Twins in IVF: Understanding Multiple Pregnancies in IVF

A multiple pregnancy occurs when more than one embryo implants in the uterus lining and develops (dizygotic or fraternal twins), or when an embryo splits and two fetuses grow from the one embryo (monozygotic or identical twins). This can happen naturally or by an Assisted Reproductive Technology procedures such as IVF. 

Today, we will help you learn more about multiple pregnancies in IVF. Can’t wait to begin? Let’s get started.

How does a multiple pregnancy occur in IVF?

In IVF, a multiple pregnancy can occur when multiple embryos are selected and transferred back into a woman’s uterus. The multiple (instead of single) embryo transfer can lead to the implantation of more than one embryo in the woman’s uterus and cause a twin or multiple pregnancy. 

How likely is for one to have a multiple pregnancy in IVF? 

The chances for each woman to have a multiple pregnancy in IVF can vary depending on a variety of factors including a number of embryos she agrees to be transferred, her age, and her underlying cause(s) of infertility. The higher number of embryos transferred the more likely a multiple pregnancy, and the chance is increased the younger the woman is. One study shows that multiple-birth rates can be as high as 45.7% for women aged 20 to 29 years, while among women aged 40 to 44 years, the multiple-birth rate was less than 25% even with 5 embryos transferred. Direct consultation with your IVF doctor will help you more precisely and accurately know and understand your chances of a multiple pregnancy from IVF.

What should I do if I want to have a multiple pregnancy in IVF?

Having a multiple pregnancy in IVF is possible but is not without a string of major concerns. For couples who are considering having twins or multiple babies via IVF, we recommend you learn about the possible issues/complications of having a multiple pregnancy in IVF and directly consult with your IVF doctor. Some of the most common major issues from having a multiple pregnancy in IVF include:

• The natural medical risks of a multiple pregnancy: There are many major complications including premature birth, low-birth weight, and in the worst case, fetal/infant death. The premature birth and low-birth weight can cause severe health issues in both long and short term to your babies and often require your babies to be cared in a neonatal intensive care unit (NICU) for a long time before being able to be taken home, which can be exhausting to you and your partner both emotionally and financially. Almost everything that can go wrong in a pregnancy, for both mother and foetus, is increased by a multiple pregnancy. 

• The high cost of IVF and its emotional and physical turmoil: IVF is a special medical treatment, meaning it is costly and is emotionally and physically dedication, especially for a female partner who will have to go through every step of IVF starting from an ovarian stimulation to an embryo transfer. In addition, it is always important to note that one IVF cycle does not guarantee success and may require you to try again and again to finally achieve a pregnancy. So, if your only requirement for IVF is to try and get a multiple pregnancy then perhaps you should re-consider.

What should I do if I want to avoid having a multiple pregnancy in IVF?

To reduce your chances of having a twin or multiple pregnancy, you can opt for transferring only a single embryo at a time.

In the past, many IVF doctors would try to transfer as many embryos back into a woman’s uterus as possible to maximize the chance of pregnancy. But today, with advanced embryo culture techniques and other technologies available, such as Blastocyst Culture, Mini-Incubators, etc., a single embryo transfer has an impressively good success rate and less risk of all complications. To find out more about our blastocyst culture technology here. 

In addition, if you choose to transfer only one embryo, you still have the option to freeze and preserve those remaining embryos for later use. In the embryo freezing process, using Vitrification technique, your embryos will be frozen ultra-rapidly, so that the water molecules don’t have time to form ice crystals, and then the embryos are held in deep frozen storage. This storage, if in a high-quality, well-maintained laboratory with consistent, regular quality control and monitoring of the liquid nitrogen and the equipment, results in long-lasting, high-quality preservation of your embryos indefinitely. When you would like to get pregnant you don’t have to start your IVF cycle all over again, you can proceed by using a frozen embryo in a process commonly known as a Frozen Thaw Embryo Transfer (FET). 

At Superior A.R.T. we have a “single blastocyst transfer” policy. That is, we recommend transferring a single blastocyst embryo, and will only transfer a maximum of two embryos where the doctor has assessed the patients’ medical condition and found them suitable.

One final question, can a single embryo transfer results in a multiple pregnancy? 

Though occurring rarely, such an incident is possible and is not a complication from IVF but rather another form of twin/multiple conception. In this conception form, instead of coming from two separate fertilized eggs, your twins were born from only one fertilized egg (a single embryo transfer). It was somehow divided or split into two embryos during its cell division process and proceeded to develop into two fetuses, commonly known as identical twins. Because coming from one fertilized egg, identical twins, therefore, share all of their genes, are the same sex, and often look exactly alike. 

About Superior A.R.T.

Superior A.R.T offers comprehensive fertility and genetic services in state-of-the-art Assisted Reproduction Technology (A.R.T.) Laboratories in Bangkok Thailand. Superior A.R.T. was founded in 2007 by a group of leading Thai Infertility specialists in collaboration with Australian world-leading fertility and A.R.T. treatment providers, Superior A.R.T is a renowned fertility clinic offering comprehensive fertility and genetic services by a team of experienced treatment providers and researchers specifically specializing in Assisted Reproduction Technology – A.R.T. Superior A.R.T. is committed to making your dream of having a healthy baby come true.

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