Recently, it has been suggested that culture of embryos in EmbryoGen medium can increase the live birth rate in IVF patients with a previous history of pregnancy loss.

Couples requiring IVF treatment and with a past experience of miscarriage and/or biochemical pregnancy will be included in the study.

Controlled ovarian stimulation protocol will consist of an agonist down regulation and follicular stimulation by recombinant FSH. Fertilization will be achieved by standard IVF or intracytoplasmic sperm injection. Fertilized eggs will be cultured in 6% CO2, 5% O2, 89% N2 atmosphere in microdrops. In the treatment group EmbryoGen culture medium (EG, Origio, Måløv, Denmark) will be adopted throughout the culture period. In the control group, inseminated oocytes will be cultured in standard culture conditions, i.e. IMS1 medium (ISM1, Origio, Måløv, Denmark), maintaining unchanged all other culture conditions.

Procedures of embryo transfer, will be carried out on day 2 using EmbryoGen or ISM1 respectively. The endometrial support will be the same in the two groups.

The investigators will consider ongoing clinical pregnancy as the primary outcome assuming a 25% of increment in ongoing clinical pregnancy rate in the group with EmbryoGen medium. As secondary outcome the investigators will assume a 5% of increment in ongoing implantation rate after 12 weeks in the group with EmbryoGen medium.

Inclusion Criteria:

- At least one (maximum 3) miscarriage and/or biochemical pregnancy after ART treatment

Exclusion Criteria:

• Frozen spermatozoa
• Frozen oocytes
• women with PCO and PCOS
• women with more than 4 ART treatments

Infertile couple with an indication for standard IVF or intracytoplasmic sperm injection. Moreover all couples had at least a previous miscarriage and/or biochemical pregnancy experience after ART treatment.