Complete Explanation and Characteristics of Monozygotic and Dizygotic Twins

It is common for couples to dream of having children soon after marriage, even more so longing for the birth of twins. There are two types of twins, monozygotic (identical) and dizygotic (fraternal) twins. The percentage of twin births between dizygotic and monozygotic twins is 80% vs 20%.

However, in Indonesia alone, there are many identical twins, and it is the dream of many couples to make the house more crowded so that the child has friends from birth. Therefore, it is likely that the children born are not identical. So, what and why can monozygotic and dizygotic twins occur? For more details, see the following review!

Description and Characteristics of Monozygotic and Dizygotic Twins

Generally, the difference between monozygotic and dizygotic twins is the origin of the fertilized egg. Some come from only one egg, and some from 2 different eggs. Let’s find out the explanation below.

What are Monozygotic and Dizygotic Twins?

Monozygotic (Identical) Twins Identical monozygotic twins are twins from the same egg fertilized by the same sperm and become 2 different embryos. Both embryos will develop into fetuses that share in the same womb. Identical twins may share the same amnion or fetal membranes (monoamniotic) or have different amnions.

These twins are more likely to be of the same sex unless the mutation is in the development of one fetus and corresponds to a tall face between babies.

What Are Conjoined Twins?

Conjoined twins are monozygotic twins with a disorder in which several parts of the twins’ bodies stick together or are connected. These twins belong to a rare condition in the world.

This condition occurs because the embryo is late, which should have divided at fewer than 2 weeks. However, these fetuses cleavage for over 2 weeks, so the division becomes incomplete. The partially splitting embryo will continue to develop into conjoined twins.

The body parts most often fused in conjoined twins are the head, chest, abdomen, back, and pelvis. These monozygotic twins have a greater potential to die while still in the womb or shortly after birth. However, many also survive to adulthood.

Furthermore, why can a woman give birth to twins? That’s because there are several influencing factors. What are these factors like? Let’s find out below.

1. Factors Supporting Twins

Indeed, not all women can give birth to twins. Only about 1 in 250 women have the opportunity to have twins. Maybe you have a chance to get pregnant with twins if you have some of the factors below.

2. Age

The factor that affects the pregnancy of the first twin is age. Pregnant women aged 35-40 years have higher hormone estrogen levels than younger women. It makes the ovaries of women between the age of 35-40 can produce more than one egg during ovulation. The chances of conceiving fraternal twins are even higher if there are two fertilized eggs,

3. Descendants

Pregnant women with dizygotic twins in the family may have non-identical twins. Meanwhile, unlike non-identical twins, identical twins are not passed down in the family.

4. Number of Previous Pregnancy

Several studies have shown that women who have been pregnant several times before are more likely to have twins. However, this still requires further research to confirm the truth.

5. Reproductive Technology Assistance

The next factor is the IVF program or in vitro fertilization (IVF) which is included in assisted reproductive technology (TRB). This process will inject one or more embryos into the uterus, thereby increasing the chances of conceiving twins. However, this program does not have a 100% success rate for producing twins.

6. Pregnant Mother Body Shape

Body shape is thought to affect the pregnancy of twins. Women whose twins are taller than those who are small have a greater chance of conceiving non-identical twins. Nutritional intake in pregnant women increases the chances of multiple pregnancies.

7. Drug Use

The last factor that affects the birth of twins is the use of drugs. Women who take drugs to increase fertility are thought to have a greater chance of conceiving twins.

The percentage increased by 20-40% of women who do not take the drug. Therefore, planning for pregnancy, whether twins or not, must be consulted with a trusted specialist so that unwanted things do not happen.

These are the explanations, characteristics, and factors that influence the pregnancy of Dizygotic (fraternal) and Monozygotic (identical) twins that we can learn. However, the percentage of monozygotic twins is 20% to 80%. Few identical twins are commonly found in society, especially in Indonesia.