The best time to start trying for a baby depends on your age, your health, and how much preparation you’ve done beforehand. From a purely biological standpoint, fertility peaks in your 20s and begins a meaningful decline in your mid-30s. But biology is only one piece of the puzzle. Financial stability, relationship readiness, and physical health all factor into the decision, and there are concrete steps worth taking months before you actually start trying.
How Age Affects Your Chances
Age is the single biggest factor in how quickly you’re likely to conceive. Before age 30, there’s roughly an 85% chance of getting pregnant within one year of trying. At 30, that drops to about 75%. By 35, it falls to 66%, and at 40, it’s around 44%. These aren’t hard cutoffs, but they reflect a real and steady decline in egg quality and quantity over time.
The decline accelerates after 35, which is why that age comes up so often in fertility conversations. It doesn’t mean you can’t get pregnant after 35. Plenty of people do. But it may take longer, and the odds of needing medical help go up. If you know you want children and you’re in a position to start, your late 20s to early 30s offer the widest window of both high fertility and reasonable life stability.
Male Fertility Has a Clock Too
Sperm quality doesn’t stay constant forever. Measurable changes in sperm begin around age 34, and after 40, both sperm count and the percentage of viable sperm start to drop. Motility, the ability of sperm to swim effectively, declines noticeably after 43. DNA damage in sperm also increases with age: men over 45 have roughly double the rate of sperm DNA fragmentation compared to men under 30.
The consequences go beyond just taking longer to conceive. Advanced paternal age, particularly beyond 45, is linked to higher rates of miscarriage, even when the mother is young. A study of couples where the mother was 20 to 29 found that miscarriage risk nearly doubled when the father was over 40 compared to fathers aged 30 to 34. Older paternal age also carries a small but real increase in the chance of conditions like autism and schizophrenia in offspring. One large Swedish study found the probability of schizophrenia in a child increased by about 1.5 times for every decade of the father’s age at conception. Major fertility organizations now cap the age for sperm donors at 45 because of these risks.
What to Do Before You Start Trying
The months before conception matter more than most people realize. A few straightforward steps can meaningfully reduce risks and set you up for a healthier pregnancy.
Start Folic Acid Early
Folic acid reduces the risk of neural tube defects, which are serious birth defects of the brain and spine that develop in the very first weeks of pregnancy, often before you even know you’re pregnant. The standard recommendation is 400 micrograms daily for all women of reproductive age. If you’ve had a previous pregnancy affected by a neural tube defect or you take seizure medication, the recommended dose jumps to 4 milligrams daily. Ideally, you’d start taking folic acid at least one to three months before trying to conceive.
Check Your Vaccinations
Certain vaccines can’t be given during pregnancy because they use live viruses, so you need to get them beforehand and then wait before conceiving. The MMR vaccine (measles, mumps, rubella) requires a 28-day waiting period after the shot before you should try to get pregnant. The varicella (chickenpox) vaccine requires at least one month after each dose. If you’re unsure whether you’re immune to rubella or chickenpox, a simple blood test can check. Getting this sorted out a few months before trying saves you from a stressful situation later.
Address Chronic Health Conditions
If you have diabetes, high blood pressure, thyroid disorders, or any condition that requires ongoing medication, talk with your doctor before trying. Some medications aren’t safe during pregnancy, and switching to alternatives takes time. Conditions like diabetes are much safer to manage through pregnancy when blood sugar is well controlled before conception, not after.
Lifestyle Changes Worth Making
Heavy caffeine intake before conception, more than about 300 milligrams a day (roughly two to three cups of coffee), has been linked to a 31% higher risk of miscarriage once you do conceive. Cutting back to minimal caffeine well before trying is a simple way to lower that risk.
Alcohol is trickier because there’s no established “safe” amount during pregnancy, and the earliest weeks are critical. The general guidance for women of reproductive age is to flag any pattern of more than seven drinks per week or more than three drinks on a single occasion as worth addressing before trying. Many people choose to stop drinking entirely once they start actively trying, since you won’t know you’re pregnant for the first few weeks.
Smoking, recreational drugs, and exposure to certain environmental chemicals are all worth eliminating before conception. These changes benefit both partners. Smoking and heavy drinking in men are associated with lower sperm quality.
Timing Around Contraception
How quickly fertility returns after stopping birth control depends on the method. Hormonal and copper IUDs and implants have the shortest delay, with most women returning to normal fertility within about two menstrual cycles. Oral contraceptives (the pill) and vaginal rings typically take about three cycles. Patch users average around four cycles.
Injectable contraceptives like Depo-Provera take the longest by a wide margin: five to eight menstrual cycles before fertility normalizes. If you’re using injections and planning to try soon, you may want to switch to a shorter-acting method several months in advance. For most other methods, stopping one to three months before you want to start trying gives your body time to resume its normal cycle, and gives you a chance to track ovulation patterns.
When to Seek Help
If you’ve been trying for 12 months without success and you’re under 35, that’s the standard point to pursue a fertility evaluation. If you’re over 35, that timeline shortens to six months. And if you’re over 40, it’s worth having that conversation with a doctor before you even start trying, so you understand your options and can move quickly if needed.
These timelines assume regular, unprotected intercourse, roughly every two to three days or timed around ovulation. If you have irregular periods, a known reproductive condition like endometriosis or polycystic ovary syndrome, or a partner with a known fertility issue, there’s no reason to wait the full 6 or 12 months before getting evaluated.