Twins - The Classic Multiple Birth
The past 30 years have seen a dramatic increase in multiple births, especially in the US. Between the years of 1980 and 2004, the number of twin pregnancies and births climbed by 70% and super twins (three or more babies) has quadrupled, and the numbers have continued to climb. The most common reason for higher order births is the use of fertility drugs and IVF. Couples who are having assisted reproduction therapy are candidates for counseling regarding the potential for a multiple birth.
Is Twinning Genetic?
It has been a common thought that heredity plays a part in the chances of having twins. However, it turns out that the only researched factor in genetic twinning is a family history of hyper ovulation. Hyper ovulation is the tendency for a woman to release more than one egg at a time at ovulation. This phenomena does occur in families, which could lead to the idea that twins "run in families." Otherwise, there is no substantial evidence to confirm the notion. Statistically, the chances of having twins in the 21st century are about 3 in 100, which is about 3%. The National Center for Health Statistics 2006 study shows that twins represented 32.21 of every 1,000 births, confirming the 3% statistic.
Identical and Fraternal Twins
There are two types of twins: monozygotic, meaning identical and dizygotic, which means fraternal. Monozygotic or identical twins result from a single fertilized egg that splits into two separate halves. These halves continue to develop into two separate but identical babies. The twins are genetically identical with the same chromosomes and similar (often identical) physical characteristics. They are the same sex, have the same blood type, hair color and eye color.
Fraternal or dizygotic twins come from two eggs that are fertilized by two separate sperm. These babies are no more alike than other children born to the same parents. Fraternal twins may be of the same sex, or not, and are the more common type of twin babies. Super-twins is the term given to higher order multiple births of three or more babies, for example, triples, quadruplets, and quintuplets. These babies can be identical, fraternal, or a combination of both.
Pregnant With Twins
A woman who is pregnant with twins will likely deliver the twin babies early, usually between 35 and 37 weeks. Nearly half of all twin births are before 37 weeks, classifying them as premature. Obviously, the higher order the multiples, the earlier the babies are born - and the risks are increased exponentially. Any expectant mother needs to take good care of herself, ensuring she is seeing her doctor, resting well, eating properly, and getting enough exercise. But, a woman who is expecting twins will probably be scheduled for more frequent visits with her obstetrician than a woman with a single baby. It is important to find health care professionals who are versed in multiple births since multiple births immediately fall under the heading of high-risk. Having the proper care is critical to the health and well being of the twin babies.
Twins have a place in history, both ancient and modern, and today there are several instances of "famous twins" in show business. The legendary founders of Rome , Romulus and Remus, were said to be the sons of the Roman war god, Mars. These twin boys were said to have been raised by wolves. In the end, Romulus killed Remus and the great city was named Rome after Romulus. You may remember having studied about these famous twins in school.
The twin sister columnists "Dear Abby" (Abigail Van Buren) and "Ann Landers" (Ann Landers) were advice writers in major publications all over North America for more than 50 years. Perhaps their genes had something to do with that. Some twins that may be more familiar are, of course, the Olsen twins, Mary-Kate and Ashley who started their acting careers in the 1980s. Both Justin Timberlake and Elvis Presley had twin siblings who died at birth - Justin had a sister and Elvis a brother. Then of course, there are the "most famous twins in the world", Vivienne and Knox, born to Angelina Jolie and Brad Pitt. You can see pictures of twins that are well known, and some not-so-well known, but checking the internet.
Indeed, twins are more common than higher order births, and as it turns out - just about anyone can have a set of twins. You don't necessarily have to have the heredity or genetic predisposition to accomplish it. Now, that's great news!