At 40, your chance of getting pregnant in any given menstrual cycle is about 5 to 10 percent, compared to roughly 25 percent in your late 20s. That’s a real difference, but it also means pregnancy is far from impossible. The key is making the most of every cycle by optimizing timing, addressing both partners’ health, and knowing when to seek help sooner rather than later.
Why Every Cycle Counts More at 40
Fertility at 40 is driven by two things: fewer eggs remaining and lower egg quality. You’re born with all the eggs you’ll ever have, and by 40 the supply has dropped significantly. The eggs that remain are more likely to have chromosomal errors during cell division, which is the main reason miscarriage rates rise and it takes longer to conceive. The risk of Down syndrome, for example, goes from about 1 in 1,250 at age 25 to roughly 1 in 100 at age 40.
None of this means you can’t get pregnant. It means you have less margin for inefficiency. Mistiming intercourse by even a day or two, or ignoring a correctable issue like thyroid imbalance, costs you more at 40 than it would have at 30.
Track Ovulation Precisely
At 40, your cycles may already be shifting. Some women notice shorter cycles, longer ones, or cycles that vary month to month. The interval between ovulation and your next period (the luteal phase) can shorten, sometimes to the point where a fertilized egg doesn’t have enough time to implant. Recognizing when you actually ovulate, rather than guessing based on a 28-day calendar, is essential.
Ovulation predictor kits (OPKs) detect the hormonal surge that happens 24 to 36 hours before you release an egg. Use them starting a few days before you expect ovulation. If your cycles are irregular, start testing earlier in your cycle so you don’t miss the window. Tracking cervical mucus is a helpful backup: the stretchy, clear, egg-white-type mucus signals your most fertile days. Basal body temperature charting confirms ovulation after the fact, which is useful for understanding your pattern over several months but won’t help you time intercourse in the current cycle.
Your fertile window is roughly five days before ovulation through the day of ovulation itself. Having sex every one to two days during that window gives you the best odds. Don’t save it all for one “perfect” day.
Get Baseline Fertility Testing Early
Most fertility specialists recommend that women over 35 seek evaluation after just six months of trying, not the standard 12 months given to younger women. But if you’re 40, there’s a strong case for getting tested before you start trying or within the first few months.
An AMH (anti-Müllerian hormone) blood test gives a snapshot of your remaining egg supply. At 40, an AMH around 1.0 ng/mL is typical. Below 1.0 is considered low, and below 0.4 is severely low. This doesn’t tell you about egg quality, but it helps you and your doctor decide whether you have time to keep trying naturally or should move quickly toward assisted options like IVF.
A basic workup also typically includes checking thyroid function, progesterone levels (to confirm you’re ovulating and your luteal phase is adequate), and a test to confirm your fallopian tubes are open. Getting this information upfront saves you from spending months on approaches that won’t work if there’s an underlying issue.
Your Partner’s Fertility Matters Too
If your partner is also 40 or older, his fertility is part of the equation. Sperm quality declines with age in ways that are less dramatic than egg aging but still meaningful. Semen volume, motility (how well sperm swim), and the percentage of sperm with intact DNA all drop with age. Higher rates of DNA fragmentation in sperm are linked to longer time to conception and higher miscarriage risk.
A semen analysis is quick, inexpensive, and should be one of the first tests you request. If results show issues with motility or morphology, a reproductive urologist can recommend targeted interventions. Simple changes like reducing alcohol, avoiding heat exposure to the testicles (hot tubs, laptops on the lap), and taking a daily antioxidant can improve sperm parameters over two to three months, which is roughly how long it takes for a new batch of sperm to fully mature.
Supplements That Support Egg Quality
CoQ10 is the most widely recommended supplement for women trying to conceive at 40. It supports the energy production process inside your eggs, which becomes less efficient with age. Fertility clinics commonly recommend between 100 and 600 mg daily, with many suggesting the ubiquinol form because it’s more easily absorbed. Starting at least two to three months before conception gives it time to make a difference, since eggs go through their final maturation over roughly 90 days.
Beyond CoQ10, a good prenatal vitamin with methylfolate (the active form of folic acid), vitamin D, and omega-3 fatty acids covers the basics. If your vitamin D level is low, correcting it is particularly important since low levels are associated with poorer fertility outcomes. DHEA is another supplement sometimes used by fertility specialists to support ovarian function, but it affects hormone levels directly and should only be taken under medical supervision after blood work confirms it’s appropriate for you.
Diet, Weight, and Lifestyle
A diet rich in vegetables, healthy fats, whole grains, fish, and legumes is consistently linked to better fertility outcomes. You don’t need to follow a rigid plan, but shifting toward this eating pattern provides antioxidants that help protect eggs from oxidative damage, along with the steady blood sugar levels that support healthy hormone balance.
Being significantly over or under a healthy weight can disrupt ovulation. Even modest weight changes of 5 to 10 percent of body weight, in either direction toward a healthier range, can restore regular cycles in some women. At 40, you want every possible advantage, and this is one of the most controllable factors.
Alcohol and caffeine both deserve attention. Heavy drinking clearly harms fertility, and even moderate intake (more than a few drinks per week) may reduce your chances. Caffeine in moderate amounts (under 200 mg per day, roughly one 12-ounce coffee) appears to be fine for most women, but cutting back further won’t hurt. Sleep quality matters more than most people realize: disrupted sleep affects the hormones that regulate ovulation, so prioritizing seven to eight hours of consistent sleep is a genuinely useful step.
When to Move to Assisted Reproduction
If you’ve been timing intercourse well for three to six months without success, it’s reasonable to discuss more aggressive options. At 40, time works against you in a way it doesn’t at 32. Waiting a full year before considering intervention can mean the difference between having options and not.
IUI (intrauterine insemination) places sperm directly in the uterus around the time of ovulation. It’s less invasive and less expensive than IVF, but success rates for women at 40 are modest, typically in the range of 5 to 10 percent per cycle. It’s sometimes worth a few attempts if your tubes are open and sperm quality is adequate, but your doctor may recommend moving to IVF sooner rather than later.
IVF offers the highest per-cycle success rates for women at 40, generally around 20 to 25 percent per egg retrieval cycle with your own eggs, though this varies widely depending on your individual ovarian reserve and egg quality. One significant advantage of IVF is the ability to test embryos for chromosomal abnormalities before transfer, which reduces miscarriage risk and increases the chance that a transferred embryo will result in a healthy pregnancy.
If your AMH is very low or previous IVF cycles have yielded few eggs, donor eggs become an option worth considering. Success rates with donor eggs are significantly higher because the eggs come from younger donors, typically in their 20s. This is a deeply personal decision, but knowing it’s available can relieve some of the pressure of a ticking clock.
Protect Your Mental Health
Trying to conceive at 40 often comes with a sense of urgency that can make each unsuccessful cycle feel devastating. That emotional toll is real and worth acknowledging. Stress itself hasn’t been conclusively shown to prevent pregnancy in otherwise fertile people, but chronic stress can disrupt sleep, appetite, and the motivation to keep up with timing and healthy habits. Finding a support system, whether that’s a partner, a therapist who specializes in fertility, or an online community of women in the same situation, makes the process more sustainable.