IVF Twins & Multiple Pregnancies: Causes & Risks

In vitro fertilisation, or IVF as it is commonly called, is the procedure that has been instrumental in bringing the joy of pregnancy to millions of couples when pregnancy naturally seemed impossible. However, IVF treatment also brings up some questions, and one of the common questions is about twins. Many people wonder if IVF automatically means twins, if it is possible to plan twins, and how safe a twin pregnancy is.

 

This blog explains the chances of twins with IVF in a clear, factual, and balanced way. The aim is to help you understand probabilities, benefits, risks, and medical decisions without creating unrealistic expectations or fear.

How Twin Pregnancy Happens in IVF?

Twin pregnancy with IVF can happen in two main ways.

 

Dizygotic or Fraternal Twins	Monozygotic or Identical Twins
In this case, two separate embryos implant and grow together. This is more likely when two or more embryos are transferred during the same IVF cycle.	In this case, a single embryo splits into two after transfer. Even if only one embryo is transferred, there is still a small chance of identical twins.

 

Although twin pregnancy is possible even in case of single embryo transfer, the chances remain low. IVF has a higher twin rate than natural conception, largely because more than one embryo may be transferred during treatment.

What Are the Chances of Twins in IVF?

The chances of twins with IVF are higher than with natural conception, but they are not guaranteed. In natural pregnancies, the chance of twins is about 1 to 2 %. With IVF, the overall twin rate ranges between 10 and 30%, depending on several factors.

 

The main reason IVF twins are more common is embryo transfer. When more than one embryo is transferred into the uterus, the chance of twins increases. Even with a single embryo transfer, twins are still possible due to embryo splitting.

 

So if you are asking, can you have twins with IVF, the answer is yes. But modern fertility practice focuses more on healthy singleton pregnancies than multiple pregnancies.

Early Symptoms of Twin Pregnancy After IVF

Some women may experience stronger symptoms in case of a twin pregnancy than in a single pregnancy, but they are not always reliable indicators. They may include intense nausea, vomiting, fatigue, breast tenderness, or early abdominal bloating. Higher hormone levels can also sometimes cause stronger pregnancy symptoms.

 

However, symptoms alone cannot confirm twins. Ultrasound remains the most reliable way to detect a twin pregnancy, usually around six to seven weeks after embryo transfer.

How Many Embryos Are Required for a Twin Pregnancy?

The number of embryos transferred plays a major role in the IVF twins rate. Doctors decide this carefully based on age, embryo quality, and previous IVF outcomes.

 

Chances of Twins With 1 Embryo

The chances of a twin pregnancy with single embryo transfer are very low, around 1 to 3%. The cases of identical twins are high in this case due to a single embryo being split. Single embryo transfer offers the safest outcome and is now considered best practice in many fertility clinics.

 

Chance of Twins With 2 Embryos

The chance of twins with the transfer of 2 embryos increases significantly, often ranging from 15 to 30%. Though the risk of triplets is low, it is not completely impossible. Due to these factors, two embryo transfers are usually reserved for selected cases only.

 

Chance of Twins With 3 Embryos

Transferring three embryos greatly increases the risk of twins and higher-order multiples. This practice is now uncommon due to safety concerns and strict guidelines. Most modern clinics avoid transferring three embryos unless there are exceptional medical reasons.

Understanding hCG Levels in IVF Twin Pregnancies

Human chorionic gonadotropin, commonly called hCG and pregnancy hormone, is measured in blood tests to confirm pregnancy after IVF. In twin pregnancies, hCG levels are often higher than in single pregnancies because more than one embryo is producing the hormone. However, hCG levels alone cannot confirm whether a pregnancy is a twin pregnancy. A pelvic ultrasound performed around six to seven weeks of pregnancy is the only reliable way to confirm twins after IVF.

 

Doctors use hCG trends mainly to check if a pregnancy is progressing normally, not to diagnose twins. There is a wide overlap between hCG levels seen in single and twin pregnancies.

Approximate hCG Levels Seen in Twin Pregnancies After IVF

 

Time After Embryo Transfer	Single Pregnancy Range (IU/L)	Twin Pregnancy Range (IU/L)
12 days post transfer	50 to 200	100 to 300
14 days post transfer	100 to 400	200 to 600
5 weeks of pregnancy	500 to 7,000	1,000 to 10,000
6 weeks of pregnancy	1,500 to 30,000	10,000 to 50,000

 

Key Note: The above values are only general observations. It is possible that some single pregnancies may show higher hCG levels, while some twin pregnancies may fall within normal single pregnancy ranges.

Pros and Cons of Multiple Pregnancies

Pros

• One pregnancy to complete family goals
• Emotional satisfaction after infertility
• Siblings grow together

Cons

• Higher medical risks for the mother and babies
• Increased chance of preterm delivery
• More frequent medical monitoring
• Longer hospital stays for newborns

 

Due to the risks involved, doctors focus on healthy outcomes rather than higher numbers.

Risks Associated With Twin Pregnancy in IVF

A twin pregnancy can bring joy to many couples; however, it is associated with more medical risks compared to a single pregnancy.

 

• Risks for mother: These include high blood pressure, gestational diabetes, anaemia, and a higher likelihood of caesarean delivery. Also, pregnancy discomforts are generally more intense with twins.
• Risks for babies: Twin pregnancies are more prone to preterm birth, low birth weight of babies, and admission to the neonatal intensive care unit.

 

These are the reasons why many fertility experts advise single embryo transfer in most cases, especially for younger patients with good quality embryos.

How to Minimise the Risk of Twin Pregnancy in IVF?

Preventing twins in IVF is often part of modern fertility planning. Below are some ways in which a twin pregnancy can be avoided during an IVF procedure:

 

• Single embryo transfer is the most effective method that many specialists prefer.
• Careful embryo selection using advanced lab techniques also helps maintain high success rates with one embryo.
• Frozen embryo transfer protocols further reduce risks without compromising pregnancy chances.
• Patients are encouraged to discuss their family goals openly with their fertility specialist before embryo transfer.

Factors Affecting the Chances of Twins in IVF

A number of factors can influence the chances of twins during IVF. These are:

 

• Age, as younger women have higher implantation rates.
• Embryo quality significantly affects success and twin chances.
• The number of embryos transferred directly increases the likelihood of twins.
• Assisted hatching and blastocyst transfer slightly increase the chance of identical twins.
• Previous IVF outcomes and uterine health also matter.

The Closing Note

Many couples wonder if IVF can cause twin pregnancy, but modern fertility care aims to prioritise health over numbers. While there is an increased chance of twins compared to natural conception, these are not guaranteed and significantly depend on the number of embryos transferred. Single embryo transfer has become the safest and most effective approach for many patients. A twin pregnancy can be beautiful, but it requires careful medical supervision. At Birla Fertility & IVF, our aim is to ensure the health of the mother as well as the baby.

FAQs

Q: Is it possible to have twins in IVF?

Yes, IVF has an increased chance of twins compared to natural conception, but this usually happens when more than one embryo is transferred.

 

Q: What are the symptoms of having twins after IVF?

Symptoms alone cannot confirm a twin pregnancy, but the woman can experience stronger nausea, fatigue, and early pregnancy discomfort

 

Q: Can one embryo result in twins?

Yes, one embryo can split and form identical twins, although this is rare.

 

Q: What is the survival rate of IVF Twins?

Most IVF twins survive and grow well with proper medical care, though they have a higher risk of preterm birth than single babies.