Did you know that......
In 2001, the National Center for Health Statistics reported that twins occurred once in 35 births in the United States. Triplets and higher multiples occurred once in 541 births. Two-thirds of all twin births are fraternal, one-third are identical. “Twin" comes from the German word "twine" meaning "two together." Gemini is the constellation or zodiac sign of twins.
Are they identical?
Identical twins occur when one egg is fertilized by one sperm. The egg divides, producing two individuals. Identical twins are always the same sex. They look alike. Both will have straight or curly haird, the same eye color, etc. Fingerprints are similar, but never the same. Placenta examination to determine if the twins are identical is not always accurate. Blood testing is more efficient and reliable. DNA testing is the most accurate, and most expensive way to determine twin type.
Are you sure they're twins? They don't look alike...
Fraternal Twins are the result of two eggs being fertilized by two separate sperm. They are no more similar than any two brothers or sisters. Fraternal twins may be boy / girl or same sex. They may look alike or very different. Only fraternal twins tend to run in families. Identical twins happen by "chance" and can happen to anyone, regardless of whether there are twins in family or not. Your own chance of having twins depends on your personal history, age, race, fertility treatments, number of pregnancies, social habits, geographic location, seasons, nutrition, and other factors.
Types of Twins:
· Identical twins - result when a single egg splits. They share 100% of their DNA. They are the same gender and tend to look very similar.
· Fraternal twins - result when two eggs are fertilized at the same time. They share 50+% of their DNA. They can be the same or different genders; they can look similar or very different.
· Conjoined twins - are identical twins that occur when the egg does not split all the way when forming in the womb. 1 in 200,000 births are conjoined.
· Mirror-image twins - are identical twins that show mirroring traits instead of identical traits. For example, one is left-handed, the other is right-handed.
About Twin Births:
· 1 in every 32 births is a twin. Since 1980, twins births have risen 62%
· Fraternal twinning occurs 1 in 60 births. Identical twinning occurs 1 in 150 births.
· A twin pregnancy causes normal pregnancy symptoms, such as nausea and morning sickness, to occur earlier. On average, twins are born 22 days premature.
· More than half of all multiple births in the United States are low birth weight. Less than 5.5 pounds.
· Also, more than half of multiple births are born before the thirty-seventh week and are considered premature.
· Multiple births are the most common in African American cultures. Multiple births are least common in Asian cultures.
· The nation with the highest number of multiple births is Nigeria.
Fun Facts:
· In the United States, over 150 identical twins are married to identical twins. Genetically their children are brother and sister, but legally their children are cousins.
· Cryptophasia is when twins have their own "twin language" that only they understand. Many twins appear to have this so-called language when they are babies.
· Sometimes it is hard to tell if twins are identical or fraternal but look alike. DNA tests are an accurate way to prove if twins are truly identical or fraternal.
Studying Twins:
· The scientific study of twins is called gemellology.
· 18-22% of twins are left handed, for non-twins the rate of lefties is only 10%.
· Studies have shown that identical twins tend to live longer than fraternal twins; researchers believe this is due to their close communication.
· Studies show that identical twins exhibit the same brain wave patterns.
· In 1875, British scientist Dr. Francis Galton was the first to say that identical twins are the same biologically and may have come from a single egg. He also said that twins that look different, fraternal twins may have come from two separate eggs.
Twin Trivia
· Most Identical Twin - John and William Reiff of Pennsylvania - have won 22 titles in most identical contests
· Tallest Twins - Male: 7'4" Michael and James Lanier of Michigan, Female: 6'6" Ann and Claire Recht of Oregon
· Shortest Twins - Male: 2'10" John and Greg Rice of Florida, Female: 4'1" Dorene Williams and Darlene McGregor
· Oldest Mom of Twins - 58 year old Samira Ellis of Israel, had Elias and Solva on March 8, 2003
· Oldest Dad of Twins - 78 year old Tom Lambert of Louisiana, had Dale and Dean in 1948
· Longest Separated Twins - Iris Johns and Aro Campbell were separated from 1914 until 1989
· Most Recent Twins Separated at Birth and Reunited - Adriana Scott and Tamara Rabi, separated for 20 years - News Article Twist of Fate
· Company Employs the Most Twins - Cirque du Soleil employs 9 sets of twins
· Most Famous Celebrity Twins - Mary-Kate and Ashley Olsen - Article Hollywood Walk of Fame Honors Olsen Sisters
· Most Multiples Born and Living - The McCaughey Septuplets from Iowa
· Largest Annual Gathering of Twins - Twins Days in Twinsburg, Ohio, according to the Guinness Book of World Records