Zhang et al (2010) described a minimal stimulation protocol christened “mini IVF” which was developed for patients desiring a less stressful and less expensive mode of IVF treatment to achieve a pregnancy. This protocol requires a reliable method for embryo cryopreservation such as vitrification, because of the negative impact of Clomiphene citrate on the endometrium.

The retrospective study included women who underwent a mini-IVF protocol from 2006 to 2009 in New Hope Fertility Center, NY, USA. In this series, patients were not denied treatment based on their day-3 FSH value or ovarian reserve. For fresh embryo transfer cycles, a day-2 or day-3 embryo was transferred, while in cryopreserved transfer cycles, a day-5 or day-6 blastocyst was transferred in a natural cycle or a hormone replacement cycle. The clinical pregnancy rate was better with vitrified–warmed embryo transfer cycles than with fresh embryo transfer cycles (41 % versus 20 %, respectively; P < 0.05). For women under 35 years of age and FSH 15 IU/L for fresh embryo transfers, the pregnancy rate per embryo transfer was 26.8 %, and for cryopreserved embryos, the pregnancy rate per embryo transfer was 47.7 % (P < 0.05). Interestingly, even for FSH > 15 IU/l, the pregnancy rate in women under 35 years of age was 52.6 %, and for those with FSH > 15 IU/l and over 40 years of age, the pregnancy rate per cryopreserved blastocyst transfer was encouragingly as high as 30.8 %. These results strengthen the argument for gentle stimulation protocols and vitrification in preference to standard conventional IVF stimulation protocols.

In a more recent study, Gandhi et al (2013) used an IVF Lite protocol for the treatment of poor ovarian responders. Poor ovarian response (POR) is not a rare occurrence in ovarian stimulation. The incidence of POR is 9.24 % in patients undergoing IVF treatment (Keay et al. 1997). Previous trials have shown that neither conventional IVF nor natural cycle IVF is an effective treatment option for poor ovarian responders (PORs) (Hanoch et al. 1998). Women with poor ovarian reserves, who commonly do not respond to conventional stimulation protocols, are left with few options when planning a family. Tarlatzis et al (2003), in their elegant systematic review, evaluating all the existing ovarian stimulation protocols applied to poor responders, have concluded that the exhausted ovarian apparatus is unable to react to any stimulation, no matter how powerful this might be. The low number of embryos available for transfer poses a great challenge in the management of PORs. A potential management of poor responders is to create a sufficient pool of embryos by accumulating vitrified good-grade embryos over several minimal stimulation cycles (ACCU-VIT). The option of accumulating embryos has become a promising reality with the advent of outstanding vitrification technologies. The study was undertaken to evaluate the efficacy of serial minimal stimulation IVF cycles with vitrification and accumulation of embryos followed by a remote frozen embryo transfer for the treatment of poor ovarian responders as compared to conventional IVF protocols. This approach allows the PORs to have consecutive cycles of embryo accumulation before the follicular reserve is depleted.

The retrospective data analysis included poor ovarian responders from June 2010 and November 2012. A total of 97 PORs underwent treatment with IVF Lite protocol, and 125 PORs underwent treatment with conventional IVF stimulation protocol. The patients identified as PORs based on the Bologna criteria were included in the analysis (Ferraretti et al. 2011). Embryos were vitrified using Cryotech vitrification protocol on day 3. Once six embryos were banked, a frozen embryo transfer was planned and a maximum of three embryos were transferred. The conventional IVF group showed a high ET cancelation rate. Interestingly, there was no significant difference in the number of MII oocytes between the two groups. The IVF Lite group had MII oocytes comparable to the conventional IVF group, with significantly less gonadotropins used. The IVF Lite group had a significantly higher percentage of good-grade embryos than the conventional IVF group. This suggests that when minimal stimulation is used, a cohort of few but better quality oocytes is obtained. The clinical pregnancy rate per embryo transfer was higher in the IVF Lite group (27.81 %) than the conventional IVF group (15.15 %). The cumulative pregnancy rate (CPR) per patient was much higher in the IVF Lite (48.45 %) than the conventional IVF group (24.0 %). The results demonstrate that the IVF Lite protocol consisting of MS-IVF, ACCU-VIT, and rET is a very successful approach in treating poor responders (Tables 11.1 and 11.2).