Improved implantation and ongoing pregnancy rates after single embryo transfer with an optimized protocol for in vitro oocyte maturation in women with polycystic ovaries and PCOS

Improved implantation and ongoing pregnancy rates after single-embryo transfer in women with polycystic ovaries or polycystic ovary syndrome result from a modified in vitro maturation protocol.

Stephen M. Junk, Ph.D. and Doreen Yeap, M.B.B.S., F.R.A.N.Z.C.O.G.

Volume 98, Issue 4, Pages 888-892, October 2012


To describe an optimized protocol for oocyte in vitro maturation (IVM) that achieves improved implantation and ongoing pregnancy rates in women with polycystic ovaries (PCO) and polycystic ovary syndrome (PCOS).

Prospective cohort study.

Hospital fertility unit.

Women with PCO and PCOS undergoing treatment for infertility.

Follicle-stimulating hormone (FSH) priming, IVM, blastocyst culture, hormone replacement therapy.

Main Outcome Measure:
Clinical pregnancy rates

Our optimized IVM protocol achieves implantation and ongoing pregnancy rates comparable to in vitro fertilization. From 66 oocyte collections, 844 oocytes were collected (12.8 oocytes/cycle), 588 oocytes matured after IVM (69.7% maturation rate), 420 oocytes fertilized after ICSI (71.4% fertilization rate), and 175 blastocyst-stage embryos resulted (41.7% blastocyst-development rate). Of these, 62 blastocyst-stage embryos were transferred as single embryos, resulting in 29 clinical pregnancies (43.9%/oocyte collection, 46.7%/embryo transfer) and 28 live births (42.4%/oocyte collection, 45.2%/embryo transfer).

In women with PCO or PCOS, improved implantation, clinical pregnancy, and live-birth rates can be achieved after single-embryo transfer by the use of an optimized IVM protocol.

  • We have used a double flushing needle. Initially we tried single lumen, but due to the low volumes of the follicles the needle kept clotting with blood. Most protocols describe a lower vacuum pressuure for IVM due to the possible fragility of the immature oocytes. We have however used a higher pressure – normally around 160-170. We have seen no problems with oocyte damage using this increased pressure.
    Blood is collected for serum using a non-toxic syringe when the patient E2 starts to rise.

  • Bert Stewart

    Hi Steve, just wanted to clarify a couple of things on their clinical
    protocol and see where it may differ to ours (our lab protocols have followed yours to the letter but without the same results)

    The article
    describes using a ‘flushing technique’ with a standard 16g needle. It does not mention whether or not it is a single or double lumen needle. IVM usually uses reduced vacuum for aspiration, what would yours be set at…or even more accurate, what would be the flow rate in ml/min using the described pick-up needle?

    Our patient serum has come from bloods taken at fairly random days of their cycles. Do you have a set day to take the blood for the serum? Is it taken by syringe or a vacutainer?

  • Micah Hill

    Thank you. That is unexpected but makes sense from your explanation!

  • Interestingly, the smaller the follicle the less flushing that seems to be required to retrieve oocytes for IVM. We believe that this is because the smaller follicles will obviously have a lower volume – therefore flushing will create a high turbulence in the smaller follicle and hence the removal of the immatiure oocyte from the follicle wall. The larger “IVM” follicles require somewhat more flushing as the pressure to remove the oocyte from the follicle wall is less due to the larger follicle volume. In these instances “small follicles” are <8mm and "larger follicles" are 10-12mm. The smaller follicles rarely require more than 1-2 flushes where as the larger follicles normally require 3-4 flushes to retrieve the oocyte.

  • Micah Hill

    Thank you for the article. I have been interested in follicle flushing and there seems to be little evidence to support its use in routine IVF. However, there seems to be little data in its use in IVM, where biologically it makes much more sense that flushing might increase oocyte yeild. I was curious if the authors have any data from their IVM experience on flushing versus not flushing on such small follicle sizes for IVM?

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