The Process of Egg Retrieval: Hour by Hour

Your retrieval is scheduled. The trigger shot is in the fridge with a sticky note on it, you have read the consent forms twice, and you are reading this at 10 pm because you want to know exactly what tomorrow morning looks like. I am going to walk you through the process of egg retrieval the way I walk my first-cycle patients through it in clinic, hour by hour, so the day stops feeling like a black box.

The thing I tell every patient before retrieval day is this: the procedure itself is the easy part. You will be asleep. The work happens in the 36 hours before, in the lab while you are in recovery, and in the week after. Retrieval is not the climax of the cycle. It is the handoff from your body to the embryology team.

Why is retrieval the only procedural part of IVF?

Up until this point, your IVF cycle has been needles and ultrasounds and bloodwork. Retrieval is the only part that involves sedation, a procedure suite, and a surgical timeout. That alone makes it feel enormous. Most patients arrive more anxious than they expect to be, even after a calm stim phase.

A few facts that help frame the day:

• The procedure is officially called transvaginal oocyte retrieval, or TVOR. Older clinic paperwork may call it ovum pick-up (OPU).
• It takes 15 to 20 minutes of actual procedure time. Total clinic time, from arrival to discharge, is usually 3 to 4 hours.
• You will be under intravenous (IV) sedation, not general anaesthesia. Most clinics use a propofol-based protocol that lets you breathe on your own while feeling nothing.³
• Timing is precise to the minute. If your trigger shot was at 9:30 pm on Tuesday, your retrieval is at 8:30 am on Thursday. There is no flexibility window. The lab needs the eggs at the moment they would have ovulated, no earlier, no later.

This last point is the one I want you to internalise. The trigger is what tells your follicles, "finish maturing and prepare to release." The retrieval has to happen just before they would release on their own. Miss it by more than an hour or two and you risk ovulating before the needle gets there, which means the eggs end up in your pelvis, not in the lab dish.

What happens in the 36 hours before retrieval?

This window is yours, and what you do during it matters more than what happens once you are in the procedure room.

Trigger night

Your trigger injection is given at the exact time your clinic specified, usually 34 to 36 hours before your scheduled retrieval slot. The medication will be one of three things, depending on your protocol:

• hCG (Ovidrel, Pregnyl, Novarel): the traditional trigger. Mimics the natural LH surge.
• GnRH agonist (Lupron): used in high-responder and OHSS-risk protocols. It triggers your own pituitary to release LH, which then matures the eggs. Lower OHSS risk because the LH surge is shorter.²
• Dual trigger: a smaller dose of hCG plus Lupron. Increasingly common, especially in PCOS-niched protocols and in patients who have had borderline maturity rates in previous cycles.

What I tell patients: take a photo of the box before you draw it up, set three alarms (one 30 minutes before, one at the exact time, one immediately after to confirm you injected), and have your partner or a friend watch the injection if you can. Trigger night is the single highest-stakes injection of the entire cycle. If you are not sure you gave it correctly, call the clinic immediately, not in the morning.

Day before retrieval

Eat normally and lightly. Hydrate well, but stop pushing fluids around 10 pm so you are not getting up to urinate all night. Avoid alcohol, NSAIDs (ibuprofen, naproxen), and any new supplements.

On the evening before retrieval you may have a "coast" night where you take no injections at all, depending on protocol. This is normal and means the lab has finished its part of the stim work.

Confirm your clinic's NPO (nil per os, nothing by mouth) cutoff. Most clinics ask for nothing to eat or drink after midnight. Some allow small sips of water until 2 hours before. The anaesthesia team needs an empty stomach to reduce aspiration risk during sedation.

Retrieval morning

The small things I ask my patients to do:

• No perfume, lotion, deodorant with fragrance, or scented body wash. The embryology lab is sensitive to volatile organic compounds.
• No nail polish (acrylic is fine). The pulse oximeter clips on a fingernail.
• No jewellery, including wedding rings. Bring a small bag or leave them at home.
• Loose, comfortable clothes you can pull on without raising your arms. You will be sore and bloated.
• Pads (not tampons) for the spotting after.
• Your driver, your phone charger, a snack and water for the ride home.

What happens during egg retrieval at the clinic?

Arrival is typically 60 to 90 minutes before your procedure slot. The flow at most clinics looks like this:

1. Check-in and consent re-confirmation: A nurse confirms your name, date of birth, partner's name, planned fertilisation method (conventional IVF or ICSI), and PGT-A plan if relevant.
2. Vitals and IV placement: Blood pressure, heart rate, temperature, a urine pregnancy test (yes, even mid-cycle, because if you happen to be pregnant they need to know). An IV line is placed, usually in the back of your hand or forearm.
3. Anaesthesia consult: The anaesthetist or anaesthesia nurse will review your history, allergies, and any prior reactions to sedation.
4. Change into gown, cap, no underwear: You will be wheeled or walked into the procedure room.
5. Procedure room: Stirrups, ultrasound probe with a needle guide attached, embryology lab visible or audible through a window or pass-through. The anaesthetist asks you to count down. You are asleep within 30 to 60 seconds.

The procedure itself: a transvaginal ultrasound probe with a thin needle guide is positioned against the vaginal wall. The needle passes through the vaginal wall into each ovary in turn, and the follicles are aspirated one by one. The follicular fluid drops into a warmed test tube, which is handed through to the embryologist in real time. They look at each tube under a microscope while you are still asleep and call out the egg count as they go.

You will not feel any of this. The procedure takes 15 to 20 minutes. The anaesthesia is calibrated to wear off within 5 to 10 minutes of the last aspiration.

Recovery is 30 to 60 minutes in a curtained bay. You will wake up groggy and cold. Most clinics have warmed blankets and a saline bolus running. You may feel nauseous; let the nurse know and they can give an antiemetic through the IV. You will cramp like a heavy period.

A nurse will tell you the egg count before you leave. Write it down or have your partner write it down. You will not remember it cleanly. Most patients are discharged 1 to 2 hours after the procedure ends.

Pain control during retrieval

The Cochrane review on pain relief for transvaginal oocyte retrieval concluded that conscious IV sedation provides effective pain control with low complication rates and is the most widely used approach.³ The needle aspiration itself is not what hurts most patients later. The soreness comes from the ovaries being enlarged and the puncture sites in the vaginal wall.

If you have ever had a strong reaction to propofol or fentanyl, tell the anaesthesia team explicitly. Alternatives exist.

What is the lab doing while you sleep?

This is the part of egg retrieval most patients never see, and it is the part that determines whether your eggs become embryos.

The embryologist receives each tube of follicular fluid as it is aspirated. They examine it under a microscope and identify the cumulus-oocyte complex (COC), a small cloud of cells with the egg in the middle. The COC is rinsed, placed in culture medium, and moved to an incubator that holds it at body temperature, body pH, and the right oxygen and carbon dioxide concentrations.

Over the next 2 to 4 hours, the embryologist strips the cumulus cells and counts mature eggs. A mature egg is at the MII (metaphase II) stage, meaning it has completed the first meiotic division and is ready to be fertilised. Immature eggs (GV or MI stage) usually cannot be used in the same cycle.

Your partner's sperm sample is collected the morning of retrieval (or thawed if frozen). It is washed, concentrated, and prepared for either conventional insemination (the sperm and eggs are placed together in a dish) or intracytoplasmic sperm injection (ICSI, where a single sperm is injected directly into each mature egg). The choice depends on sperm parameters and clinic protocol.

Insemination usually happens 4 to 6 hours after retrieval. By the time you are home eating soup, your eggs may already be in contact with sperm.

What will you feel after egg retrieval?

I want to be specific here because vague reassurance does not help on retrieval night.

During the procedure: nothing. You are asleep.

Waking up: groggy, cold, sometimes nauseous, sometimes briefly tearful. This is the propofol coming off. It is not a sign of anything.

That afternoon: crampy like a heavy period, bloated, sore in the lower abdomen on both sides. You may want to lie on your side with a heating pad. Acetaminophen (paracetamol) is the first-line pain medication. Avoid NSAIDs until your clinic clears you, because they can interfere with implantation if you are planning a fresh transfer.

Spotting: light pink or brown spotting for 1 to 3 days is expected from the vaginal puncture sites. Bright red bleeding that fills a pad in under an hour is not normal.

Bloating: this is the part that surprises patients most. Bloating peaks 3 to 5 days after retrieval, not the day of. Your ovaries were enlarged from stim, and the puncture creates a small amount of fluid shift. If you have any OHSS risk, the bloat tells you something. (More on this in the red flag section.)

Mood: a hormone crash starts 4 to 8 days after retrieval as your oestradiol drops from peak stim levels back toward baseline. Sudden tearfulness, low mood, or anxiety in that window is real and not "in your head." We see it every cycle.

How do eggs become mature eggs, fertilized eggs, and blastocysts?

Patients hear an egg number and assume that is the number of embryos. It is not. The funnel from retrieved oocytes to a usable embryo is the most misunderstood part of IVF.

Here is how the math typically works:

• Eggs retrieved (total aspirated): roughly 70 to 90 percent of follicles seen on the last scan. Not every follicle yields an egg.
• Mature (MII) eggs: typically 70 to 85 percent of retrieved.
• Fertilized (2PN) eggs: typically 70 to 80 percent of mature. (2PN means two pronuclei, the signal that fertilisation happened normally.)
• Day 3 cleavage embryos: most fertilised embryos make it to day 3.
• Day 5 to 6 blastocysts: typically 30 to 60 percent of fertilised, with younger patients at the higher end.
• Euploid blastocysts (if PGT-A): heavily age-dependent. Around 60 to 70 percent at age 30. Around 25 to 35 percent at age 40.

The honest summary: every step is a filter. The number you hear on retrieval day is the widest point of the funnel.

There is a separate post for what your specific number means by age and AMH. The headline finding from the Sunkara analysis of 400,135 IVF cycles: live birth rates plateau around 15 eggs retrieved and decline above 20. The reason is that high yields raise OHSS risk, and embryo quality can drop in very high responders.⁴ Fifteen is not a target. It is a population observation.

I do not let my patients celebrate or grieve the retrieval number on the day. I tell them: this is the funnel start. The number that matters is at the end.

What are the red flags to watch for after retrieval?

The vast majority of retrievals are uneventful. But because you may be home alone or with a partner who has never seen post-retrieval recovery, here is what to call the clinic about.

Call the clinic same day if you have:

• Severe, one-sided abdominal pain that is not relieved by rest or paracetamol. This can signal ovarian torsion (an enlarged ovary twisting on its pedicle) or internal bleeding from a puncture site.
• Heavy vaginal bleeding that soaks a pad in less than an hour.
• Fever over 38°C (100.4°F). Pelvic infection is rare but reported.
• Inability to keep liquids down for more than 12 hours.

Call the clinic urgently or go to ER if you have:

• Sudden severe bloating with shortness of breath. This can be early severe ovarian hyperstimulation syndrome (OHSS).
• Decreased urine output for more than 6 hours, especially if you are also bloating.
• Calf pain or swelling. Stim cycles carry a small increase in venous thromboembolism risk.
• Chest pain or fainting.

The complication rate of transvaginal oocyte retrieval is low. Series of several thousand consecutive procedures report serious complications under 1 percent, but they are real and worth recognising early.

What should you ask the day of and the day after?

Write these down so you do not forget them in the propofol haze.

On the day:

• How many eggs were retrieved and how many were mature?
• What fertilisation method are we using (conventional, ICSI, or a split)? Why?
• When is the day-1 fertilisation check call?
• What pain medication can I take tonight? When can I resume ibuprofen?
• Is there anything in my retrieval that suggests OHSS risk this cycle?

On day 1 and day 5:

• How many embryos fertilised normally (2PN)?
• Are we doing a fresh transfer, freeze-all, or banking?
• If freeze-all, why specifically (OHSS risk, lining, PGT-A, scheduling)?
• When will I get the blastocyst report on day 5 or 6?
• If PGT-A is planned, when will biopsy results come back?

These questions are not pushy. They are routine. Every embryologist and every nurse coordinator expects them, and most will offer the information before you ask.

What can you do tonight after retrieval?

After you get home from retrieval:

• Eat something soft and salty. Broth, eggs, toast, plain pasta. Add electrolytes (coconut water, oral rehydration solution, or a sports drink without dye if that is what you have).
• Drink to thirst, not to a target. Forced hyper-hydration does not prevent OHSS and can worsen it.
• Heating pad on the lowest setting on your abdomen for cramping.
• Pads, not tampons.
• No driving for 24 hours after sedation, no signing legal documents, no important work decisions.
• No intercourse, no baths, no swimming, no tampons for at least 1 to 2 weeks per your clinic's guidance.
• Walk gently the next morning. Walking from day 1 reduces blood clot risk and helps the bloat resolve.

Sleep. Tomorrow your phone will ring with the fertilisation report and a whole new set of numbers to interpret. The process of egg retrieval is finished. Tonight your only job is to recover.

What's next

• If your recovery is on track and you want the day-by-day map of the week ahead: /ivf/recovering-after-egg-retrieval
• If your retrieval number landed and you are trying to interpret it by age and AMH: /ivf/good-egg-retrieval-numbers
• If you are heading toward a fresh transfer: /ivf/embryo-transfer-explained
• If you have OHSS risk factors or are watching for symptoms: /ivf/ohss-prevention
• If this cycle does not produce a viable embryo: /when-things-dont-go-to-plan/failed-ivf-decoding-next

Related in this cluster

• Recovering After Egg Retrieval: Day 0 to Day 7
• How Many Eggs Is 'Good': Numbers by Age and AMH

Sources

1. Practice Committee of the American Society for Reproductive Medicine. Performing the embryo transfer: a guideline. Fertility and Sterility 2017;107(4):882-896. https://doi.org/10.1016/j.fertnstert.2017.01.025
2. Humaidan P, Kol S, Papanikolaou EG, Copenhagen GnRH Agonist Triggering Workshop Group. GnRH agonist for triggering of final oocyte maturation: time for a change of practice? Human Reproduction Update 2011;17(4):510-524. https://doi.org/10.1093/humupd/dmr008
3. Kwan I, Bhattacharya S, Knox F, McNeil A. Pain relief for women undergoing oocyte retrieval for assisted reproduction. Cochrane Database of Systematic Reviews 2018;5:CD004829. https://doi.org/10.1002/14651858.CD004829.pub4
4. Sunkara SK, Rittenberg V, Raine-Fenning N, Bhattacharya S, Zamora J, Coomarasamy A. Association between the number of eggs and live birth in IVF treatment: an analysis of 400,135 treatment cycles. Human Reproduction 2011;26(7):1768-1774. https://doi.org/10.1093/humrep/der106
5. Magnusson Å, Källen K, Thurin-Kjellberg A, Bergh C. The number of oocytes retrieved during IVF: a balance between efficacy and safety. Human Reproduction 2018;33(1):58-64. https://doi.org/10.1093/humrep/dex334