Several factors within your control can meaningfully improve your chances of conceiving, from what you eat and how much you weigh to specific supplements and reducing exposure to certain chemicals. Fertility is also shaped by factors you can’t change, like age, but understanding the full picture helps you focus your energy where it matters most.
How Age Affects Your Odds Each Month
Age is the single strongest predictor of fertility, and it’s worth understanding the numbers before diving into what you can change. A large North American preconception study tracked couples trying to conceive naturally and found that women aged 28 to 30 had a 62% chance of becoming pregnant within six cycles and about 78% within twelve. For women 34 to 36, those numbers dropped only slightly: 56% at six cycles and 75% at twelve.
The real shift happens after 40. Women aged 40 to 45 had roughly a 28% chance of conceiving within six cycles and about 56% within a year. Put another way, women in this age group were 60% less likely to conceive in any given cycle compared to women in their early twenties. These numbers don’t mean conception is impossible at any age, but they do explain why the American Society for Reproductive Medicine recommends different timelines for seeking help: 12 months of trying for women under 35, six months for women 35 and older, and a more immediate evaluation for women over 40.
A Mediterranean-Style Diet Makes a Measurable Difference
Of all the dietary patterns studied in connection with fertility, the Mediterranean diet has the strongest evidence behind it. This means building meals around vegetables, fruits, whole grains, legumes, fish, and olive oil while limiting red meat and processed foods. In one study of women undergoing fertility treatment, those with the highest adherence to a Mediterranean diet had a clinical pregnancy rate of 50%, compared to 29% among women with the lowest adherence. Another study found that high adherence nearly doubled the likelihood of clinical pregnancy.
The benefits likely come from the overall pattern rather than any single food. Mediterranean eating is rich in antioxidants, healthy fats, and fiber, all of which support hormone balance and reduce inflammation. You don’t need to follow the diet perfectly. Even moderate improvements in eating habits, like swapping refined grains for whole grains and adding more vegetables, shift you in the right direction.
Weight: The U-Shaped Curve
Body weight affects fertility in both directions. Research using national health data found a U-shaped relationship between BMI and infertility, meaning both underweight and overweight women face reduced chances of conceiving. The inflection point in one large analysis was a BMI of about 19.5, with risk rising as weight moved away from the normal range in either direction.
If you’re significantly above or below a BMI of 18.5 to 24.9, even modest weight changes can improve ovulation regularity and hormone levels. Losing 5 to 10% of body weight in women with a higher BMI has been shown to restore ovulation in many cases. For underweight women, gaining enough to resume regular periods is often the most important step.
Supplements Worth Considering
The CDC recommends that all women capable of becoming pregnant take 400 micrograms of folic acid daily. This is non-negotiable for preventing neural tube defects, but folic acid also plays a supporting role in healthy cell division during early pregnancy.
CoQ10 has gained attention for its potential to improve egg quality, particularly in women over 35 or those with diminished ovarian reserve. Clinical trials have used doses of 200 mg per day for women with normal ovarian reserve and 600 mg per day for those with reduced reserve, typically starting 60 to 90 days before trying to conceive or beginning fertility treatment. At these doses, researchers observed increases in follicular fluid levels and improvements in clinical pregnancy rates.
For women with polycystic ovary syndrome (PCOS), myo-inositol is one of the more promising options. A daily dose of 4 grams (usually split into two doses), combined with 400 micrograms of folic acid, has been shown to improve ovulation rates and help regularize menstrual cycles. Multiple studies support this combination as a safe first-line approach for PCOS-related infertility.
Male Fertility Matters Just as Much
Roughly half of infertility cases involve a male factor, yet the conversation often focuses exclusively on women. Zinc is one of the most well-studied nutrients for sperm health. Supplementation has been shown to improve sperm concentration, motility (how well sperm swim), vitality, and normal morphology in men with suboptimal semen quality. These improvements translated into better conception and pregnancy outcomes in clinical studies.
Beyond supplements, the same lifestyle basics apply to men: maintaining a healthy weight, limiting alcohol, avoiding excessive heat to the testicles (from laptops, hot tubs, or tight clothing), and reducing exposure to environmental chemicals. If a couple has been trying to conceive without success, a semen analysis is one of the simplest and most informative first tests to pursue.
Reducing Chemical Exposures
A growing body of evidence links certain everyday chemicals to impaired fertility in both men and women. The three most concerning categories are BPA, phthalates, and perfluorinated compounds (often called “forever chemicals”).
BPA, found in some plastics, canned food linings, and thermal receipt paper, has been associated with sexual dysfunction and reduced sperm quality in men. One occupational study found that workers with high BPA exposure had dramatically elevated urinary BPA levels (about 50 times higher than unexposed workers) alongside reduced sexual function and ejaculatory problems.
Phthalates, common in fragranced personal care products, vinyl flooring, and flexible plastics, have been linked to poor semen quality in men and miscarriage in women. Prenatal exposure has also been associated with hormonal effects in male offspring. Perfluorinated compounds, found in nonstick cookware, stain-resistant fabrics, and some food packaging, were associated with reduced fertility in a cohort of over 1,700 women.
Practical steps to reduce exposure include choosing fragrance-free personal care products, avoiding heating food in plastic containers, using stainless steel or cast iron cookware instead of nonstick, and filtering drinking water. You can’t eliminate every exposure, but reducing the biggest sources makes a difference.
Caffeine and Alcohol: What the Data Actually Shows
Caffeine is one of the most common fertility worries, but the research is more reassuring than most people expect. A dose-response meta-analysis of cohort studies found no association between caffeine intake up to 400 mg per day and any change in the odds of conceiving. That’s roughly four standard cups of coffee. Even at 600 mg per day, there was no significant increase in the time it took to become pregnant. The concern around caffeine may be more relevant during pregnancy itself (when guidelines are stricter) than during the conception phase.
Alcohol is a different story. Heavy drinking clearly impairs fertility in both men and women. For women, even moderate drinking (more than a few drinks per week) has been associated with longer time to pregnancy in some studies. If you’re actively trying to conceive, keeping alcohol intake low or eliminating it entirely removes one potential variable.
Timing and Tracking Ovulation
No amount of dietary optimization matters if you’re missing your fertile window. You’re most likely to conceive during the five days before ovulation and the day of ovulation itself. The simplest way to identify this window is to track your cycle length and use ovulation predictor kits, which detect the hormone surge that happens 24 to 36 hours before an egg is released. Basal body temperature tracking can confirm that ovulation occurred but is less useful for predicting it in advance.
Having sex every one to two days during your fertile window gives you the best statistical chance. Daily sex is fine and doesn’t reduce sperm quality in most men, despite the persistent myth that “saving up” improves sperm count. Consistency through the fertile window matters more than frequency on any single day.
When Lifestyle Changes Aren’t Enough
If you’ve been timing intercourse correctly, eating well, maintaining a healthy weight, and addressing the factors above for the recommended duration (12 months under 35, six months at 35 or older), a fertility evaluation is the logical next step. This typically involves bloodwork to check hormone levels and ovarian reserve, imaging to assess the uterus and fallopian tubes, and a semen analysis for the male partner. Many causes of infertility are treatable, and earlier evaluation means more options.