Early Signs You Might Be Pregnant With Twins

When you're newly pregnant, it's normal to wonder whether you have more than one baby on board—and how early you can find out if you're having twins. Twins only account for 3% of all births in the US. But there are some things that can increase your personal chances of having twins.

So how early can twins be detected? While twins can't officially be detected until you've had an ultrasound, you might experience signs that you're carrying more than one baby. We turned to the experts to learn more about the early signs of twins, common twin pregnancy symptoms, and how early twins can be detected.

Early Signs of Twins and Risk Factors

Are there early signs of twins? The short answer is yes and no. Every pregnancy is different. Just like people with singleton pregnancies, people who are pregnant with twins can experience a wide range of pregnancy symptoms. That said, certain physical signs might clue you into how many babies you're expecting, like intense morning sickness and "showing" earlier than expected.

Certain people also have a greater chance of getting pregnant with twins than others. If you're experiencing an early sign of twins and have one or more risk factors for twins, you just might be carrying multiples.

That said, while there are some symptoms that are commonly reported among people pregnant with twins, those symptoms can't confirm or rule out a twin pregnancy. That is to say that you can experience common "twin pregnancy symptoms" with a singleton pregnancy, and it's also possible to be pregnant with twins and not experience the so-called signs of twins.

How Early Can Twins Be Detected?

In most cases, twins can be detected as early as seven weeks of pregnancy with an early pregnancy ultrasound, says Amos Grünebaum, MD, a professor of obstetrics and gynecology at the Zucker School of Medicine in Hempstead, New York, and the founder of BabyMed and Obie.

However, not all pregnant people will have access to an early ultrasound, and some health care providers may not do a prenatal ultrasound until later in the first trimester or even the second trimester.

Common Twin Pregnancy Symptoms

While you won't know for sure that you're pregnant with twins until you have an ultrasound, there are some physical signs that are more common with twin pregnancies.

Elevated hCG levels

Higher-than-normal levels of hCG may indicate that you're pregnant with multiples. When you become pregnant, your body starts making human chorionic gonadotropin hormone (hCG). Levels of hCG start to increase after implantation and rise every 39–53 hours in the first few weeks of pregnancy. With twin pregnancies, hCG levels can be 30% to 50% higher than those where only one embryo is present.

Only an hCG blood test, like the one done at your doctor's office, can provide a look at the levels of hCG in your body at a given point in time. And even if you do have high hCG levels in early pregnancy, it still doesn't mean that multiples are a sure thing.

"Twin pregnancies often have increased hCG levels, but so do some singleton pregnancies," explains Dr. Grünebaum. "There is a wide range of normal hCG levels both for twins and singletons, and it's impossible to be sure it's twins even when the early hCG levels are elevated."

Abnormal AFP test results

An alpha-fetoprotein (AFP) screening is a blood test performed on pregnant people during the second trimester. Also known as maternal serum screening or multiple marker screening, it's used to identify increased risks of certain congenital disorders.

A twin pregnancy can produce an unusually high or "positive" result. When this happens, the health care provider will respond by scheduling an ultrasound for further assessment.

Exaggerated pregnancy symptoms

Since many pregnancy symptoms are caused by hormonal changes, it makes sense that people expecting twins (who often have more substantial hormonal changes than people expecting one baby) can experience more severe symptoms.

Christine Greves, MD, an OB-GYN at Winnie Palmer Hospital for Women & Babies in Orlando, Florida, explains that people who are pregnant with twins have a "higher risk" for many things, including more severe pregnancy symptoms.

People with twins may experience the same common early pregnancy symptoms as people who are pregnant with one baby, but the symptoms may feel more intense. While more intense physical symptoms can suggest twins, severe symptoms can also occur with a singleton pregnancy.

Intense nausea and vomiting

Due to elevated levels of hCG, people carrying multiples may experience more nausea and vomiting than those carrying only one baby, explains Dr. Greves. For instance, hyperemesis gravidarum (HG), a pregnancy condition characterized by severe and uncontrolled vomiting, is more likely with a twin pregnancy. HG causes nausea and vomiting so severe that a person may need intravenous (IV) fluids and other assistance, Dr. Greves says.

Research has shown that twin pregnancies are associated with higher rates of severe nausea and vomiting when compared to singleton pregnancies alone. And interestingly enough, when both babies were females, the rates of nausea and vomiting were reported as even more severe. So pregnancies with twin girls may cause the most severe morning sickness of all.

A bigger "bump"

Dr. Grünebaum says the appearance of an early pregnancy bump isn't a definitive indicator of twin pregnancy because height, pre-pregnant weight, diet, body type, and number of previous pregnancies also come into play. However, many who have carried multiples say their quickly growing bellies tipped them off. Others report faster and greater weight gain in early pregnancy with twins.

Fundal height, a measurement from the pubic bone to the top of the uterus, can also be larger in twin pregnancies. However, fundal height measurements aren't typically considered accurate until after 24 weeks of pregnancy, by which point most people will already know if they are expecting twins. Additionally, fundal height measurements can be less accurate in people with obesity or a history of fibroids.

Intuition

Just as some people have a hunch they're pregnant, others might instinctively guess they're expecting twins. And while there may be no way to accurately measure a pregnant person's intuition for twins, one study found that over half of pregnant people who claimed to have an intuition about their baby's sex were accurate.

Even more impressive? The pregnant people who reported having a "very strong sense of intuition" had even higher accuracy rates, at 62% correct. So who knows? Pregnancy intuition may be a powerful thing.

Additional reporting by Pamela Prindle Fierro