Over the past century, social progress has greatly altered the age at which women opt to have children. Whereas most women in the past gave birth in their early twenties or teens, the trend has since dramatically changed. Women in nations such as the U.S., South Korea, and in Europe are now delaying motherhood to well into their 30s. Indeed, the average age of first-time mothers in most OECD countries now stands at about 30.But biology has not kept pace with society. Women's fertility is still tied to the natural aging of a woman's reproductive apparatus – something that modern medicine is always trying to get around. With career aspirations, education, and individual choice rewriting the schedules of motherhood, an urgent question presents itself: how far can we push back female fertility?How Does The Biological Clock Work?At the very center of female fertility is a game of numbers – one that is decided even before a girl is born. Women are born with a limited number of eggs, usually one million. By the time they reach puberty, this count drops to about 300,000. Of these, only some 300 to 400 will ever develop and get released during ovulation.By age 37, egg stores decrease to around 25,000, and by age 51 – the average age of menopause in the United States – only 1,000 are left. Yet, ovulation and fertility do not necessarily persist up to menopause. In the majority of women, natural fertility declines sharply 7 to 10 years before, typically by the early 40s.Though this fall has been around for some time, its raw statistics still stun: natural conception chances fall from about 25% per cycle during a woman's 20s to less than 5% per cycle by her 40s.What Does the Egg Supply Do at Each Age?More important than the declining egg quantity is the sharp decline in egg quality with advancing age. Each egg contains chromosomes that make up the DNA map for a new life. When egg quality falls, so does the chance for a successful pregnancy.By age 30, nearly 25–30% of a woman’s eggs may carry chromosomal abnormalities. By 35, this rises to 40%, and after 40, it spikes dramatically. Studies show that beyond age 40, up to 75% of eggs may have abnormalities. Such eggs are less likely to fertilize, implant, or lead to a healthy baby.The dangers posed by low quality of eggs are miscarriage, unsuccessful fertility treatment, and chromosomal abnormalities such as Down syndrome.How Far Can Science Go in Extending Fertility?With the help of improvements in assisted reproductive technologies (ART), the limits of biological fertility are gradually being extended. Methods like egg freezing (oocyte cryopreservation), in vitro fertilization (IVF), and the employment of donor eggs have helped many women give birth well into their 40s – and, in some instances, even their 50s.Egg freezing, specifically, has been a game-changer. It enables women to save their younger, healthier eggs to use later in life. It's not a surefire insurance policy, though. Success is dependent on age at the time of freezing, number of eggs saved, and overall health.Nevertheless, though technology may provide additional time, it will not halt the natural aging of the ovaries or enhance the genetic quality of aging eggs. There is still a biological limit.Decrease in Male Fertility LevelMen, too, experience a decline in fertility – but it tends to occur more gradually. Starting around age 40 to 45, men see a drop in sperm quality and volume, but they often retain the ability to father children into their 60s and beyond. Unlike women, men continuously produce new sperm, whereas women are working from a non-renewable stockpile of eggs.This disparity implies that while more and more couples are opting to wait to have children, the responsibility of the "biological clock" remains mostly on women.Although most of the discussion about female reproductive aging centers on wanting to have children, it is important to note that it also marks more general changes in a woman's health – specifically the onset of menopause and its attendant risks. Perhaps one of the most important but most underappreciated is the increasing significance of regular reproductive screenings, particularly as women get older.Among these, cervical cancer screening stands out as a powerful tool to protect women’s health beyond their childbearing years.Pap smears and HPV testing are able to pick up on abnormal cell changes before they develop into cancer. Because the immune system shifts with age and hormonal changes impact cervical health, regular screening is even more important. Women in their 30s and 40s – the same time frame when fertility is actively shifting – need to continue to be vigilant about their yearly OB-GYN checkups.Actually, while women are thinking of or undergoing fertility treatments or assessing their reproductive future, this is the ideal opportunity to make sure their cervical health is under surveillance. New technologies in at-home HPV testing, liquid-based cytology, and co-testing provide more convenient and precise diagnoses ever before.So is there a boundary beyond which female fertility can be prolonged? Biologically, yes. Despite incredible scientific strides, the natural aging of eggs and of the ovaries places limits that technology can only stretch so far.Yet reproductive health is more than fertility. By broadening the story to encompass cervical screenings and preventive care, we give women the ability to take holistic control of their reproductive path – whether they opt to become mothers at 25, 35, or older because prolonging fertility isn't merely about having the capacity to conceive, it's about maintaining a lifetime of reproductive health.