A multi-stage procedure, In Vitro Fertilisation (IVF), is one of the most comprehensive fertility treatments that increase your chances of conceiving on every level.
After you have given the fertility specialist permission to initiate the IVF treatment, they will prescribe hormonal injections and medicines to stimulate your ovaries. These medications will produce multiple mature follicles, which will improve your rate of conceiving. Once the ovary follicles have matured, the fertility doctor will receive your eggs and your partner’s sperm.
The patient’s egg and sperm will then be fertilised in a laboratory to produce an embryo. The embryo will be kept in an incubator for several days and will be keenly monitored by fertility doctors.
As soon as the embryo has reached a certain age of maturation, the fertility specialists will call you to the clinic to transfer the embryo directly to your uterus, where the implantation and the pregnancy will take place.
While many fertility specialists will advise you to get embryo transfer on a specific day based on your medical history, morphology, and morphokinetics, it will ultimately be your decision to choose between day 3 or day 5 embryo transfer.
In order to help you make the right decision and increase your chances of pregnancy, we will break down the pros and cons of day 3 or day 5 embryo transfer. So, without any further delay, let’s begin.
What Is the Best Day for Embryo Transfer?
The day of IVF transfer is decided by the fertility specialist after they have thoroughly examined the growing embryo in the laboratory. The embryologist will determine the quality and number of good-quality embryos to decide what’s best for you.
For example, if the number of good-quality embryos is less than three, the fertility doctor will ask you to get a day 3 transfer. While on the flip side, if the number of healthily growing embryos is five to six, the doctor will recommend a day 5 embryo transfer.
Key Takeaway: Whether you opt for day 3 or day 5 embryo transfer, both can lead to a successful pregnancy and live birth. Consult with our IVF fertility specialist to evaluate all the factors, including the quality of the embryo and the patient’s preference, in order to determine the best embryo transfer day for you.
Pros and Cons for Day 3 or Day 5
By the end of day 3, most of the embryos have undergone cellular development and growth, comprising six to ten cells each. Day-three embryos are also known as “Cleavage Stage Embryos” as they are dividing into sub-molecules but aren’t growing in size.
On the other hand, day 5 embryos are mature and better in quality. They are known as “Blastocysts” as they tend to divide and increase in size rapidly. The advantages and disadvantages of day 3 or day 5 embryo transfer are as follows:
Advantages of day 3 and day 5 transfers
Day 03 Embryo Transfer:
One of the most prominent benefits of day 03 IVF transfer is that more than one or two embryos are transferred. Another reason why day-three embryo transfer is preferred is that during the incubation time, the artificial environment can cease the development of some cells at an early stage, making them non-viable.
There’s also a low chance of cycle cancellation. Plus, in case you are planning to freeze embryos, day 3 is the perfect time to do so. There’s also no option for genetic testing after a three-day IVF transfer.
Day 05 Embryo Transfer:
Compared to a day 3 embryo transfer, during a day 5 embryo transfer, the fertility specialist will implant not the weak cells but the full-grown blastocyst in your uterus. Therefore, the biggest advantage of a day 5 IVF transfer is that the embryologist will conduct a single embryo transfer ensuring to implant of the highest quality embryo, increasing your chances of a successful pregnancy.
The fertility specialists can synchronise the blastocysts transfer with your endometrial lining, which guarantees higher implantation and live birth rates. There is no risk of multiple pregnancies and future complications. You also have the choice of preimplantation genetic testing.
Disadvantages of day 3 and day 5 transfers
Day 03 Embryo Transfer:
Despite technological advancements, no morphological scoring method can provide you with an accurate success rate of preimplantation embryos. Even if the embryo of the highest quality is transferred, there’s always a risk of cycle failure.
Because the cells are artificially created, placing them into a uterus in a volatile state can compromise their viability as they try to become blastocysts. It is a common practice to transfer three or more embryos during this stage which increases the risk of embryo implantation failure and multiple pregnancies, putting the life of the mother and child at risk.
Day 05 Embryo Transfer:
Despite the advantages, there’s always a possibility that the genetically normal embryo might fail to develop into a blastocyst in an artificial environment (incubator). Furthermore, if the number of egg retrieval is low, the chances of a successful IVF cycle are lesser.
Can All Day 3 Embryos Make it to Day 5?
On average, around 40 to 50% of embryos that are of good quality on day 3 will safely progress to the blastocyst stage on day 5. However, it ultimately depends on the medical condition of you and your partner and the quality of the sperm and egg.
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Day 3 Embryo Transfer Success Rates
Human Preproduction published a study in 2001, according to which 201 women were randomly treated with day 3 and day 5 embryo transfer. Two and three of the highest-quality embryos were transferred into the mother’s uterus in both groups.
Although the implantation rate of day 5 (24%) was slightly better than day 3, which was 21% because the fertility specialists transferred more embryos for the day 3 IVF transfer, the pregnancy result was the same for both groups (39%).
Another group of medical professionals conducted an experiment in Denmark in 2003. The final outcome of day 3 and day 5 embryo transfer proved that the success rate of day 3 was better compared to day 5. The results are given below:
| Day 03 | Day 05 | |
| Implantation Rate | 44% | 37% |
| Clinical Pregnancy Rate | 61% | 51% |
What Happens After Day 3 Embryo Transfer
During the 1990s and 2000s, medical professionals recommended a day 3 embryo transfer as they believed that the greater the number of embryos, the higher your chances of getting pregnant.
| Days Past Transfer | Embryo Development |
| Day 01 | Once implanted, the embryo will continue to develop and grow. It will turn from a six to eight-cell embryo into a morula. |
| Day 02 | Morula’s cells will continue to divide and will start taking the form of a blastocyst. |
| Day 03 | The blastocyst will start hatching out of its shell. |
| Day 04 | The blastocyst will continue hatching. Once it has wholly hatched, the blastocyst will start attaching itself to the uterus. |
| Day 05 | The blastocyst will continue to attach itself deeper into the uterus lining. This will begin the process of implantation. |
| Day 06 | Implantation continues. |
| Day 07 | Now that implantation is complete, the cells will eventually form a placenta, and the development of the fetus will initiate. |
| Day 08 | hCG (Human chorionic gonadotropin) will enter the bloodstream. |
| Day 09 | hCG secretion and fetal development continue. |
| Day 10 | hCG secretion and fetal development continue. |
| Day 11 | hCG levels are high enough to be detected by a pregnancy test. |
Day 3 Transfer Success Over 40
According to this report, day 3 embryos resulted in successful pregnancies for 2,705 women over the age of 40. The study said, “The live birth rate per cycle start was 14% at the age of 40, declining to 1%-2% at the age of 44-45, and 0% over the age of 45.”
Furthermore, after multiple IVF cycles, the same group of women had a cumulative IVF success rate of 28% at the age of 40 years and 0% over the age of 45 years.
Therefore, while medical professionals might recommend a day 5 embryo transfer for young women, a day 3 transfer is advised for women over 40. Note that the more the number of embryo transfers, the higher the chances of conceiving.
MD and professor of obstetrics and gynaecology at the Stanford Medical School, Dr. Ruben Alvero, said, “This patient may be older, let’s say over the age of 40, or they may have a history of having poor outcomes with previous IVF cycles,” Maybe we know that their sperm quality or egg quality is not very good. Or their pre-stimulation testing tells us that they’re not going to be good responders.”
Therefore, in such a case, we will recommend a three-day embryo transfer to improve the chances of pregnancy.
Do you want to increase your chances of getting pregnant? Here are some lifestyle changes that will do wonders:
- Don’t lift anything heavy.
- Avoid vigorous exercise.
- Eat healthily.
- Restrain from smoking or drinking and limit your caffeine intake.
- Try to stay calm.
- Spend as much time with your loved ones as possible.
Day 5 Embryo Transfer Timeline
Once your fertility doctor has successfully transferred the embryo on day 5, you will now be waiting for them to implant naturally. In order to ensure successful implantation and sustain the pregnancy, you will need to elevate the level of some hormones in your body. The chart below shows a day-by-day breakdown of what you should expect after a day 5 embryo transfer.
| Days Past Transfer | Embryo Development |
| Day 01 | The blastocyst will break out of its shell. This process is called hatching. These cells will then keep on dividing throughout the process. |
| Day 02 | As the blastocyst continues to hatch out of the shell, it will start attaching itself to your uterus lining. |
| Day 03 | The blastocyst will continue to attach itself deeper into your uterine lining. This will begin the process of implantation. During this stage, it is normal to experience some spotting or bleeding. |
| Day 04 | The embryo implantation continues as the blastocyst attaches itself to the endometrial blood supply. While some people experience high bleeding at this time, lack of bleeding shouldn’t be a concern. |
| Day 05 | The process of implantation is finally complete. The cells will become the placenta, and the fetus will start developing. |
| Day 06 | The placenta will secrete hCG (Human chorionic gonadotropin) and start entering your bloodstream. |
| Day 07 | Secretion of hCG and fetal development continues. |
| Day 08 | hCG secretion and fetal development continue. |
| Day 09 | The embryo is now a fetus, and the hCG levels are high enough to detect a pregnancy. |
Day 5 Blastocyst Transfer Success Rates
The success rate of day 5 or day 3 embryo transfer depends on the quality of the embryo and the sample size. For example, a fertility clinic in Chicago recorded its own data, according to which the success rate of the day 3 embryo transfer was 46.6%.
In contrast, the success rate for the day 5 embryo transfer was 68.5%. However, according to the report of a fertility clinic in Turkey, the success rate of day 5 of embryo transfer was statistically the same as day 3.
Furthermore, data from the Spanish Society of Fertility (SEF) proved that the success rate of day 5 blastocyst transfer was higher than on day 3. The results showed that out of 11.2% blastocyst transfers, 47.3% were positive pregnancies, and out of 51.2% cleavage stage (day 3) transfers, only 37.9% ended with a pregnancy.
Simply put, because the embryo has completely developed, the success rate of a day five blastocyst transfer is consistently higher compared to day three. Here are some tips to help you improve the success rate after an embryo transfer:
- Resting but not too much.
- Eating a healthy diet full of whole grains, antioxidant-rich whole foods, cruciferous vegetables, vitamins, minerals, zinc, and magnesium.
- Maintaining a healthy body weight.
- Meditation to reduce stress.
- Stay hydrated
Overall, leading a healthy lifestyle can increase your chances of pregnancy. So, prioritise your mental health, exercise regularly, limit the intake of caffeine, and stay as happy as possible. Because the stronger the connection between your mind and body, the higher will be chances of you having a baby.
Summary – Day 3 or Day 5 Embryo Transfer
As simple as it might sound, deciding between day 3 or day 5 embryo transfer can be a difficult process, especially because it directly affects the success rate of your pregnancy.
The catch here is that even after years of medical research, fertility specialists have not yet been able to determine the best day for embryo transfer, leaving the final decision up to you.
With that said, in this article, we have provided you with enough information to make a choice. For instance, if four or more embryos are thriving on day 3, you must opt for a blastocyst culture (day 5 embryo transfer).
However, if three or fewer embryos are available on day three, opt for an embryo free or transfer right away. In all cases, we recommend adhering to the advice of your fertility specialist, as they have the knowledge and experience to help you understand what’s best in your individual case.
If you still have additional questions, schedule a consultation with a reliable fertility doctor today!
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