General medical knowledge for the past 50 years has maintained that a woman's fertility drastically declines after age 35. This has caused many women in their late 30s and early 40s to go running to a fertility doctor at the first sign of difficulty conceiving. Some of these women may not have even been trying for a baby for very long, yet their desperation to have a child while they can leads them to go to drastic (and expensive) measures.

New studies, however, are challenging this outdated theory and turning our perception of women's fertility on its head. A growing number of researchers are now arguing that older women typically don't have any more trouble getting pregnant than younger women and that information to the contrary is based on outdated information. In fact, several recent studies show no correlation between a woman's age and her ability to get pregnant as long as she hasn't gone through menopause. Two medical studies this year have shown that 80 percent of women between the ages of 35 and 40 will get pregnant naturally within a year of trying to conceive (TTC). If these women had sex twice a week or more, the percentage rose to 82. These figures are only four percent lower than women younger than 35.

Most modern pregnancy books state that only two-thirds of women aged 35 and older will get pregnant naturally within a year of trying. This information that sends older women scrambling to the doctor for fertility treatments. They often go before they have even been trying for a year. They want to use whatever fertility they think they have left before it's too late.

Those studying fertility in older females, however, are finding that the evidence for some of the claims that female fertility declines with age is from French birth records between 1670 and 1830. One commonly cited article published in Human Reproduction in 2004 even used these birth records to claim that one-third of women between the ages of 35 and 39 will not become pregnant within a year of trying. Clearly, these records alone are not sufficient evidence for claiming the decline of female fertility with age.

According to Jean Twenge in her article called "How Long Can You Wait to Have a Baby?" there aren't actually many "well-designed" studies on age and female fertility involving 20th century women. However, the few studies there are show a more positive outlook for older women who want to get pregnant. The majority of modern studies indicate fertility seems to hold steady in women up to age 40. Even if we check historical records, there is proof of women getting pregnant into their late 40s. However, the current trend amongst fertility books and doctors seems to be to focus on the decline of female fertility with age, regardless of the lack of definitive evidence.

So, do women over 35 need to panic if they don't get pregnant within a month of trying? Not necessarily. The conventional medical wisdom among women younger than 35 states that you should only see a doctor if you haven't gotten pregnant within a year of trying. The most recent studies on age and female fertility seem to indicate that the same holds true for women over 35. In most of these women, natural conception within a year should not be a problem unless there is an underlying medical condition that's preventing it. A fertility doctor can often correct those conditions. First, however, a woman should try to conceive for a year.

Source:

• Twenge, Jean. "How Long Can You Wait to Have a Baby?" The Atlantic. June 19, 2013.
• Goldwin, Claire. "Is everything you thought you knew about fertility WRONG? A controversial new book claims getting pregnant after 35 is far easier than doctors say." DailyMail. July 24, 2013.