Difference Between Single and Twin Pregnancy Symptoms
By OBGYN Dr. Kenosha Gleaton
Experiencing a multiple pregnancy can bring on additional challenges, questions, and concerns. Maybe you have a suspicion that you’re carrying twins, or you’re having symptoms that seem a bit strange. The truth is that many symptoms are similar for single and twin pregnancies, but there are a few unique signs you may notice if you’re carrying twins.  Keep in mind that the most reliable method of confirming a twin pregnancy is with prenatal ultrasound, so you should speak to your provider if you have questions or concerns about your pregnancy. 
Identical vs. Fraternal Twins
When someone conceives twins, they are either identical or fraternal. Identical twins occur when one embryo divides into two.  Identical twins are the same sex, and may or may not share a placenta. Fraternal twins occur when two sperm fertilize two eggs during one menstrual cycle. Fraternal twins can be the same or different sex, and will always have two placentas. 
What Are The Chances of Having Twins?
The chances of having twins are typically pretty low, about one in 250.  That being said, the chance of conceiving twins may be greater for some people. Let’s take a look at some of the factors that can increase your chances of twins :
- You are older than 35: People who are over the age of 35 are more likely to release multiple eggs when they ovulate. This increases the likelihood of more than one egg being fertilized, potentially leading to fraternal twins.
- You are a fraternal twin yourself or if fraternal twins run in your family: There has been a genetic link observed on the maternal side of the family. If there has been a history of fraternal twins on your mom’s side, you may be more likely to conceive twins.
- You’ve conceived twins already: Research shows that if you’ve had twins during a previous pregnancy, you’re more likely to conceive them again.
- You’re undergoing fertility treatments: Depending on the fertility treatment you’re using, you may be more likely to have twins. This is because some medications, like ovulation induction drugs, can increase the likelihood of more than one egg being released. While less common today, some providers may also implant more than one fertilized egg during procedures such as in vitro fertilization (IVF). Learn about Getting Pregnant with Twins from Clomid.
- You are obese: Having a BMI above 30 classifies someone as obese. Some research shows that people who are obese are more likely to have increased levels of certain hormones, such as follicle-stimulating hormone (FSH).  This increases the likelihood of having twins.
Twin Pregnancy Symptoms
You may be expecting a noticeable difference in symptoms between a singleton pregnancy and a twin pregnancy, but the truth is, symptoms are very similar. Symptoms often experienced during a twin pregnancy include :
- Breast tenderness
- Morning sickness (get Anti-Nausea gummies here!)
- Increased appetite
- Frequent urination
Many of these symptoms can also be seen in a single fetus pregnancy. It is possible that symptoms may be more intense during a multiple pregnancy, as the level of hCG is higher.  Certain symptoms, such as nausea and vomiting, are thought to be correlated to the increase of hCG during early pregnancy. Worsened nausea and vomiting have also been associated with elevated hCG levels, commonly seen in people carrying twins. 
Even though there are many symptoms shared between singleton pregnancies and multiple pregnancies, there are also some less common signs that may point to a twin pregnancy :
- Quick weight gain
- High levels of hCG or alpha-fetoprotein (AFP)
- Hearing more than one heartbeat on a fetal Doppler
- Early fetal movement
- Fetal movement in more than one area
- A larger fundal height than is expected, meaning someone’s baby bump is larger than expected for the gestational age.
Please note that experiencing one or more of these symptoms does not confirm that someone is carrying twins.
Twin Pregnancy Risks
While having twins may sound ideal to you or your family, it’s important to know that there can be risks associated with a multiple pregnancy. Being pregnant with twins can increase the risk of [1,4]:
- Preterm labor and birth
- High blood pressure
- Intrauterine growth restriction
- Birth defects
- Fetal brain bleed
- Low birth weight
- Fetal vision problems
- Cesarean delivery
- Postpartum complications
- Amniotic fluid abnormalities
- Twin-to-twin transfusion syndrome (TTTS)
Consistent prenatal care can help catch any issues earlier on, potentially improving outcomes.  It’s also important to eat a healthy diet, take prenatal vitamins, drink plenty of water, and rest.
Support Your Pregnancy With Natalist
Whether or not you’re having twins, comprehensive prenatal care is extremely important. Natalist is proudly led by doctors and moms who understand the many ups and downs of pregnancy. Get evidence-backed, plastic-neutral, and high-quality products like pregnancy tests, supplements to support fertility, and self-care products to manage uncomfortable pregnancy symptoms. Read more about pregnancy on the Natalist blog.
Dr. Kenosha Gleaton is board-certified in gynecology and obstetrics and is the Medical Advisor of Natalist. She received her MD from MUSC and completed her residency at Carolinas Medical Center in Charlotte, NC.
Dr. Gleaton is passionate about women, youth, and mentoring. She is a Scrubs Camp instructor, a program to increase student entry in healthcare, and serves as a Compassion International adoptive parent. She is also a member of the American College of Obstetrics & Gynecology, the American Association of Gynecologic Laparoscopists, and the American Association of Professional Women.
- Twin Pregnancy. Cleveland Clinic. June 2022. https://my.clevelandclinic.org/health/articles/23158-twin-pregnancy
- Vaajala M, Liukkonen R, Kuitunen I, Ponkilainen V, Kekki M, Mattila VM. Obesity increases the odds of multiple pregnancies: A nationwide register-based cohort study in Finland. Int J Gynaecol Obstet. 2023;162(2):725-729. doi:10.1002/ijgo.14748
- Bustos M, Venkataramanan R, Caritis S. Nausea and vomiting of pregnancy - What's new?. Auton Neurosci. 2017;202:62-72. doi:10.1016/j.autneu.2016.05.002
- Complications of Multiple Pregnancy. Johns Hopkins Medicine. Accessed November 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/staying-healthy-during-pregnancy/complications-of-multiple-pregnancy