Gene expression in women conceiving spontaneously over the age of 45 years

Objective: To examine gene expression profiles of women conceiving spontaneously after the age of 45. Design: Expression profiling by complementary DNA microarray analysis. Setting: University departments. Patient(s): Eight women 45 years or older (study group) who conceived spontaneously and were 6 months after their last delivery were compared with six women aged 45 years old (control group) who had their last delivery before the age of 30. Intervention(s): Blood samples were collected from each woman for RNA isolation from peripheral blood mononuclear cells (PBMC). Main Outcome Measure(s): Expression profiles of PBMC isolated from each woman were determined by using Affymetrix DNA microarray analysis covering about 15,000 identified genes. Result(s): Microarray of global gene expression revealed 671 genes that showed statistically significant differential expression between the study and control groups: 383 genes were overexpressed and 288 were underexpressed. The most significant functional groups defining these genes were: apoptosis, ubiquitination, and energy production. As many as 60 genes also participated in ovarian physiology. Conclusion(s): These observations suggest that extended fertility is associated with a unique ability to enrich cellular processes, leading to delayed ovarian senescence.