The 10 pregnancy hormones (and their functions)

For a correct development of the fetus and to prepare the body for childbirth, the gestation process is accompanied by a whole series of physiological mechanisms, mainly a series of bodily and hormonal changes occur in pregnant people.

These changes result in the appearance of some somewhat unexpected conditions that occur frequently during the course of pregnancy. The presentation of spots, fluid retention accompanied by swelling, numbness of the legs, emotionality and lack of concentration, are some examples.

Specifically, the main responsible for all the manifestations mentioned are the hormones. This powerful cocktail of chemical messengers causes much of the changes that occur in the body during the nine months of gestation.

But, hormones and their balance are essential for the regulation of the gestation process and its stages; they prepare the uterus for implantation and growth of the fetus, cause the mammary glands to produce milk and allow the formation of the baby's bones, among other important functions.

Hormones affect growth and development, metabolism, sexual function, and reproduction. In this article we will talk about the main hormones involved in pregnancy and childbirth, explaining in detail their functions in the gestation process.

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What are the main hormones of pregnancy?

The correct balance of hormones is essential for a successful pregnancy. Hormones act as chemical messengers in the body, sending feedback messages and responses between different tissues and organs. They are able to intervene in the functions of other cells.

The hormones travel through the bloodstream, and bind to proteins on the cell membranes called receptors.. In response, the target tissue or organ changes its function to maintain the pregnancy. Initially, the ovaries and then the placenta are the main producers of hormones related to pregnancy. Hormones are essential to create and maintain the proper conditions necessary for the gestation process.

Throughout the nine months of pregnancy and childbirth, different hormones are involved, the best known of which are the so-called sex hormones: progesterone and estrogen. However, pregnancy is a much more complex process at the endocrinological level, where many more hormones that make possible the correct development of the fetus and prepare the body for the Birth.

Next WE WILL SEE the main hormones that have their own function before, during and after pregnancy.

1. estrogen

Estrogen is one of the main feminizing hormones; helps with sexual development, including breast growth, and initiates and regulates a woman's menstrual cycle. It also helps maintain bone health and control cholesterol levels.

estrogen it is produced by the ovaries and then by the placenta, and is responsible for the growth of the uterus. Other of its main functions are the maintenance of the lining of the uterus, the regulation of other key hormones and the control of the development of the organs of the fetus. When it's time to breastfeed, estrogen promotes the growth of breast tissue and helps milk flow.

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2. progesterone

Progesterone is produced in the ovaries, 15 days after the start of the period, after ovulation. Mainly, it helps regulate the menstrual cycle and, along with estrogen, is part of the so-called female hormones.

progesterone activates shortly after ovulation to assist the uterine lining with implantation of the egg, in the event that there has been fertilization. The hormones progesterone and relaxin can cause some gastrointestinal problems, such as heartburn, indigestion, constipation, and bloating.

Combined with relaxin, progesterone helps soften ligaments and cartilage and relaxes joints in preparation for childbirth. Swollen and bleeding gums, as well as excessive sweating, can be caused by high levels of progesterone.

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3. Follicle stimulating hormone (FSH)

FSH is produced by the pituitary gland in the brain and goes to the ovaries to make eggs and estrogen.

FSH is the first of a series of hormones necessary to initiate the gestation process.even before it starts. FSH stimulates the growth of eggs in the ovaries, thereby increasing estrogen production. Rising estrogen levels signal the body to increase production of another hormone, leading to ovulation.

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4. luteinizing hormone (LH)

Luteinizing hormone is also produced by the pituitary gland and works alongside the hormone FSH in coordination of the menstrual cycle. Luteinizing hormone levels increase just before ovulation and are responsible for the release of an egg from the ovary, which makes possible fertilization possible.

Hormones can influence and be influenced. While FSH stimulates estrogen production, estrogen causes LH to rupture the follicle and release the egg. After the release of the oocyte, the corpus luteum is created, which produces estrogen and progesterone. If pregnancy does not occur, the corpus luteum breaks down in about 14 days, at which time the hormone levels of LH decrease and the period begins.

If the egg is fertilized by the sperm, the corpus luteum continues to produce the appropriate hormones, including progesterone, to mature the uterus and nourish the developing fetus.

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5. Human Chorionic Gonadotropin (HCG)

Human chorionic gonadotropin is a hormone that is only produced during pregnancy.

On the other hand, human chorionic gonadotropin increases the production of estrogen and progesterone necessary for pregnancy.

HCG is the chemical used in pregnancy tests.. Early in pregnancy, HCG levels are quite low, but soon begin to rise dramatically; they double every two days, peak between weeks 7 and 12, and fall again at three months. The placenta is then primarily responsible for producing estrogen and progesterone, although chorionic gonadotropin is still present. In fact, this hormone affects the immune system, and makes pregnant people more susceptible to some infectious diseases, such as colds and flu.

6. prolactin

Prolactin, like human chorionic gonadotropin hormone and luteinizing hormone, is produced by the pituitary gland. In its name is the word "lact" that refers to its main role, which is to allow breastfeeding.

The main function of prolactin is to increase the size and volume of the breasts and to produce the necessary milk to feed the newborn in the first months of life. Prolactin also causes the adrenal glands to cause hair growth in unexpected places, such as the abdomen and face, but this hair usually disappears, when levels drop, usually six months after the delivery.

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7. Placental growth factor (PlGF)

In pregnancy there is a considerable increase in blood volume, between 40% and 45% more than normal. More blood is needed to nourish the developing fetus and also to prepare the body for the loss that occurs during childbirth.

Placental growth factor is needed to promote the growth of blood vessels, which allow more blood to be carried.

Not enough of this pregnancy hormone can cause blood vessels in the placenta to get smaller instead of wider, which can lead to high blood pressure and possible pre-eclampsia; Pre-eclampsia is a serious pregnancy condition that can lead to serious and even fatal complications for both the mother and the fetus if not treated in time.

Fortunately, medicine is making progress in treating the problem early, and new blood and urine tests are helping to measure placental growth factor for detection early.

8. The human placental lactogen

Human placental lactogen (hpl) is also known as human chorionic somatomammotropin. This hormone is only present during pregnancy and its blood levels are proportional to the growth of the fetus and the placenta. Its main function has to do with milk production..

Placental growth factor is produced by the placenta and helps prepare the breasts for lactation by adjusting the body's metabolism to feed the baby. It helps produce colostrum, which is a substance rich in antibodies and is the first milk produced by the mammary glands.

Some studies suggest that hpl and placental growth factor are responsible for gestational diabetes that some people experience during pregnancy.

9. relaxin

Relaxin is a hormone that is crucial in the female reproductive process. Its levels increase after ovulation and help prepare the uterine wall for implantation of the ovum. If pregnancy does not occur that month, relaxin levels drop again until the next menstrual cycle.

In pregnancy, relaxin performs different tasks, but mainly prepares the body for childbirth. First of all, it helps to relax the bones, joints, ligaments and muscles of the woman's pelvis. This is done to make labor and delivery easier. Also, relaxin also lengthens and softens the cervix, to help deliver the baby.

10. oxytocin

The hypothalamus it is responsible for producing oxytocin, which is important for pregnancy and fundamentally for childbirth. Oxytocin is present throughout the gestation process, but It is best known for causing the muscular contractions of the uterus that allow delivery. If labor is too slow, the synthetic version of oxytocin can be given to speed up labor. After giving birth, oxytocin helps the uterus regain its shape and also moves milk into the breasts.