Any woman with a ticking biological clock or a nagging mother-in-law dreads the looming "AMA" on her medical chart: Advanced Maternal Age (motherhood after the age of 35). Other couples are glad to spend their youth travelling the globe without a baby (or babysitter) in tow. The freedom The Pill has provided has given women the opportunity to hold off on motherhood until they are ready and given them the chance to focus on their careers. Egg donation, IVF and freezing one's eggs have lifted the fear of pregnancy before they are "prepared" for some couples.

This is progress, right? We, as a society, are so advanced in technology and so progressive in our thinking that it just seems natural that women are having babies at 38 and 42 instead of 18 and 22.

While that popular narrative does make sense and does hold truth, history shows that childbearing age has always been based on the culture and economics of a particular time period, according to an Op-Ed piece in Live Science.

Eugenicists in the early 20th century warned women that having a child before the age of 24 would cause the baby to suffer from the mother's immaturity (both biological and emotional). Having a child too soon after matrimony would also cause gossip and judgment.

The same manuals warned not to wait too long, though, or sterility would set in. The 1930s brought The Great Depression and more families were holding off on creating one more mouth to feed during that bleak economic time. American birthrates dropped, according to Live Science.

Editor of the Journal of the American Medical Association Dr. Morris Fishbein complained in 1942 that young couples were too selfish to have children, according to Live Science. Why have children when you can have state-of-the-art kitchen appliances?

It was only after 1945, when World War II ended, that couples started to have children earlier, according to Live Science. The economy was strong and the men were back from war - the "baby boom" lasted about 20 years. American birthrates were at their highest in 1957, with 96.3 births per 1,000 teens between the ages of 15 and 19. (Current adolescent females in the same age range have a birth rate of 26.6 births per 1,000 women).

In the 1970s, the age of a woman's first childbirth increased. More women were having their first child between the ages of 30 and 34. By 1986, the birth rate for women between 30 and 34 rose 140 percent over 1970 levels. Last year, the birth rate for a first pregnancy for women between ages 30 and 34 rose to 29.5 per 1,000 births.

The birth control pill and feminism helped to push back the age of first births starting in the 1970s, but there was also another reason, according to Live Science: the drooping economy.

Inflation rose and wage power fell. Two working parents became less of a feminist value and more of a necessity. Two salaries were required to maintain the middle income lifestyle that one salary used to uphold.

The post-war "baby boom" was not the standard by which we need to be held, according to Live Science. Early marriage and early childbirth was atypical.

The magic age at which a woman's ovaries wither away and blow away like tumbleweeds is supposedly 30, but according to Live Science, fertility is individual. Technology is not the savior for couples who have waited to have a family that includes children.

Carl Djressai, creator of the birth control pill, recently predicted that by 2050 all women will have to rely on IVF and egg freezing. Pregnancy would always be "tomorrow" without repercussions. According to Live Science, that future is not inevitable, but if having children is treated as an obstacle to economic growth and a hindrance to society, then Djressai might end up being right.