The arrival of twins is a unique and celebratory event, most often followed by a barrage of questions and inquiries. Perhaps the most common question is identical vs fraternal twins—what’s the difference?. Expectant mothers and fathers need to know this information so that they can predict trends of development, medical considerations, and the special connection that is present between twins. This article discusses the fundamental differences, informing readers as to what non-identical twins are known as, and how identical twins differ from fraternal twins.
Identical twins, also known as monozygotic twins, are caused by a single fertilised egg that splits to create two embryos at the earliest stages of development. Two such people develop through this split because they are formed from nearly identical genetic material. Therefore, identical twins will always be of the same gender and share similarities in physical features. Environmental factors and individual experience later lead to differences in appearance and temperament.
Non-identical twins are called fraternal twins, and they may be the same or opposite sex. Fraternal twins, or dizygotic twins, are formed from two separate eggs that are fertilised by two sperm. Unlike their identical counterparts, fraternal twins possess distinct characteristics, in which they share approximately 50% of their genes, just like regular siblings born apart. Their physical similarity varies, and they may look alike as much as any other siblings.
Knowing the difference between identical and fraternal twins involves considering some important points:
● Genetic Makeup: Identical twins share nearly 100% of identical genes, while fraternal twins share about 50%.
● Sex: Identical twins are always of the same sex; fraternal twins can be the same or opposite sex.
● Physical Features: Identical twins look similar to one another, while fraternal twins may be quite dissimilar.
● Placenta and Amniotic Sac: Identical twins may share the same placenta and amniotic sac, depending on when the splitting occurred. Fraternal twins have both their own placenta and amniotic sac.
● Prevalence: Fraternal twins occur more frequently than identical twins. Age of the mother, heredity and fertility medication can increase the likelihood of fraternal twins.
Identical or fraternal twin pregnancies require specialised medical attention. Identical twins who share a placenta may be at risk of developing conditions like Twin-to-Twin Transfusion Syndrome (TTTS), where the circulation of blood between twins is not equal. Fraternal twins, having their separate placentas, are likely to experience fewer complications common to them, but must also be watched carefully due to the added stress on the mother's body.
Regular prenatal visits, ultrasounds and obstetric care with experience in twin births are all significant. Dietary counselling and lifestyle modifications can also be recommended to enhance both the mother's and the baby twins' well-being.
It is possible to determine whether twins are identical or fraternal by using several methods:
● Ultrasound: Early ultrasounds may, at times, indicate twin type by the number of placentas and amniotic sacs.
● Genetic Testing: Postnatal DNA testing provides a conclusive response by analysing the genetic similarity of the twins.
● Physical Characteristics: Physical observation can give clues, but it is not a reliable method because fraternal twins may look alike, and identical twins may acquire differences over time.
Having twins means having special emotional and social dynamics. Identical twins will tend to have a deeper bond due to their genetic linkage, being very much synchronised in their likes and behaviour. Fraternal twins, though still very intimate, tend to be more independent in their natures.
Growing individuality is essential to twin development. Parents must take the effort to recognise and foster each child's unique interests and talents, encouraging them to find a sense of self alongside their twinhood.
At Cloudnine, we understand the complexity and joy of twin pregnancies. Our experienced obstetricians and medical staff provide customised care as per the requirements of twin mothers. From high-tech prenatal checkups to postpartum care, Cloudnine has a comprehensive approach to taking care of twin pregnancies with the health and well-being of the mother and babies in mind.
Navigating the journey of twin parenthood begins with understanding the concept of identical vs fraternal twins. Recognising what non-identical twins are called and the differences between identical and fraternal twins provides parents with the knowledge to make informed decisions and to embrace the one-of-a-kind experience of having twins.
Cloudnine believes in guiding families through each step of this incredible journey with the finest expert advice and care according to the details of twin pregnancies. If you're expecting twins or starting a family, book an appointment at Cloudnine to receive the specialised care you deserve.
