DuoStim Explained: Two Egg Retrievals in One Cycle for Low and Poor Responders

The hardest part of being a poor responder usually isn't the first cycle. It's the second one.

A woman with low ovarian reserve goes through the entire IVF process—weeks of injections, repeated ultrasound scans, and an egg retrieval under sedation—only to end up with three eggs. One fertilises, one develops into a blastocyst, and that single embryo either fails to implant or is found to be chromosomally abnormal during testing. The recommendation is often to rest, wait two or three months, and begin the process all over again.

For women with very few eggs and limited time, those waiting months can feel devastating. Every passing cycle may reduce ovarian reserve even further.

DuoStim offers a different approach. Instead of completing one stimulation cycle and waiting for another month, ovarian stimulation is performed twice within the same menstrual cycle, allowing two egg retrievals before the cycle ends.

This approach may benefit women who consistently produce only a small number of eggs during IVF or those facing urgent fertility preservation before treatments such as chemotherapy.

Why One Egg Retrieval Often Isn't Enough

Women with a normal ovarian reserve may produce 10 to 12 eggs during a single IVF cycle, providing multiple opportunities to create healthy embryos.

For women with diminished ovarian reserve, the numbers are very different. A typical cycle may produce only two or three eggs, and the numbers decrease further throughout the IVF process.

• Not every egg reaches maturity.
• Not every mature egg fertilises successfully.
• Not every fertilised egg develops into a blastocyst.
• Not every blastocyst is chromosomally normal.

Starting with only a few eggs often means there may be no embryo available for transfer at the end of the cycle.

For many years, the only way to increase the total number of eggs collected was to undergo multiple IVF cycles over several months.

What Is DuoStim?

DuoStim, or Double Stimulation IVF, involves two separate rounds of ovarian stimulation and two egg retrievals within a single menstrual cycle.

The first stimulation follows the standard IVF protocol during the follicular phase of the menstrual cycle and ends with an egg retrieval.

Approximately five days later, a second round of ovarian stimulation begins during the luteal phase, followed by a second egg retrieval.

Instead of waiting an entire month between retrievals, both procedures are completed within approximately 30 days.

All eggs or embryos collected during DuoStim are frozen. A fresh embryo transfer is not performed during the same cycle.

Why the Ovaries Can Be Stimulated Twice

For many years, fertility specialists believed that the ovaries recruited only one group of follicles during each menstrual cycle.

Modern research has shown that follicles are recruited in multiple waves throughout the cycle. Even after the first egg retrieval, additional follicles remain capable of responding to ovarian stimulation during the luteal phase.

DuoStim takes advantage of this second wave by stimulating these remaining follicles before they naturally disappear at the end of the cycle.

Are Eggs Retrieved During the Second Stimulation as Good?

This is one of the most common concerns among patients considering DuoStim.

Research has shown that eggs retrieved during the luteal phase perform similarly to those collected during the first stimulation.

• Comparable fertilisation rates
• Similar blastocyst development rates
• Similar rates of chromosomally normal embryos
• Comparable pregnancy and obstetric outcomes

Some studies have even reported that the second stimulation retrieves one or two additional eggs compared to the first stimulation.

For women with poor ovarian reserve, this can significantly increase the likelihood of obtaining at least one genetically normal embryo within a much shorter period.

Who May Benefit from DuoStim?

DuoStim is not recommended for every IVF patient.

It is generally considered in two main situations:

• Women with diminished ovarian reserve or poor ovarian response who consistently produce very few eggs during conventional IVF.
• Patients requiring urgent fertility preservation, such as those preparing to begin chemotherapy or other medical treatments that could affect fertility.

In these situations, collecting more eggs in a shorter period may improve the chances of creating healthy embryos before valuable time is lost.

What to Expect During a DuoStim Cycle

DuoStim is more intensive than a conventional IVF cycle.

Patients undergo:

• Two separate ovarian stimulation phases
• Additional hormone injections
• More ultrasound monitoring appointments
• Two egg retrieval procedures within the same menstrual cycle

Because both stimulations occur within a hormonally altered cycle, the uterine lining is generally not suitable for immediate embryo transfer.

Instead, all embryos are frozen, and a frozen embryo transfer (FET) is scheduled during a later menstrual cycle when the uterus is better prepared for implantation.

What DuoStim Cannot Do

DuoStim increases the number of eggs collected in a shorter period, but it does not improve egg quality.

It cannot reverse age-related decline or restore ovarian reserve.

A woman in her early forties will still have age-related changes in egg quality regardless of whether one or two retrievals are performed.

The advantage of DuoStim is simple—it creates more opportunities to obtain a healthy embryo by collecting more eggs within the available time.

Current Evidence and Ongoing Debate

Although DuoStim has produced encouraging results, much of the current evidence comes from observational studies rather than large randomised clinical trials.

Some fertility specialists recommend reserving DuoStim for carefully selected patients until more high-quality evidence becomes available.

For women with poor ovarian response or those facing urgent fertility preservation before cancer treatment, however, DuoStim addresses a challenge that conventional IVF cannot—it allows more eggs to be collected before time runs out.

Final Thoughts

If your previous IVF cycle produced only a small number of eggs or you're facing fertility treatment under significant time pressure, DuoStim may be worth discussing with your fertility specialist.

At MMC IVF, every treatment plan is tailored to each patient's ovarian reserve, fertility goals, and medical circumstances. Our fertility specialists can help determine whether DuoStim is the right approach for maximising your chances of building healthy embryos in the shortest possible time.

Book a consultation with MMC IVF today to explore your personalised fertility treatment options.

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