Reproductive potential in the older woman.

There is a definite increase in the number of women bearing children in the 30- and 40-year-old age groups. The total number of women who are 35 to 40 years of age in the United States is projected to increase 42% and the percent births to this age group is projected to increase 37%. This is apparently because of a trend to postpone childbearing and first birth due to women's career priorities, advanced education, control over fertility, financial concerns, late and second marriages, and infertility. Associated with this is an increase in visits to the infertility specialist for older women who have an intrinsic decrease in fecundity with advancing age. Although, on the average, a woman will not experience menopause until about 50 years of age, her effective childbearing period may stop almost a decade earlier. A woman in her late 30s and, especially, early 40s is at some disadvantage in terms of conception delay, ability to carry a chromosomally normal fetus until term, and risk of trisomic conception. Certain endocrinologic parameters have been identified for the woman entering the transition to menopause. Biologic aging of the hypothalamic-pituitary-ovarian axis is intertwined with changes in the endocrine milieu of the perimenopause and preperimenopause. Despite a clear association of decreased fecundity in older women due to multiple biologic and social influences, so long as the individual has regular cycles and essentially normal endocrine parameters, she should be a candidate for an expedited infertility workup and ovulation induction, if not more aggressive treatment. Her obstetric profile is much improved, except for an increase in congenital anomalies and chromosomal defects. Chorionic villus biopsy study or amniocentesis is advised in all cases, regardless of therapy.