Fraternal twins are like siblings who grew up together in their mother’s womb at the same time. But here’s a twist: Instead of one egg splitting into two, two separate eggs are fertilized by two different sperm. This means they are like two separate pregnancies happening at the same time!
Fraternal Twins: Breed, Genetics, and Parenting
Now, identical twins are like a copy-and-paste situation. One egg is fertilized and then splits into two, creating two babies with identical DNA. That’s why they often look very similar.
But fraternal twins are more like regular siblings who happened to be born at the same time. They may or may not look alike, like other siblings. Their personalities and health may also be similar or different, depending on their genes and the world around them.
So, in this article, we’ll discuss how fraternal twins happen, how they differ from identical twins, what happens to them as they grow in the belly, and if there are any health considerations to be aware of.
Facts about fraternal twins
When it comes to creating fraternal twins, it’s like a special event in the body called hyperovulation. Normally, a woman’s ovaries release only one egg during each menstrual cycle. But sometimes, they release two or even more eggs, which increases the chance of twins.
Scientists have found that women who naturally conceive fraternal twins tend to have higher levels of follicle-stimulating hormone (FSH) in their blood. This hormone helps the egg grow before being released. Therefore, when there is more FSH around, there is a greater chance of multiple eggs being released during ovulation. If one or more eggs meet a sperm at the right time, success occurs—twin pregnancy!
Sometimes twin pregnancies occur due to fertility treatments such as in vitro fertilization, where eggs are fertilized outside the body and then placed back into the uterus. These treatments have become more common over the years, so we’re seeing more and more twins born this way.
Now, let’s talk about genes. Fraternal twins come from different eggs, so they are just like regular siblings who happened to be born together. They share only half their genetic material, like other siblings born at different times.
Read more: Fraternal and Identical Twins
Are twins hereditary?
Oh, got it! Imagine that your body has a special way of deciding whether you want twins. Sometimes, it’s like a family secret – it runs in the family. So, if your mom or sister has twins, this is like a little hint that maybe you can have twins too!
Now, scientists have been peering into our genes to see if they can find out more. They found two genes called FSHB and SMAD3 that appeared to be important. There are different versions of these genes, like different flavors of ice cream. Some versions make it more likely that a person will have twins. These genes control the levels of FSH hormone in the body. FSH is like a superhero hormone that helps eggs grow in the ovaries. So if your genes produce a lot of FSH, it could mean more eggs are released during ovulation, increasing your chances of giving birth to twins. Guess what? These gene versions can run in families, so if your family has them, you probably have them too!
Factors that produce fraternal twins
- Fertility medications: Medications such as Clomid boost a hormone called FSH, which helps release eggs from the ovaries. This can increase the chance of giving birth to twins.
- Age: As women age, their bodies naturally produce more FSH. This hormone helps eggs to be released from the ovaries. If there are two good eggs and a lot of FSH, both eggs may come out, giving birth to twins.
- Family history: If twins run in your family, especially your mother’s side, your chances of having twins increase. This is because certain genes that release more eggs can be inherited.
- Height: Taller people tend to have more of a protein called IGF, which makes the ovaries more sensitive to FSH. This also increases the chances of releasing more eggs and giving birth to twins.
Identical twins and fraternal twins:
– Origin: Identical twins come from one egg and one sperm, while fraternal twins come from two eggs and two sperm.
– Genes: Identical twins have exactly the same genetic material, while fraternal twins are like regular siblings and share about half the genes.
– Appearance: Identical twins usually look very similar, but fraternal twins can look completely different, just like any other siblings.
– Gender: Identical twins always have the same gender, but fraternal twins can have the same or different genders.
– Genetic disorders: Fraternal twins may have different genetic disorders depending on the genes they inherit, whereas identical twins have the same genetic risk.
So, identical twins are like two peas in a pod, while fraternal twins are more like two different peas in the same pod!
Different ways fraternal twins occur:
- The conventional way: Typically, fraternal twins occur when two eggs are released from the ovaries and fertilized by sperm at around the same time. This is the most common way.
- Superfetation: This is very rare! This is when the second egg is fertilized and sticks to the uterus a few weeks after the first egg has grown into a baby. You might suspect this if your twins are different body types.
- Heteropteran superfertilization: another rare phenomenon! When a woman releases two eggs in one cycle, and they are fertilized by sperm from two different men during two different times of sex.
Test, growth and birth——Identifying fraternal twins:
ultrasound:
If the ultrasound shows that the placentas and sacs of the two babies are separate, it is likely that they are fraternal twins. Twins of different genders can also be fraternal, while twins of the same gender can be fraternal or identical.
DNA testing:
The most reliable way to tell is to test the baby’s DNA after birth. If they share half of their genes, they are brothers.
Growth issues:
– Intrauterine growth restriction (IUGR): Sometimes one or both twins don’t grow as fast as they should in the womb, which can cause health problems after they are born.
born:
– Preterm birth: Twins are often born earlier than expected, which can lead to health problems because their bodies are not quite ready. They are at higher risk of health problems and premature death.
– Mode of delivery: Many twins are born by C-section because it is safer for them or their mother, or because they are born prematurely or in a breech presentation.
So while having twins is exciting, it can also come with some challenges. It is important for doctors to pay close attention to the baby’s growth and for parents to prepare for the possibility of a C-section.
Raising fraternal twins
Treat them individually: Each twin is unique, so it’s important to recognize their differences in personality, talents, and emotions.
– Give Them Space: Allow each twin time to develop their relationship and skills separately. Spend one-on-one time with each person and encourage individual activities and lessons as they grow.
– Ask for support: When you feel overwhelmed, don’t hesitate to ask for help from your partner, family, friends, or your pediatrician.
Learn about twins through research:
Genetics and environment:
Twin studies help scientists understand how genes and growth influence traits and health.
For example: If one identical twin has schizophrenia, there is a high chance that the other twin also has schizophrenia, showing a strong genetic link. But if one fraternal twin has the disease, the other has a lower risk, suggesting less genetic influence.
Ongoing research: Researchers are studying twins with various conditions, including diabetes and arthritis, to learn more about their causes and treatments.
Summary:
– Fraternal twins are formed from two separate eggs fertilized by two separate sperm and have approximately 50% identical DNA.
– Factors such as fertility medications, genetics and the mother’s age can increase the chance of having fraternal twins.
– Twin pregnancy carries risks such as growth problems and premature birth, but with good prenatal care these risks can be minimized.
In short, while fraternal twins share a special bond, they are also unique individuals like any other siblings. Understanding their differences and finding support can make raising twins a rewarding journey.
FAQ
Question: Do fraternal twins have the same blood type?
Fraternal twins, also called fraternal twins, may have the same blood type or they may be different. Since they only share part of their DNA, their blood types may be the same or different. In contrast, identical or identical twins usually have the same blood type because they have the same genetic makeup.
Q: What causes the physical differences between fraternal twins?
The main factor is their genetic makeup. Fraternal twins share only about 50% of their DNA. For example, one twin may inherit blue eyes from one parent, while the other twin inherits brown eyes from the other parent.
Essentially, genetically speaking, fraternal twins are similar to siblings born at different times.
Q: How do doctors tell the difference between identical twins and fraternal twins in the womb?
Typically, fraternal twins develop with two different placentas, while identical twins share one placenta. This difference can be seen through ultrasound. Additionally, if twins are born with different sexes, they are most likely to be fraternal twins (although same-sex twins can still be fraternal or identical).
However, the most reliable way to determine whether twins are identical or fraternal is through postnatal DNA testing.
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