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Notes on Women's Health
Notes on Women's Health

Aging, Fertility and a Woman’s Biological Clock

Pregnant woman on bed American women are having babies later in life. The last few decades have seen the average age at which women have their first child gradually rise, and this trend has been particularly notable since 2016. According to the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics, more women are first becoming mothers in their thirties rather than their twenties. This is the first time this phenomenon has been observed in American history. Furthermore, the only segment of the population to see an overall increase in birth rates since 2016 is women over 40.

A combination of factors is likely driving this shift in average maternal age. Now that women have access to a plethora of educational opportunities and occupations, many choose to firmly establish their careers before having children. Additionally, advances in in-vitro fertilization (IVF) and other fertility treatments mean that older women are now more likely to have successful pregnancies than in the past. So, is there still such a thing as the biological clock for women today?

At What Age Does Female Fertility End?

As you may guess, there is no “magic age” when a woman loses her fertility. Although menopause is often associated with the end of fertility, the fact is that women gradually become less fertile years before menopause begins. The age at which a drop in fertility first begins varies among individual women, just as the age for puberty and menopause does. However, the American College of Obstetrics and Gynecology (ACOG) has stated that fecundity – or the ability to have children – starts to decrease among women at approximately age 32. It falls more sharply beginning at about 37.

Of course, there have been cases of women well into their fifties or even sixties delivering children, but this is the exception rather than the rule. As a general guideline, otherwise healthy women can expect increasing difficulty with fertility beginning at about their late thirties/early forties.

Why Does Female Fertility End?

Men also experience an age-related decrease in fertility but not to the same extent as women. There have been many reports of men in their eighties fathering children. But with women, age-related fertility is mainly tied to oocyte, or egg, count.

According to ACOG, a female has around 1-2 million oocytes at birth. By puberty, this number has decreased to about 300,000-500,000. At age 37, the average number of oocytes is only around 25,000, and at 51 – the average age of menopause in the US – women typically only have about 1,000 eggs. Of course, the greater the number of eggs present, the higher the chance of successful fertilization.

Is Your Biological Clock Ticking?

The term “biological clock” is often used to refer to a subjective increase in maternal feelings in childless women, particularly women around their late thirties. This is an ill-defined concept, but there are some more concrete physical signs that you may be experiencing – or may soon experience – a drop in fertility. These signs include unexplained fatigue, hot flashes, and changes in the volume and duration of your menstruation.

ACOG acknowledges that many women over 35 have difficulty conceiving. The group recommends that any woman over 35 who has unsuccessfully attempted conception for at least six months receive “expedited evaluation and undergo treatment.” Women over 40 should receive immediate treatment if they are having problems conceiving.

Your OB-GYN’s office should be your first stop for fertility issues and questions. They can often help, and, if necessary, refer you to a specialist in fertility medicine.

Pregnancy at an Older Age

Every year, a multitude of women in their thirties and forties have uneventful pregnancies and deliver healthy children. However, it is an inescapable fact that mothers over 35 have a higher risk of complicated pregnancies and certain birth defects among their children. These problems include – but are not limited to – high blood pressure or preeclampsia during pregnancy, gestational diabetes, preterm births, and chromosomal-related birth defects.

If you are over 35, you can mitigate these risks by consulting with your OB-GYN as soon as you decide to become pregnant and then following with them throughout your entire prenatal care. Good choices, such as taking folic acid and maintaining a healthy weight, are important even before conception. Adhere to your doctor’s instructions on diet, exercise, medication, and other matters. Note that you also may need more extensive prenatal testing and screening than many younger mothers.

About the Connecticut OBGYN Practice

Dr. John Garofalo, M.D., is an OBGYN located in Fairfield County, Connecticut, providing care for Norwalk, Darien, New Canaan, Weston, Rowaytan and the surrounding areas. He has more than 20 years of practice and surgical experience covering many facets of obstetrics and gynecology.

Laury Berkwitt, APRN, is a nurse practitioner specializing in women’s health in Fairfield County, Connecticut. Laury has a passion for providing quality women’s healthcare in a safe and comfortable manner by creating a trusting patient-practitioner relationship. She has been in practice for more than 10 years, caring for women of all ages.

For more information, go to www.garofaloobgyn.com. John Garofalo, M.D., and Laury Berkwitt, APRN, can be reached for personal consultations by calling 203.803.1098.