HCG in early pregnancy

HCG during early pregnancy can be an important diagnostic sign not only of the pregnancy itself, but also of its course. Understanding the nature of this hormone and determining its level can be important for diagnosing the course of pregnancy and the condition of the fetus.

What is hCG?

HCG decoding allows us to define this concept as human chorionic gonadotropic hormone. This is one of the hormones that is an indicator of endocrine function in women outside of pregnancy and during pregnancy.

HCG is a classic pregnancy hormone that is produced by the placenta. When you test at home with a pregnancy test, you are actually testing for the presence of HCG. If HCG is present, the pregnancy test will be positive, meaning you are pregnant unless there is a false positive pregnancy test.

Human chorionic gonadotropin is a placental hormone that is initially secreted by cells (syncytiotrophoblasts) from the implanting embryo for about a week, maintaining the ovarian corpus luteum, which in turn maintains the endometrial lining and therefore maintains pregnancy. hCG is released into the blood shortly after implantation and is detected by pregnancy tests. hCG begins to be produced by the placenta immediately after implantation. This occurs about a week after fertilization and ovulation, when the embryo implants and placenta attach to the uterine lining.

Implantation occurs on average 9 days after ovulation (range 6-12 days) or about 5 days before a missed period. HCG levels are detectable in the blood as early as 2-3 days and in the urine as early as 3-4 days after implantation. A urine pregnancy test is expected to be positive around the time of the missed period or 14-15 days after implantation (which may be as early as a few days before the missed period).

Other potential cellular sources of hormone synthesis may include hyperglycosylated hCG produced by cytotrophoblast cells, free beta subunit produced by several primary nontrophoblastic malignancies, and pituitary hCG produced by gonadotropin cells of the anterior pituitary. Therefore, the measurement of different types of hCG has different meanings.

The functions of hCG, which is synthesized by the trophoblast, are very broad. It promotes the production of luteal progesterone in the woman's body, which maintains pregnancy. hCG promotes angiogenesis (formation of blood vessels) of the uterine vasculature. It promotes differentiation of cytotrophoblasts, immune suppression, and blocking the phagocytosis of invading trophoblast cells. hCG affects the growth of the uterus in accordance with fetal growth, as well as promoting the growth and differentiation of fetal organs. The growth and development of the umbilical cord is also promoted by hCG. hCG receptors in the adult brain hippocampus, hypothalamus, and brainstem can cause nausea and vomiting in pregnancy. The hormone has many other roles, including stimulating the occurrence of fetal steroidogenesis, and high levels have been shown to be teratogenic to the fetal gonads.

HCG is a marker that has the potential to predict the likely outcome of pregnancy from the moment of conception and is more informative than other means

Pregnancy monitoring. To a lesser extent, hCG levels have been studied to assess the potential for pregnancy duration. hCG levels are also studied along with other biochemical and physical markers for use in predicting genetic abnormalities in pregnancy.

That is why it plays a decisive role in a woman’s body not only during pregnancy, but also before pregnancy.

Indications for the procedure HCG in early pregnancy

Indications for hCG testing are limited to three main reasons. The first and primary reason is the detection of a normal pregnancy. Pregnancy testing is performed during the investigation of amenorrhea, to confirm clinical signs and symptoms of pregnancy, and for early detection of implantation. Although qualitative hCG assessment is usually sufficient, quantitative measurement has been suggested as a valuable means of estimating early gestational age, where the log hCG value is plotted against gestational age.

Second, hCG has been shown to be valuable in the detection and follow-up of potentially abnormal pregnancies. Patients with ectopic pregnancy, threatened abortion, or incomplete abortion typically have low blood hCG concentrations for the gestational age. These features are useful in evaluating a patient with abnormal uterine bleeding or abdominal pain when qualitative hCG measurement has demonstrated the presence of trophoblastic tissue. Quantitative hCG assays in combination with ultrasound scanning have been recognized as valuable adjuncts to the evaluation of the clinical features of pregnancy.

Indications for measuring hCG are also monitoring tumor activity, in particular gestational trophoblastic disease (choriocarcinoma). These tumors secrete large amounts of the hormone, which allows the use of tumor hCG to monitor the progress of the disease.

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Preparation

Preparation for the hCG test depends on the method and conditions of the test. If a woman wants to qualitatively determine the presence of hCG in urine at home, then no specific preparation is required. The test is performed in the morning on an empty stomach, when the maximum amount of hCG in urine is expected during pregnancy.

If it is necessary to control or determine hCG in the blood, then there are some conditions. The analysis is also carried out on an empty stomach. Blood is taken from a vein, so the day before it is important to adhere to a healthy diet with the exclusion of fatty foods and harmful substances.

Technique HCG in early pregnancy

The technique for determining hCG depends on the method used. Immunological methods have many advantages today. Quantitative analysis is widely used to measure hCG in serum and is usually based on ELISA or IRMA methods. The main thing you need to know about the technique is that a woman's blood is drawn from a vein, and then the blood is analyzed on special equipment and the hCG level is determined.

The apparatus for carrying out the analysis can have different modifications.

What is the hCG level in early pregnancy? As mentioned, the normal hCG level in early pregnancy is 25 to 5000 mIU/ml. In the first 2-4 weeks after fertilization, hCG usually doubles every 48-72 hours. An increase of 35% within 48 hours in early pregnancy is considered normal. If its level is 1200 mIU/ml, hCG usually doubles every 48-72 hours. The maximum level is usually reached at 10 or 11 weeks. After 10 weeks or so, hCG usually decreases.

Normal performance

The level of hCG in urine increases at least 6 days after the estimated day of conception. hCG levels rise rapidly in the earliest days of pregnancy and can be detected very early. The point at which hCG can first be detected depends on the method used to assess conception and the sensitivity of the hCG assay. Several studies have shown detection of hCG in maternal urine as early as 6 or more days after the estimated day of conception. Plasma hCG can be detected as early as 8 days after conception. However, these assays rely on extremely sensitive measurements performed under precise conditions.

Since hCG is produced by trophoblast cells, it should not be determined if there is no pregnancy. Therefore, the hCG norm for non-pregnant women is a negative test or its digital value from 0 to 5 units. If a non-pregnant woman has an increase in hCG, then it is necessary to look for the cause.

Technically, hCG tests are designed to qualitatively detect or measure the hormone in urine or blood, and there are other reasons besides pregnancy that can cause hCG. Here are some of those reasons.

1. Chemical Pregnancy. A chemical pregnancy occurs when a woman is pregnant but has a spontaneous loss of the fetus before she even knows she is pregnant. If the hCG test occurs before all the hCG has been metabolized from the body, then the hCG may be detected by a laboratory test. This situation is not as uncommon as one might think for two reasons. First, hCG tests are often performed in a medical setting to identify a pregnant patient in order to avoid any medical interventions that are potentially harmful to the fetus. Second, hCG tests are capable of detecting very low concentrations of the hormone. The high frequency of testing combined with the analytical sensitivity of the tests means that biochemical pregnancies are easily detected.
2. Pituitary hCG. Although the placenta usually produces hCG during pregnancy, this function can also be performed by the pituitary gland. The pituitary gland is a small structure in the brain that secretes many different hormones that function to regulate many endocrine systems of organs. Interestingly, three hormones normally produced by the pituitary gland (thyroid stimulating hormone, follicle-stimulating hormone, and luteinizing hormone) are structurally similar to hCG. Pituitary hCG is more often found in women over 55 years of age, but can be detected in women as young as 41 years of age. Non-pregnant women with pituitary hCG usually have low concentrations of hCG present in their blood and urine. It is important to note that hCG concentrations produced by the pituitary gland do not show the rapid increase that is seen during pregnancy.
3. Cancer cells sometimes produce hCG. Although many cancers have been shown to have the hormone, it is most often associated with gestational trophoblastic diseases and some types of testicular germ cell tumors.
4. Interfering antibodies. Some women have antibodies in their blood that can interfere with hCG tests, causing a positive or elevated result when hCG is not present. Only hCG tests performed on blood can be affected by this problem, as the interfering antibody molecules are not usually present in urine. This can be a serious problem because some women have been misdiagnosed with cancer due to a false-positive hCG test result and have been subjected to unnecessary treatments. Over the past few years, hCG test manufacturers have worked to minimize the potential for interference from these antibodies, but nothing can be done to eliminate the problem entirely.

Therefore, just because an hCG test result is interpreted as positive does not automatically mean that the woman is pregnant. There are very good reasons for detecting hCG in the absence of pregnancy. However, when the hCG test result does not correspond with the clinical picture, the laboratory should still question the validity of the values obtained.

In 85% of normal pregnancies, hCG levels double every 48 to 72 hours. As you get further into pregnancy and your hCG levels get higher, the time it takes to double can increase to about 96 hours. Levels will peak in the first 8 to 11 weeks of pregnancy and then decline for the rest of the pregnancy.

Care should be taken when creating too many hCG numbers. A normal pregnancy can have low hCG levels and still result in a perfectly healthy baby. Ultrasound results after 5-6 weeks of pregnancy are much more accurate than using hCG numbers.

HCG is measured in milli-international units per milliliter (mIU/mL). There is a wide range of normal hCG levels and values, and values vary between serum and urine. Urine hCG levels are usually lower than serum hCG levels. Blood hCG testing is much more sensitive than urine HPT. This means that a blood test can detect pregnancy several days earlier than a urine test, as early as 2-3 days after implantation or 8-9 days after fertilization.

An hCG level less than 5 mIU/ml is considered negative for pregnancy, and anything above 25 mIU/ml is considered positive for pregnancy.

HCG levels between 6 and 24 mIU/mL are considered a grey area and you will likely need to have a repeat test to see if levels rise to confirm pregnancy.

Urine tests measure hCG qualitatively, meaning the results are either “positive” or “negative.” During the first missed period (14+ days after ovulation), over 95% of hCG is usually positive.

Blood hCG levels are not very useful for checking the viability of a pregnancy if the hCG level is above 6000 or after 6-7 weeks of pregnancy. Instead, to better check the health of the pregnancy, a sonogram should be performed to confirm the presence of a fetal heartbeat. Once a fetal heartbeat appears, it is not recommended to check the viability of the pregnancy with hCG levels.

HCG levels are also higher in women carrying a female fetus compared to women carrying a male fetus, so it is possible that a pregnancy test will become positive later in women carrying a male fetus.

There are two common types of hCG tests. A qualitative hCG test simply looks to see if there is hCG in the blood. A quantitative hCG (or beta hCG) test measures the amount of hCG actually present in the blood.

HCG during pregnancy varies by day, which should be taken into account when interpreting the data. But one level of hCG cannot be assessed in the context of the course of pregnancy and the health of this pregnancy; hCG data should be assessed together with clinical changes.

HCG levels during the weeks depend on the gestational age:

• 3 weeks: 5 - 50 mIU/ml
• 4 weeks: 5 - 426 mIU/ml
• 5 weeks: 18 - 7,340 ml / ml
• 6 weeks: 1080 - 56,500 mIU/ml
• 7-8 weeks: 7,650 - 229,000 mIU/ml
• 9-12 weeks: 25,700 - 288,000 mIU/ml
• 13 - 16 weeks: 13,300 - 254,000 mIU/ml
• 17 - 24 weeks: 4060 - 165,400 mIU/ml
• 25 - 40 weeks: 3,640 - 117,000 mIU/mL

1. Non-pregnant women: 0 - 5 mIU/mL
2. Postmenopausal women: 0 - 8 mIU/mL

These numbers are just a guide - each woman's hCG level may rise differently. It is not necessarily the level that matters, but rather the change in level.

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Raising and lowering of values

There is a wide range of normal hCG levels and values vary in serum or urine. There is no single normal human chorionic gonadotropin level that always indicates a healthy pregnancy. Therefore, elevated hCG in early pregnancy is a fairly broad term. Determining what exactly constitutes a “high” hCG level can be difficult because the normal range of hCG levels in early pregnancy is wide and hCG levels can rise and fall at different rates. Depending on how far along you are in your pregnancy, there are general guidelines that doctors use. Generally, elevated hCG levels will typically be levels that rise by more than 60% over 48 hours.

High hCG levels can indicate a number of different things, most of which are not that important. It could mean that your pregnancy due date calculation is incorrect and that you are further along than previously thought. It could also mean that you are having more than one baby, such as twins. If you are taking fertility drugs, your hCG levels will also increase.

The hCG level in twins is higher than in singleton pregnancies because two trophoblasts are working and producing more hormone. However, it is not possible to diagnose a twin pregnancy based on hCG alone. There is not enough scientific evidence to prove that twins always have a faster than normal rise in hCG. Normal hCG levels can vary up to 20 times in normal pregnancies. Variations in hCG increases are not necessarily a sign that the pregnancy is abnormal or that there are two or more fetuses.

A decrease in hCG in early pregnancy is more informative than an increase. Your baby's estimated due date is calculated based on your last menstrual period. If you have a history of irregular periods or are unsure of your last menstrual period before pregnancy, it may be more difficult to tell how far along you are in your gestational age. If your pregnancy is very early or past 12 weeks of pregnancy, your hCG levels may be low. Ultrasound and repeat hCG levels may be needed to correlate hCG levels and gestational age.

A miscarriage is the spontaneous loss of a pregnancy before 20 weeks of pregnancy. Miscarriage can cause hCG levels to drop. A pregnancy that does not develop a placenta cannot secrete higher levels of hCG. In such cases, hCG levels may be normal initially and then decrease in the event of a miscarriage.

A retained egg occurs when an egg is fertilized and attaches to the uterine wall but does not develop. The cells develop a gestational sac and can release the hormone hCG, although the fertilized egg does not develop further. Such a frozen pregnancy can cause a decrease in hCG over time, because it only increases at first, and then the level decreases, since the fetus does not develop.

An ectopic pregnancy occurs when a fertilized egg becomes lodged inside the fallopian tube, the tube that carries the egg from the ovary to the uterus, or outside the uterus. An ectopic pregnancy is a life-threatening condition, as it can cause the fallopian tube to rupture and bleed. HCG levels can help differentiate a normal pregnancy from an ectopic pregnancy, as the hCG level in an ectopic pregnancy will be lower than expected for the gestational age.

In early pregnancy, there are two hormones that tend to increase in the body after implantation - progesterone and human chorionic gonadotropin. Levels of both hormones tend to increase in women with a viable pregnancy, but not in women with an expected miscarriage. And in the last few decades, it has become common for doctors to prescribe progesterone supplements to women with recurrent miscarriages, the idea being that underproduction of progesterone may be the cause of the miscarriage.

However, progesterone is a subject of controversy among doctors, as many believe that low progesterone is a sign of a failed pregnancy rather than a contributing factor to a failed pregnancy, and progesterone supplements have not yet been proven for women at risk of miscarriage.

Much less attention has been given to the idea of supplementing another pregnancy hormone, hCG, to prevent miscarriage, even though hCG is the hormone measured in home pregnancy tests and serial blood tests used by doctors to assess the viability of early pregnancies.

HCG injections during early pregnancy may be useful in preventing miscarriages, as endogenous hCG is known to play an important role in establishing pregnancy. Hormonal hCG plays a key role in helping to establish pregnancy, and it is theoretically possible that decreased hCG production may play a causal role in miscarriages. In most cases, these injections may be needed during the first trimester of pregnancy, and sometimes during the second trimester. As the embryo grows, the amount of hCG secreted increases significantly. In other words, an adequate supply is necessary for normal development during pregnancy.

Existing research has shown that the treatment may benefit women with infrequent and irregular periods (oligomenorrhea). But unfortunately, that doesn’t mean you should go to your doctor and ask for early hCG injections the next time you’re pregnant, even if you have oligomenorrhea. Too little is known about whether the treatment works. Assuming it does, more research is needed before the treatment can be widely used.

If you take an hCG injection during ovulation, it may increase your chances of having multiple pregnancies.

HCG injections can cause certain side effects. For starters, since HCG is a pregnancy hormone, it can cause and worsen some common pregnancy-related symptoms such as nausea, breast tenderness. Some other mild side effects associated with HCG injections include water retention, headache, irritability, fatigue, abdominal discomfort, and soreness at the injection site. Women who take HCG injections during pregnancy are also at risk of developing ovarian hyperstimulation syndrome. This is a health condition that can be life-threatening. It can cause severe abdominal and pelvic pain, shortness of breath, nausea, vomiting, diarrhea, infrequent urination, and even swelling of the extremities.

In fact, the risks associated with using hCG scans during pregnancy far outweigh the benefits it offers to the mother and baby. Therefore, it is important that you take it only after consulting with your gynecologist.

HCG during early pregnancy can be the first sign that will confirm that you are really pregnant. In the future, monitoring this indicator can tell you about the state of your pregnancy, but only when assessing the clinical data of the course of pregnancy.

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