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Duo stimulation for IVF treatment

Patient information A-Z

Cambridge IVF

What is duo stimulation?

During a typical IVF cycle fertility drugs are used to allow the growth and transvaginal collection of multiple eggs and the creation of multiple embryos. Duo stimulation method is based on double ovarian stimulation during the same cycle. The stimulation starts as usual on the second or third day of a menstrual cycle and typically takes up to 14 days. The second ovarian stimulation starts a few days following the egg retrieval. The follicles which did not grow enough during the first stimulation phase can grow and mature during the second stimulation. In 10 to 14 days after the stimulation the second egg collection happens. This method allows the collection of an additional set of eggs from poor responder patients. Often in such protocol we achieve the growth of one-two follicles during the first stimulation phase, and up to five-six follicles, during the second stimulation phase, increasing the number of collected eggs by several times.

All resulting embryos undergo freezing (cryopreservation) on day 5 or day 6 (blastocyst stage) and a transfer of a subsequent frozen thawed embryo(s) will happen only during another cycle. There are no fresh embryo transfers in a duo stimulation cycle.

Who can benefit from Duo Stimulation?

  • Women with low ovarian reserve, women older than 40 years old (age factor) or younger women with Premature ovarian failure (e.g. due to surgical intervention)
  • Women with an anti-mullerian hormone (AMH) level lower than 5.4pmol/l
  • Women with a total number of antral follicles not more than five in both ovaries
  • Women who obtained not more than three poor quality eggs in a previous treatment cycle (irrespectively of the age of a patient).

Double stimulation IVF with asynchronous follicle growth

  • The doctor may offer you a transition to such stimulation scheme even after standard IVF program started if the doctor observes asynchronous follicle growth (one or two follicles are growing fast and the others are strolling in the back and remain immature before egg collection).
  • Second ovarian stimulation allows immature follicles to catch up. There are many examples of successful pregnancies among women with poor ovarian reserve who underwent a duo stimulation program.
  • However, duo stimulation IVF program is not a universal cure and cannot fit every patient (couple). Sometimes during ovulation stimulation a doctor observes the growth of only one or two eggs, with no other additional follicles in the ovaries. In such cases dual stimulation will not trigger any results, and the doctor will have to offer a different treatment plan.
  • Individualized approach to ovarian stimulation is our special feature which allows us to achieve the best results for all our patients

How successful is duo stimulation?

In a recent study conducted by Vaiarelli A and coworkers (1), 100 poor prognosis patients underwent a duo stimulation IVF cycle from among 310 poor responders. This study found that both stimulation phases yielded eggs with equivalent quality, but that the second stimulation helped to increase the proportion of patients who had at least one euploid (genetically normal) blastocyst from 42.3% to 65.5%. The second stimulation cycle also yielded more eggs when compared to the first stimulation cycle.

The live birth rate increased from 7% after the conventional IVF cycle to 15% after the duo stimulation cycle.

Is duo stimulation safe?

Duo stimulation has been successfully used in women for fertility preservation before undergoing cancer treatment. Luteal phase stimulation and freezing of all embryos or eggs have been proven to be safe due to their use for fertility preservation.

What are the risks of duo stimulation?

Duo stimulation is a new strategy and randomized controlled studies are not available at the moment. A cost benefit analysis has also not been performed.

There is a high risk of cancellation of the treatment cycle.


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Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151