Hormones in pregnancy

The hormone is the chemical substance produced in an organism and transported to stimulate specific cells or tissues into action through specific fluids like blood. Endocrine glands produce hormones and release them directly into the blood to reach the target site. These hormones regulate and coordinate the functioning of different organs present in an organism. Some of the endocrine glands in humans are Pituitary gland, pancreas, Gonads, Thyroid gland, etc... Among these glands, the pituitary gland is known to be a Master gland because it controls remaining endocrine glands in the body by releasing hormones into the blood.

Hormones play a major role in successful pregnancy. Pregnant women experience sudden and dramatic increases in oestrogen and progesterone and these hormones leads to various changes in the posture of pregnant women. There are many hormones that produce during pregnancy majorly, HCG, HPL, and prolactin including Oestrogen, progesterone. Hormones will play an important role in the development of the fetus.

Pregnancy is the period during which we can see considerable changes in a human body. These changes would affect virtually every part of the body towards growing and developing a healthy baby. All the changes begin from the day of conception when the zygote implants in the wall of the uterus. Pregnancy period may last an average of 40 weeks from the day of the menstrual period. The pregnancy period is divided into three stages; they are first trimester, second trimester, and third trimester.
Once the egg is fertilized, a new embryo starts to develop giving a signal to the mother in identifying the onset of pregnancy. When a zygote is formed in the fallopian tube, it travels through the tube to the uterus and attaches to the wall of the uterus on the sixth day of fertilization.

Oestrogen: Oestrogen is the hormone which stimulates the endometrium of the uterus to support the fertilized egg which has to be implanted. During the first trimester, the placenta produces, and this continues until near the end of the pregnancy.

Oestrogen helps in increasing the level of the blood supply which makes everything grow. Oestrogen will produce more during one pregnancy in women than throughout her entire life when she is not pregnant. Oestrogen enables the uterus and placenta to enable the fetus to develop and mature.
The sudden increase in the 0estrogen levels the first semester may cause nausea, enlargement of the breast, moles and skin tags get bigger, spider veins become prominent. Some women, however, are lucky enough to experience the upside of pregnancy 'glow,' which is largely attributed to oestrogen levels. Morning sickness will start from the week 5-6 of pregnancy and will subside by week 12-16 of pregnancy. Some women may suffer throughout the pregnancy.

Progesterone: Progesterone hormone is used to relax all smooth muscle mainly, the muscle wall of the uterus in the body where the fetus starts to develop. The changes in the level of progesterone can cause a loosening of ligaments and joints throughout the body. High levels of progesterone in the blood can cause the increase in the size of the uterus. Progesterone is helpful in transforming the uterus from the size of a small pear state to a uterus that can allow the growth of a full-term baby. The relaxant property of Progesterone may play a role in keeping the uterus from contracting until term. This hormone involves in preventing the contraction of muscles in the uterus till the labor onsets.

Progesterone stimulates the growth and normal function of the placenta. This hormone present in the blood leads to the relaxation of blood vessels in the body and lower the normal blood pressure causing dizziness and also some of the pregnancy symptoms like nausea, vomiting, heartburn, reflux, gas, belching, and constipation. It can also help in the growth of hair.

Human Placental Lactogen (HPL): Human placental lactogen is a growth hormone, which is produced by the placenta during pregnancy. The cause of morning sickness is mostly due to this hormone. It also interferes with the metabolism by breaking down fat, which can be utilized to provide nutrition for the growth and developing a baby. A pregnant woman in the first trimester would feel some discomfort in the pelvic region and lower back because of the release of the hormone called relaxing. This hormone is helpful in relaxing the muscles, joints, and ligaments to make a spacious room for the growing baby.

Human Gonadotropic Hormone (HCG): HCG hormone is a hormone, which is initially produced by blastocyst during week 2 and later it is produced by the placenta in the womb. During the first ten weeks of pregnancy HCG levels double for every two days. HCG circulates throughout the body and is sent out through urine. HCG interacts with the luteinizing hormone receptor of the ovary and promotes the functioning of the corpus luteum in the beginning of pregnancy. This permits corpus luteum to release the hormone progesterone during the first trimester. HCG value doubles every two days in the early part of the first trimester. This increase in HCG levels helps us to detect pregnancy in the first trimester.

Prolactin: Prolactin is also known as a luteotropic hormone. Prolactin plays a vital role in metabolism, regulation of the immune system and development of the pancreas. It stimulates the mammary glands to produce milk (lactation) when the oestrogen and progesterone decrease in the blood at the end of pregnancy. The main regulator for the onset and regulation of lactation is prolactin hormone.

Oxytocin: Oxytocin is the hormone that triggers labor. This hormone is called love hormone as it makes a bond with feelings of love between mother and baby. At the end of the pregnancy, the uterus becomes so sensitive and becomes responsive to oxytocin hormone and then the labor begins. Oxytocin is also the hormone that helps in stretching of the cervix during labor and also stimulates the nipples to produce milk.

Thus, these hormones play an essential role in the development and growth of a fetus from fertilization to the birth of a baby.