A pragmatic, multicentre, randomized double-blind controlled trial with an intention-to-treat analysis, of the use of preimplantation genetic screening (PGS) for aneuploidy by means of microarray comparative genomic hybridization (CGH) for the chromosomal analysis of the polar bodies (PB) of oocytes collected after ovarian stimulation for in vitro fertilization (IVF), and with the intention to assess the genetic competence of oocytes of advanced biological age, and the effect of this technique on reproductive outcome.

Inclusion Criteria:

• infertility as an indication for IVF or ICSI;
• patients between their 36th and 41st birthdays (at time of signing ICF i.e. max 40years and 364days at the day of signing the informed consent);
• BMI range 18 to 30 kgs per m2;
• patients prepared to accept transfer of up to two embryos;
• absence of any type of genetic abnormality in the patient's personal and family history;
• normal karyotype (optional)

Exclusion Criteria:

• treatment involving donor oocytes (donor sperm is allowed subject to local practice and regulations and provided karyotype of the sperm donor is available and normal);
• menstrual irregularity (<24 and >35 days);
• three or more previous failed IVF or ICSI cycles, with the present partner. (Definition of a failed cycle: 'absence of a clinical pregnancy relating to a treatment with embryo transfer resulting from oocyte retrieval for the current intended pregnancy and with the current partner; the transfers include transfers of fresh and frozen within this treatment; clinical pregnancy is defined as the presence of a gestational sac at the earliest ultrasound and includes early clinical miscarriage, late miscarriage and clinically confirmed extrauterine pregnancy, and excludes preclinical miscarriage (biochemical pregnancy); -
• three or more clinical miscarriages;
• poor response in any previous cycle;
• low ovarian reserve (At least one of the following two features must be present: (1) a previous poor ovarian response (≤ 3 oocytes with a conventional stimulation 119 protocol); (2) an abnormal ovarian reserve test (i.e. AFC < 5 follicles or AMH < 0,5 ng/mL)* (adapted from Ferraretti et al., 2011);
• cycles requiring surgical sperm recovery procedures;
• total asthenozoospermia and/or globozoospermia.
• any type of genetic abnormality or family history of genetic abnormality in subject or partner