You know those twins who look exactly alike? Well, they might seem the same, but they’re really not! Identical twins, also called monozygotic twins, come from the same egg when they’re made. And they’re always both boys or both girls. Fraternal twins, also called dizygotic twins, come from two different eggs fertilized at the same time. They could be the same or different sexes.

Some things can make it more likely for someone to have twins. Like using special drugs or treatments to help have a baby, or if the mom is over 30. Also, if twins run in the family, that could increase the chances too. But having twins can also mean they might be born too early or be smaller than usual.

This article is going to talk about the things people get wrong about identical twins. It’ll also show how they’re similar and different, and give some tips for parents who have twins.

Types of Twins

Twins come in two main types: identical and fraternal. They’re different in how they’re made and what they inherit from their parents.

Fraternal vs. Identical twins

Identical twins are like genetic copies of each other. They share all their genes and are always the same sex. That means if one twin is a boy, the other will be too.

Fraternal twins, on the other hand, are more like regular siblings who happen to be born at the same time. They only share about half of their genes, just like any other siblings. Fraternal twins can be the same sex or different sexes.

Identical twins often look so much alike that it’s hard to tell them apart. Fraternal twins, though, might look more like regular brothers or sisters rather than twins.

Read More : Do You Know About Identical Twins And Fraternal Twins?

Conceived twins

The way twins are made, or conceived, determines whether they’re identical or fraternal.

For identical twins, it happens when a single fertilized egg splits into two, creating two separate embryos that grow into babies. But for fraternal twins, it’s a bit different. Two eggs are fertilized at the same time by two different sperm.

– Family history of twins increases the likelihood of having twins.

– Maternal age over 30 is associated with a higher chance of having twins.

– Previous pregnancies can also increase the chances of having twins.

– Using fertility treatments such as ovulation-stimulating drugs or in vitro fertilization (IVF) can raise the likelihood of having twins.

Third twin theory

The third twin theory suggests the presence of semi-identical twins, an unusual twin type that inherits all their genes from their mother but only a portion from their father.

– Two distinct sperm fertilize a single egg.

– The egg then splits into two embryos.

– As a result, the twins share all of their genetic material from their mother but only a portion from their father.

This unique combination results in semi-identical twins, challenging the traditional binary view of twin types.

Role of Twin Genes in Family History

You might’ve heard that twins tend to run in families, but experts think it’s a mix of genetics and the environment that influences having twins. Identical twins, making up about 3% to 4% of births in the US, usually happen without a known cause.

Fraternal twins, on the other hand, might have a family link. They make up about 6% to 8% of births in the US. If a woman’s mother or sister had fraternal twins, she’s twice as likely to have them too.

Fraternal twins occur when a woman releases more than one egg during her menstrual cycle, called hyperovulation. This tendency can also run in families and is influenced by factors like:

– Maternal age

– Race

– Ethnicity

– Body type

– Number of previous pregnancies

– Use of fertility treatments

Benefits of identical twins

Identical twins offer invaluable insights to researchers through twin studies. Here are the benefits:

1. Nature vs. Nurture:

  • By comparing identical twins who share all their genes but may have different environments, researchers can unravel the complex interplay between genetics and environmental factors in shaping health conditions and traits.

2. Genetic Influence:

  • Identical twins provide a natural experiment to assess the impact of genetic makeup on various traits. Since they share identical DNA, any differences observed between them can be attributed to environmental influences.

3. Comprehensive Analysis:

  • Twin studies have examined a vast array of human traits, ranging from physical attributes like height and weight to complex conditions such as chronic diseases. This comprehensive analysis helps researchers understand the relative contributions of genetics and environment to different aspects of human health and behavior.

Through these studies, researchers gain a deeper understanding of the origins of health conditions and traits, paving the way for advancements in prevention, diagnosis, and treatment strategies.

Testing, Growth, and Birth

 Twin pregnancies come with unique challenges compared to singleton pregnancies, requiring more prenatal care and often leading to more complex delivery scenarios:

1. Diagnosis: Identifying a twin pregnancy can sometimes be delayed, with up to 40% going undetected until the 13th week of pregnancy. Ultrasound is commonly used to confirm and determine whether the twins are identical or fraternal.

2. Preterm Delivery: Twin pregnancies have a higher likelihood of ending in preterm birth, before 37 weeks gestation, compared to singleton pregnancies. This is partly due to the ineffectiveness of typical interventions for preventing preterm labor in twin pregnancies. 

3. Low Birth Weight: Twins are more prone to being born with low birth weight due to their increased risk of preterm delivery.

4. Labor and Delivery: Twin pregnancies often require delivery in an operating room, as they are more likely to necessitate cesarean section (C-section) surgery. However, vaginal delivery is also possible for some twin pregnancies, but it’s essential to discuss delivery options with a healthcare provider to prepare accordingly.

Given these factors, twin pregnancies require close monitoring and specialized care to ensure the best possible outcomes for both the mother and the babies.

Challenges with twins 


1. Feeding: Twins might need extra care with feeding, especially if they’re born too early.

2. Money: It costs more to take care of twins, like buying double the diapers and clothes.

3. Being Different: Even though they look the same, twins are their own people with different likes and dislikes.

4. Sibling Feelings: Older brothers or sisters might feel a bit left out with new twins around.

How to Help Your Twins:

1. Special Time: Spend time alone with each twin to make them feel special.

2. Be Different: Let them do things they like on their own to discover who they are.

3. School Decisions: Decide with their teachers whether they should be in the same class or not.

Read More : Mind-Blowing 8 Secrets to Raising Twins: You Won’t Believe

Taking Care of Yourself:

1. Friends Time: It’s harder to see friends when you have twins, so find support from other parents.

2. Feeling Sad: Sometimes moms might feel very sad after having twins. It’s important to talk to a doctor if you feel this way.

3. Money Matters: Understand how much it costs to take care of twins and plan for it.

4. Rest: Taking care of twins is tiring, so make sure to rest when you can.

Telling Them Apart:

Use different colored clothes or bracelets when they’re babies. As they grow, you’ll see their personalities shine through, making it easier to tell them apart.

In short, even though twins are very close, it’s important to treat them as individuals and take care of yourself too. 

FAQ About Identical twins

Do identical twins read each other’s minds?

  • Identical twins have a special bond and can understand each other in unique ways. While they can’t read each other’s minds, they often pick up on each other’s facial expressions and gestures because they spend so much time together. This closeness gives them a deep understanding of each other.

Are identical twins rare?

  • Identical twins make up about 3% of all live births in the United States. While they’re not as common as fraternal twins, they’re still a significant part of the twin population.

Which parent passes on the twin genes (Identical twins)?

  • Fraternal twins are more likely to run in families, and this might be because of genetics. When a woman releases more than one egg during her menstrual cycle, it increases the chance of having twins. Since it’s the mother who ovulates, she’s the one responsible for the increased likelihood of twins.

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