What Do You Call Four, Five, Six or More Babies?

name for different sets of multiple babies
Illustration by Hugo Lin. © Verywell, 2018.

Multiple births are on the rise, especially of twins, and the public fascination with multiples continues to grow as well. This results in many questions, including what you call different sets of multiples. Learn the nomenclature and other facts about multiple births.

A Simple Chart of Multiple Birth Terms

This quick-reference can help you know what to call sets of multiples.

Number of BabiesTerm Used
1Singleton
2Twins
3Triplets
4Quadruplets (quads)
5Quintuplets (quints)
6Sextuplets
7Septuplets
8Octuplets
9Nonuplets

The prefixes for the numbers four through nine come from Latin for those numbers. Single, twin and triplet come from Middle English.

Twins Are More Common Than Triplets or More

According to the United States National Vital Statistics Report, there are approximately 33.4 sets of twins born for every 1,000 live births and 101.4 sets of triplets or more per 100,000 births.

In other words, twins are a lot more common (about 3 percent of all live births) versus a pregnancy with three or more babies (about 0.1 percent of all live births). This may surprise some people, considering the number of multiple births seen in the media or on reality television shows.

Changes in Triplet and High-Order Multiple Births

The rate of twin, triplet, and high-order births began to climb in the 1980s, especially among white non-Hispanic women age 25 and over due to the use of fertility drugs and assisted reproduction techniques.

While the rate of twin births increased by over 50 percent, the rate of triplet and higher order multiples increased by over 400 percent.

The rate peaked for triplets and higher multiples from 1998 to 2004 and has since been dropping, again in the same demographic group responsible for the rise. This is due to a change in assisted reproduction treatments, especially in the transfer of fewer embryos.

The rates are still three times what they were in the early 1980s. This is a concern because the risks of mortality and long-term morbidity continue to be far higher for triplets and higher order multiples than for singletons.

How Multiple Births Occur

You may wonder exactly how a woman conceives multiple babies. The biology behind it is quite intriguing.

Identical 

Every month, a woman releases an egg from her ovary (this process is called ovulation), which can then be fertilized by a sperm to form an embryo and, eventually, a developing fetus or baby.

If an embryo happens to split into two or more embryos, identical twins (or more) may result. Due to the splitting of the embryo, identical twins share the same DNA. This is why they are always of the same gender.

Fraternal 

On the other hand, some women release more than one egg during ovulation; they "hyperovulate," so to speak. Experts are not quite sure why some women hyperovulate and others do not, but there is believed to be a genetic component to it—a hyperovulation gene. In addition, age plays a role, as women older than age 35 are more likely to release more than one egg during each menstrual cycle.

If a woman releases two (or more) eggs during ovulation, then each may be fertilized by a different sperm, forming unique embryos.

In this case, twins would be fraternal (not identical), and they can be of different genders or the same gender.

Interestingly, sometimes both of the above processes occur. This can be difficult to wrap your head around so here is an example scenario: A woman hyperovulates, releasing multiple eggs during the middle of her menstrual cycle. These eggs are each fertilized by a sperm, and then one or more of these embryo splits. In this instance, a woman could have multiple births (such as quadruplets) with two of the babies being fraternal twins and two being identical.

Complications of Multiple Pregnancies

In a multiple pregnancy the mother is more at risk of these complications:

  • The most common complication of a multiple pregnancy is preterm birth.
  • Preeclampsia is more common in a multiple pregnancy than in a woman pregnant with one.
  • A multiple pregnancy puts a woman at high risk of developing gestational diabetes.
  • Postpartum depression and early parenthood mental health problems may be more likely to occur in women who have a multiple pregnancy.

A Word From Verywell

If you, your partner or a loved one is expecting multiple babies, it's good to gain knowledge. Be sure to talk with your doctor about some of the more difficult topics like the maternal and fetal risks of a multiple pregnancy versus a singleton pregnancy.

Sources:

American College of Obstetricians and Gynecologists. (July 2015). Multiple Pregnancy. FAQ188, July 2015. https://www.acog.org/Patients/FAQs/Multiple-Pregnancy.

Martin JA, Osterman MJK, Thoma ME. Declines in Triplet and Higher-order Multiple Births in the United States, 1998–2014. NCHS Data Brief No. 243, April 2016. https://www.cdc.gov/nchs/products/databriefs/db243.htm.

Multiple Births. Centers for Disease Control and Prevention. https://www.cdc.gov/nchs/fastats/multiple.htm.

Wenze SJ, Battle CL, Tezanos KM. Raising Multiples: Mental Health of Mothers and Fathers in Early Parenthood. Archives of Women’s Mental Health. 2015;18(2):163-176. doi:10.1007/s00737-014-0484-x.