, as noted in studies on lactation and prolactin levels 1. A significant rise above the patient's established lactation baseline or values exceeding 300-400 ng/mL may suggest tumor recurrence, necessitating further evaluation with visual field testing and MRI imaging, preferably without gadolinium if the patient is breastfeeding, as recommended in the management of pituitary adenomas 1. Most microadenomas remain stable during pregnancy and breastfeeding, so dopamine agonist therapy, such as cabergoline, is typically only restarted if there's evidence of significant tumor growth or if prolactin levels rise substantially above the expected lactation range, with cabergoline being the preferred dopamine agonist due to its superior effectiveness and lower adverse effect profile 1. This approach balances tumor surveillance with supporting the woman's choice to breastfeed, recognizing the challenges posed by physiologic hyperprolactinemia of lactation in distinguishing normal from pathologic elevations. Key considerations include:

• Serial prolactin measurements during breastfeeding
• Comparison to lactating women's reference ranges
• Monitoring for symptoms of tumor growth
• Use of cabergoline as the first-line dopamine agonist if therapy is required
• Balancing tumor surveillance with the support of breastfeeding, as emphasized in recent consensus guidelines 1.

From the Research

Determining Elevated Prolactin Levels in Breastfeeding Women with a History of Prolactinoma Microadenoma

To determine elevated prolactin levels in a breastfeeding woman with a history of prolactinoma microadenoma after stopping dopamine agonist medication, several factors should be considered:

• Prolactin levels are naturally elevated during breastfeeding, making it challenging to determine what constitutes "too high" 2, 3.
• Studies have shown that prolactin levels in women with prolactinoma microadenoma do not increase further during pregnancy, unlike in women without the condition 3.
• The risk of symptomatic tumor enlargement during pregnancy is low (2-3%) for microprolactinomas, and breastfeeding has no harmful effect on tumor growth 2, 4.
• Clinical evaluation and periodic monitoring during pregnancy and breastfeeding are essential to detect any potential tumor growth or symptoms 5, 6.
• If tumor expansion is suspected, confirmation can be made through MRI and visual field testing, and reintroduction of dopamine agonist medication or surgery may be necessary 6.

Key Considerations

• Dopamine agonist medication, such as bromocriptine or cabergoline, can be discontinued during pregnancy in women with microprolactinomas, but should be reintroduced if symptomatic tumor growth occurs 2, 5.
• Breastfeeding does not increase the risk of tumor growth, and dopamine agonist treatment can be postponed as long as breastfeeding is desired 2, 4.
• Women with a history of prolactinoma microadenoma should be closely monitored during pregnancy and breastfeeding to detect any potential complications 3, 6.