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Genetic Research of Identical Twins

Twin Births

Twins can be fraternal or identical. Fraternal twins are twins who aren't identical, although they can be of the same sex.

The incidence of twins has certainly seen an explosion in the last several decades. The higher rate of multiple births is primarily due to an increase in the use of fertility drugs and the older age of many women at the time of conception. However, there are other factors that are associated with twin births as well.

• Location-Where you live may have a direct bearing on the chances of conceiving twins. For example, certain states have been found to have a higher incidence of twin births, such as Connecticut and Massachusetts.
• Time of year-Did you know that there are fewer twin conceptions in the month of January, while there are more in the month of July?
• Diet-While the verdict is still out, diet could also play a role in the conception of twins. Certain foods may contain higher levels of hormones that are similar to estrogen, such as yams, which may influence ovulation and conception.

About Genetic Research of Identical Twins

Most clinicians agree that number of twin conceptions is much higher, although the actual pregnancy and birth may only result in one baby after the other fetus is lost in early miscarriage. Identical twins, also referred to as monozygotic, are certainly less common than fraternal. Identical twins are formed when one fertilized egg is split into two during the first twelve days after the egg is fertilized.

Is there really a bond that is found in identical twins? Genetic research of identical twins actually supports this theory. Studies of identical twins' brains have found an almost perfect match in brainwave patterns, and this phenomenon could explain why twins appear to have extra-sensory perception when it comes to their sibling. In other words, twins may really have the capability to know what the other is thinking and whether the other is feeling any pain, sadness, etc. On the physical side, twins sometimes have other commonalities, such as missing the same tooth.

More Interesting Facts

Genetic research of identical twins identifies many other interesting facts, like the following:

• Identical twins do not run in the family, although fraternal twins do. In fact, women who have conceived fraternal twins have an increased chance of doing so again!
• The chance of conceiving identical twins is approximately one in 285, while the chance of conceiving fraternal twins is around one in 80.
• Identical twins do not have the same fingerprints, even though they share the same DNA.
• Twins are typically born earlier than 40 weeks, with the average being around 36 weeks. They are generally considered full term at 38 weeks.
• Identical twins don't always share the same placenta, although if the egg splits after the first week they probably do.
• The majority of twins are born through Cesarean birth.
• Some twins are referred to as "mirror image twins". These twins may have mirror image characteristics, such as opposite fingerprints, opposite dominant hands, and even opposite hair parts. This phenomenon is usually attributed to the timing of when the fertilized egg was split and may be identified in nearly 25 percent of identical twins.

Identical twins certainly are fascinating. It is important to remember, however, that while identical twins do share the same DNA makeup, they are separate individuals with separate emotions and personalities. In some cases, much like any other siblings, they may be very alike, while in other cases, they may be extremely different.

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