In the Womb: Multiples

Saturday, Monday and Tuesday we have been watching In the Womb: Multiples, a National Geographic video.

Did you know...

• About 95 percent of all multiple births in the United States are twins.
  
  
• 34 out of every 1,000 births in the United States are multiples.
  
  
• Between 1980 and 1998, the rate of triplets and higher order births in the United States increased by 400 percent. In recent years, this rate has been more stable.
  
  
• A woman has an estimated one in 64 million chance of conceiving identical quads.
  
  
• Women reaching the end of their reproductive years are more likely to have a multiple pregnancy.
  
  
• The window for an egg splitting to form identical twins is very short. If the egg doesn’t split into two separate but identical eggs within the first 14 days after conception, it never will.
  
  
• The record number of fetuses in a human womb at one time is 15.
  
  
• It’s estimated that for every 400 sets of fraternal twins, one set is made up of twins who will have different fathers.
  
  
• At birth, single babies on average weigh more than twins.
  
  
• Some fetuses spend the first trimester of pregnancy with a companion that later disappears—a phenomenon called the “vanishing twin syndrome.”
  
  
• Movements such as kicking, pushing, and what looks like kissing are all documented in twins.
  
  
• Interaction between twins may be beneficial, helping to accelerate their development.
  
  
• About half of twins are delivered by Caesarean section (or C-section).

To learn more go to the video's website.