Didi twins, also known as identical twins, are twins that develop from a single fertilized egg that splits and forms two embryos. This results in twins with the same genetic makeup and the same sex. Didi is a colloquial term used predominantly in China to refer to identical twins of the same sex. The term highlights the similarities between identical twins. Let’s explore more about didi twins and what makes them unique.
What causes didi twins?
In typical conception, a sperm fertilizes an egg and forms a single zygote which then divides and develops into a fetus. With identical twins, the fertilized egg splits into two embryos very early in development, usually within the first 12 days after conception. The two embryos have the same genetic makeup and go on to develop into two separate but genetically identical babies. This early splitting of the fertilized egg is why identical twins share nearly 100% of their DNA.
What triggers the fertilized egg to split is not fully understood, but it is believed to be influenced by both genetic and environmental factors. Having a family history of identical twins increases the chances of having identical twins. The age of the mother also matters – older women are more likely to have identical twins than younger women. Assisted reproductive techniques like in vitro fertilization (IVF) further increase the chances of conceiving identical twins.
How common are didi twins?
Identical twins are less common than fraternal (non-identical) twins. They account for about 1 in 250 natural pregnancies. This means that only about 0.4% of pregnancies worldwide result in identical twins. The incidence does vary by region – rates are higher in certain ethnic groups like people of African descent and lower in groups like Asians.
Today, the rates of twin births are increasing globally. A key reason is the rise in availability and use of fertility treatments like ovulation induction medications and IVF. Since such treatments increase the chance of multiple eggs being fertilized, they also increase the odds of having identical twins.
Identical twin rates by region
| Region | Rate of identical twins per 1,000 deliveries |
|---|---|
| United States | 7.4 |
| Europe | 6.9 |
| Africa | 17.6 |
| Asia | 4.7 |
Characteristics of didi twins
Let’s look at some of the key characteristics of identical or didi twins:
- Same sex – Identical twins are always the same sex since they come from the same fertilized egg.
- Physical similarity – Given their identical genetic makeup, didi twins look nearly alike. They have the same hair and eye color, blood type, height, etc. Minor differences can occur due to environmental factors during development.
- Shared placenta – Most identical twins share a placenta in the womb. A few may have separate placentas if the split occurs very early.
- Shared amniotic sac – Over 75% of identical twins share an amniotic sac. The rest have separate sacs.
- Natural conception – Majority of didi twins occur spontaneously via natural conception.
- Run in families – Having an identical twin sibling or parent increases your chances of having identical twins.
Differences between didi and fraternal twins
Fraternal or non-identical twins develop from two separate eggs fertilized by two different sperm. This key difference means fraternal twins share only 50% of their DNA, just like non-twin siblings. Here is a comparison between identical (didi) and fraternal twins:
Identical (Didi) Twins vs Fraternal Twins
| Identical Twins | Fraternal Twins | |
|---|---|---|
| Genetic makeup | 100% identical | 50% identical |
| Sex | Always same sex | Can be same or different sex |
| Physical similarity | Nearly identical | Resemble siblings |
| Placenta | Often shared | Separate |
| Amniotic sac | Often shared | Separate |
As seen from the table, didi twins share nearly 100% of their DNA and physical characteristics. Fraternal twins only share 50% of their genetic makeup and will have differences in appearance just like non-twin siblings.
Unique features of didi twins
Identical twins have fascinated mankind for centuries. Their similarities and bond often make them subjects of great interest. Here are some intriguing features seen in didi twins:
- Twin bond – Many identical twins share an exceptionally close emotional bond and can often sense each other’s feelings, thoughts, and pain.
- Secret language – Up to 50% of identical twins invent their own secret language only understood by each other.
- Mirror image twins – Some didi twins may have asymmetric features like opposite hair whorls or birthmarks. This happens when the split egg divides in a mirror image pattern.
- Mixed handedness – Identical twins may sometimes have opposite dominant hands, with one being right-handed and the other left-handed.
- Twin telepathy – There are many anecdotal accounts of didi twins sharing a type of mental connection or ‘sixth sense’. More research is needed to prove if such telepathy truly exists.
Documented cases of extraordinary didi twins
There are several remarkable real-life cases of identical twins demonstrating their inexplicable bond and similarities:
- Twins Jim Lewis and Jim Springer were separated at birth and reunited at age 39. They had married women with the same name, divorced, and remarried women with the same name again, unbeknownst to each other!
- Bahadoran twins Ibrahim and Abbas were separated at birth but when reunited showed astounding similarities like same career choice, same smoking habits, same favorite vacation spot, etc.
- Twins Barry and Brent Bottoms both built circular white windmills at the back of their adjoining properties with no knowledge of the other’s!
Such stories continue to reveal the mystifying connection and coincidences between genetic identicals.
Interesting facts about didi twins
Here are some fascinating facts about identical or didi twins that highlight their special bond:
- Mothers of twins tend to live longer than average.
- Identical twins have nearly the same fingerprints – even forensic experts may struggle to tell them apart!
- Twins are more likely to unlock each other’s phones using facial recognition compared to regular siblings.
- Didi twins may end up having a similar career choice as their co-twin.
- Studies show identical twins are likely to die within hours or days of each other, even when separated.
- Elvis Presley had an identical twin named Jesse Garon who died during childbirth.
Potential health concerns
While identical twins allow for fascinating research on the balance between genes and environment, they also carry some unique health risks:
- Preterm birth – Over 60% of identical twins are born prematurely before 37 weeks.
- Low birth weight – Sharing a placenta often restricts growth, causing didi twins to have lower birth weights.
- Twin-to-twin transfusion syndrome – This condition causes uneven blood flow between shared placenta twins.
- Congenital heart defects – Identical twins have a higher rate of heart issues like ventricular septal defects.
- Cerebral palsy – Prematurity and low birth weights make cerebral palsy more likely in didi twins.
However, most identical twins go on to develop normally like single babies. Close medical monitoring during pregnancy and childbirth can help prevent complications.
Conclusion
Identical or didi twins are a source of great wonder and insight. Their shared genes and environment provide a perfect real-world experiment to analyze how biology and environment shape human development. While didi twins enjoy an incredibly special bond, they also face higher risks during pregnancy and birth.
Advances in prenatal testing like ultrasound scans and DNA tests can accurately identify identical twins during pregnancy itself. This allows parents and doctors to provide extra monitoring and care when needed. As fertility treatments continue rising worldwide, we are likely to see more intriguing cases of didi twins in the future.