A healthy couple in their mid-20s has roughly a 25 to 30 percent chance of conceiving in any given month. That number drops steadily with age, falling to about 5 percent per cycle by age 40. Those odds might sound low, but several evidence-backed strategies can help you make the most of each cycle.
Timing Intercourse Around Ovulation
Sperm can survive inside the body for up to five days, but a released egg lives for less than 24 hours. The highest pregnancy rates occur when sperm meets egg within four to six hours of ovulation. That means the days leading up to ovulation matter more than the day after it.
For most women with a roughly 28-day cycle, the fertile window falls between days 7 and 20. Ovulation prediction kits, which detect a hormone surge in urine, can narrow this window to a one- to two-day heads-up. Tracking basal body temperature or cervical mucus changes can also help, though these signals confirm ovulation after the fact rather than predicting it.
As for how often to have sex: daily intercourse in the week before ovulation slightly improves sperm quality. A study of men who ejaculated daily for seven days found that 81 percent saw an average 12 percent decrease in sperm DNA damage, while sperm motility actually rose slightly. Semen volume and sperm concentration did drop, but not enough to offset the quality gains. For couples with normal sperm counts, daily sex in the fertile window is a reasonable approach. Every other day works well too if daily feels like pressure.
Body Weight and Ovulation
Weight has a measurable effect on fertility, particularly through its influence on ovulation. Studies report that 30 to 36 percent of women with obesity experience menstrual cycle irregularities, and the prevalence of missed or infrequent periods rises with increasing weight. Women with a BMI above 27 have roughly 2.4 times the risk of anovulatory infertility (cycles where no egg is released) compared to women at a normal weight.
Even when ovulation does occur in women carrying excess weight, the hormonal profile of those cycles tends to differ: lower levels of key reproductive hormones, longer follicular phases, shorter luteal phases, and reduced progesterone. These subtle shifts can make it harder for a fertilized egg to implant successfully.
Being underweight (BMI below 18.5) also disrupts ovulation, often by signaling to the brain that the body doesn’t have enough energy reserves to support a pregnancy. If your periods are irregular or absent, reaching a BMI in the 18.5 to 24.9 range is one of the most impactful changes you can make. Even a modest weight shift of 5 to 10 percent in either direction can restore regular cycles for many women.
Diet and Nutrition
A Mediterranean-style eating pattern, rich in fruits, vegetables, whole grains, legumes, nuts, fish, and olive oil as the primary fat source, shows the most promising links to fertility. This diet is naturally high in unsaturated fats, fiber, and micronutrients while being low in saturated fat and processed meat. Research reviews describe the association between Mediterranean diet adherence and improved fertility outcomes as “suggestive,” meaning the signal is consistent but not yet proven to be causal.
What likely matters most is the overall pattern rather than any single food. The combination of antioxidants from produce, healthy fats from olive oil and nuts, and complex carbohydrates from whole grains supports hormone balance and reduces inflammation. On the flip side, diets heavy in processed foods, trans fats, and added sugars have been linked to worse reproductive outcomes in observational studies.
Folic acid deserves special attention. The CDC recommends all women capable of becoming pregnant take 400 micrograms daily. This doesn’t improve your odds of conceiving, but it protects against major brain and spine birth defects that form in the earliest weeks of pregnancy, often before you know you’re pregnant. Starting before conception is the whole point.
Caffeine, Alcohol, and Smoking
If you drink coffee or tea, keeping caffeine under 200 milligrams per day (roughly two standard cups of coffee) is the recommended threshold when trying to conceive. Above that level, some studies suggest a modest increase in time to conception and miscarriage risk.
Alcohol and smoking both have clearer negative effects. Smoking accelerates egg loss and damages sperm DNA. Alcohol, even at moderate levels, can disrupt ovulation and lower sperm quality. Cutting both out entirely gives you the cleanest slate.
Protecting Sperm Health
Sperm production is sensitive to heat. Testicles sit outside the body for a reason: they need to stay slightly cooler than core body temperature. Hot tubs and hot baths are one of the more dramatic examples. In a small study, men who had been soaking in hot tubs for at least 30 minutes per week were told to stop. Three months later, nearly half of them saw their motile sperm counts jump by an average of 491 percent.
Laptops placed directly on the lap add another half-degree Celsius to scrotal temperature on top of the warming that happens just from sitting with legs together. Using a desk or table, or at least a lap pad, is a simple fix. Tight underwear also raises testicular temperature by about half a degree, though whether that’s enough to meaningfully affect fertility on its own is still unclear. Switching to boxers is low-cost and may help.
Beyond heat, the same lifestyle factors that protect general health protect sperm: maintaining a healthy weight, exercising regularly without overdoing it, sleeping enough, and managing stress. Sperm take about 74 days to develop, so any changes you make now will show up in sperm quality roughly two to three months later.
Reducing Exposure to Endocrine Disruptors
Endocrine disruptors are chemicals that mimic or block natural hormones. They’re found in plastic food containers, personal care products, cosmetics, and pesticides. Two of the most studied are phthalates (common in fragranced products and flexible plastics) and BPA (found in some food can linings and hard plastics). Women tend to have higher phthalate exposure than men because of greater use of cosmetics and personal care products.
These chemicals can interfere with the hormone signals that trigger ovulation, damage developing eggs through oxidative stress, and reduce egg quality. Some effects may be long-lasting, as BPA exposure has been linked to altered DNA patterns in developing follicles that persist into adulthood. On the male side, endocrine disruptors can impair sperm production and quality.
Practical steps to reduce exposure include choosing fragrance-free personal care products, avoiding heating food in plastic containers, opting for glass or stainless steel for food storage, eating fewer canned foods, and washing fruits and vegetables to remove pesticide residue. You can’t eliminate all exposure, but reducing it where you can is worthwhile.
Choosing the Right Lubricant
Most commercial lubricants slow sperm movement, and saliva does the same. If you need lubrication, look for products specifically labeled “fertility-friendly” or “sperm-friendly,” which must meet FDA evaluation standards before they can carry that label. The best options are hydroxyethylcellulose-based, which closely match the consistency of natural cervical mucus and don’t impair sperm motility. Avoid lubricants with fragrances or parabens, and skip household oils like coconut oil.
When to Seek Help
The American Society for Reproductive Medicine recommends that women under 35 seek a fertility evaluation after 12 months of well-timed, unprotected intercourse without conception. For women 35 and older, that timeline shortens to 6 months. Women over 40 may benefit from more immediate evaluation. These timelines also apply if you have known risk factors like irregular periods, a history of pelvic infections, endometriosis, or if the male partner has a known reproductive issue. A basic fertility workup typically involves bloodwork to check hormone levels, an ultrasound to examine the ovaries and uterus, and a semen analysis for the male partner.