Hormones Present During Pregnancy - Assignment Example

This paper will analyze the role of hormones in pregnancy, initiating birth, and lactation.

Human chorionic gonadotropin (hGC) is a hormone synthesized by placental cells. The primary role of the hGC hormone is to nourish the egg after fertilization and attachment to the uterine wall. It also inhibits the menstrual cycle by initiating an elevated production of estrogen and progesterone in the corpus luteum. In early pregnancy, hGC production is high and pregnancy symptoms such as morning sickness can be attributed to this hormone.

Progesterone is one of the major hormones produced during pregnancy. Initially, progesterone is produced by the corpus luteum, however, as the pregnancy progresses it is also produced by the placenta. Its levels continue to rise until labor and birth; after this, there is a rapid decrease in the level of progesterone in the body. The sharp drop in progesterone levels is one of the initiating factors of labor. In the implantation phase, progesterone reduces maternal immunity to facilitate the pregnancy process in the body.

Progesterone also reduces the level of contractility in the uterine muscles by inhibiting contractions, which helps maintain the pregnancy. It also initiates the thickening of the endometrium and the uterus lining. This creates a supportive environment for the fetus, which is maintained throughout the pregnancy. Estrogen is also a very important hormone produced during pregnancy. It is produced by the corpus luteum, ovaries, placenta, and fetal and maternal adrenal glands. This hormone interacts with progesterone during the pre-ovulation period making ovulation possible. It also helps monitor progesterone production by the placental cells as a decrease in progesterone can lead to pregnancy loss. It regulates uterine blood flow and increases blood supply to the mucous membrane.  However, one of the key roles of estrogen during pregnancy is to stimulate vital organ development. It initiates maturation of the lungs, kidney, liver, and moderates bone density. Estrogen also helps in the normal growth of the placenta and prepares pregnant women for the lactation period. It also serves as a protective medium for in utero female babies against adverse effects from male hormones.

Along with progesterone, estrogen plays a vital role in the lactation period. Progesterone stimulates the growth of the lobes and alveoli in the female breasts. Its purpose before birth is to inhibit lactation, however, a rapid decrease in progesterone levels after birth stimulates the onset of copious milk production.  Estrogen on the other hand triggers the growth and differentiation of the milk duct system within the breasts. In addition, estrogen enhances the effects of prolactin, which increases milk production. Prolactin is a hormone produced in the pituitary gland, which stimulates the growth of alveoli within the mammary glands. It contributes to enhanced differentiation of the milk ductal structures causing enlargement of the breasts.  Prolactin levels are higher at night, hence breastfeeding at night is recommended for mothers. Milk production is also triggered by the suckling effect from babies.

Relaxin is also a hormone produced by the placenta, corpus luteum, and mammary glands during pregnancy. This hormone relaxes smooth muscles, ligaments, joints, and increases the dilation of blood vessels in the uterus, breasts, and heart. The culmination of these events leads to an increase in the birth canal space allowing the baby to pass through at birth. In addition to these effects, relaxin also softens the pelvis.

Oxytocin is a hormone mainly produced by the hypothalamus and stored in the posterior pituitary gland. This hormone induces rhythmic uterine contractions during labor and stimulates receptors in the vagina during birth. The reflex of the fetal ejection, which is the final stage of childbirth, can also be attributed to oxytocin. In addition, oxytocin is also responsible for the ‘placental ejection reflex’ and the ‘milk ejection reflex. The suckling effect from the baby stimulates oxytocin production in the hypothalamus.

There are also several other hormones that are present during pregnancy. These include Beta endorphins which have analgesic effects and suppress immunity during early pregnancy. They also create feelings of euphoria and pleasure during lovemaking and help reduce pain during childbirth. Epinephrine and norepinephrine facilitate a surge of strong contractions, which helps speed up the ejection of the baby at the end of childbirth.