Human chorionic gonadotropin (HCG) is the primary pregnancy hormone that appears during the first trimester of pregnancy. Doctors also look at HCG levels in pregnant women to assess the risk of a birth defect. After implantation, the placenta forms and secretes HCG. The levels double every 48-72 hours. HCG signals the corpus luteum to produce progesterone continuously to maintain the uterine lining. This process supports the developing embryo.
Every woman has levels of HCG, regardless of whether she is pregnant or not. The levels are much lower, typically, 5 IU/ML, which is not enough to detect pregnancy. Pregnancy is detected when the levels rise to higher than 25 IU/ML. At-home pregnancy tests can recognize if you’re pregnant, but they can’t tell you the actual amount of HCG present in your urine. The tests merely give you an answer of yes or no.
The Discovery of HCG
HCG was discovered by German scientists Bernhard Zondek and Selmar Aschheim in the 1920s. They observed that the hormone had stimulated ovary development in mice and rabbits as well as the formation of the corpus luteum in women. HCG consists of a beta subunit and an alpha subunit. The beta subunit has 30 amino acids that don’t occur in any other hormone. The alpha subunit is similar to the follicle and thyroid stimulating hormone.
Because of HCG’s composition, early pregnancy tests in the past were significantly less successful than today’s. The test was unable to differentiate the alpha subunit from other hormones linked to pregnancy. In 1960, the hemagglutination inhibition test was developed to test for pregnancy. The test used a mixture of the HCG hormone and the patient’s urine. When the cells clumped together in a particular pattern, the test produced a positive result. While efficient, the test was not readily responsive. In 1966, a radioimmunoassay for HCG was introduced. It suffered from the same issue as the hemagglutination inhibition test and could not readily detect HCG from other common hormones.
In 1972, a more sophisticated radioimmunoassay was created that distinguished between the two substances. The radioimmunoassay is accurate enough to use a few days after a missed menstrual period. The FDA approved this immunoassay for use in the first home pregnancy kit in the United States.
Generally, at-home pregnancy tests are very reliable and will detect HCG levels as low as 25 IU/ML. A typical home pregnancy test should be administered about 7-10 days after conception. Women who have irregular periods should test at least 30 days after their last period. These tests are so accurate that false negatives are usually caused by human error. Taking the test too early or diluting the urine sample are typical examples.
Positive HCG in the Absence of Pregnancy
There are reasons why HCG is present in a woman who is not pregnant. In a biochemical pregnancy, a woman becomes pregnant but miscarries the fetus without even knowing. It takes time for that HCG to metabolize out of the body. If HCG testing is done before that happens, the hormone will be detected by the lab. Cancer cells can sometimes produce HCG. It is most commonly associated with specific types of tumors in the testes or gestational trophoblastic diseases. Some women have antibodies in their blood that can create a positive HCG result even when the hormone isn’t present.
Using HCG for Diet
HCG hormones are used for diets as a way to lose weight. HCG guarantees that your developing fetus is getting enough nutrients and calories to grow on top of the calories you’re consuming from food. Our bodies choose to maximize caloric intake in case it ever gets into a point of starvation mode. Typically, for women, most excess calories tend to accumulate in the stomach, thighs, hips and buttocks. However, in pregnant women, fat is released from these problem areas when HCG is present and makes its way to feed the fetus. This process is crucial in case a woman doesn’t consume enough nutrients that are necessary for fetal growth. The fat reserves are sufficient to provide vitamins and minerals to the fetus. After the first trimester of pregnancy, levels of HCG begin to decrease.
In the early 1930s, Dr. A.T.W. Simeons determined that boys who were being treated with HCG for underdeveloped testes were able to eat less and lose weight without experiencing hunger pains. He then began to focus his research on using HCG as a diet aid. After two short years, he developed a program that uses the hormone as a tool for weight loss. The HCG diet is an extreme regimen that causes a fat loss rate of 1-2 pounds per day without feeling hungry. On the program, you must eat a low-calorie diet of around 500 calories per day. You must also take the HCG hormone, either by injection or in liquid form each day. You can find the oral drops sold over-the-counter at many health and wellness stores. When you take the HCG supplements, it’s signaling your body that you’re pregnant. Your body will then be able to pull from your fat stores and use them for energy. The HCG diet can boost your metabolism and help you lose significant amounts of fat.
The diet is divided into three phases. The loading phase starts by taking the HCG supplement and eating foods high in fat and calories for two days. The next is the weight loss phase where you will continue taking HCG and eat only 500 calories a day for 3-6 weeks. Lastly, on the maintenance phase, you will stop taking HCG and slowly introduce starch into your diet for three weeks.
If you have less weight to lose, sticking with the diet for only three weeks is recommended. For those who have a lot of weight to lose, your doctor may advise you to repeat the cycle several times. Most people who follow the HCG diet go by an approved list of foods for easy reference. It’s encouraged that you drink a lot of water on the regimen and avoid butter, sugar and oils.