In order to reduce complications associated with the conventional IVF procedure, modified natural cycle IVF (mnc-IVF) and mild IVF (m-IVF) cycles have been adopted. However, there is speculation that the pregnancy and live birth rates may be lower with both these approaches compared to conventional cycles, probably due to the lower use of medicines and shorter treatment duration. Now, a 10-year Swedish study published in the journal, Reproductive BioMedicine Online highlights that mnc-IVF and m-IVF have comparable pregnancy rates to conventional cycles.
Arthur Aanesen and coworkers from the IVF Unit, Queen Sophia Hospital, Stockholm, conducted the study on 43 patients (129 cycles) and 145 couples (250 cycles) undergoing mnc-IVF and m-IVF, respectively, between 1996 and 2007. The results were compared to patients who underwent conventional IVF cycles during the same period. The study findings are listed in the table given below.
| Parameters Tested | mnc-IVF | m-IVF | Conventional IVF |
| Ongoing pregnancy rate/embryo transfer (%) | 26.7 | 27.2 | 34.3 |
| Ongoing pregnancy rate/embryo transfer for patients ≥38 years (%) | 0 | 17.5 | 27.0 |
| Cancellation Rate (%) | 53.5 | 39.6 | 13.7 |
It was also found that in comparison to the least expensive conventional IVF cycle, the medication costs were lower by 97.5% and 96.3% in the mnc-IVF and m-IVF groups, respectively. Based on the analysis, the researchers noted the following with respect to the two approaches when compared to conventional cycles.
• Acceptable pregnancy rates per embryo transfer
• Reduced medication cost
• Substantially decreased risk of complications
• Psychologically more acceptable to patients
Similar findings on the efficacy of mnc-IVF and m-IVF were reported in several other studies. In one such randomized open-label prospective trial, Heijnen et al (Nederlands Tijdschrift voor Geneeskunde, 2008) divided 404 subjects to receive either of the two:
• m-IVF: gonadotrophin releasing hormone (GnRH) antagonist for ovarian stimulation in combination with single embryo transfer
• standard treatment: prolonged stimulation using a GnRH agonist along with the transfer of two embryos
It was observed that cumulative pregnancy rates, which resulted in full-term live births after 1 year, were 43.4% and 44.7% in the mild and standard groups, respectively. Also, the multiple pregnancy rates and the overall cost were substantially lowered with mild treatment. The researchers support the use of m-IVF and single embryo transfer in clinical practice.
Similarly, Pelinck et al (Human Reproduction, 2007), in a single center study, indicated the mnc-IVF protocol as an effective treatment option for patients opting for IVF.
An earlier report of the International Society for Mild Approaches in Assisted Reproduction (ISMAAR) noted growing concerns regarding the extensive use of conventional IVF treatment (high stimulation protocol) and its associated limitations such as safety, patient discomfort, and cost. In view of this, numerous research groups are developing new treatment protocols to ensure:
• Lower risk of complications, such as ovarian hyperstimulation syndrome and multiple pregnancy
• Improved endometrial and oocyte quality
• Decreased financial and emotional burden to the patients
With evidence indicating that the advantages of mnc-IVF and m-IVF, there is a renewed interest and resurgence of these approaches in clinical practice. In an earlier review, Nargund and Frydman (Reproductive BioMedicine Online, 2007) indicated a trend towards a more patient-friendly approach in IVF, suggesting the likelihood of mnc-IVF or m-IVF replacing conventional treatment in down-regulated cycles.
References
1. Aanesen A, Nygren KG, Nylund L. Modified natural cycle IVF and mild IVF: a 10 year Swedish experience. Reprod Biomed Online. 2010 Jan;20(1)156-62.
2. Heijnen EM, Eijkemans MJ, de Klerk C, et al. Reduction of patient discomfort, risks and costs, but not pregnancies, by a mild strategy for in-vitro fertilisation. [in Dutch]. Ned Tijdschr Geneeskd. 2008 Apr 5;152(14):809-16.
3. Pelinck MJ, Vogel NE, Arts EG, Simons AH, Heineman MJ, Hoek A. Cumulative pregnancy rates after a maximum of nine cycles of modified natural cycle IVF and analysis of patient drop-out: a cohort study. Hum Reprod. 2007 Sep;22(9):2463-70.
4. Nargund G, Fauser BC, Macklon NS, et al. The ISMAAR proposal on terminology for ovarian stimulation for IVF. Hum Reprod. 2007 Nov;22(11):2801-4.
5. Nargund G, Frydman R. Towards a more physiological approach to IVF. Reprod Biomed Online. 2007 May;14(5):550-2.
