In view of insufficient evidence to routinely use Preimplantation Genetic Screening (PGS) to improve success rates after IVF, we test the hypothesis that patients with advanced maternal age (AMA) have a higher implantation rate (IR) after embryo transfer (ET) of chromosomally normal embryos following PGS compared to patients who had an ET without PGS.

In a randomized controlled trial (RCT) in patients with AMA (≥ 35 years), the clinical IR per embryo transferred will be compared after ET on day 5 or 6 between the PGS group (embryo biopsy and analysis of chromosomes 13, 16, 18, 21, 22, X and Y) and the control group without PGS.

Inclusion Criteria:

• All couples with a medical indication for IVF and with a female age of at least 35 years are invited to participate in the study.

Exclusion Criteria:

• Cycles were excluded from the study if ≤ 2 fertilized oocytes were available on day 1 after oocyte retrieval (OR), or if ≤ 2 ≥ 6c stage embryos were available on day 3 after OR.