Newsletters

Healthy Child Fall/Winter 2003

The More The Merrier: Fun Twin Acts

• Your chances of having twins are better than ever now. Researchers have recorded an increase of over 50 percent since the early 1980s. The National Center for Health Statistics reports that twins now represent 26.8 of every 1,000 births. The statistics for higher order multiples have also increased dramatically. The odds of conceiving “spontaneous” triplets (without the aid of fertility enhancements) is 1 in 8,100 births. The odds of spontaneous quadruplets are 1 in 729,000 births.
• Famous twins include Montgomery Clift, John Elway, Ann B. Davis (Alice of the Brady Bunch), Vin Diesel and Liberace. Famous parents of multiples include parents of twins, Denzel Washington, George W. Bush, Margaret Thatcher and William Shakespeare; and parents of triplets, Richard Thomas (The Waltons).
• It is thought that fraternal twins are conceived due to higher levels of Follicle Stimulating Hormone (FSH) in the mother. This hormone stimulates the growth
  and ripening of eggs. Once you have had fraternal twins, your chance of having another set of twins is three to four times that of the general population.
• It is not known how identical twinning occurs, but there are some theories. One theory is that it may be related to aging of the egg after ovulation: an
  “over-ripe” egg. Another theory states that since the rate of identical twins is higher in mothers who are either very young or very old, identical twins may be
  due to the hormonal imbalances seen at these ages. The intelligence (IQs) of identical twins rarely varies more than five points, while the IQs of fraternal twins may be as different as those for any siblings in a family
• Identical twins usually have similar social development. Each is typically as outgoing and communicative as the other, and they tend to share similar attitudes and reactions. Fraternal twins, on the other hand, differ from each other as any siblings would. The term “twins” derives from the ancient German word twin or twine meaning “two together.”
• Identical twins exhibit almost identical brain wave patterns.
• The Vanishing Twin: An interesting phenomenon has been noticed now that ultrasound exams are available for most pregnancies. There have been many cases in which early-pregnancy ultrasound exams showed twins, only to have a subsequent ultrasound show only one fetus, with no sign of the other having been present. Generally, the vanishing twin fetus is absorbed back into the uterus or degenerates as pregnancy advances. It is conjectured that since twins are more likely to be left-handed than the normal population, lefthanded singletons may be surviving co-twins of a vanishing identical.

Sources: National Organization of Mothers of Twins and Twins Magazine

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