If you’re concerned about having twins, or if you have been told that your hCG levels indicate there are two little ones on the way, here’s everything you need to know about hCG (human chorionic gonadotropin) and if you might be having twins.
When you get a positive pregnancy test at home, one of the first things you need to do is make an appointment with your obstetrician for your first prenatal visit. At that appointment, your doctor will want to test your hormone levels, specifically your hCG level, to confirm your pregnancy. hCG (human chorionic gonadotropin) is a hormone produced by the body during pregnancy to support fetal growth and development.
Today, we are going to dive into the world of hCG and how and why this is something you should pay attention to during early pregnancy.
What is an hCG Level?
hCG or “the pregnancy hormone” is the most commonly measured hormone during pregnancy. It’s normally produced in the placenta after the egg (or eggs) has been fertilized and traveled to the uterus. hCG is the hormone that alerts your body that you’re pregnant. hCG levels are used as an indicator for the health of your pregnancy. hCG is a useful marker to estimate the gestational age of your pregnancy and to help you determine how far along you are in weeks. hCG levels also assist with determining whether or not you will experience a miscarriage, but hCG testing is not always 100% accurate.
Can a Store-Bought Pregnancy Test Show How High Your HCG level Is?
If you take a home pregnancy test, the results will be based on two main hormones – estrogen and hCG. Levels of these hormones are approximately 1000 times higher during pregnancy than in non-pregnant women. At this time, a store-bought pregnancy test can not give you a specific hCG level; only a woman’s first visit to the doctor can determine the amount of hCG in her system through a simple blood draw.
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What Weeks of Pregnancy Does hCG Show Up?
hCG can be detected in the bloodstream about 11 days after conception, with a level of 6 – 40 mIU/ml hCG. The level of hCG doubles every 48-72 hours during early pregnancy. In most normal pregnancies, hCG values increase from the day a fertilized egg implants into the uterine wall, eventually peak around 8-10 weeks after implantation, and plateau as the pregnancy progresses.
The hCG Levels That Mean You’re Having Twins
According to several studies, women pregnant with twins may have a higher level of hCG baseline levels compared to the normal level of hCG in a singleton pregnancy. hCG is the hormone that alerts your body that you’re pregnant. hCG levels are highest during early pregnancy and gradually decline as the pregnancy progresses to term. hCG will be at its highest level when an embryo implants into the uterus.
hCG typically reaches 90,000-100,000 mIU/mL for a singleton pregnancy. Your doctor will be paying closer attention to trends instead of numbers due to the fact that there’s a wide range of normal hCG levels. As long as hCG rises as expected, your doctor will consider your pregnancy as healthy.
Here is a chart of standard hCG levels for a singleton pregnancy. If your levels are on the higher end of the standard hCG range, this could be a clue that you’re having twins.
|Week of Pregnancy||Typical hCG Range|
|3 weeks||5–50 mIU/mL|
|4 weeks||5–426 mIU/mL|
|5 weeks||18–7,340 mIU/mL|
|6 weeks||1,080–56,500 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||4,060–165,400 mIU/mL|
|25–40 weeks||3,640–117,000 mIU/mL|
What Do High hCG Levels Indicate?
In most pregnancies, the level of hCG normally doubles every 48-72 hours and increases by at least 60% every two days. The higher your levels of hCG are initially, the higher they will be throughout your entire pregnancy. If your HCG levels are higher than average, you could be having twins. An hCG level that is 30%-50% higher than a standard singleton pregnancy could mean a twin pregnancy.
Can hCG Levels Be Found In Urine?
The hormone hCG can be detected in a urine test, but the exact level of hCG can only be measured through a blood test.
Does a High Level of HCG Mean You’re Having Twins?
High levels of hCG do not necessarily mean that you will have twins. You can have high levels of hCG with a singleton pregnancy. The chances of having twins increase with higher levels of hCG, but they cannot be predicted accurately based on this alone. The only way to confirm that you’re having twins is to have an ultrasound, as early as 6 weeks of pregnancy. hCG levels that are higher than normal during pregnancy can sometimes be the result of a problem with the pregnancy, including an hCG-producing tumor (also known as choriocarcinoma), ectopic pregnancies, or a molar pregnancy.
How Common are Twin Pregnancies?
Twin pregnancies occur in three to four out of every 100 pregnancies. Twins account for nearly 80 percent of all multiple births. Triplet and quadruplet births are less frequent but still occur once per 1000 deliveries.
Signs You Are Having Twins
According to research studies, it has been proven that if hCG levels are higher than expected for someone’s week of gestation, then they may be carrying multiple fetuses. Another study revealed that twin pregnancies tend to start out with higher hCG levels than single pregnancies do.
Some studies show that women pregnant with multiples had higher hCG base level counts. Increased hCG levels may indicate a pregnancy that includes twins.
What low hCG levels might mean
Low hCG levels mean that hCG is not being produced in high quantity by the body, which could be the result of testing very early in the pregnancy when the levels are too low. Typically, within a few days, the hCG level will rise much higher. However, in some cases, hCG levels that are too low or not increasing can indicate a miscarriage, also known as a chemical pregnancy. If your hCG levels are not following expected patterns, your doctor may request additional blood draws every few days in order to get a better idea of how the levels are changing.
What high hCG levels might mean
A high hCG level means that hCG is being produced in high quantity by the body, typically due to a strong single pregnancy or a multiple-birth pregnancy. But if your levels aren’t high, that doesn’t automatically mean that there’s something wrong with your pregnancy. It truly depends on what point in time you are in your pregnancy, which can be difficult to determine if you’re not sure of the date of your last period.
High hCG levels alone typically do not indicate that you are having twins, but it may increase your chance of pregnancy with multiples over the normal baseline hCG value for a singleton pregnancy.
Is hCG monitored prior to ultrasound?
Yes, typically, your doctor’s office will check that your blood is showing hCG levels high enough to be considered a healthy pregnancy before scheduling your first ultrasound.
What are the signs of twin pregnancy?
Signs of a twin pregnancy are cramping, bleeding, spotting, nausea or vomiting, and fatigue — the same symptoms as for singleton pregnancies, but when you’re having twins, these symptoms are typically a LOT stronger. Read this article about signs of twin pregnancy to learn more about the signs that you might be having twins.
It is understandable that pregnant women will be curious about the possibility of having multiples. If your doctor has requested additional blood draws in order to get a better idea of how hCG levels are changing, it could mean they suspect you may have twins on board. Keep an eye out for any other symptoms and contact your physician if anything seems off or unusual. And hang in there until you can get that ultrasound done and know for sure if you’re having twins!
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Pregnant with twins and not sure where to start? Visit the Ultimate Twin Pregnancy Guide to find all the top articles and resources to get you ready for twins. While you’re at it, check out our expecting twin classes and Twiniversity shop!