Ms. Lin, a 32-year-old married woman, experienced irregular menstruation and occasional breast swelling and milk secretion after giving birth to a baby boy two years ago. After trying to conceive for six months without success, she underwent an examination and was diagnosed with hyperprolactinemia. Her PRL (prolactin) level was measured at 165 ng/ml. Following two months of treatment with prolactin-lowering medication and monitoring her basal body temperature, she has successfully become pregnant.

 

This is a common scenario in infertility clinics. Prolactin is a hormone secreted by the lactotroph cells in the anterior pituitary gland. It is normal for lactation to occur during pregnancy or postpartum period. However, if there is milk secretion without pregnancy or breastfeeding, accompanied by menstrual abnormalities, it is a cause for concern.

 

Generally, in a blood test, if prolactin levels are significantly elevated, it is referred to as hyperprolactinemia. Hyperprolactinemia can cause menstrual abnormalities or even absence of menstruation. This is because high levels of prolactin suppress the action of gonadotropin-releasing hormone, leading to anovulation and consequently hindering pregnancy.

 

According to statistics, approximately 15% of women with infertility issues show elevated prolactin levels in blood tests. Therefore, it is recommended to include prolactin testing as part of the routine hormonal evaluation for women with infertility. Prolactin secretion exhibits diurnal rhythm, with a rapid increase during sleep, reaching a peak between 3 am and 5 am. Additionally, factors such as sexual intercourse, breast stimulation, psychological stress, exercise, use of tranquilizers, and eating can also increase prolactin secretion.

 

For optimal prolactin measurement, it is recommended to follow specific instructions provided by healthcare professionals. These instructions typically include having a full meal and sufficient rest the night before, abstaining from sexual activity, refraining from intense physical exercise on the morning of the test, avoiding breakfast, ensuring a positive mood, and completing personal grooming routines. The most appropriate time for blood collection is usually around 9-10 am at the hospital or as advised by the healthcare provider.

 

Certainly, if prolactin levels are significantly elevated, exceeding 100 ng/ml or even reaching 200-300 ng/ml, the doctor will likely arrange further examinations of the brain. The most common tests are X-ray imaging or MRI of the sella turcica region to detect any tumors in the pituitary gland or hypothalamus that may be causing excess prolactin secretion. Once these factors are ruled out, appropriate treatment can be initiated.

 

The primary goal of treatment is to suppress prolactin secretion, restore normal menstrual and ovulatory function, reduce milk production, and improve visual disturbances. Medications that lower prolactin levels are dopamine agonists, which can normalize prolactin levels within 1 to 3 months. However, initial use of these medications may occasionally cause side effects such as nausea, vomiting, dizziness, and headache. Therefore, it is recommended to start with a low dose taken before bedtime or with a light snack, gradually increasing the dosage on a weekly basis. Blood tests are used to monitor the decrease in prolactin levels. With patience and compliance, most women can restore their menstrual cycles and achieve pregnancy within six months.