For many expecting parents, the excitement of pregnancy can bring up a lot of questions, especially if there is a possibility of having twins. One of the common early indicators that might lead to this assumption is the level of human chorionic gonadotropin (hCG) in the body.

hCG is a hormone that rises during pregnancy. Higher-than-average levels have often been associated with multiple pregnancies.

However, does high hCG mean twins? It is a question that has intrigued many. Understanding this connection requires a deeper look into hCG and its role during pregnancy.

What Is hCG and How Is It Measured?

Human chorionic gonadotropin (hCG) is a hormone produced by the placenta shortly after implantation of the fertilized egg.

Its primary role is to maintain the production of progesterone during early pregnancy. This helps support the growing fetus. The presence of hCG is what pregnancy tests detect–signaling that you are pregnant.

Typically, hCG levels are measured through a blood test or urine test. During the early weeks of pregnancy, hCG levels rise quickly. Doctors often track these levels to confirm the pregnancy and monitor its progress. The hormone reaches its peak around 10 to 12 weeks of pregnancy and then begins to decline.

A key point of confusion arises when women are pregnant with multiples, such as twins. Higher hCG levels can sometimes be a sign of a multiple pregnancy. However, they do not guarantee it. Multiple factors influence hCG levels. Variations in hCG levels can occur in singleton pregnancies as well.

The Role of hCG in Pregnancy

hCG is often called the “pregnancy hormone” because it is one of the first indicators of pregnancy. The hormone can be detected in blood tests within days of conception. This is why it is so useful for confirming pregnancy.

Its levels can give insight into the pregnancy’s viability, especially in the early stages. However, there is much more to hCG than just confirming pregnancy.

hCG and Pregnancy Progression

In a typical pregnancy, hCG levels double every two to three days during the first four weeks after conception. After that, the rate of increase slows down.

In healthy pregnancies, hCG levels peak around the 10th week and then gradually decline. This decline does not signify a problem but rather signals that the placenta is now fully capable of supporting the pregnancy.

hCG and Miscarriage

In some cases, irregular hCG levels can signal problems. For example, an unusually low increase in hCG during early pregnancy might be a warning sign of a miscarriage or a non-viable pregnancy.

Similarly, a sudden drop in hCG levels after they have been rising steadily can also be an indicator of a miscarriage or failed pregnancy.

Does High hCG Mean Twins?

Higher-than-average hCG levels may be one of the indicators of a twin pregnancy, but it is not definitive. Studies have found that women carrying twins often experience higher base levels of hCG.

However, these women will also experience a typical doubling pattern of the hormone, similar to women pregnant with a single baby.

Understanding the Range of Normal hCG Levels

hCG levels can vary widely between individuals, and even between pregnancies. For instance, during the early weeks of pregnancy, normal hCG levels can range from 5 mIU/mL to over 10,000 mIU/mL.

At the 5-week mark, levels may vary from 200 mIU/mL to 7,000 mIU/mL.

By week six, levels may reach 200 to 32,000 mIU/mL, and so on. This variation in hCG levels makes it difficult to diagnose a twin pregnancy purely from hCG readings.

What Can High hCG Levels Indicate?

While higher hCG levels are often associated with twins, they can also indicate other pregnancy-related conditions, such as:

• Molar Pregnancy: A rare condition where abnormal tissue grows inside the uterus instead of a fetus.
• Ectopic Pregnancy: Though hCG levels rise in an ectopic pregnancy, they may not rise at the expected rate.
• Miscalculation of Pregnancy Dates: If a woman’s last menstrual period (LMP) was miscalculated, it could lead to an overestimate of the pregnancy’s age and skew hCG levels.
• Fertility Treatments: Women who undergo treatments such as in vitro fertilization (IVF) may have higher hCG levels, even with a singleton pregnancy.

How to Confirm If You Are Pregnant with Twins

While high hCG levels may suggest twins, the only sure way to confirm this is through an ultrasound. A pregnancy ultrasound is a valuable tool in early pregnancy because it can show the presence of one or more embryos. This allows your healthcare provider to confirm if you are expecting multiples.

When Can You Confirm a Twin Pregnancy with Ultrasound?

It is possible to detect multiples as early as six weeks after conception. By this point, your doctor will be able to see if one or more embryos are present in the uterus.

The heartbeat of each fetus can also be detected–one of the clearest signs of a twin pregnancy.

The Role of Ultrasound in Monitoring Twin Pregnancies

Ultrasound is used throughout the pregnancy to monitor the growth and development of the fetuses. In the case of twins, ultrasounds become even more important.

Multiple pregnancies tend to carry a higher risk for complications, such as preterm labor or gestational diabetes. Regular ultrasounds help certify the health and well-being of both the mother and the babies.

Other Signs You Might Be Having Twins

In addition to high hCG levels, there are other symptoms that might indicate a twin pregnancy. However, these symptoms are not definitive on their own and should be confirmed through an ultrasound.

• Increased Morning Sickness

Women pregnant with twins may experience more intense and prolonged morning sickness compared to those carrying a single baby.

The heightened nausea and vomiting are often linked to the significantly higher levels of pregnancy hormones, particularly human chorionic gonadotropin (hCG). These are produced in greater amounts in multiple pregnancies.

Some women may find that their symptoms start earlier, last longer, or require additional management strategies, such as dietary adjustments or medical intervention.

• Excessive Fatigue

Expecting twins can take a greater toll on the body. This can lead to pronounced fatigue. Many women carrying multiples report feeling unusually exhausted, even in the early weeks of pregnancy.

The increased tiredness is likely due to the body’s extra effort in supporting two growing fetuses. This requires higher energy levels and additional nutrients.

Increased blood volume, hormonal shifts, and the strain on metabolic processes may also contribute to persistent fatigue.

• Faster Weight Gain

Though weight gain can vary widely between individuals, women carrying twins may begin to gain weight more quickly than those with a singleton pregnancy.

• Detecting a Second Heartbeat

During a routine prenatal visit, your healthcare provider may detect a second heartbeat. This is a clear sign that you are pregnant with twins, although a follow-up ultrasound is usually needed to confirm the number of babies.

Understanding High hCG Levels and Twin Pregnancies

While high hCG levels can be a clue that you are carrying twins, they are not a guarantee. There are many factors that influence hCG levels, and they vary greatly from person to person. The best way to confirm if you are pregnant with multiples is through a pregnancy ultrasound.

Rosh Maternal & Fetal Medicine focuses on providing high-quality pregnancy care, including expert ultrasounds to monitor your pregnancy closely. If you suspect you might be carrying multiples or have concerns about your hCG levels, we are here to guide and support you through every step of your pregnancy.

We understand that every pregnancy is unique, and we are committed to assuring your health and the well-being of your babies.