HCG

A. What it is

The Human chorionic gonadotropin also most commonly known as (hCG) is the hormone for the maternal recognition of a pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantation. The presence of hCG is detected in some pregnancy tests (HCG pregnancy strip tests). Some cancerous tumors produce this hormone; therefore, elevated levels measured when the patient is not pregnant may lead to a cancer diagnosis but we will only be focusing on the pregnancy relation to this hormone for this blog.

It is produced by cells that are surrounding a growing embryo, which eventually forms the placenta. hCG can be detected in your body as early as 1 week after an egg is fertilized, which forms the basis of most over the counter pregnancy tests. hCG also ensures the corpus luteum, a temporary endocrine gland a woman’s body produces after ovulation, continues to produce progesterone during the first trimester of pregnancy.

B. What it does

The levels of hCG increases every two to three days as your little one continues to develop. hCG levels peak around the sixth week of pregnancy. Afterwards, hCG will be found in your body, but the levels will begin to decrease. Once the placenta is fully formed, it serves as a source of progesterone production and assistance from hCG to support ovarian function is no longer essential.

Human chorionic gonadotropin interacts with the LHCG receptor of the ovary's and promotes the maintenance of the corpus luteum for the maternal recognition of pregnancy at the beginning of pregnancy. This allows the corpus luteum to secrete the hormone progesterone during the first trimester. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus.

It has been hypothesized that hCG may be a placental link for the development of local maternal immunotolerance. For example, hCG-treated endometrial cells induce an increase in T cell apoptosis (dissolution of T cells). These results suggest that hCG may be a link in the development of peri trophoblastic immune tolerance, and may facilitate the trophoblast invasion, which is known to expedite fetal development in the endometrium. It has also been suggested that hCG levels are linked to the severity of morning sickness or Hyperemesis gravidarum in pregnant women.

Because of its similarity to LH, hCG can also be used clinically to induce ovulation in the ovaries as well as testosterone production in the testes. As the most abundant biological source is in women who are presently pregnant, some organizations collect urine from pregnant women to extract hCG for use in fertility treatment.

C. Discomforts it may cause

As pregnancy progresses and hCG levels rise even more, many women begin experiencing more symptoms.

Some of the most common include:

• dizziness or lightheadedness due to hormonal shifts and changes in the blood pressure and heart rate

• nausea, especially when hungry

• vomiting

• strong aversions to certain foods or smells

• changes in the sense of smell

• fatigue

• bloating and water retention