What actually improves your chances of conceiving — and what's just an old wives' tale.
Most couples under 35 who are having regular unprotected sex will conceive within 12 months. But there are specific, evidence-backed steps that can meaningfully improve your odds. Here's what actually works — and what doesn't.
The single biggest mistake couples make is timing sex to day 14 of the cycle assuming ovulation happens then. Ovulation actually happens 14 days before your next period — which means if you have a 32-day cycle, you ovulate around day 18, not day 14. Use a period tracking app with BBT and cervical mucus logging to identify your actual ovulation timing.
Studies show that sex every 1–2 days during the fertile window achieves higher conception rates than timing to a single "peak" day. Sperm quality is higher with regular rather than saved-up ejaculations, and you're more likely to hit the ovulation window without needing to predict it perfectly.
Folic acid (400mcg daily) significantly reduces the risk of neural tube defects and should be started at least 3 months before trying to conceive — not after a positive test. By the time most women know they're pregnant, the critical developmental window for neural tube formation has already passed.
Smoking significantly reduces both female and male fertility. In women, it accelerates egg depletion and affects oocyte quality. In men, it reduces sperm count and motility. Quitting at least 3 months before trying to conceive improves fertility meaningfully.
Even moderate alcohol consumption (5+ drinks per week) is associated with reduced fertility. During the two-week wait, alcohol should be avoided entirely — you may already be pregnant. After a positive test, no safe level of alcohol in pregnancy has been established.
Both underweight (BMI under 18.5) and overweight (BMI over 25) negatively affect fertility. Excess body fat increases estrogen production, disrupting the hormonal environment for ovulation. Underweight causes hypothalamic amenorrhea (loss of periods due to low body fat). Even modest weight changes can significantly affect cycle regularity.
Chronic stress disrupts the hormonal cascade that triggers ovulation. Cortisol interferes with GnRH production, which is why women under significant stress often have irregular or missed cycles. This doesn't mean "just relax" — instead, focus on practical stress reduction: adequate sleep, regular movement, and cutting unnecessary stressors.
Thyroid disorders are common, often undiagnosed, and significantly affect fertility. Both hypothyroidism and hyperthyroidism disrupt ovulation and increase miscarriage risk. A simple blood test (TSH) can identify this — worth doing before months of trying.
Most standard lubricants — including saliva, olive oil, and water-based lubricants — are harmful to sperm motility. If lubricant is needed, use a product specifically labeled "sperm-friendly" or "fertility lubricant" (Pre-Seed is the most studied option).
Twelve months of regular, unprotected sex without conception is the standard threshold for investigation (6 months if over 35, or immediately if you have known conditions like PCOS, endometriosis, or irregular cycles). Many causes of subfertility are treatable — early investigation is better than extended waiting.
| Factor | Evidence Strength | Action |
|---|---|---|
| Fertile window timing Most Impact | Strong | Track ovulation accurately |
| Folic acid | Strong | 400mcg daily from 3mo before TTC |
| Quitting smoking | Strong | Stop 3+ months before TTC |
| Healthy BMI | Strong | Aim for 18.5–25 |
| Sex frequency | Strong | Every 1–2 days in fertile window |
| Limiting alcohol | Moderate | Under 5 drinks/week while TTC |
| Stress management | Moderate | Sleep, movement, reduce stressors |
BBT, cervical mucus, cycle tracking — everything you need to maximise your conception chances. Free.
Start free →The highest-impact steps are: identify your actual fertile window (using cycle tracking + BBT or cervical mucus), have sex every 1–2 days in that window, start folic acid, maintain a healthy BMI, and quit smoking.
The 2–3 days before ovulation and ovulation day itself are the highest-fertility window. Having sex every 1–2 days during this period is more effective than trying to pinpoint a single peak day.
Most couples under 35 conceive within 6–12 months of regular, unprotected sex. By 12 months, approximately 85% of couples have conceived. See a doctor after 12 months (or 6 months if over 35).
Folic acid doesn't improve fertility but it significantly reduces the risk of neural tube defects in early pregnancy. It should be started 3 months before trying to conceive because the critical window is before most women know they're pregnant.