The aim of the present study is to evaluate the effect of increasing the proportion of D-chiro-inositol (DCI) in a combination with myo-inositol (MYO) in improving fertility in women with polycystic ovarian syndrome (PCOS). Sixty women diagnosed with PCOS will randomly take twice a day for 12 weeks a capsule containing 550 mg of myo-inositol and 150 mg of D-chiro-inositol or capsules containing 550 mg of myo-inositol and 13.8 mg of D-chiro-inositol.

Polycystic ovarian syndrome (PCOS) is the most prevalent endocrinopathy in women of childbearing age. It affects 4-8% of the population and of them, approximately 74% present anovulatory cycles and, therefore, fertility problems.

Both myo-inositol and D-chiro-inositol are 2 natural substances that have been shown to improve ovarian function and metabolism in women with polycystic ovarian syndrome.

The aim of the present study is to compare the effect of 2 ratios of myo-inositol /D-chiro-inositol on parameters related to the fertility of women with PCOS.

It is a multicenter, controlled, randomized, double-blind, parallel-group, 12-week clinical trial which will be conducted in 13 public and private hospitals from Spain.

Inclusion Criteria:

• Being diagnosed with PCOS according to Rotterdam criteria.
• Being in in vitro fertilization treatment.
• Body mass index less than 30 kg/m2.
• Accept freely to participate in the study and sign the informed consent document.

Exclusion Criteria:

• Contraindication to perform techniques of assisted reproduction or stimulation of ovulation.
• Advanced state of endometriosis (III or IV).
• Classified as poor responder in fertility treatment.
• Premature ovarian failure.
• Severe male factor (cryptozoospermia).
• Few expectations of compliance and/or collaboration.