**4. Hyperprolactinemia**

218 Prolactin

This image is propriety of our laboratory and created by us.The data was taken from Fuchs, F. y Koppler A. Endocrinología de la Gestación. 1982. Segunda edición. Salvat Editores,S.A. Capítulo 12. Pag. 249-72

This image is propriety of our laboratory and created by us. The data was taken from Tyson JE, Hwang P, Guyda H,

Friesen Hg. Studies of prolactin secretion in human pregnancy. Am J Obstet Gynecol 1972;113:14-20.

**Figure 4.** Prolactin's limits of reference (I)

**Figure 5.** Prolactin's limits of reference (II)

As it has been described before, prolactin is secreted by lactotroph cells from the anterior hypophysis and it is subjected to the dopamine inhibitory effect in the hypothalamus. Any cause which interferes in its synthesis, the transport to the pituitary gland or the action over the dopamine receptors can produce hyperprolactinemia (Table 1).



Physiological and Pathological Hyperprolactinemia: Can We Minimize Errors in the Clinical Practice? 221

Serum prolactin rises in a progressive way during gestation, but in a variable manner (18-

Around the 6th week from the labor the normoprolactinemia is restored. Although the prolactin concentration is high before the labor, the milk secretion only takes place after it, because the high presence of estrogens and progesterone in pregnant women has an inhibitory effect over the milk secretion. When these hormones levels drop after the labor,

During gestation the prolactin levels in the amniotic liquid can reach the 1000 ng/ml, higher concentration that any other organic fluid, this happens around the 15th and the 20th week of gestation and it drops slowly until the end of the pregnancy to 450 ng/ml. It is supposed to be produced by the fetal and the mother´s hypophysis, with a possible function of fetal osmoregulation to survive in the intrauterine liquid environment, helping and contributing to the pulmonary maturing raising the content of phospholipids and changes in the lecithin-

Nipple suction, probably by neural via, during breastfeeding, rises the serum values of prolactin, especially in the first weeks after giving birth in direct relation to the lactotroph

Any kind of stress, physical or psychical, can cause hyperprolactinemia, which is normally

There is a dopamine decreasing after orgasm, immediately, the prolactin rises, in men and women, acting as a sexual satiation mechanism (21). In men, without any doubt contributes

Kruger TH et al have demonstrated that sexual intercourse with orgasm induced not only the well-established immediate prolactin increasing of 300% but also an additional prolactin elevation around noon of the next day. These fluctuations were measured on top of regular

Pathological hyperprolactinemia can be caused by: lactotroph hyperplasia, lactotroph cells

to the "turn around and snore" phenomenon. In women, its effects can be delayed.

hypertrophy by the estrogenic stimulus of the pregnancy (18-20)

19). At the end, the mean value is around 200 ng/ml but the range is 35-600.

**5. Physiological causes** 

1. Pregnancy

lactation is produced.

sphingomyelin ratio (20).

slight, and rarely over 40 ng/ml.

2. Breast stimulation

3. Stress

4. Sexual contact

circadian rhythm (22).

**6. Pathological causes** 

adenoma (prolactinoma) and miscellaneous.

HRT: Homone replacement therapy Iv: intra-venous

**Table 1.** Hyperprolactinemia causes

The most important cause of hyperprolactinemia is the secretory pituitary adenoma. Nevertheless, the most common cause are drugs and, when it is possible, the serum prolactin determination should be done once those are suspended.
