Comments by:
Michael Alper , USA
Sherman Silber, USA
Dominique De Ziegler, France
Norbert Gleicher, USA

The below protocol was developed by Prof. Kuang and his team at the Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, China. The unit performed more than 7,000 IVF cycles a year with 100% of Frozen Thawed Embryo transfer with 55-60% pregnancy rate in women age below 38 y.o..
This protocol is based on double stimulation during the same cycle, using letrozole, clomid, hMG and GnRH-agonist. The unique of this protocol is that there is the second stimulation takes place during the luteal phase, it allows retrieving more oocyte (which suits the poor responder group) with the eradication of OHSS.

The above mentioned protocol enables to stimulate the patients twice during one cycle. All embryos are being cryopreserved and being replaced in a subsequent natural cycle (or controlled stimulated cycles). In this protocol it is feasible to perform ovarian stimulation and capture good-quality oocytes in the luteal phase and the possibility to develop OHSS do not exist.

The protocol is based on initial stimulation by letrozole 2.5 mg/d and clomid 25 mg/d from the second day of the cycle, for the first 4 days. On day 6, the letrozole is being replaced with hMG, 150 IU/d every second day while the clomid continue. Monitoring is done with ultrasound and estrogen serum concentration to determine the day of GnRH-agonist administration, which induces final stage of oocyte maturation to be followed by egg collection. All embryos developed are being cryopreserved.

The regimen for the second stimulation, which is started 2-3 days after the first egg collection, is started with letrozole 2.5mg and HMG 225IU every day. After 7-8 days of stimulation an ultrasound examination is performed to follow the treatment. When the leading follicle reach the diameter of 14 mm letrozole is being stopped while hMG still continue in a dose of 225 IU/d. Final oocyte maturation is again being stimulated by GnRH agonist (triptoreline 0.1mg), to follow by egg collection 32-36 h following the drug administration. Again, all available embryos are being cryopreserved.
This unique stimulation protocol eliminates OHSS at all, and allows retrieving more oocyte from poor responder patients.

More details about the protocol and the results will be presented by the unit team at the BCGIP-COGI in Shanghai, 21-24 November 2013.

Points for discussion

1. Why to use both Clomid and letrozole? (Response by Dr. Qiuju Chen from the unit team)

Clomid and letrozole have different mechanisms to promote dominant follicles development and we presume it is possible to cooperate with each other. This is the main reason we use both clomid and letrozole although we did not do research of controlled trial of both drugs compared with each drug.

2. Why to continue Clomid to the time of GnRH-agonist administration? (Response by Dr. Qiuju Chen from the unit team)

One previous report demonstrated that the addition of CC to HMG during ovarian stimulation showed beneficial effects of CC during ovarian stimulation to prevent a premature LH surge in COS/IUI [1]. Our studies showed in a long protocol of GnRHa/ HMG, adjuvant CC to HMG in the late follicular phase resulting lower serum LH level on the hCG day compared with those on CC starting day [2]. A recent study reported the regimen of HMG in combination with CC in mid-to-late follicular phase resulted in the same pregnancy outcome as short protocol. The serum LH concentration on day 8-10 was similar with that on the day of hCG administration (2.43±1.92 IU vs 2.51±2.05IU). These evidences showed that adjuvant treatment with CC in mid-to-late follicular phase may take the advantage of suppressing premature LH surge [3]. Later we found that CC 25mg had the same effect as 50mg so reduced the dose to 25mg in the regimen.

Reference
1. Al-Inany H, Azab H, El-Khayat W, Nada A, El-Khattan E, Abou-Setta AM. The effectiveness of clomiphene citrate in LH surge suppression in women undergoing IUI: a randomized controlled trial. Fertil Steril. 2010; 94(6):2167-71
2. Kuang YP, Wu S, Hong QQ. Application of clomiphene citrate in middle-late phase of controlled ovarian hyperstimulation for LH surge suppression. The Journal of Reproductive Medicine. 2010; 10(19):13-17 ( in Chinese).
3.Kang Y, Hong QQ, Chai WR, Fu YL, Ai Ai, Chen QJ, Kuang YP. Clomiphene citrate as an adjuvant to HMG stimulation of the ovaries in mid-to-late follicular phase and subsequently pregnancy outcome of frozen-thawed embryo transfers. Journal of Reproduction and Contraception, 2013; 24(1):10-20

3. Why to add letrozole to the second stimulation protocol? (Response by Dr. Qiuju Chen from the unit team)

Letrozole is an important factor in the regimen of luteal–phase ovarian stimulation but we do not fully understand the inherent mechanism until today. Our first case is an occasional success that initiated ovarian stimulation with HMG and letrozole from day 3 and convert into luteal phase unwarily, with a satisfactory ovarian response and pregnancy outcome (detailed in attached file). We had attempted to perform ovarian stimulation in the luteal phase with only HMG and found the stimulation duration was very long (20.6 days) and low-efficient in the preliminary phase. The adjuvant administration of letrozole appeared to increase the sensitivity of follicles to gonadotropins and reduce the stimulation duration (10.2 days), but the specific mechanism should be further investigated.

Comment to the new Shanghai protocol of Double stimulation during one cycle

By Michael Alper , USA

· Interesting approach. I would be concerned about the quality of the eggs and embryos derived from the second stimulation. Where implantation rates the same from embryos from follicular or Luteal stimulation?
· Given the minimal stimulation, how many extra eggs are obtained from the Luteal stimulation
· What is the true advantage..... save a couple of weeks of time? If used in poor responders there is no concern about OHSS.
· What are the outcomes data with this approach?

By Sherman Silber, USA

The Shanghai group actually learned the mini-ivf protocol from the Kato Clinic originated by Dr Shokichi Teramoto, who began doing this and promoting it decades ago.

Then Dr John Zhang and myself modified it, as it was very unpopular around the world because of the problem of premature ovulation. That is, clomid suppresses the LH surge partly but does not always completely block it, resulting in a premature LH surge and premature ovulation in 10 to 20 per cent of cases of mini-ivf. So it never became popular.

However, then we modified it in the united states to solve that problem in two ways:
1) Give indocin (indomethacin) at the time of the GnRH agonist trigger so as to give you several hours of grace before ovulation occurs even if there was a premature LH surge.
2) Follow the LH daily as the clomid will prevent a sudden surge. As the LH "creeps" up first before surging, you can then add 8 micrograms of antagonist, a very low dose, and avoid the premature surge that way. We have already published this in RBMOnline several years ago.

Zhang J, Silber S. Response: low-intensity IVF: real progress? Reprod Biomed Online. 2012 Feb;24(2):254.

I am currently in St Louis writing up our remarkable experience strictly with women over 40 and women with low ovarian reserve, for whom this technique is especially useful.

By Dominique De Ziegler, France

Ever since IVF existed – now universally called assisted reproductive technologies (ART) – there have been women whose response to controlled ovarian stimulation (COS) is judged insufficient. These women are ungracefully yet, universally identified as being 'poor responders'. According to a recent ESHRE sponsored consensus conference – the Bologna conference (1) – it was determined that women whose oocyte yield was <3 oocytes qualified as 'poor responders'.

The medical community as a whole is at a loss when it tries to figure out which is the best possible regimen capable of improving the ovarian response of so-called 'poor responders'. In a seminal publication Schoolcraft et al. (2) reported that the micro-flare protocol – a short-type reduced-dose GnRH-a protocol associated with 225IU of FSH and 226IU of hMG/day – performed particularly well. In a comparative trial, the micro-flare protocol was later found to be equaled by a typical 300IU-FSH regular antagonist protocol (3). In short however, it is just sheer honesty to recognize that none of the COS options proposed for poor responders are remarkable. We therefore have to humbly admit our inability at efficiently handling women whose ovarian response to COS is below average.
In this context, the findings made by Prof. Kuang and his team at the Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, China are most intriguing and interesting. Briefly, these investigators initiated a classical letrozole (2.5mg/day) and clomiphene citrate (CC) on day 2 of the cycle for 4 days. Starting on the next day (cycle day 6), letrozole was discontinued and replaced by hMG (150IU) every other day, while CC was continued. When the presence of pre-ovulatory follicles was witnessed on ultrasound, ovulation was triggered with GnRH-a, the oocytes retrieved and all the embryos obtained cryopreserved.
Two to three days after the 1st oocyte retrieval, the investigators initiated a second COS, using letrozole (2.5mg/d) and hMG 225IU/day until an ultrasound was done for assessing follicular maturation. Letrozole was stopped as soon as the leading follicle reached 14mm in diameter, while hMG (225IU) was continued until this second cohort of follicles reached maturity and ovulation was triggered using GnRH-a. Oocytes were collected 36h later and embryos were cryopreserved. .
These investigators underscore the astuteness of their approach, which enables maximizing the number of oocytes available – and thus, number of embryos to choose from – while limiting the increase in the duration of the treatment. It is certainly remarkable that the ovaries respond to the 2nd stimulation so close from the 1st one. The astuteness of this innovative approach revolves also around the triggering of ovulation with GnRH-a – rather than hCG – and the combination of letrozole and CC together with hMG. This approach – most provocative – may open to brand news avenues for treating ART patients notably those whose ovarian response is weak. We eagerly await a comparative trial assessing the relative merit of this brand new approach to the problem caused by poor response to COS in ART against the outcome of the classical approaches used to this date.

References
1. Ferraretti AP, La Marca A, Fauser BC, Tarlatzis B, Nargund G, Gianaroli L. ESHRE consensus on the definition of 'poor response' to ovarian stimulation for in vitro fertilization: the Bologna criteria. Hum Reprod 2011;26:1616-24.
2. Schoolcraft WB, Schlenker T, Gee M, Jones GS, Jones HW, Jr. Assisted hatching in the treatment of poor prognosis in vitro fertilization candidates. Fertility and sterility 1994;62:551-4.
3. DiLuigi AJ, Engmann L, Schmidt DW, Benadiva CA, Nulsen JC. A randomized trial of microdose leuprolide acetate protocol versus luteal phase ganirelix protocol in predicted poor responders. Fertility and sterility 2011;95:2531-3.

By Norbert Gleicher, USA

What the Chinese are doing is exactly where we are currently trying to go. What our experience with DHEA/androgens has taught us is that we need to go away from treating the menstrual cycle unit, and especially the 2 weeks of gonadotropin sensitivity, and start treating the whole process of follicle maturation from recruitment on as one cycle. This will be the new treatment paradigm for infertility for the next 20 years until stem cells will take over.