Doctors routinely warn women about age-related fertility risks lower chances of conceiving, higher chances of complications. But how much of that warning reflects the real numbers, and how much is overstated? The question came into sharp focus in 2017, when Professor Cathy Warwick, then head of the UK’s Royal College of Midwives, argued that fears around age and fertility were mostly unfounded, and that clinicians shouldn’t be pressuring women into having children earlier than they’re ready to.
Why the Conversation Started
The backdrop to her comments is a genuine demographic shift. In the UK, the average age for a first child rose from 23.5 in 1970 to 28.6 in more recent decades, and the number of first-time mothers over 40 has roughly trebled over the last thirty years. Warwick’s argument was that this shift shouldn’t automatically be treated as a crisis and the underlying research is more nuanced than a simple “fertility falls off a cliff” message suggests.
What the Data Actually Shows
A widely cited study published in the Human Reproduction Journal found that 86% of women aged 27–34 conceived within a year of trying, compared with 82% of women aged 35–39 a real but modest difference, not the dramatic drop-off many expect. The picture changes more noticeably after 40, though even here, the odds of conceiving naturally and delivering a healthy baby have improved over time as understanding of fertility has advanced.
Not everyone in the field agrees the risk should be downplayed, however. Adam Balen, chairman of the British Fertility Society at the time, pushed back on Warwick’s framing, pointing out that celebrities who conceive later in life often do so with help from IVF or egg donation a detail that rarely makes headlines. His concern was that not stating this publicly risks giving other women false hope about how easily late motherhood happens naturally.
The Numbers on Chromosomal Risk
Age-related risk isn’t limited to how easily someone conceives it also affects pregnancy outcomes. The risk of chromosomal abnormalities, including Down syndrome, rises significantly between 30 and 40; widely cited estimates put it at roughly 1 in 800 at age 30 versus roughly 1 in 100 at age 40, though the exact ratio varies somewhat between studies. Stillbirth rates follow a similar pattern, running higher for mothers over 40 compared with mothers aged 30–34. Because of this, non-invasive prenatal testing (NIPT) is now commonly recommended for all pregnancies, regardless of maternal age, rather than being reserved only for older mothers.
It’s Not Just About the Mother’s Age
One detail that’s often left out of this conversation: paternal age matters too. The average age of first-time fathers has followed a similar upward trend, and a meaningful share of children today are born to fathers over 40. Research increasingly points to paternal age as a contributing factor in some chromosomal and developmental risks, not just maternal age a reminder that fertility planning is rarely a one-sided conversation.
So, Is the Risk Overstated?
The honest answer sits between the two positions above. The data doesn’t support blanket alarm about trying to conceive in your mid-to-late 30s the drop in success rates over that period is real but gradual. At the same time, the risks after 40 are real and worth planning around, not dismissing. For anyone weighing these odds against their own timeline, understanding where donor eggs or IVF can help is often more useful than a single headline statistic. You can get in touch with our team to talk through what the numbers mean for your specific situation.
