The Complete Guide to IVF Twins: Odds,Risks and Signs

Last Updated on July 23, 2019

When you choose a type of fertility treatment, there is the likelihood of multiple conceptions. You might wonder whether IVF maximizes the odds of having twins or not. And the truth is that this form of treatment does play a part in this respect. Research points out that the growing popularity of fertility treatments has contributed to the increase in multifetal pregnancies as well.

With that in mind, if you’re thinking about choosing in vitro fertilization to conceive, you should discuss the possibility of IVF twins with your doctor. Depending on the type of treatment you’re going for, the chances of conceiving twins vary.


The Likelihood of IVF Twins

Since the 1980s, the rate of twin births has increased by up to 80 percent. More specifically, women between the ages of 35 and 39 gave birth to twins; the official rate has actually doubled. The record for twin births was achieved in 2014 when, out of 1,000 births, 33.9 were twins. In the US alone, since the 1980s, one million twins were born.

Even if these statistics don’t refer exclusively to IVF twins, 40 percent out of the total of pregnancies relied on in vitro fertilization treatment for conception. That being said, if we were to compare the rates of multiple births in the case of natural conception, the odds are significantly lower than in the case of in vitro fertilization.

In spite of this, it appears that many state-of-the-art fertility clinics are turning to technology in order to diminish the odds of getting twins through IVF. This is in order to diminish the risks associated with multiple babies in one pregnancy. This has to do with the fact that the risks that come with multiple births are much higher when compared to single births.

Multiple births are, typically, linked with babies with lower birth weight, pre-term delivery and disability, and perinatal and infant mortality. Regardless of the fact that the idea of IVF twins may seem appealing to some parents, the risks shouldn’t be overlooked.

Why Are the Odds of Conceiving Twins so High with In Vitro Fertilization?

In order to understand the reason why IVF twins are widely common, you have to understand the way in which in vitro fertilization functions – namely what techniques are used in order to maximize the odds of a successful pregnancy. During the in vitro fertilization process, a specialist prepares several embryos before they are to be implanted in the uterus.

For years now, fertility doctors have transferred several embryos during the implantation process. This is done in order to ensure that at least one of the embryos will stick, resulting in a successful pregnancy. However, depending on the case, the transfer of the embryos might either fail or succeed. In case multiple embryos are successfully implanted, this will lead to a birth of multiples.

But is this approach really necessary? Is the transfer of multiple embryos mandatory to secure a safe, successful pregnancy? In the past, due to limited screening technology, it was very challenging for doctors to assess the quality of the embryos prior to the transfer. This is why transferring multiple embryos made more sense, in order to increase the odds of pregnancy.

On a different note, considering the high costs associated with in vitro fertilization, it is easy to understand why many couples prefer the transfer of multiple embryos. This practice comes with a higher chance of success.

The good news is that, thanks to the state-of-the-art technology, fertility specialists can now analyze in more detail the genetic material and quality of the embryo prior to the transfer. Aside from this, a technique that is quite popular is that of leaving the embryos to mature for a bit before the implantation. This has been linked with a higher incidence of success. On this ground, some clinics might not transfer multiple embryos.

As a matter of fact, recent research by the American Society of Reproductive Medicine (ASRM) points out that, in some in vitro fertilization cases, implanting several embryos at the same time is not the best course of action. In other words, women that have a reasonable likelihood of conceiving and are under the age of 35 should be transferred a single embryo. Ideally, they should not be transferred more than two embryos at a given time. As for women aged between 35 and 40, the maximum number of embryos that should be transferred is three.

Do You Want to Conceive Twins with IVF?

The topic of IVF twins is a complex one, and each couple should carefully assess their own situation before making a decision in this respect. There are several reasons why conceiving twins may seem like an appealing option for some couples.

For one thing, the aspect of limited funds is to be taken into account. If a couple struggles with fertility problems and the high costs of in vitro fertilization may be an impediment, having twins might seem like an appealing option. Some also consider this due to older maternal age.

On that note, if you want to conceive twins using IVF, you should discuss this in detail with your fertility doctor. This way, you will know all the pros and cons that come with the decision, as well as the potential risks that could apply in your case. Aside from this, your individual background details will also matter in weighing the balance into having twins or not.

However, the following factors will play a part in determining the possibility to conceive twins:

  • Body type – Your body type may also influence this, as research points out that taller and overweight women are more likely to conceive IVF twins.
  • Family history – If you have twins in your family, the likelihood of being pregnant with twins is higher.
  • Age – According to research, age is another important element, as women over the age of 30 are more likely to conceive twins.
  • Past pregnancies – women who have been pregnant before have a higher chance of conceiving twins or multiples.

What Are the Risks Associated with IVF Twins?

We’ve briefly mentioned that there are some risks that shouldn’t be overlooked when it comes to IVF twins. Now, we’ll look at these risks in more detail so that you know what to expect before going down this path.

Nowadays, pregnancy is the safest as it can be for the mother and the baby alike. In spite of this, when there is more than one baby, the risks are still higher. Research points out that in the case of multiple births, the possibility of complications is increased.

  • Pre-Eclampsia

For one thing, twin pregnancies might grow the risk of pre-eclampsia. This refers to a mix of symptoms – general swelling in the body, high blood pressure and increased levels of protein in the urine. These can ultimately affect both the mother and the baby throughout the duration of the pregnancy.

  • Premature Birth

This is another risk that comes with IVF twins. When a mother carries multiple babies, this applies more pressure and strain on her body. This may also increase the risk of premature birth.

As a matter of fact, statistically speaking, approximately 60 percent of twins are born prior to the due date. This is also applicable to twins, as 37 percent out of the twin babies conceived with in vitro fertilization are born prematurely. The risk is three times higher than in the case of normal twin pregnancies.

  • Twin-Twin Transfusion Syndrome (TTTS)

Another thing you should bear in mind when it comes to twins with IVF is the risk of TTTS. The good thing is that this syndrome occurs only in 5 to 10 percent of pregnancies, but the risk increases in the case of twin pregnancies. This syndrome happens when two identical twins share the placenta.

This means that one of the babies gets more blood than the other, which could cause life-threatening conditions.

  • Intrauterine Growth Restriction (IUGR)

This is another condition that may occur in the case of multiple pregnancies. It means that one of the babies isn’t developing at the pace at which he/she should. Due to this delayed growth, several health implications are imminent for either one or both of the babies.

  • Cesarean Section

Moving on, carrying twins might also mean that you will have to opt for a cesarean section to deliver your baby. Although having a single baby doesn’t exclude this scenario altogether, the likelihood is still higher in the case of twins.

In comparison with vaginal birth, recovering from a cesarean section requires more time, not to mention that looking after two babies as you recover from surgery can be very difficult.

  • Low Birth Weight

Since most twins are at risk of premature birth, this also means that their birth weight is lower than it should be. Depending on the time of the birth, heart problems, problems with breathing, hearing, vision, cerebral palsy are all issues that may occur.

Is It Possible to Avoid Twins with IVF?

Considering that you don’t want to have IVF twins, due to all the risks outlined above, you should openly discuss this with your healthcare provider at your chosen fertility clinic. That is to say, you should talk about the possibility of transferring a single embryo into the uterus as opposed to transferring multiple embryos.

This procedure implies choosing the healthiest embryo with the highest rate of success for implantation. The bottom line is that, whether you want to avoid twins or you’re thinking that this is the right thing for you, this is a topic you should talk about with a specialist at your fertility clinic.

Twins Signs During IVF

As a rule of thumb, women that are pregnant with twins are prone to experience a range of symptoms earlier than most women. Some of these symptoms are:

  • High HCG Levels

Essentially, an increase in HCG levels is the first indicator of a twin pregnancy. HCG – Human Chorionic Gonadotropin is the hormone whose presence points whether you are pregnant or not. In comparison to a single pregnancy, the HCG levels for a twin pregnancy are up to 50 percent higher – they can reach up to 200 to 1750 mlU/ml.

Bear in mind that the body cannot produce HCG. It is actually the developing baby that secretes a given amount of HCG. In the case of twin pregnancy, the amount secreted is obviously double, which explains the high levels of HCG. These hormones aim at thickening the uterus during the pregnancy, whose purpose is to support the baby throughout the entire time.

As for high HCG levels, this may lead to more severe nausea and vomiting, as vomiting and nausea are connected with high HCG levels.

  • Weight Gain

Moving on, if you have gained a lot of weight right from the start of the pregnancy, this might mean that you’ve conceived twins. This is true especially if you’ve gained more weight than compared to singular pregnancies.

  • Early Positive Result

If your pregnancy test indicates a positive result even before you’ve missed a period, then this may also be a sign that you’re having twins. A pregnancy test essentially measures the levels of HCG. In the case of twin pregnancies, the HCG levels are higher, which is why the pregnancy might be detected earlier.

The Bottom Line

On a final note, transferring more than one embryo for conception is a pretty outdated practice. It was widely used in the past when access to accurate technology was limited. This approach ensured that the success rate of the treatment is maximized. However, things are different nowadays, due to all the technological advancements in the field of medicine.

Thanks to state-of-the-art technology, you can have a say and decide whether you want to have IVF twins or not. Make sure you make a decision after factoring in all the health issues, as well as your health condition. And most importantly, as outlined above, you should discuss all the aspects beforehand with a specialist.