Frozen embryo transfer day by day timeline

One of the crucial stages of the in-vitro fertilisation (IVF) process is embryo transfer. The process involves transferring a fertilised egg (an embryo) into a woman’s womb, hoping it will implant and lead to a successful pregnancy. 

As a soon-to-be parent, it's normal to experience excitement, anticipation, fear, or anxiety after an embryo transfer. It's also understandable to feel overwhelmed or confused about what's going on in your body in the two-week wait between the embryo transfer and taking a pregnancy test. 

Keep reading to find out what to expect and for a fresh or frozen embryo transfer timeline, day by day. 

Preparing for a frozen embryo transfer

Preparing for a frozen embryo transfer is slightly different to preparing for a fresh embryo transfer. In a fresh embryo transfer, the transfer occurs within the same cycle as the egg retrieval. However, in a frozen embryo transfer timeline, as the embryos have been previously frozen, there is more flexibility for which subsequent cycle you have the transfer in.

Usually, you’ll discuss which future cycle you wish to have a frozen egg transfer in with your clinic. Then, on day one of your period, you’ll contact your clinic to begin treatment.

For a frozen egg transfer, embryos can be transferred in a natural or hormone-regulated cycle There is no need for ovarian stimulation for either since the embryos are already available. In a natural cycle, no medication is used, and transfer is timed to your natural menstrual cycle.

In a hormone-regulated FET cycle, the hormonal medication focuses on ‘switching off’ the ovaries and preparing the endometrium for implantation. Oestrogen and progesterone are used to prepare the lining of your womb. If the transfer is successful and you become pregnant, you will continue to take the hormones until 12 weeks of pregnancy.

Day 1: Embryo transfer

A few days after the eggs are collected (known as Day 0) and fertilised, the embryo is transferred back into your womb — usually on day three or five. If you’re having a frozen embryo transfer (FET), the embryo will be thawed on the day of the procedure.

You’ll need a full bladder for your egg transfer as this allows your fertility doctor to see your womb more clearly when carrying out the ultrasound that helps with positioning the catheter used to deposit the embryo into the uterus.

When it's time to transfer embryos into the womb, the doctor uses a speculum to open the vagina enough to see the cervix. Then, they'll use a thin, long catheter to deliver the embryos into the uterus through the cervix. The process is relatively painless and usually takes about 15 minutes.

Before transferring embryos to the womb, fertility doctors look at two stages of their development: cleavage (on day two or three of development) and blastocyst stage (on day five or six of development).

The main difference is that blastocyst embryos have more time to develop in the lab, making it easier for the embryologist to select the best-quality embryos that are more likely to implant in the womb.

In the UK, about three-quarters of people have a blastocyst transfer, but it's important to know that not all embryos that reach the blastocyst stage will survive, and in some cases, there might not be any embryos left to transfer. It’s impossible to know if transferring the embryo at the earlier cleavage stage would have resulted in a successful pregnancy.

You may wonder what to do after embryo transfer to increase success. The best thing you can do is look after yourself: eat healthy, keep hydrated, ensure you get plenty of sleep, avoid strenuous activity and minimise stress.

You’ll be able to go home straight after transfer. You may have some mild pain or discomfort, but this is usually short-lived. Vaginal discharge and/or light bleeding is also not uncommon and does not indicate if your transfer has been successful.

Day 2: Preparing for implantation

As the blastocyst starts to break out of its shell (called the zona), it moves closer to the uterus, usually on the upper posterior wall, and makes contact with the uterine lining (the endometrium). This is the "apposition" stage of implantation.

Day 3-5: The implantation process 

The blastocyst starts to attach itself and move deeper into the uterine lining. This is the adhesion and invasion stage of implantation. By day five, the blastocyst has completely penetrated the endometrium, which means the implantation process is complete. You may experience implantation symptoms, such as cramping, bloating, sore breasts, and light spotting.

Day 6: Division and development

​​The cells that will form the foetus and placenta keep dividing and start secreting human chorionic gonadotropin (hCG) into your bloodstream. This hormone signals the development of pregnancy, which a pregnancy test detects in your blood and urine. 

Day 7-9: Nurturing the embryo

As the embryo develops, the cells in the placenta keep producing hCG to nourish the embryo attached to the uterus wall. At this stage, the levels of hCG may be high enough for a blood test to detect signs of pregnancy, but it's probably still too early to use an at-home pregnancy test.

Day 10-14: The two-week wait

The wait for the results of an IVF cycle can feel overwhelming, especially during the two weeks after the embryo transfer and before doing a pregnancy test. This period can be emotionally taxing, and feeling anxious, excited, and maybe worried is natural. 

You might be tempted to take a pregnancy test earlier than your doctor recommended, but remember that an early pregnancy test may not accurately detect pregnancy. If you take a pregnancy test too soon after the embryo transfer, the result might be positive because of the hormonal medications you took before the egg collection. On the flip side, there might not be enough hCG for the test to detect, resulting in a false negative. Being patient is a frustrating necessity of IVF.

Day 15: Pregnancy test

Once the dreaded two-week wait is over, you’re ready to take a pregnancy test. Your clinic will let you know if you can take an at-home test or whether you should come in for a blood test, which is a lot more reliable in detecting pregnancy. 

This can be a tough day, regardless of the test results. Remember to be gentle with yourself during this time and know that you are not alone in the emotions you are experiencing. 

If your test result was positive, that  means the treatment was successful. A positive pregnancy test can feel like a massive accomplishment and the start of a new journey (pregnancy). In rare cases, however, a positive result might not lead to an ongoing pregnancy or live birth. The risk of this happening also contributes to the anxiety and stress you might experience during IVF — that’s why Apricity offers ongoing support to IVF patients. 

If the test result was negative, you might take comfort in knowing that it’s not uncommon to need several rounds of IVF before conceiving, but there is hope for the future. Learning that an embryo transfer wasn’t successful can be incredibly disheartening, so you might find it helpful to speak to a counsellor (which should be provided by your clinic) or support group. 

Conclusion

Whether you’ve gone through multiple egg retrievals or just one, reaching the embryo transfer stage is a significant achievement in the IVF journey.

After your embryo transfer, you may feel anxious and closely monitor any signs of successful treatment. Remember that while some people may experience implantation or early pregnancy symptoms in the two weeks after an embryo transfer, others may not feel anything at all.

With Apricity, your fertility team will be there at every stage to support you and answer any questions you may have. If you want to know more about the IVF process or are interested in embryo freezing, you can speak to an Apricity fertility advisor.  Book a free consultation today. 

References

1. (n.d.). What happens in IVF? National Institute for Health and Care Excellence. https://www.nice.org.uk/guidance/cg156/ifp/chapter/What-happens-in-IVF#step-6-transfer-of-embryos 

2. Glujovsky, D., Retamar, A. M. Q., Sedo, C. R. A., Ciapponi, A., Cornelisse, S., & Blake, D. (2022). Cleavage‐stage versus blastocyst‐stage embryo transfer in assisted reproductive technology. Cochrane database of systematic reviews, (5). https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002118.pub6/full 

3. (n.d.). Decisions to make about your embryos. Human Fertility and Embryology Authority. https://www.hfea.gov.uk/treatments/explore-all-treatments/decisions-to-make-about-your-embryos/

4. Kim, S. M., & Kim, J. S. (2017). A review of mechanisms of implantation. Development & reproduction, 21(4), 351. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5769129/ 

5. d’Hauterive, S. P., Close, R., Gridelet, V., Mawet, M., Nisolle, M., & Geenen, V. (2022). Human chorionic gonadotropin and early embryogenesis. International Journal of Molecular Sciences, 23(3), 1380. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8835849/