Most healthy couples conceive by having regular sex during the fertile window, which spans about seven days each cycle. A healthy 30-year-old woman has roughly a 20% chance of getting pregnant in any given month, so even with perfect timing, it often takes several months. Beyond timing, your chances improve significantly when you optimize lifestyle factors, track ovulation, and know when to seek help if things aren’t progressing.
Timing Sex Around Ovulation
Your fertile window includes the five days before ovulation, the day of ovulation itself, and the day after. That seven-day stretch matters because sperm can survive inside the reproductive tract for three to five days, waiting for the egg to be released. The egg, by contrast, is only viable for about 12 to 24 hours after ovulation. Having sex every day or every other day during this window gives you the best odds each cycle.
If you don’t know exactly when you ovulate, a simple starting point is to count backward 14 days from when you expect your next period. For someone with a 28-day cycle, that puts ovulation around day 14. But cycles vary, and that’s where tracking tools come in.
How to Track Ovulation
Ovulation predictor kits (OPKs) detect a hormone surge in your urine that happens one to two days before ovulation. This gives you advance notice so you can time sex before the egg is released. The kits are widely available at pharmacies and are one of the most practical tools for pinpointing your fertile days. The main downside is that it’s possible to miss the surge if you skip a day of testing or if your urine is too dilute.
Basal body temperature (BBT) tracking, where you take your temperature first thing every morning, works differently. Your temperature rises slightly after ovulation has already occurred. That makes BBT useful for confirming that you do ovulate and learning your cycle patterns over several months, but it won’t help you catch the current month’s window in time. By the time your temperature spikes, the egg is already gone. Many people use both methods together: BBT to learn their pattern and OPKs to act on it in real time.
Cervical mucus also changes during the fertile window, becoming clear, slippery, and stretchy (similar to raw egg whites). Noticing this change is a free, no-tech signal that ovulation is approaching.
Lifestyle Factors That Affect Fertility
Start taking 400 micrograms of folic acid daily before you begin trying to conceive. The CDC recommends this for all women who could become pregnant, because it helps prevent neural tube defects that develop in the earliest weeks of pregnancy, often before you even know you’re pregnant. If you’ve had a previous pregnancy affected by a neural tube defect, the recommended dose is much higher at 4,000 mcg daily, starting at least a month before conception.
Body weight plays a direct role in fertility. A BMI between 18.5 and 24.9 is associated with the most regular ovulation. Being underweight (BMI of 18.5 or less) can cause your body to stop producing enough estrogen, leading to irregular or absent periods. Being overweight has the opposite problem: fat cells produce extra estrogen, and too much of it can trick your body into behaving as though you’re on hormonal birth control, suppressing ovulation. If your BMI falls well outside the normal range, even a modest change in weight can restore more regular cycles.
Smoking, heavy alcohol use, and high stress levels all reduce fertility in both women and men. Cutting back or eliminating these factors before trying to conceive gives you a measurable advantage.
Male Fertility Matters Too
About half of infertility cases involve a male factor, so the partner providing sperm should also be paying attention to their health. Smoking is linked to lower sperm counts. Heavy drinking reduces both sperm count and testosterone. Being overweight is associated with decreased sperm count and reduced sperm movement.
Heat exposure is another factor that often gets overlooked. Elevated scrotal temperature can impair sperm production, so wearing loose-fitting underwear and limiting time in hot tubs and saunas may help. Exposure to pesticides, lead, and other environmental toxins also affects sperm quality. Certain medications, including some blood pressure drugs, antidepressants, and anabolic steroids, can lower fertility as well. Even some lubricants can interfere with sperm movement, so couples actively trying may want to use fertility-friendly options or skip lubricant when possible.
How Age Affects Your Chances
Fertility declines gradually through the 30s and drops more sharply after 35. At 30, a healthy woman has about a 20% chance of conceiving per cycle. By 40, that falls to less than 5%. This decline reflects both a decrease in the number of eggs remaining and a higher rate of chromosomal abnormalities in those eggs, which also increases miscarriage risk.
These numbers don’t mean pregnancy at 40 is impossible. They do mean it typically takes longer, and the window for trying naturally before seeking help is shorter. The American College of Obstetricians and Gynecologists recommends a fertility evaluation after 12 months of trying if you’re under 35, after 6 months if you’re over 35, and right away if you’re over 40.
Fertility Treatments When Natural Conception Doesn’t Work
If timed intercourse isn’t resulting in pregnancy, fertility treatments offer several options with varying levels of intervention and cost.
Ovulation-Inducing Medications
For women who aren’t ovulating regularly, oral medications can stimulate the ovaries to release an egg. These are often the first step a doctor will suggest, sometimes combined with timed intercourse or insemination. They’re relatively affordable compared to more advanced treatments.
Intrauterine Insemination (IUI)
IUI involves placing concentrated, washed sperm directly into the uterus around the time of ovulation. It’s less invasive and less expensive than IVF, making it a common next step. For women 38 and older, live birth rates per IUI cycle range from about 10% at age 38 down to 3% at age 44.
In Vitro Fertilization (IVF)
IVF involves stimulating the ovaries to produce multiple eggs, retrieving those eggs, fertilizing them in a lab, and transferring an embryo back into the uterus. It’s the most effective fertility treatment available. For women aged 38, the live birth rate per IVF cycle is about 28%, compared to roughly 10% with IUI. At 42, IVF still produces a live birth rate of about 10% per cycle, nearly double the IUI rate at the same age. By 44, the success rates for both procedures converge at around 3%.
IVF is also the primary path for same-sex couples, single parents by choice, and anyone using donor eggs, donor sperm, or a gestational carrier. For women who want to preserve fertility for the future, egg freezing uses the same ovarian stimulation and retrieval process as IVF, banking eggs for later use.
When to Get a Fertility Workup
A fertility evaluation typically involves checking whether ovulation is happening, whether the fallopian tubes are open, and whether the sperm is healthy. For the partner with ovaries, this usually means blood tests to check hormone levels and an imaging test to look at the uterus and tubes. For the partner providing sperm, a semen analysis measures count, movement, and shape.
You don’t need to wait for a formal infertility diagnosis to start this process if something feels off. Irregular periods, very painful periods, a history of pelvic infections, or known conditions like polycystic ovary syndrome or endometriosis are all reasons to talk with a provider before spending months trying on your own. The same goes for known male factors like a history of undescended testicles, prior chemotherapy, or sexually transmitted infections, which can cause lasting damage to fertility if untreated.