Pregnant with twins even though there are no twins, what can you do?

Although the presence of twins in the family tree can increase your chances of having twins, heredity is not absolutely necessary for you to be able to get pregnant with identical twins.

Is genetic factor important for having twins?

Fraternal twins, which are often referred to as non-identical twins or different-egg twins, occur when the mother's uterus releases more than one different egg at a time (dizygotic). In other words, she ovulates more than once per menstrual cycle. About 12 pairs of fraternal twins are born in every 1000 birth rates.

Fraternal twins are the result of two eggs being fertilized simultaneously. Ovulation is a natural process that is controlled by the operation of many genes. Some women have a version (allele) of the gene that makes them more likely to hyperovulate. This means that there is a greater chance that two eggs can be fertilized at the same time.

Genes play a large role in the determination of fraternal twins, but the gene that causes a woman to conceive fraternal twins is unknown. One theory is that levels of the hormone FSH, aka follicle-stimulating hormone, may be higher in mothers with fraternal twins.

FSH is needed for egg growth and is commonly used as a fertility drug. Mothers of fraternal twins tend to be taller and have shorter menstrual cycles. This characteristic can also be caused by high hormone levels.

Ethnic background also matters

Apart from that, ethnic background - which is also genetics - also plays an important role in the chances of getting pregnant with twins. For example, a woman of African ethnicity is twice as likely as a white woman to conceive fraternal twins and four times more likely than an Asian woman.

Because they come from different sperm-egg pairs, the DNA of the two fraternal twins will be different. In fact, the DNA of fraternal twins is no more similar than the DNA of other siblings. This is also the reason why many of the fraternal twins are boys and girls.

Meanwhile, identical twins are the result of the division of one embryo - from a fertilized egg - which then divides into two during pregnancy. This means that these two embryos have the same genes and DNA. This is the reason why identical twins will be difficult to distinguish, even if their fingerprints are still different.

Almost all women have the same chance of getting pregnant with identical twins, because in the pregnancy of identical twins, no genes are involved. It also doesn't run in families. The occurrence of the embryo splitting is a random event, aka random that happened by chance and was rare.

How do I know if I am pregnant with identical twins?

You will probably want to know as early as possible in your pregnancy if the twins you are carrying are identical or not. Regardless of curiosity, knowing whether or not the two fetuses share a placenta (monochorionic twins) will help doctors and midwives adapt to their treatment to deal with potential complications.

Reporting from the Baby Center, your sonogram technician will scan your baby and their placenta during an ultrasound scan in your first trimester. This must be done before you reach the 14th week of your pregnancy.

Your identical twins might be categorized as:

Dichorionic diamniotic (DCDA): each baby has its own placenta and separate inner and outer membranes for each. DCDA is one-third of cases of identical twins and non-identical twins. So, DCDA twins may or may not be identical.
Monochorionic diamniotic (MCDA): both babies share a single placenta and a single outer membrane, but each has a separate inner membrane. MCDA twins are the case of two thirds of identical twins, so MCDA twins are the most common type of identical twins. MCDA twins are identical twins.
Monochorionic monoamniotic (MCMA): both babies share a placenta, inner membrane, and outer membrane. MCMA twins are very rare, only 1% of total births of identical twins. MCMA twins are identical twins.

If your sonographer is unsure whether your baby shares a placenta, he or she will do a second scan and may seek a second opinion.

An ultrasound scan is generally an accurate way of determining whether or not your two babies share a placenta. However, there is no guarantee that your sonogram technician will be able to tell if you are pregnant with identical or non-identical twins. Sharing placentas may be a sign of identical twins, but using the placenta alone is not a definite guideline, because placentas from non-identical twins can also fuse.