A woman in her early to mid-20s has roughly a 25–30% chance of conceiving in any given month, even when everything goes right. That number declines with age, dropping to around 5% per cycle by age 40. Those odds might sound low, but several evidence-backed strategies can meaningfully improve them, from timing intercourse correctly to making specific lifestyle adjustments that affect egg and sperm quality.
Know Your Fertile Window
The single most impactful thing you can do is have sex during the right days of your cycle. Pregnancy is most likely when intercourse happens in the three days before ovulation. Having sex two days before ovulation gives about a 26% chance of conception, while waiting until just one day after ovulation drops that to roughly 1%. The egg survives only 12 to 24 hours after release, but sperm can live inside the reproductive tract for up to five days, which is why the days leading up to ovulation matter most.
Ovulation typically occurs around day 14 of a 28-day cycle, but cycles vary. Tracking methods include ovulation predictor kits (which detect a hormone surge 24–36 hours before the egg releases), basal body temperature charting, and monitoring cervical mucus changes. Ovulation predictor kits are the most straightforward option for most people. Having sex every one to two days during your fertile window covers your bases without requiring pinpoint precision.
Body Weight and Ovulation
A BMI between 18.5 and 24.9 is associated with the best fertility outcomes. Women at both extremes, underweight and obese, are more likely to experience irregular ovulation or skip ovulation entirely, which makes conception significantly harder. Women with a BMI over 30 have lower pregnancy rates compared to those with a normal BMI.
The encouraging news is that even modest changes help. Losing just 5–10% of body weight in overweight individuals can restore regular ovulatory cycles and improve natural fertility. For someone weighing 200 pounds, that’s 10 to 20 pounds. On the other end, gaining weight to reach a healthy BMI can restart ovulation in underweight women. These changes often make a measurable difference within a few months.
Supplements That Actually Help
Folic acid is the most important preconception supplement. The CDC recommends 400 micrograms daily for all women who could become pregnant. It doesn’t improve your odds of conceiving, but it prevents serious birth defects of the brain and spine that develop in the earliest weeks of pregnancy, often before you even know you’re pregnant. Start taking it at least one month before trying, ideally three months.
CoQ10, a compound that supports energy production in cells, has shown promise for both egg and sperm quality. In men with fertility issues, taking 200 mg daily for six months increased sperm motility. The typical dosage range studied is 100 to 600 mg daily. For women, CoQ10 may support egg quality by improving mitochondrial function, which becomes increasingly relevant after age 35 as eggs naturally accumulate more cellular damage. Talk to your provider about the right dose for your situation.
What Men Can Do
Sperm quality is half the equation and responds meaningfully to lifestyle changes. New sperm take roughly two months to fully mature, so any improvements a male partner makes today will show up in sperm quality about two months later. This means starting lifestyle changes well before you begin trying is ideal.
Heat is one of the most well-documented threats to sperm production. The testicles sit outside the body for a reason: they need to stay cooler than core body temperature. Using a laptop directly on the lap raises scrotal temperature by 2–3°C, enough to potentially impair sperm development over time. Hot tubs and saunas have a similar effect. Placing a laptop on a desk or table and limiting prolonged heat exposure are simple fixes.
Tight underwear, prolonged sitting, and cycling for long durations can also raise scrotal temperature. Switching to looser-fitting boxers and taking breaks from sitting during the workday are small changes that add up over a full sperm development cycle.
Caffeine, Alcohol, and Smoking
Women trying to conceive should limit caffeine to the equivalent of one to two cups of coffee per day. Higher intake has been linked to longer time to conception and increased miscarriage risk in some studies. You don’t need to quit caffeine entirely, but keeping it moderate is a reasonable precaution.
Alcohol is a different story. Current guidelines recommend avoiding alcohol entirely when trying to conceive and during pregnancy. Even moderate drinking can disrupt hormonal balance and ovulation. For men, heavy alcohol use reduces testosterone levels and sperm quality, though occasional light drinking appears to have less impact.
Smoking affects fertility on both sides. In women, it accelerates egg loss and can bring menopause forward by several years. In men, it reduces sperm count and motility. Quitting before trying to conceive is one of the highest-impact changes either partner can make.
Watch Your Lubricant Choice
This is one of the lesser-known factors that can work against you. Most commercial lubricants, including popular brands like Astroglide, K-Y Jelly, Replens, and FemGlide, significantly decrease sperm motility. Some also damage sperm DNA integrity. If you need lubrication during intercourse, look for fertility-friendly options. Pre~Seed is the most studied alternative and does not cause a significant decrease in sperm motility or DNA quality. It’s specifically formulated to mimic the body’s natural cervical fluid.
How Long to Try Before Seeking Help
Most couples under 35 conceive within a year of trying. The general guideline is to seek a fertility evaluation if you haven’t conceived after 12 months of regular, well-timed intercourse. If you’re over 35, that timeline shortens to six months. Women over 40 should consider getting an evaluation before they start trying, since both egg quantity and quality decline more steeply at this point and earlier intervention can make a significant difference in outcomes.
Certain signs warrant earlier evaluation regardless of age: irregular or absent periods, a history of pelvic infections, known conditions like endometriosis or polycystic ovary syndrome, or a male partner with a history of testicular injury or surgery. About one-third of fertility issues trace to the female partner, one-third to the male partner, and one-third to a combination of both or unexplained factors, so both partners should be evaluated together.