How Perimenopause Affects Fertility and Pregnancy
Today’s posting addresses the topic of perimenopause, a crucial period in a woman’s life that takes place after her peak reproductive years but before she reaches menopause and her period stops. As this subject has only recently been explored in lay media, it’s little wonder why the possibility of pregnancy during this time is also seldom discussed. This can lead to confusion and even hopelessness for perimenopausal women who hope to conceive later in life. If you’re a woman in perimenopause who wants to have a baby — or if you know a woman in this situation — we think you’ll find this article both interesting and uplifting.
The CHR’s Editorial Staff
How Perimenopause Affects Fertility and Pregnancy
By Jaclyn Anglis, MA, who is a Communications Specialist and Editor at the CHR and as such is the Associate Editor for production on the CHR’s Editorial Board. She can be reached through the CHRVOICE or directly at janglis@thechr.com.
Right now, millions of women around the world are going through perimenopause. However, this important transitional phase before menopause remains widely misunderstood by the public. This paves the way for myths and misconceptions to spread about fertility and pregnancy during perimenopause, sometimes even wrongly leading women in their 40s to believe that they’ve missed out on their chance to have a baby.
Let’s therefore take a close look at what really happens to a woman’s fertility during perimenopause, what she can do to improve her chances of conceiving, and how a pregnancy during perimenopause differs from a pregnancy that happens during earlier reproductive years.
What is Perimenopause?
The American College of Obstetricians and Gynecologists (ACOG) defines perimenopause as the last few years leading up to menopause. During this time, the amount of estrogen produced by a woman’s ovaries starts to fluctuate, often leading to noticeable changes in her menstrual cycle before she eventually reaches menopause and her period stops entirely.1
“This is usually not an on-and-off switch,” explains Sonia Gayete-Lafuente, MD, PhD, a Fertility Specialist and Director of Medical Education at the Center for Human Reproduction (CHR). “There is usually a certain period of time at the end of our reproductive lifespan where our cycles become a little more irregular, sometimes cycles tend to shorten, sometimes we can skip some ovulation, because basically the ovaries are doing the best they can with the very little ovarian reserve that is left in there.”
Many women begin perimenopause around their late 40s, eventually reaching menopause by their early 50s.2 However, this can vary quite a bit. For women who reach early menopause, their perimenopause phase can begin while they’re still in their 30s.
Dr. Gayete-Lafuente says the number one sign of perimenopause is the emergence of constant period irregularities, but some other signs can include hot flashes, night sweats, mood changes, fatigue, insomnia, and low libido. According to ACOG, perimenopausal women may also experience vaginal dryness, leading to possible pain during sex and an increased risk of vaginal infections. As a woman’s ovaries work with a lower and lower number of eggs, her estrogen levels drop, leading to the above-mentioned unpleasant symptoms.
Since some of these symptoms can also occur during menopause, how does a woman know that perimenopause is over and she’s reached menopause? Clinically, doctors consider a woman menopausal if she’s gone one year — a full 12 months — with no menstrual period.
The Truth About Perimenopause and Fertility
Though menopause is well known among the public (who hasn’t seen a t-shirt or coffee mug with the classic joke, “I’m still hot, it just comes in flashes now”?), the same cannot be said for perimenopause. This has led to a widespread lack of understanding about what’s really happening to a woman’s fertility and her chances for pregnancy during this time.
“One of the biggest myths is that if you are perimenopausal, you cannot get pregnant,” says Dr. Gayete-Lafuente. “As long as there is an egg, there is still a chance. Of course, the chance will be lower than it would have been 10 years ago… but if there is an egg, there is always a chance of having an embryo and eventually having a child. A low chance is not no chance.”
Even after a woman has reached menopause and has no more eggs, she can still carry a pregnancy if she undergoes an embryo transfer with the appropriate hormonal support and treatment. This could be an embryo created with the help of an egg donor — or an embryo that was previously created by the aspiring mother herself during her reproductive years.
While a woman is still in perimenopause, she is no longer as fertile as she was in earlier years, but the specifics of her fertility can vary based on her age and any health conditions she has.
For example, a woman who starts perimenopause early in her 30s may have very few eggs, but they — possibly compensating for the low number — likely will be higher-quality eggs than those of a woman in her 40s. On the flip side, an older patient with polyendocrine metabolic ovarian syndrome (PMOS) — formerly known as polycystic ovary syndrome (PCOS) — may have a higher number of eggs than a younger woman. Though many of this patient’s eggs will probably be of low-quality, the larger number also provides more chances for a high-quality egg to emerge.
These differences are exactly why perimenopausal women need treatments specifically tailored to them if they’re interested in conceiving. According to Dr. Gayete-Lafuente, this should begin with a full evaluation of the woman’s age, health conditions that may be affecting her reproductive capabilities, follicle-stimulating hormone (FSH) levels, and the current state of her ovarian reserve. For women who have a diminished ovarian reserve (DOR), fertility doctors will want to do everything they can to maximize the amount and quality of her eggs in a treatment cycle. This often requires pretreatments of her ovaries to get them into the best possible shape and tailored ovarian stimulation before retrieving eggs during in vitro fertilization (IVF).
Under physician supervision, some women may find that androgen pre-supplementation may help in getting their ovaries into the best shape. The CHR prefers to do this through dehydroepiandrosterone (DHEA) supplementation rather than direct testosterone supplementation since the latter can more easily lead to over-supplementation. Normalizing abnormally low androgen levels can help ovaries with their response to the fertility treatments they undergo. Women may also consider limiting refined sugars and trans fats in their diets and adding more antioxidants — the Mediterranean diet is a good potential option here. “Antioxidants promote healthy fertilization, implantation, and embryo development, so that would be a way to improve their chances of success in a low interventional way,” says Dr. Gayete-Lafuente.
According to the European Society of Human Reproduction and Embryology (ESHRE), other potential adjustments to improve female fertility are avoidance of smoking and excessive drinking of alcohol, staying physically active, and maintaining a healthy weight.3
All combined, tailored ovarian stimulation, a carefully planned IVF cycle, and implementing the above-noted positive lifestyle changes can improve even a perimenopausal woman’s chances of still getting pregnant with her own eggs. But there, of course, never can be a guarantee that this will happen. If a patient doesn’t respond to fertility treatments or if she struggles to produce high-quality embryos, egg donation may, ultimately, have to be the way to go.
But what distinguishes the CHR from most other IVF clinics is that the CHR considers third-party egg donation to be – strictly – a last-resort treatment. If a patient reaches the point where she is convinced that only egg donation will make her a mom, then it becomes a wonderful treatment option, and by delivery, the woman will have forgotten where the egg came from because going through pregnancy with a developing fetus is what makes her the mom of this baby. That said, women who enter egg donation too early can sometimes face second thoughts later in life, wondering whether they couldn’t have also done it with their own eggs.
“Lots of patients are a little resistant to egg donation at the beginning,” says Dr. Gayete-Lafuente. “But after many years in the field, I also want to say that when women use egg donation as a last resort and are successful in having their baby, many repeat the experience and no one regrets. We nowadays have women in their 50s (and in full menopause) quite routinely having babies with the help of donor eggs. This can be seen as a testimonial from thousands of women from all over the globe. It’s really -ultimately - a beautiful experience.”
Important Things to Know About Being Pregnant During Perimenopause
As women grow older, there are more risks associated with being pregnant. These risks are usually not linked to perimenopause itself. This is, of course, especially true for women with premature ovarian aging, who, therefore, start perimenopause early, - often only in their 30s. But once perimenopausal women are in their 40s, they should be aware of risks related to their advanced maternal age before and after conception.
An important consideration is that at advanced female ages, the chromosomes in eggs can become imbalanced, leading to an increased risk of carrying a child with a chromosomal disorder, - a so-called aneuploidy. The likely best-known aneuploidy is Down syndrome (trisomy 21), which nowadays – together with other frequently occurring aneuploidies – is routinely screened for early on during pregnancies with a simple maternal blood test recommended for all pregnant patients regardless of age. More aneuploidies are also one reason why older pregnant women have a higher risk of miscarriages.
Older perimenopausal women can also have an increased risk of gestational diabetes, high blood pressure disorders (including so-called preeclampsia), and preterm labor. In principle, almost any medical problem increases in prevalence with age. This is especially the case with thyroid issues and heart problems. This is why it’s so important for perimenopausal women who still want to go through pregnancy to disclose all details of their past medical history to their fertility doctors — and why their doctors need to make sure that the patient and treating physicians can manage their patients appropriately and without surprises before and during a pregnancy.
The older a woman is, the more likely it is that she will require multidisciplinary care from a variety of doctors during her pregnancy — and not only from her obstetrician (her infertility doctor will already likely be out of her medical life). Depending on her specific needs, her care may require an adjustment of the medications she’s taking and/or making significant changes to her lifestyle.
Aside from making regular doctor’s visits and heeding professional advice, Dr. Gayete-Lafuente says there are also some other important, yet simple, ways in which perimenopausal women can prioritize their health during pregnancy. This is, of course, particularly important during the sweltering summer months. After all, the last thing you want to do while you’re pregnant is faint! Therefore, “remember to stay very well hydrated,” she says. “Many times, older women don’t tolerate heat well, or tend to get dehydrated easily, so it’s very important that they keep up with fluids because pregnancy is physically very demanding.”
Another thing to keep in mind is that your Vitamin D levels will decline while you’re pregnant because they are diluted in a ca. 40% larger blood volume. This can lead to other health risks. So make sure you’re either getting enough Vitamin D in your diet (it’s found naturally in cheese, egg yolks, and the flesh of fatty fish)4 or simply supplement with oral Vitamin D.
While pregnancy during perimenopause certainly comes with its challenges and vulnerabilities, there are plenty of ways to help improve your experience and protect your health during this important time. You, of course, owe it to your future self, and your new baby.
REFERENCES:
American College of Obstetricians and Gynecologists. “The Menopause Years.” Last reviewed: December 2025. https://www.acog.org/womens-health/faqs/the-menopause-years
Wegrzynowicz AK, Walls AC, Godfrey M, Beckley A. Insights into Perimenopause: A Survey of Perceptions, Opinions on Treatment, and Potential Approaches. Women (Basel). 2025 Mar;5(1):4. doi: 10.3390/women5010004. Epub2025 Jan 31. PMID: 40264725; PMCID: PMC12014197.
European Society of Human Reproduction and Embryology. International Reproductive Health Education Collaboration. “Female fertility and age.” PDF Only.
National Institutes of Health: Office of Dietary Supplements. “Vitamin D.” Last updated: June 27, 2025. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/