Find out everything you need to know about the egg retrieval process and what you should be aware of before and after.
Key Facts
- Follicular puncture is used to retrieve mature eggs from the ovaries for in vitro fertilisation (IVF) or egg freezing (social freezing).
- To obtain multiple eggs, the ovaries are hormonally stimulated.
- Ovulation is triggered 36 hours before the procedure using an injection of hCG or GnRH agonist.
- The aspiration is performed under light sedation and takes about 15-20 minutes.
- The older the woman, the more eggs are needed to achieve a pregnancy.
Introduction
Egg retrieval is a central component of fertility treatments such as IVF (in vitro fertilization) and ICSI (intracytoplasmic sperm injection), as well as social freezing. This procedure allows mature eggs to be gently retrieved from the follicles in the ovaries. Our experienced team will ensure that you feel safe and well cared for throughout the entire process.
During fertility treatment, these eggs are then fertilised with sperm in the laboratory. In IVF, the egg and sperm are combined in a dish and fertilisation happens naturally. In ICSI, a single sperm is injected directly into an egg. This process paves the way for pregnancy, whether the goal is to start a family now or preserve fertility for the future.
What is IVF Egg Retrieval?
Egg retrieval is a minimally invasive procedure in which mature eggs are retrieved from the follicles in the ovaries. Ovulation is artificially controlled. The goal is to obtain eggs that can be fertilised in the laboratory with a sperm sample and then transferred to the uterus as fertilised eggs (embryo transfer). For egg freezing, the retrieved eggs are prepared and frozen on the day of egg retrieval.
The Egg Retrieval Procedure
1) Preparation:
- Ovarian Stimulation: To encourage the maturation of multiple follicles simultaneously and increase the chances of successful fertilisation, the ovaries are hormonally stimulated. This typically involves the use of medications containing follicle-stimulating hormone (FSH), or a combination of FSH and LH (luteinizing hormone). The aim is usually to retrieve 10-12 eggs. A study found that women under 35 had very good chances (44%) of becoming pregnant if at least 10 eggs were retrieved. If only 1-4 eggs were retrieved, the chances were just under 30%. Women between 35 and 39 had the best chances (35%) when 5-9 eggs were retrieved. For women over 40, however, the chances were higher the more eggs were retrieved.
- Ultrasound Examinations: Regular transvaginal ultrasound scans and blood tests are performed to monitor follicle growth and determine the day to trigger ovulation.
- Trigger Shot: When the follicles have reached a certain size, human chorionic gonadotropin (hCG) or a GnRH agonist is injected to trigger ovulation. One study found that follicles with a diameter of 12-19 mm on the day of triggering contained the most mature eggs. Another study suggests that the optimal follicle size should be between 19-22 mm, but size alone is not the only factor for successful egg maturation and fertilisation. Oestrogen levels also play an important role. Too rapid a rise in oestrogen can lead to a premature LH surge, which triggers ovulation before the egg is fully mature.
2) Procedure (Day of Egg Retrieval):
- Light Sedation: In most cases, egg retrieval is performed on an outpatient basis under light sedation. An anaesthetist monitors the sedation and the patient's vital signs. In rare cases, general anesthesia may be necessary.
- Vaginal Access: Egg retrieval is performed transvaginally. Under ultrasound guidance, the fertility specialist inserts a thin needle through the vaginal wall into the ovary.
- Aspiration of Follicular Fluid: The follicles are punctured with the needle and the follicular fluid containing the eggs is aspirated.
- Counting the Eggs: The retrieved eggs are examined in the laboratory for maturity and quality and prepared for fertilisation. You will be told how many eggs were retrieved while you are still in the recovery room.
In this video you can see how the follicular fluid with the egg is aspirated from the mature follicle:
3) Further Course after Egg Retrieval:
- Fertilisation of the Eggs: Fertilisation of the eggs can be done by conventional IVF (in vitro fertilisation) or ICSI (intracytoplasmic sperm injection). You will discuss whether IVF or ICSI is suitable for you in advance and after a detailed fertility analysis with your doctor.
- Embryo Transfer: The fertilised eggs are usually cultured in an incubator for 5-6 days, where they develop into blastocysts. The embryologist selects a blastocyst to be transferred into the uterine cavity via a thin catheter.
- Cryopreservation: Unused embryos can be frozen by cryopreservation and used for later treatment cycles (frozen embryo transfer).
- Pregnancy Test: A pregnancy test is carried out about two weeks after the embryo transfer, in which the hCG level in the blood is measured.
In this video you can learn everything you need to know about the egg retrieval procedure:
Possible Risks and Side Effects
Although egg retrieval is generally a safe procedure, there are some risks. These include:
- Bloating
- Bleeding
- Infection
- Ovarian hyperstimulation syndrome (OHSS)
- Injury to surrounding organs (very rare)
Benefits and IVF Success Rates
Egg retrieval allows the retrieval of multiple eggs, which increases the chances of successful implantation and pregnancy.
An average of 8-15 follicles are aspirated per puncture, but not all punctured follicles contain mature eggs or any eggs at all. It can also happen that a follicle is empty. On average, 70-80% of the eggs retrieved are mature and fertilisable.
The success rates of an IVF cycle depend on many factors, including the woman's age and sperm quality. The pregnancy rate per embryo transfer is about 30-40% while the live birth rate in the first cycle is 29.5%.
Frequently Asked Questions (FAQ)
Is egg retrieval painful?
Egg retrieval is usually performed under light sedation, so no pain is felt during the procedure. Mild pain, comparable to menstrual cramps, may occur after the procedure. If only one egg is retrieved, as in IVF in the natural cycle, the procedure can also be performed without anaesthesia.
How long does it take to recover from the egg retrieval?
Most women recover from egg retrieval within a few days. After the procedure, you should rest and drink plenty of fluids to prevent ovarian hyperstimulation syndrome.
When is ovulation triggered before the aspiration?
Ovulation is triggered around 36 hours before the planned egg retrieval. You will discuss the exact time to trigger ovulation individually with your doctor.
How many eggs are normal at aspiration?
According to studies, the average number of eggs retrieved during egg retrieval is between 8 and 15. The number of eggs retrieved depends on the woman's age, ovarian reserve, stimulation protocol and response to hormonal stimulation.
Do women with PCOS have more eggs?
Women with polycystic ovary syndrome (PCOS) often have an increased number of antral follicles in their ovaries. These are small follicles that can potentially grow into mature eggs. A meta-analysis in Human Reproduction Update (2013) showed that women with PCOS produced significantly more eggs during IVF treatment compared to women without PCOS.
What factors influence egg quality?
Egg quality is influenced by the woman's age, her menstrual cycle, her hormone levels and her response to the stimulation medication. Genetic factors, environmental factors, lifestyle (smoking and alcohol consumption) as well as certain conditions (e.g. endometriosis) or medications also play an important role.
Why am I not allowed to wear nail polish before egg retrieval?
Nail polish can interfere with the measurement of blood oxygen saturation, which is routinely done via a sensor on the finger during anaesthesia. It is therefore important to remove nail polish before egg retrieval.
What else should I bear in mind before the egg retrieval?
Before the retrieval you must not eat or drink anything for a certain time before the procedure. Exactly how long depends on the clinic and the type of anaesthesia. It is usually 6-8 hours.
You should also bring comfortable clothes with you for the retrieval. A long T-shirt or nightdress is ideal. Bring warm socks with you as you may get cold during the procedure. Also make sure you remove any jewellery, piercings and contact lenses beforehand.
Arrange for someone to accompany you and take you home after the procedure, as you will not be allowed to drive yourself after the anaesthesia.
Where does egg retrieval take place?
Egg retrieval is performed in a fertility centre or fertility clinic with the appropriate expertise. At Cada, all medical experts are available to you in one place at the Cada Clinic.
Takeaway
Egg retrieval is an essential part of assisted reproductive technology (ART) and social freezing. The procedure allows mature eggs to be efficiently retrieved from the ovaries to increase the chances of successful fertilisation. Thanks to hormonal stimulation and careful monitoring, an optimal number and quality of eggs is aimed for.
Although the procedure is safe and generally well tolerated, comprehensive medical care is essential to minimise risks and ensure the well-being of patients. Individual factors such as the woman's age, hormone levels and general health play a crucial role in the success of the IVF process.