Embryo transfer is the final and one of the most important phases of the in vitro fertilization (IVF) process. It is the moment when the embryo (or embryos) that have successfully developed under laboratory conditions are transferred into the woman’s uterus with the goal of achieving pregnancy.
The embryo transfer procedure itself is quick, generally painless, and non-invasive. However, despite its apparent simplicity, it is the culmination of the entire IVF process and carries significant emotional weight for patients. This procedure requires precision, preparation, and coordination between the patient, embryologists, and gynecologists to ensure the best possible conditions for embryo implantation.
In this article, we will explain the embryo transfer process, how patients prepare for it, factors that can influence success, and address the most common questions patients have about this stage of the IVF journey.
EMBRYO-TRANSFER-PROCEDURE
Embryo transfer is performed a few days after egg retrieval and fertilization under laboratory conditions. High-quality embryos are often frozen and transferred in a later cycle, allowing the woman’s body to recover from hormonal stimulation. The timing of embryo transfer depends on its development and the embryologist’s assessment. Typically, the transfer occurs on day 3 of development (when the embryo is still in the cleavage stage) or on days 5–6, when it has reached the blastocyst stage.
The procedure is similar to a routine gynecological exam, does not require anesthesia, and takes only a few minutes. Despite being minimally invasive, this step is one of the most critical in the entire IVF process, as embryo implantation and the ultimate success of the procedure depend directly on it.
WHAT ARE THE STEPS OF EMBRYO TRANSFER?
– Embryo Preparation: After fertilization, embryos are cultured in the laboratory for a few days. Their quality is then assessed to select the best ones for transfer. The remaining embryos may be frozen for future attempts.
– Embryo Selection: Based on morphological criteria, the embryologist selects the highest-quality embryos for transfer into the uterus. The same criteria apply to embryos that will be frozen for future procedures.
– Patient Preparation: The patient arrives for the transfer with a full bladder, which improves uterine visualization during ultrasound-guided monitoring. During the procedure, the patient lies in a gynecological position, and the transfer is performed under ultrasound guidance to ensure precision.
– Transfer Procedure: A thin, flexible catheter is inserted through the cervix into the uterine cavity, and the embryo is carefully placed in the optimal implantation zone.
– After the Transfer: The patient typically rests for 10–15 minutes at the clinic before resuming daily activities with certain precautions.
WHAT PREPARATIONS PRECEDE EMBRYO TRANSFER?
Preparation for embryo transfer is of great importance as it can influence the final outcome of the procedure. In addition to medical preparation, a patient’s lifestyle habits in the days leading up to the transfer also play a crucial role.
To create the best possible conditions for successful embryo implantation, it is recommended to:
– Adherence to Medication Therapy: The use of hormone therapy, including progesterone and other medications that prepare the endometrium, should be continued according to the doctor’s instructions.
– Moderate Physical Activity: Heavy physical activities, lifting weights, and intense exercise should be avoided, but light walks can be beneficial for circulation.
– Stress Management: Stress can negatively impact hormonal balance, so relaxation techniques such as meditation and breathing exercises are recommended.
– Healthy Nutrition: Consuming foods rich in antioxidants, healthy fats, and proteins can support hormonal balance and endometrial health.
WHAT HAPPENS AFTER EMBRYO TRANSFER?
After embryo transfer, a waiting period of about two weeks begins, after which a pregnancy test is performed. During this time, the body undergoes hormonal changes, and many women wonder what they can and cannot do to increase their chances of success.
– Rest and Physical Activity: Prolonged bed rest after embryo transfer is not necessary. Women are advised to continue their usual daily activities but should avoid strenuous physical exertion.
– Avoiding Alcohol and Nicotine: These substances can negatively affect embryo implantation success.
– Adherence to Prescribed Therapy: If the doctor has prescribed progesterone or other hormones, it is essential to continue taking them until the pregnancy test is performed.
– First Pregnancy Test: The β-hCG test (a blood test for the pregnancy hormone) is usually done 10–14 days after the transfer to confirm pregnancy. A home urine test may be taken beforehand to avoid unnecessary blood draws.
FACTORS AFFECTING THE SUCCESS OF EMBRYO TRANSFER
Several factors influence the success of embryo transfer, with some of the most important being:
– Patient’s Age: Women under 35 have a higher success rate compared to those over 40.
– Embryo Quality: Higher-quality embryos significantly increase the chances of successful implantation.
– Endometrial Preparation: The thickness and receptivity of the endometrium are crucial for successful embryo implantation.
– Number of Transferred Embryos: In some cases, transferring multiple embryos may increase the chances of pregnancy but also raises the risk of multiple pregnancies.
FREQUENTLY ASKED QUESTIONS ABOUT EMBRYO TRANSFER
Is the procedure painful?
No, embryo transfer is generally painless, but some women may feel slight pressure or mild cramping.
How long does recovery take?
The patient can return to normal activities the same day while avoiding heavy physical exertion.
When can I take a pregnancy test?
It is recommended to take a β-hCG blood test 10–14 days after the transfer, as well as a urine pregnancy test.
Should I rest after the transfer?
A short rest is recommended, but prolonged bed rest is not necessary.
What are the risks of embryo transfer?
The risks are minimal, but in rare cases, mild cramping or infections may occur.
What if the transfer is unsuccessful?
If pregnancy does not occur, the doctor will analyze possible causes and suggest the next steps.
REFERENCES
– Gardner, D. K., & Lane, M. (2007). Culture and selection of viable blastocysts: a feasible proposition for human IVF? Human Reproduction Update, 13(5), 429–441.
– Papanikolaou, E. G., Camus, M., Kolibianakis, E. M., Van Landuyt, L., Van Steirteghem, A., & Devroey, P. (2006). In vitro fertilization with single blastocyst-stage versus single cleavage-stage embryos. The New England Journal of Medicine, 354(11), 1139–1146.
– Practice Committee of the American Society for Reproductive Medicine. (2017). Evidence-based treatments for couples with unexplained infertility: a guideline. Fertility and Sterility, 107(2), 400–416.