A 40-year-old member asked:
Heterochromia in one identical twin, not the other. are they fraternal?
1 doctor answer • 2 doctors weighed in
Dr. Nikolaos Zachariasanswered
Maternal-Fetal Medicine 28 years experience
Not necessarily.: Identical vs. Fraternal twins are archaic terms that no longer apply to the modern perinatal terminology., however are still generally true and understandable to lay people. The color of eyes is not the determining factor in zygocity or chorionicity of twins - check prenatal records and placental pathology!
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
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A 45-year-old member asked:
How do I know if I am having identical or fraternal twins?
2 doctor answers • 9 doctors weighed in
A Verified Doctoranswered
32 years experience
Depends: You can determine it based on ultrasound if there is only one placenta. However, often times you need to have babies tested after they are born. Even twins that "look" identical may not actually be identical.
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
Dr. Michael P Vaughn commented
Allergy and Immunology 36 years experience
Some times blood typing is done for twins in the hospital, if the twins have different blood types then they would not be identical, conversely, the same blood type would not prove identity.
Oct 31, 2011
Dr. Patrick Weix commented
Specializes in Obstetrics and Gynecology
If the twins share a sac inside the uterus, such as monochorionic /diamniotic or monochorionic/monoamniotic, then they are identical.
Oct 31, 2011
A 35-year-old member asked:
Are fraternal or identical twins more common?
2 doctor answers • 2 doctors weighed in
Dr. Sheila Goodmananswered
Specializes in Obstetrics and Gynecology
Yes: Fraternal twins are 3 times as frequent as identical. Fraternal twins happen when there is double ovulation and 2 eggs get fertilized. They are the type of twins that run in families. Identical twins come from 1 fertilized egg which separate in early gestation. Depending on when they separate, the babies can be in 2 distinct sac (di/di), 2 sacs within a shared sac (mono/di) or 1 sac (mono/mono).
Created for people with ongoing healthcare needs but benefits everyone.
6.6k viewsAnswered >2 years ago
Last updated Sep 15, 2017
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