Egg Retrieval (Oocyte Pickup) — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Egg retrieval (oocyte pickup, OPU) is the minimally invasive procedure in which mature eggs (oocytes) are aspirated from ovarian follicles using a transvaginal ultrasound-guided needle under intravenous sedation. It is a critical step in IVF (in vitro fertilisation) and ICSI (intracytoplasmic sperm injection) cycles, performed approximately 36 hours after the trigger injection (hCG or GnRH agonist) that initiates final oocyte maturation. Egg retrieval is performed by a reproductive endocrinologist or fertility specialist in a dedicated IVF laboratory suite. The aspirated follicular fluid is immediately handed to adjacent embryologists who identify and grade the eggs under a microscope, selecting mature metaphase II (MII) oocytes for insemination or ICSI. The procedure is also performed for egg donation cycles (where a donor's eggs are retrieved and transferred to a recipient), fertility preservation before gonadotoxic cancer treatment (social or oncological egg freezing), and embryo creation for preimplantation genetic testing (PGT). Egg retrieval follows 10–14 days of controlled ovarian hyperstimulation (COS) with injectable gonadotrophins (follicle-stimulating hormone, FSH) to stimulate multiple follicle development. Egg retrieval is the pivotal step in all IVF, ICSI, and egg donation or freezing cycles. It is typically performed 34–36 hours after the ovulation trigger injection.

Egg retrieval is performed in all patients undergoing IVF or ICSI treatment for any cause of infertility, including tubal factor, male factor, unexplained infertility, diminished ovarian reserve, endometriosis, and anovulation. It is also indicated for: elective fertility preservation in women wishing to delay childbearing (social egg freezing — ASRM recommends this for women under 38 years for optimal outcomes); oncofertility — fertility preservation before chemotherapy, radiotherapy, or oophorectomy that could permanently impair ovarian function; egg donation — healthy women aged 21–34 (ASRM recommended range) donate oocytes to recipients unable to use their own eggs; creation of embryos for preimplantation genetic testing for chromosomal aneuploidy (PGT-A) or monogenic disorders (PGT-M) in couples with inherited conditions or recurrent miscarriage; and surrogacy arrangements where the intended mother's eggs are used with a gestational carrier. Patients with very poor ovarian reserve (AFC <5, AMH <0.5 ng/ml) may be counselled that egg retrieval yield may be low (1–3 eggs) and donor egg options discussed.

The patient attends the clinic with a companion to assist post-sedation. An intravenous cannula is placed and intravenous sedation (propofol, fentanyl, or midazolam) administered. The patient is positioned in lithotomy, the vagina is cleaned with saline (not antiseptic, to avoid oocyte toxicity), and a transvaginal ultrasound probe fitted with a sterile needle guide is inserted. The aspiration needle (16–17 gauge, 35 cm length) is advanced under real-time ultrasound guidance through the vaginal wall into each ovarian follicle sequentially, aspirating follicular fluid containing the egg at a negative pressure of 90–100 mmHg. Each follicle is flushed 1–3 times if no egg is found in the initial aspiration. The follicular fluid is collected in warm (37°C) test tubes and immediately passed to the embryologist through a pass-through window. The embryologist places the fluid in a heated petri dish, searches under the microscope for the cumulus-oocyte complex (COC), and grades eggs as mature (MII), intermediate (MI), or immature (GV). Flushing media may improve yield from smaller follicles. The procedure takes 20–30 minutes for average-yield cycles. Both ovaries are aspirated; accessible follicles on the contralateral ovary are reached by angling the probe through the uterus. The entire procedure from sedation to recovery typically takes 20–40 minutes.

An average of 8–15 eggs is retrieved per IVF stimulation cycle depending on ovarian reserve (measured by antral follicle count, AFC, and anti-Müllerian hormone, AMH), patient age, and stimulation protocol. Of retrieved eggs, 70–80% are typically mature (MII) and suitable for fertilisation. IVF fertilisation rates are 60–75%; ICSI fertilisation rates are 70–85%. The cumulative live birth rate per egg retrieval cycle increases with the number of eggs obtained: retrieving 15–20 mature eggs yields cumulative live birth rates of 70–80% across all resulting blastocyst transfers, compared to 40–50% for 5–10 eggs. Egg freezing (vitrification) of spare embryos or eggs for future use is highly successful with survival rates exceeding 90% after thaw. Elective freeze-all strategies — freezing all embryos for transfer in a subsequent natural or hormone-replacement cycle — reduce OHSS risk and improve uterine receptivity, with equivalent or superior live birth rates compared to fresh transfer in high-responders. The number and quality of retrieved eggs directly determines the probability of achieving a live birth, making optimal ovarian stimulation and follicle aspiration technique critical to IVF success.

Egg retrieval is a well-tolerated procedure with a low serious complication rate. Ovarian hyperstimulation syndrome (OHSS) is the most significant risk: mild OHSS (bloating, discomfort, mild abdominal distension) affects 20–33% of IVF patients; moderate OHSS (nausea, vomiting, ovarian enlargement) affects 3–8%; severe OHSS (ascites, pleural effusion, haemoconcentration, thromboembolism) occurs in 1–2% of patients. OHSS risk is highest in women with polycystic ovary syndrome (PCOS), high AMH, large numbers of retrieved eggs (>20), and those receiving hCG trigger. GnRH agonist trigger (instead of hCG) significantly reduces severe OHSS risk in high-risk patients. Vaginal bleeding from the puncture sites is common but usually stops spontaneously; significant intraperitoneal bleeding from ovarian vessel injury requiring surgical intervention occurs in less than 0.1% of retrievals. Pelvic infection post-retrieval is rare (<0.5%) and treated with antibiotics; prophylactic doxycycline is routinely given. Bladder or bowel injury from misdirected needle passage is extremely rare. Oocyte damage during aspiration is uncommon with experienced operators.

Post-procedure monitoring in the clinic for 2–4 hours is standard while the sedation wears off. The patient must not drive and requires a responsible adult to accompany them home. Mild pelvic cramping (similar to menstrual pain), bloating, and light vaginal spotting are normal for 1–3 days post-retrieval and respond to paracetamol or ibuprofen (except where there is concern about bleeding). Rest is recommended for the remainder of the retrieval day; normal light activities may resume the following day. Strenuous exercise, sexual intercourse, and alcohol should be avoided for 48–72 hours post-retrieval. Progesterone supplementation (pessaries, vaginal gel, or injections) begins on the evening of egg retrieval or the morning after to support the luteal phase and prepare the uterus for embryo transfer. For patients at high risk of OHSS or in freeze-all cycles, progesterone continues until after the first frozen embryo transfer. The embryology team typically contacts the patient on the day after retrieval to report fertilisation results. Fresh embryo transfer (if planned) occurs 3 or 5 days after retrieval.