Mild Ovarian Stimulation (MOS)

Dr Knight is the Australia pioneer and recommends the new Mild Ovarian Stimulation approach in IVF treatment for most of his patients. The aim of MOS therapy is to help women get pregnant sooner while minimising side effects.

Because of the nature of this approach there are several advantages. These include:

  • Less drugs required, 8-10 days rather than 40 days
  • Less side effects
  • Less emotional drain
  • No blood tests
  • Less IVF clinic visits
  • Less embryo transfers per baby
  • Same number of babies per cycle as a traditional IVF cycle
  • Less expensive

MOS is a state-of-the-art procedure providing a safer, less demanding and more cost-effective alternative to conventional IVF where high doses of fertility hormones are applied to generate as many eggs for collection as possible. Unlike traditional IVF where as many eggs are retrieved in the initial treatment phase as possible MOS involves the retrieval of fewer developing eggs but ones of a higher quality. 1 This approach reduces the need for high doses of fertility hormones and in turn decreases potential risks to the patient.

Dr Knight notes that the side-effects and emotional burden associated with hormone treatment and daily blood tests are major reasons that couples drop out of IVF therapy. Mild ovarian stimulation is as effective as traditional IVF but without the same financial, physical and emotional drain.

While both techniques have been associated with similar pregnancy rates (31 percent in mild ovarian stimulation compared with 29 per cent in standard IVF) the essential difference is that MOS takes approximately two weeks less than traditional IVF, is matched to a woman’s menstrual cycle and involves fewer hormone injections and blood tests.


1. Verberg M.F.G. et al. Mild ovarian stimulation for IVF. Human Reproduction Update 2009. 15(1):13-29.

2. Collins J. Mild stimulation for in vitro fertilisation: making progress downward. Human Reproduction Update 2009. 15(1):1-3.