About One in Ten Women Is Still Fertile at Fifty
Body · The Reading Room · 8 min read · Why fertility fades rather than switches off, why a blood test cannot tell you when you are safe, and the age most guidelines actually use
Based on the published work of Andrew M. Kaunitz, MD, FACOG, Professor and Associate Chair of Obstetrics and Gynecology, University of Florida College of Medicine–Jacksonville, whose research and clinical writing focus on contraception and menopause. UF Health profile · UF College of Medicine–Jacksonville · the review in CMAJ
Fertility at this age does not switch off. It flickers. And a flicker is still a light.
Nine days late. Sore breasts. A faint queasiness at the smell of the coffee machine that you put down, reasonably, to a bad week.
You are forty-seven. Your periods have been all over the place for a year. Everyone, including your own sensible brain, has been telling you this is the transition, and it probably is.
But at eleven at night, standing in the bathroom, the question arrives in a very specific form: can you get pregnant during perimenopause? And the honest answer is not the one you were hoping to read.
Informational, not medical advice, and worth taking to your clinician rather than instead of one. This is a reading of published research and guidance. We are not clinicians; the findings belong to the researchers and institutions named below, and the plain-English version is ours.
The short answer: yes. Fertility falls steeply in your forties, but ovulation becomes irregular rather than stopping, so pregnancy remains possible until menopause is confirmed.¹ Andrew Kaunitz, a gynecologist who specializes in contraception and menopause, puts it plainly: at age 50, about 10 percent of women remain fertile.² Because hormone blood tests cannot reliably tell you when that has ended, guidelines generally advise continuing contraception until around age 55, or until you have gone a set time without periods.²³
The skim version
- Still possible: women in their forties have lower fertility and take longer to conceive, but still need effective contraception until menopause.¹
- In donor insemination studies cited by Allen, Cwiak and Kaunitz, the chance of conceiving per cycle fell from about 0.2 under 35 to about 0.06 over 40.¹
- About 10 percent of women remain fertile at 50, according to Kaunitz.²
- In the United States, 1,188 babies were born to women aged 50 and over in 2024.4
- FSH tests are not a reliable guide to when you can stop contraception.²³
- The UK Faculty of Sexual and Reproductive Healthcare says all women can stop contraception at 55, when spontaneous conception is exceptionally rare.³
In this article: How it is still possible · Pregnancy or perimenopause? · The myths, side by side · When contraception can stop · The one move · FAQ
Can you get pregnant during perimenopause?
Yes, and the reason is the same irregularity that makes the transition so frustrating.
In perimenopause, many cycles do not release an egg. But some still do, and there is no reliable way to tell in advance which ones. A cycle that follows two months of nothing can be an ovulatory one. That unpredictability is exactly what makes the late forties a risky time to assume you are finished.
Rebecca Allen, Carrie Cwiak and Andrew Kaunitz set out the picture in a 2013 review in the Canadian Medical Association Journal. Women in this age group have lower fecundity, meaning a lower chance of conceiving in a given cycle, and take longer to conceive. In the donor insemination studies they cite, the per-cycle chance fell from about 0.2 in women under 35 to about 0.06 in women over 40. Lower is not zero, and their conclusion follows directly: women who no longer want children still need effective contraception until menopause has occurred.¹
The national birth figures show it happening. In 2024 there were 1,188 births in the United States to women aged 50 and over, a number that has generally risen since 1997.4 Those figures do not say how many were planned or involved fertility treatment. The point is simply that the age at which pregnancy becomes impossible is later than most women assume.
What the research found
The review. Allen, Cwiak and Kaunitz, “Contraception in women over 40 years of age”, Canadian Medical Association Journal, 2013.
The finding. Women over 40 have lower fecundity and take longer to conceive, but still require effective contraception until menopause. The risks of miscarriage and chromosomal abnormalities rise markedly after 40, as do risks of gestational diabetes, high blood pressure, placenta previa, cesarean delivery and maternal death. For women without contraindications, hormonal methods can be continued safely until age 55.¹
The limitation: much of the fertility data comes from studies of women seeking to conceive, including donor insemination, which may not match natural conception in the general population. The review’s abortion figures are Canadian and from 2006. The direction of the evidence is clear; the exact odds for any one woman are not.
If a late period has become one more thing you are quietly managing along with everything else this year, it can help to see all of it in one place instead of in the bathroom at eleven at night. Start here.
The source for this piece
Andrew M. Kaunitz, MD, FACOG
Professor of Obstetrics and Gynecology at the University of Florida since 1994, Associate Chair of the Department of Obstetrics and Gynecology in Jacksonville, and Medical Director of UF Health Women’s Specialists–Emerson. His specialties are general gynecology, contraception and menopausal medicine. He received the American College of Obstetricians and Gynecologists’ Roy M. Pitkin Award in 2010, served as president of the Florida Obstetric and Gynecologic Society, and has served on the editorial board of the journal Menopause.
What we read: Allen, R. H., Cwiak, C., and Kaunitz, A. M., CMAJ, 2013,¹ and his published interview on contraception in perimenopause.²
Where to follow his work: UF Health Jacksonville · UF College of Medicine–Jacksonville · Kaunitz on Women’s Health, Medscape · MDedge author page · Florida Obstetric and Gynecologic Society presidency
Is it pregnancy or perimenopause?
From the inside, they can feel almost identical, which is the whole problem.
A late or missed period, tender breasts, tiredness, nausea, mood changes: every one of those is a normal feature of the transition, and every one of them is also an early sign of pregnancy. There is no way to tell them apart by how you feel.
There is, however, a very cheap way to tell them apart by testing. A home pregnancy test detects the pregnancy hormone, which perimenopause does not produce. If you have had sex without contraception since your last period, the test answers in three minutes the question that would otherwise sit in the back of your mind for a week.
Can you get pregnant during perimenopause? The myths, side by side
| What many women assume | What the evidence says |
|---|---|
| “My periods are irregular, so I am not ovulating” | Some cycles still release an egg, unpredictably. Contraception is needed until menopause¹ |
| “Nobody gets pregnant at 50” | About 10 percent of women remain fertile at 50;² 1,188 US births to women 50+ in 20244 |
| “A blood test will tell me I am safe” | FSH is not a reliable guide to when contraception can stop²³ |
| “Hormonal contraception is not safe in my late forties” | For women without contraindications, hormonal methods can continue to 55¹ |
| “Symptoms will tell me which it is” | Early pregnancy and perimenopause share symptoms. A test is the only quick way to know |
Five beliefs that feel like common sense, and each one has a specific answer. None of them needs a crisis to resolve.
Who else has measured this
Rebecca H. Allen, MD, MPH, of The Warren Alpert Medical School of Brown University and Women & Infants Hospital of Rhode Island, trained in family planning at Harvard and is first author of the 2013 CMAJ review on contraception in women over 40.¹
Women & Infants Hospital · Doximity profile
Carrie Cwiak, MD, is co-author of the same review with Allen and Kaunitz.¹
the 2013 review in CMAJ
The Faculty of Sexual and Reproductive Healthcare, the UK professional body for contraception, sets out when women over 40 can stop contraception, noting that effective contraception is required until menopause and that measuring hormones does not give accurate information on when to stop.³
FSRH guideline: Contraception for Women Aged Over 40 Years
The National Center for Health Statistics at the CDC publishes the national birth data, including births to women aged 45 and over.4
Births: Final Data for 2024
Lower is not zero. It never was.
When can you stop contraception in perimenopause?
Later than most women think, and not on the strength of a blood test.
Kaunitz is direct that FSH, the hormone often tested in perimenopause, is not a reliable guide because it varies too much. He follows the broad consensus of continuing contraception into the mid-fifties, around 55, when the likelihood of conception becomes very low.² The UK guideline reaches the same age: all women can stop contraception at 55, because spontaneous conception after that is exceptionally rare. Depending on the method a woman uses, it describes earlier stopping points based on a year without periods for women over 50, or two years for women under 50.³
There is a practical upside, too. Kaunitz notes that women using hormonal contraception can move directly on to menopausal hormone therapy when the time comes, without a hormone-free gap or laboratory testing.² The contraception conversation and the menopause conversation can be the same conversation.
When this belongs with a doctor
If a pregnancy test is positive, contact a clinician promptly, whatever you plan to do, since pregnancy after 40 carries higher risks that are worth monitoring early. Get urgent care for one-sided pelvic pain, shoulder-tip pain, fainting or heavy bleeding with a positive test. If you smoke, have high blood pressure, migraine with aura or a history of clots, ask which contraceptive methods are safe for you.
The sentence to take with you: “I am in perimenopause and I do not want to get pregnant. Which contraception suits my health, how long should I continue it, and can it help with my symptoms or move me onto hormone therapy later?”
The one move: test first, then settle the plan to 55
Two steps, in this order.
If your period is late and you have had sex without contraception, take a home pregnancy test tonight or tomorrow morning. It is the only thing that turns the question from a worry into a fact.
Then, whatever it says, book one appointment to settle the longer plan: which method, until when, and how it fits with any symptoms you are managing. A plan that runs to around 55, as the guidelines suggest,²³ means you never have to stand in the bathroom counting days again.
Common questions
Can you get pregnant during perimenopause?
Yes. Fertility is lower, but ovulation still happens unpredictably, so effective contraception is needed until menopause.¹ About 10 percent of women remain fertile at 50.²
How do I know if I am pregnant or in perimenopause?
The symptoms overlap heavily, including missed periods, breast tenderness, tiredness and nausea. A home pregnancy test is the reliable way to tell, since perimenopause does not produce the pregnancy hormone it detects.
At what age can I stop using contraception?
Guidance generally points to around 55. The UK Faculty of Sexual and Reproductive Healthcare says all women can stop at 55, with earlier stopping points possible after a year without periods over 50, or two years under 50, depending on the method.³
Can a blood test tell me if I can stop contraception?
Not reliably. FSH varies too much in perimenopause to be a dependable guide.²³
Is pregnancy after 45 risky?
The risks of miscarriage, chromosomal abnormalities, gestational diabetes, high blood pressure and other complications rise markedly after 40.¹ Early contact with a clinician matters if a test is positive.
The one move
Late period and unprotected sex: take a test now. Then book one appointment to agree a contraception plan that runs to around 55.
If this is one of several things the transition has made uncertain at once, seeing them together on one page can take some of the weight off. Start here.
You are very probably in the transition. Probably is simply not a contraception plan.
Related reading: why the cramps can come without the period, how long each stage of the transition lasts, and telling perimenopause apart from other causes.
On the researchers. Andrew Kaunitz and Rebecca Allen are gynecologists cited for published reviews and commentary on contraception after 40; neither is your clinician, and the fertility figures describe groups of women rather than any individual’s chances.
Sourcing, disclosure and disclaimers
This is not medical advice. Blue Leaf Journal publishes general information for a general readership. Nothing here is a diagnosis, a treatment recommendation, or a substitute for care from a clinician who knows your history. Informational, not medical advice: see your clinician.
We are not clinicians. Blue Leaf Journal is an independent publication and its bylines carry no medical or academic credential. We read published research and translate it. The findings belong to the researchers and institutions named and linked above; the plain-English rendering is ours, and so is any error in it.
No affiliation and no endorsement. Blue Leaf Journal is not affiliated with Andrew M. Kaunitz, Rebecca H. Allen, Carrie Cwiak, the University of Florida, Brown University, Women & Infants Hospital, the Faculty of Sexual and Reproductive Healthcare or the CDC’s National Center for Health Statistics. None of them has reviewed, approved or endorsed this article, and none of them is responsible for it.
No commercial relationship. Nobody named above paid for or was paid for this coverage. There are no affiliate links, no sponsored placements and no product recommendations in this article.
How this was checked. Every figure above was checked against the cited source on 16 September 2026, and each source is linked below. If you find something we have got wrong, write to norawhitfield@blueleafjournal.com and we will correct it and say that we did.
References
1. Allen, R. H., Cwiak, C., Kaunitz, A. M. “Contraception in women over 40 years of age.” Canadian Medical Association Journal, 2013, 185(7):565. cmaj.ca
2. Contemporary OB/GYN, “Helping perimenopausal women make informed contraceptive choices, with Andrew Kaunitz, MD”.
3. Faculty of Sexual and Reproductive Healthcare, “Contraception for Women Aged Over 40 Years”, 2017, amended 2025.
4. National Center for Health Statistics, “Births: Final Data for 2024”, National Vital Statistics Reports.
Keep reading
Nora Whitfield writes for Blue Leaf Journal, where the working rule is that a mechanism you can name is easier to live with than one you cannot. She reads the limitations section before the conclusion, and passes on what she finds there.
Written by Nora Whitfield for Blue Leaf Journal. Updated: 16 September 2026.
