DuoStim: Two Egg Retrievals in One Cycle

How DuoStim works

In a standard IVF cycle you stimulate once, in the first half of the menstrual cycle (the follicular phase), have one retrieval, and either transfer fresh or freeze. If you need more eggs, for example to build up embryos for genetic testing or because you respond poorly, you'd usually wait for another cycle and repeat.

DuoStim compresses this:

1. Stimulation 1 (follicular phase): standard injections, monitoring, trigger, and retrieval.
2. Stimulation 2 (luteal phase): injections restart shortly after the first retrieval, with no waiting for a period, followed by a second trigger and retrieval.
3. Freeze-all: eggs or embryos from both retrievals are frozen. Transfer happens in a later cycle, often after genetic testing if that's part of the plan.

Exact timing and medications vary by clinic and by how you respond, so your protocol sheet may look different from someone else's.

Why a second stimulation is possible

The older textbook picture was one wave of follicle growth per cycle. Proponents point to research describing multiple waves of follicle recruitment within one menstrual interval. Their argument is simple: if another group of follicles is available in the luteal phase, you can stimulate it rather than let it go to waste.

The rationale explains why DuoStim is possible. Whether it produces more babies than other strategies is a separate question, and that's where the evidence is more modest.

Who it's offered to

• Poor or suboptimal responders who need several retrievals to accumulate enough eggs or embryos
• People planning PGT-A (embryo genetic testing) who want more embryos to test before any transfer
• Urgent fertility preservation, such as before cancer treatment, where there may be only a short window
• People with time pressure, whether from age, an upcoming medical treatment, or limited time off for travel

It's generally not used when you want a fresh transfer, because the second stimulation happens during the luteal phase, the window when a fresh transfer would otherwise occur.

What the evidence shows

Most published DuoStim research is observational, and much of it comes from centers that pioneered the approach. Randomized trials exist but are fewer. In their 2025 paper, Canosa and colleagues described one randomized trial comparing two stimulations in one cycle with two conventional cycles (Massin et al., 2023) as having "inconclusive results."

The 2025 study by Canosa and colleagues in the journal Life gives a useful picture of the trade-off. It compared 66 poor or suboptimal responders who had DuoStim with 46 who planned two conventional follicular-phase stimulations, all accumulating eggs for PGT-A. It was retrospective and not randomized.

Canosa S, et al. Life 2025;15(6):899. Retrospective, single clinic, small sample.

The takeaway: in that study, DuoStim got people to the same place faster, and fewer people gave up between stimulations. It didn't get them to a better place. For someone racing a clock, faster can matter a lot. For someone who isn't, it may not be worth the extra intensity.

What ESHRE's 2025 guideline says

ESHRE's updated guideline on ovarian stimulation for IVF/ICSI (2025 update) addresses double stimulation and related luteal-phase approaches directly:

• "Double stimulation can be used with the intention to accumulate oocytes or embryos when fresh transfer is not planned."
• "Double stimulation can be considered for urgent fertility preservation cycles."
• "Luteal start ovarian stimulation could be used when a fresh transfer is not intended."
• For low responders, "late luteal phase start of gonadotropins with fresh transfer is probably not recommended."

Read together: ESHRE treats DuoStim as a legitimate tool for accumulating eggs or embryos when you're freezing everything anyway. It doesn't present it as a way to improve live birth chances in poor responders.

Trade-offs: time, cost, and two procedures

On cost, ask how the clinic prices it: as one package, as two cycles, or as a cycle plus an add-on. Get the full itemized estimate before you agree, including freezing, storage, and genetic testing if relevant.

For many poor responders, DuoStim sits next to other strategies with their own evidence profiles. Our guide to growth hormone for poor responders covers an adjuvant that's often offered at the same point. If someone is offering ovarian PRP, know that it's experimental.

Signs it may not be the right fit

DuoStim tends to make the least sense when the main advantage, speed, doesn't matter much to you. That might be the case if:

• You'd prefer a fresh transfer and have no reason to freeze everything.
• You respond well to stimulation and one retrieval is likely to give you enough embryos.
• The physical or emotional load of back-to-back stimulations would be hard right now. Several weeks of near-continuous injections, scans, and two procedures is a lot, and it's fine to say so.
• The added cost would stop you from affording a later transfer or another cycle.

It's also reasonable to treat the decision as staged. Ask whether the plan can be reviewed after the first retrieval, so the second stimulation goes ahead only if it still makes sense given how you responded.

DuoStim and traveling for treatment

If you're traveling for IVF, DuoStim can mean one longer trip instead of two separate ones. That's a real practical advantage. It's also a reason to be careful, because convenience alone shouldn't decide a medical protocol. If cost or logistics are pushing you to look abroad, colombianivf.com is a resource for people considering IVF in Colombia. Ask any clinic you consider how often it uses DuoStim, for which patients, and what its own outcomes look like compared with conventional cycles.

If you'll freeze embryos abroad and transfer at home later, read our guide to shipping embryos internationally before you start.

Questions to ask before choosing it

• What's the goal: a specific number of eggs, embryos, or euploid embryos? How many retrievals do you expect that to take?
• Why DuoStim for me rather than two conventional cycles? Is the benefit time, or do you expect better odds?
• How many DuoStim cycles does your clinic do, and what are your outcomes compared with conventional cycles?
• What's the full cost, itemized, and is it priced as one cycle or two?
• What happens if the first stimulation goes very well, or very poorly? Can we skip the second?
• When would a frozen transfer realistically happen?

Frequently asked questions

Sources