In 1959, a free booklet for 10-year-olds printed by the Kotex Co. extolled, with cheery drawings, that the onset of menstrual periods signified a girl was on her way "to becoming a young lady." Typical of that era, not a word of explanation about conception or its prevention was offered. Today, a half-century later, every preteen watcher of "Glee" knows that girls emotionally unready to become mothers nevertheless peak reproductively in their teens and early 20s.

A lot has happened to affect our baby-birthing status in those 50 years. The FDA approved medically prescribed oral contraceptives in 1960. Though married women had used birth control methods before then, it was never as effective as those small oval compacts. With other social changes that decade, women suddenly had access to jobs and educational opportunities and, in a fortuitous coincidence of timing, the new found ability to put off conceiving children, seemingly indefinitely. In a 1972 Supreme Court decision, the right to prescription birth control was expanded to unmarried women, and in another decision a few months later, the court further extended reproductive freedom by allowing pregnant women the choice of safe and legal abortion.

What the sisterhood did not see coming was the impact their collective liberation would have on the span of their individual fertility cycles. Today's women, particularly those in their 30s, understand that though ovum production ceases with menopause, the staleness date on their uteri can arrive about a decade earlier. While they were busy establishing themselves as adults, their biological capacity for motherhood was taking a nosedive.

Ria's recent evolutionary bulletin that our descendants' daughters will have (slightly) longer reproductive windows than their great-grandmothers may be good news for career women of the future, but today's potential "older" moms hoping to reproduce find themselves uncomfortably relying on scientific advancements to enhance their birth-giving schedule.

Thanks to the evolution of synthetic progesterone and its chemical sisters, fertility treatment for women is one of the fastest-growing and expensive areas of medicine. Until nature catches up with practical life choices, the assistance afforded by Clomid, hormonal injections or in vitro fertilization remains the last stand for well-insured ladies to find maternal happiness.