Prolactin and progesterone relationship

Hormones of pregnancy and labour | You and Your Hormones from the Society for Endocrinology

prolactin and progesterone relationship

Learn what prolactin is, what it does, and how it affects breastfeeding, your period , However, the high levels of estrogen and progesterone produced by the The relationship between these hormones keeps your breast milk supply up and . Women with the mildest cases involving high prolactin levels may ovulate regularly but not produce enough of the hormone progesterone after. Luteinizing hormone (LH) and prolactin were measured by radioimmunoassay and progesterone by competitive protein-binding. Basal levels of LH were around .

Levels of this hormone increase steadily until birth and have a wide range of effects, including: Maintaining, controlling and stimulating the production of other pregnancy hormones Needed for correct development of many fetal organs including the lungs, liver and kidneys Stimulating the growth and correct function of the placenta Promoting growth of maternal breast tissue along with progesterone and preparing the mother for lactation breastfeeding Other hormones produced by the placenta The placenta also produces several other hormones including human placental lactogen and corticotrophin-releasing hormone.

The function of human placental lactogen is not completely understood, although it is thought to promote the growth of the mammary glands in preparation for lactation. Corticotrophin-releasing hormone is thought to regulate the duration of pregnancy and fetal maturation. For example, when pregnant women experience stress, particularly in the first trimester of pregnancy, the placenta increases the production of corticotrophin-releasing hormone.

There is a good reason for this: Later in pregnancy, it improves the blood flow between the placenta and fetus. In the last weeks of pregnancy corticotrophin-releasing hormone levels climb even higher — a rise which coincides with a major spike in cortisol levels.

Side-effects of pregnancy hormones High levels of progesterone and oestrogen are important for a healthy pregnancy but are often the cause of some common unwanted side-effects in the mother, especially as they act on the brain. The majority of women will experience morning sickness — a feeling of nausea, any time of day, which may lead to vomiting. The exact cause of morning sickness is unknown but it is likely to be because of the rapid increase in: Morning sickness usually starts around week of pregnancy and should subside by weekalthough some women suffer throughout pregnancy.


Many women experience pain and discomfort in the pelvis and lower back during the first trimester. This is mostly due to a hormone called relaxin. Relaxin becomes detectable by week and is produced throughout pregnancy. The effects of relaxin are most concentrated around the pelvic region; softening the joints of the pelvis can often lead to pain in the area.

The joints being softer can also decrease stability and some women may notice it is harder to balance. There is also an increase in constipation associated with reduced gut motion because of the relaxin and the growth of the fetus.

Luteinizing hormone, prolactin and progesterone relationships in vivo (data from the cow).

Although uncomfortable and frustrating at times, all these side-effects will usually lessen or even subside by the end of the first trimester. Hormones and labour The exact events leading up to the onset of labour are still not fully understood. For the baby to arrive, two things must happen: The hormone oxytocin plays a key role in labour. This is also true of another hormone released during labour called prolactin.

prolactin and progesterone relationship

Oxytocin levels rise at the onset of labour, causing regular contractions of the womb and abdominal muscles. Oxytocin-induced contractions become stronger and more frequentwithout the influence of progesterone and oestrogen, which at high levels prevent labour. The cervix must dilate open to around 10cm for the baby to pass through.

Oxytocin, along with other hormones, stimulates ripening of the cervix leading to successive dilation during labour.

prolactin and progesterone relationship

Oxytocin, with the help of the high levels of oestrogen, causes the release of a group of hormones, known as prostaglandinswhich may play a role in ripening of the cervix. Levels of relaxin also increase rapidly during labour. As labour contractions become more intense, natural pain relief hormones are released.

One type of neurosecretory cell is a magnocellular cell that releases the hormone oxytocin from the posterior pituitary. These cells are stimulated by suckling. Oxytocin causes milk ejection, in which smooth muscle-like cells called myoepithelial cells contract to push the milk from the glands into the breast ducts so that the infant can easily suck it out. The other neurosecretory cell is a parvocellular cell that releases dopamine at the median eminence.

prolactin and progesterone relationship

Dopamine acts as a hormone, traveling to the anterior pituitary via the hypophyseal portal vessels to inhibit prolactin secretion by anterior pituitary cells. Suckling, via neural connections inhibits dopamine secretion, thereby removing inhibition to allow increased prolactin secretion and stimulation of milk production in the breast.

  • You and Your Hormones

Causes and Treatments Hyperprolactinemia is most often caused by a prolactinoma, a common type of pituitary tumor that hypersecretes prolactin. Hyperprolactinemia high prolactin secretion causes infertility because prolactin inhibits GnRH secretion. Thus, hyperprolactinemia is an example of the type of infertility called hypogonadotropic hypogonadism, where low gonadal function results from low gonadotropin secretion.

Topic | HIGH PROLACTIN / LOW PROGESTERONE | Moms community and forums

In females this causes anovulation lack of ovulation. Typically, females with hyperprolactinemia will present with amenorrhea lack of menstruation and sometimes galactorrhea abnormal milk production.

Prolactinomas seem to be less common in males, but in males hyperprolactinemia also causes hypogonadism, which causes infertility and loss of libido.

prolactin and progesterone relationship

Another concern with hyperprolactinemia is that decreased gonadal steroid secretion will lead to osteoporosis. Drugs that are dopamine antagonists are another cause of hyperprolactinemia.