Quick Facts and Figures about Twins

• Identical twins share the same DNA, but will have their own fingerprints!

• About 25% of identical twins are called mirror image twins. For example if one has a mole under her right eye, the other will have it under her left eye.

• Chances of having a twin pregnancy naturally is increased by maternal age ( 30+), genetics and number of previous pregnancies.

• According to the National Center for Health Statistics the number of multiple births has increased about 74% since 1980.

• Twin pregnancy is considered full term at 36 weeks and 3 days.

• The average weight of twins at term is about 5.5 lbs

• The average or recommended weight gain for average sized mothers of twins is between 35-45 lbs.

• Studies have shown that mothers who gain about 24 pounds by week 24 have reduced their chances of giving birth either prematurely or to low birth-weight babies.

• Women pregnant with twins will have more ultrasounds, tests and prenatal appointments than women pregnant with singletons.

• Male twins will not have twins unless their wives have the ability to produce 2 eggs.

• Fraternal twins (girls) have twice the chance of giving birth to twins than singletons. According to the American College of Obstetricians and Gynecologists:

• 1 in 250 pregnancies can result in identical twins.

• In some African countries such as Nigeria, the rate of twin pregnancies can be as high as 1 in 20.

• China has the lowest rate of Twinning in the world.

• 22% of Twins are left handed (including one of mine) where as in singletons only 10% of them are left handed.

• Did you know that Mary-Kate and Ashley Olsen are actually fraternal twins?!! One way to be sure if your identical looking twins are actually fraternal is to do a Twin Zygosity Test.

• According to the Guinness book of records there are 3 known cases in the US where parents gave birth to 2 sets of twins siblings on the same day. The mothers are Caroline Cargado, Laura Moore and Michele Gorney.

• Heteropaternal Superfecundation is the term used when a woman becomes pregnant from two different man and gives birth to fraternal twins.

• Gemellology is term use for the scientific study of Twins. Use that in the next game of Scrabble you play and impress people!

• The highest rate of twinning belongs to the Yoruba Tribe of Nigeria and the lowest rate belongs to China.

• Elvis Presley had a twin who did not survive after birth. His name was Jesse Garon.

• Ideoglossia is the term used for the secret language of twins. This secret language actually does not exist. Once twins, as in any other baby, learn to talk, they mispronounce words but because their other half is capable of recognizing and understanding those words, it seems as if they have their own language.

• It is a myth that fraternal twins skip a generation.

• The Twins Law was first passed in Minnesota which allowed parents to actually have a voice in their twins’ placement at schools. In Canada Schools do actually listen to parents and the separation is not mandatory unless it is better for the twins’ social and academic performance.

• Quaternary Marriage is the term used when one set of twins marries a second set of twins.

• In case of identical twins marrying identical twins, genetically speaking their children will be more than cousins, they will be genetic siblings.

• On December 31, 2009 a mother of twins gave birth to one set of identical twin boys at 11:59 and the other one on January 1, 2010 at 12:00 am.

• On October 2, 2010 Gabrielle Vaudremer and Marie Hendrix turned 100 years old and are currently known as the oldest set of twins in the world.


  1. ilyssa

    is it always going to be hard raising twin boys 

  2. Kellie

    I had identical twin girls in 2007, my cousin and his wife had identical twin girls in 2009, and in 2013 another cousin and his wife had fraternal boy- girl twins… So my mother, her sister and her brother all have twin grandkids. My grandma has. 3 sets of great grand-twins. My grandma had twin brothers but that’s closest family thing… How rare is this to happen? None of us had any medications to help get pregnant. Also curious which state has the most twins?

  3. Mary

    My family has history of twins on both sides. Nice article to read.

  4. Twindragonmummy

    Is it usual for one twin to reach their milestones later than the other?

    • Mother of Twins

      With what I have researched each identical twin can have his/her milestone. One is usually head or behind. As for fraternal twins well they will separate milestones as well.

  5. Fab5

    My doc said that full term for twins is still 40 weeks. he thinks I’ll go full term and the girls will weigh around 8lbs a piece

  6. salma

    nice article


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