Does hyperprolactinemia (elevated prolactin levels) affect pregnancy?

Impact of Hyperprolactinemia on Pregnancy

Hyperprolactinemia can significantly affect pregnancy by causing infertility, increasing risk of miscarriage, and potentially leading to tumor expansion during pregnancy if caused by a prolactinoma. 1

Effects of Hyperprolactinemia on Fertility and Pregnancy

Fertility Impact

• Hyperprolactinemia disrupts normal reproductive function by:
  • Interfering with gonadotropin-releasing hormone (GnRH) pulsatility
  • Causing hypogonadism and anovulation in women
  • Leading to menstrual irregularities (oligomenorrhea or amenorrhea) 1, 2
  • Causing luteal phase insufficiency in cycling women 2
  • Being associated with recurrent miscarriage 2

During Pregnancy

• For women with prolactinoma who become pregnant:
  • Prolactin-secreting adenomas may expand during pregnancy due to estrogen stimulation 1, 3
  • Compression of optic or other cranial nerves may occur, potentially requiring emergency pituitary surgery 3
  • Visual field impairment is a known complication that requires monitoring 3
  • In most cases, compression resolves following delivery 3

Management Recommendations for Women with Hyperprolactinemia Planning Pregnancy

Pre-Pregnancy Evaluation

• Complete pituitary evaluation is essential before treatment to detect prolactin-secreting adenomas 1, 3
• Careful assessment of visual fields in patients with macroprolactinoma 1
• Exclude other causes of hyperprolactinemia (medication effects, hypothyroidism) 2

Treatment Approach

• Dopamine agonists are the treatment of choice 1, 2
  • Cabergoline is more effective and better tolerated than bromocriptine 4
  • However, bromocriptine has more safety data during pregnancy 4
  • Treatment should normalize prolactin levels at the lowest possible dose 2

Medication Management During Pregnancy

• Dopamine agonists should be discontinued once pregnancy is confirmed unless there's risk of tumor expansion 1
• For women with macroprolactinomas:
  • Close monitoring throughout pregnancy is essential 1, 3
  • Watch for signs of tumor enlargement (headaches, visual changes) 3
  • Some patients may need to continue dopamine agonist therapy during pregnancy if risk of tumor expansion is high 1

Special Considerations and Monitoring

Visual Field Monitoring

• Regular monitoring of visual fields is crucial, especially for women with macroprolactinomas 1, 3
• Secondary deterioration of visual fields may develop despite normalized prolactin levels due to traction on the optic chiasm 3
• Rapidly progressive visual field loss requires immediate neurosurgical evaluation 3

Pregnancy Testing and Follow-up

• Pregnancy testing is recommended at least every four weeks during amenorrheic periods 3
• Once menses return, pregnancy testing should be done whenever a menstrual period is missed 3
• Patients must be monitored closely throughout pregnancy for signs of tumor enlargement 3

Potential Complications and Pitfalls

Tumor Expansion Risk

• Discontinuation of treatment in patients with known macroadenomas has been associated with rapid tumor regrowth and increased serum prolactin 3
• Cerebrospinal fluid rhinorrhea has been observed in some patients with prolactin-secreting adenomas treated with dopamine agonists 3

Medication Side Effects

• Bromocriptine may cause symptomatic hypotension, particularly in the first days of treatment 3
• Rare but serious adverse events including hypertension, myocardial infarction, seizures, and stroke have been reported in postpartum women treated with bromocriptine 3
• Cabergoline side effects occur in about 13% of patients (nausea, dizziness, headache) 1

By properly managing hyperprolactinemia before and during pregnancy, most women can achieve successful pregnancies with minimal complications. The key is early diagnosis, appropriate treatment, and careful monitoring throughout pregnancy, especially for women with macroprolactinomas.