Women in their 30s experienced the highest increase in fertility rates. The increase was driven by women who were more educated. This increase is closely tied to rising wage inequality. As wages increase, the relative cost of child care is lower. Therefore, high-wage women are more likely to be able to afford child care, leading to an increase in fertility.
Rise in wage inequality
A study in the United States has examined the relationship between income and fertility and the rise in wage inequality. The study found that fertility was decreasing in a population that had a decline in income inequality. This result is consistent with the Kuznetz curve, which shows that inequality has an inverted U-shape relationship with average income. However, there are other factors that could account for this result, such as the rapid abandonment of farming and the diffusion of knowledge that influences reproductive preferences.
Declining fertility is not just a problem for women. A number of factors may be to blame. These factors include economic, political, and ideational factors. The financial crisis, for example, may have contributed to the decline in fertility by creating economic uncertainty. However, the overall pattern of decline in fertility has remained consistent across all Nordic countries and across educational categories.
Loss of ovarian reserve
Loss of ovarian reserve occurs when there is a decrease in the number of eggs that are mature and fertile. This is caused by a variety of factors, including genetics, age, and medical conditions. While many women who lose their ovarian reserve can still conceive, others may require treatment. In some cases, a woman with diminished ovarian reserve may require a donor egg to help conceive. This treatment involves using eggs from a donor who is younger than the recipient woman, which increases her chances of conception.
Changes in sperm counts
One theory suggests that sperm counts are plummeting because of a recent increase in exposure to endocrine disruptors, or chemicals that mimic hormones. However, other research has found that exposure to these chemicals during fetal development can affect male sexual development. However, there’s no reliable data on global sperm counts.
IVF treatments are now widely used to increase fertility. In 2014, almost half of all women under 35 who underwent IVF treatments gave birth to a live child. Of these, 11.8% were twins, and 0.4% were triplets. Because of the growing demand for IVF, more research is being conducted and more technologies developed. The majority of IVF cases involve infertile couples who are trying to conceive a child. Couples are also increasingly opting for this treatment in an effort to avoid the passing of single-gene mutations to their child. In addition, the use of donor sperm is now more common for couples who are unable to conceive. Some clinics have even made gestational carriers available to women who are unable to carry their own child.
Age-specific fertility rates
A good way to compare the rates of fertility in different countries is to look at age-specific fertility rates. This means looking at the rates of women at a particular age. In 1980, for example, the total fertility rate was 1.84 children per woman. In that year, girls aged 15 were expected to bear 1.84 children. Today, we can see that age-specific fertility rates have decreased dramatically.