Intro
Trying to conceive can be hopeful, exciting, and emotionally demanding all at once. Many people focus on what to add, such as prenatal vitamins, ovulation tracking, or healthier meals, but it is just as useful to know what to avoid. Certain exposures, habits, and extremes in lifestyle can affect ovulation, sperm quality, implantation, early embryonic development, and pregnancy outcomes.
This article is written for medically literate readers who want practical, evidence-informed guidance without fear-based messaging. Fertility is multifactorial, and no single behavior guarantees or prevents pregnancy. Still, reducing modifiable risks before conception can support reproductive health for both partners and may make the transition into pregnancy safer.
Highlights
Avoid extremes: significant weight changes, very intense exercise, heavy alcohol use, smoking, and drug exposure can interfere with reproductive physiology.
Both partners matter. Sperm quality is affected by smoking, alcohol, diet, heat exposure, certain drugs, and general metabolic health.
Food choices do not need to be perfect, but reducing high-mercury fish, ultra-processed foods, and frequent processed meats may support fertility and early pregnancy safety.
Medication and supplement safety should be reviewed before conception, especially for retinoids, weight-loss drugs, and therapies that may be teratogenic or hormonally active.
Preconception care is not only about avoiding harm; it is also a chance to update vaccines, optimize chronic conditions, and plan safer routines.
Avoid smoking, vaping, and secondhand smoke
Tobacco exposure is one of the clearest modifiable risks to fertility and pregnancy health. Cigarette smoking is associated with reduced ovarian reserve, impaired egg quality, earlier menopause, tubal dysfunction, and increased risk of miscarriage and . In males, smoking is linked with lower sperm concentration, impaired motility, abnormal morphology, and increased oxidative DNA damage.
Vaping is not a safe substitute when . Nicotine vascular function and reproductive hormones, while e-cigarette aerosols may contain ultrafine particles, heavy metals, and other chemicals. Evidence is still evolving, but the uncertainty is not reassuring enough to consider vaping fertility-friendly.
If either partner smokes or vapes, stopping before conception is ideal. This is not about blame; nicotine dependence is biologically powerful. Ask a clinician about cessation options, behavioral support, and . Reducing secondhand smoke exposure in the home, car, and workplace is also important.
Avoid heavy alcohol use and consider abstaining during the fertile window
Heavy alcohol use can impair fertility in both women and men. In women, alcohol may affect hypothalamic-pituitary-ovarian signaling, ovulation, implantation, and early embryonic development. In men, alcohol testosterone production, impair sperm quality, and contribute to erectile or ejaculatory difficulties.
The exact threshold at which low-to-moderate alcohol intake affects conception is difficult to define, partly because studies vary in design and confounding factors. However, once pregnancy occurs, there is no established safe amount of alcohol for fetal development. may not be recognized for several weeks, many clinicians advise avoiding alcohol when actively trying, especially after ovulation and during the luteal phase.
If alcohol is used to cope with stress, sleep problems, or grief after prior losses, it may help to discuss safer supports with a healthcare professional. Fertility care should include emotional health, not only laboratory values and cycle tracking.
Avoid cannabis, recreational drugs, and nonmedical substance use
Cannabis, cocaine, opioids used nonmedically, anabolic steroids, methamphetamines, and other recreational substances can interfere with reproductive hormones, sexual function, gamete quality, implantation, and fetal development. Some substances can remain detectable or have physiologic effects after use, so stopping only after a positive pregnancy test may be later than ideal.
Cannabis deserves specific attention because it is often perceived as low-risk. Cannabinoid receptors are present in reproductive tissues, and cannabis exposure has been associated in some studies with altered ovulation, sperm concentration, motility, and early pregnancy concerns. Data are complex, but when trying to conceive, avoidance is the more cautious approach.
People using prescribed opioids, medication for opioid use disorder, psychiatric medication, or other controlled substances should not stop abruptly without medical supervision. The safest plan is individualized and may involve obstetrics, reproductive endocrinology, psychiatry, addiction medicine, or primary care.
Avoid major weight swings, crash dieting, and under-fueling
Reproductive function is sensitive to energy availability. Rapid weight loss, restrictive dieting, or very low body fat can suppress gonadotropin-releasing hormone pulsatility, leading to luteal phase abnormalities, anovulation, or amenorrhea. On the other end, significant weight gain and insulin resistance can contribute to ovulatory dysfunction, inflammation, and altered sex hormone metabolism.
The goal is not a specific aesthetic body size. Many people conceive across a wide range of body weights. The more useful focus is metabolic stability: adequate calories, consistent meals, sufficient protein, fiber-rich carbohydrates, healthy fats, and treatment of conditions such as thyroid disease, diabetes, or polycystic ovary syndrome when present.
Avoid extreme preconception diets, detoxes, appetite-suppressant supplements, and unsupervised very-low-calorie plans. If weight change is medically recommended, a gradual, supported approach is safer than rapid cycling. A clinician or registered dietitian can help tailor nutrition to ovulatory function, metabolic markers, and any underlying conditions.
Avoid over-exercising, but do not avoid movement
Physical activity generally supports fertility by improving insulin sensitivity, cardiovascular health, mood, sleep, and weight stability. The concern is not exercise itself; it is excessive training combined with inadequate recovery or insufficient energy intake.
High-volume endurance training, frequent high-intensity workouts, or compulsive exercise may disrupt ovulation in susceptible individuals, particularly when paired with low caloric intake or low body fat. Signs that training may be too much include cycle irregularity, missed periods, persistent fatigue, recurrent injuries, low libido, poor sleep, and declining performance despite intense effort.
A fertility-supportive exercise pattern usually emphasizes moderation: regular walking, strength training, yoga or mobility work, and aerobic activity at a sustainable intensity. Athletes trying to conceive should consider working with clinicians familiar with relative energy deficiency in sport and reproductive endocrinology rather than stopping all training abruptly.
Avoid high-mercury fish and be selective with seafood
Seafood can be beneficial before and during pregnancy because it provides omega-3 fatty acids, iodine, vitamin D, selenium, and high-quality protein. The issue is mercury. Methylmercury is a reproductive and neurodevelopmental toxin that can accumulate in larger predatory fish.
When trying to get pregnant, avoid high-mercury fish such as swordfish. Other commonly cautioned high-mercury species include shark, king mackerel, tilefish, bigeye tuna, and marlin, depending on local guidance. Safer lower-mercury options often include salmon, sardines, trout, anchovies, and many shellfish, but local advisories matter, especially for recreationally caught fish.
Food safety also becomes more important as pregnancy approaches. Avoid raw or undercooked seafood and handle refrigerated smoked fish, deli foods, and leftovers carefully according to pregnancy food-safety recommendations, because early pregnancy immune changes begin before many people realize they are pregnant.
Avoid making ultra-processed foods and high-glycemic carbohydrates your default
No single food causes infertility, and fertility diets should not become a source of shame. Still, habitual intake of ultra-processed foods, sugar-sweetened beverages, and refined high-glycemic carbohydrates may worsen insulin dynamics and inflammation in ways that can affect ovulation and reproductive hormone signaling, particularly in people with insulin resistance or PCOS.
Consider reducing frequent reliance on white bread, pastries, sugary cereals, sweetened drinks, fast food, and highly processed snack foods. Replace them when possible with whole grains, legumes, vegetables, fruit, nuts, seeds, fermented dairy or alternatives, eggs, fish, and other minimally processed proteins.
High intake of red and processed meats has also been associated in some research with poorer sperm quality and fertility markers. You do not necessarily need to eliminate these foods unless advised for medical reasons, but it is reasonable to limit processed meats and diversify protein sources with fish, poultry, beans, lentils, tofu, eggs, yogurt, and nuts.
Avoid unreviewed medications, supplements, and skin-care actives
Preconception is the right time for a medication review. Some medications are unsafe in pregnancy, while others are essential and should be continued with monitoring. The risk-benefit balance depends on the condition being treated, dose, timing, alternatives, and the consequences of stopping therapy.
Examples that deserve specific discussion include systemic retinoids, some anti-seizure medications, certain blood pressure drugs, anticoagulants, immunosuppressants, methotrexate, and some migraine or psychiatric medications. Topical retinoids are often avoided out of caution when trying to , even though systemic absorption varies. GLP-1 receptor agonists and other weight-loss medications should also be discussed before conception because many are and may require a planned discontinuation interval.
Supplements are not automatically safe because they are natural. Avoid high-dose vitamin A in retinol form, fertility blends with undisclosed ingredients, hormone-modulating herbs, and megadose regimens unless supervised. A standard prenatal vitamin with folic acid or folate is commonly recommended, but the ideal formulation may differ for people with anemia, thyroid disease, bariatric surgery history, vegan diets, or prior neural tube defect-affected pregnancy.
Avoid skipping vaccines and preconception health checks
Being under-immunized can create avoidable risk. Some infections, such as rubella and varicella, can be serious in pregnancy and may be preventable with vaccination before conception. Live vaccines are generally , so checking immunity before trying, or early in planning, can prevent delays and anxiety.
Preconception care can also identify issues that may affect fertility or early pregnancy outcomes, including uncontrolled diabetes, thyroid disease, hypertension, sexually transmitted infections, anemia, medication interactions, and genetic carrier risks. Dental care, cervical cancer screening when due, and review of occupational or environmental exposures can also be relevant.
If you have irregular cycles, known endometriosis, PCOS, prior pelvic infection, recurrent pregnancy loss, prior chemotherapy, or a partner with known sperm abnormalities, earlier medical input is reasonable. In general, many clinicians suggest fertility evaluation after 12 months of trying if under 35, after 6 months if 35 or older, or sooner when known risk factors are present.
Avoid heat and toxin exposures that may affect sperm
Because sperm development takes roughly several months, preconception changes in the male partner ideally begin early. Heat exposure can impair spermatogenesis in some men. Frequent hot tubs, saunas, very hot baths, laptops placed directly on the lap, and tight heat-trapping clothing may be worth reducing if semen parameters are a concern.
Workplace and environmental exposures also matter. Pesticides, solvents, heavy metals, radiation, and endocrine-disrupting chemicals may affect reproductive health depending on dose and duration. People working in agriculture, manufacturing, healthcare imaging, laboratories, salons, or industrial settings should ask about safety data sheets, ventilation, protective equipment, and occupational health guidance.
This does not mean you must live in a bubble. The practical approach is exposure reduction where feasible: wash produce, avoid smoking environments, use protective gear, improve ventilation when using chemicals, and discuss high-risk occupational exposures with a clinician.
Avoid turning conception into a constant stress test
Stress alone is rarely the sole explanation for infertility, and people should not be told to simply relax. That advice can feel dismissive and inaccurate. However, chronic stress can worsen sleep, libido, relationship strain, substance use, eating patterns, and adherence to medical care, all of which may indirectly affect the trying-to-conceive process.
Avoid over-monitoring if it is increasing distress. Ovulation predictor kits, basal body temperature apps, and cervical mucus tracking , but become overwhelming. If tracking makes intimacy feel clinical or anxiety spikes each cycle, consider simplifying to timed intercourse every 1 to 2 days during the .
Support may include therapy, peer groups, mindfulness-based stress reduction, couples counseling, or simply setting boundaries announcements and unsolicited advice. is a legitimate part of preconception care.
When to get medical guidance promptly
- Do not stop prescription medications suddenly without asking the prescribing clinician.
- Seek urgent care for severe pelvic pain, heavy bleeding, fainting, or suspected ectopic pregnancy symptoms.
- Ask for earlier fertility evaluation if cycles are absent or very irregular, or if there is known endometriosis, PCOS, tubal disease, or male-factor infertility.
- Discuss alcohol, cannabis, tobacco, or other substance dependence with a healthcare professional; effective help is available.
- Review vaccines before pregnancy, especially rubella and varicella immunity, because some vaccines require timing considerations before conception.
Tools & Assistance
- Schedule a preconception visit with an obstetrician-gynecologist, midwife, reproductive endocrinologist, or primary care clinician.
- Request a medication and supplement safety review before actively trying to conceive.
- Use evidence-based smoking or vaping cessation support, including counseling and clinician-approved pharmacotherapy when appropriate.
- Consider a registered dietitian for fertility-supportive nutrition, insulin resistance, PCOS, eating disorder history, or weight concerns.
- Use ovulation predictor kits or cycle tracking only if they reduce uncertainty rather than increase anxiety.
FAQ
Do I need to avoid caffeine completely when trying to get pregnant?
Complete avoidance is not usually required for everyone, but very high intake is generally discouraged. Ask your clinician what limit is appropriate for you, especially if you have miscarriage history, arrhythmia, anxiety, or sleep problems.
Should my partner make changes too?
Yes. Sperm quality can be affected by smoking, alcohol, cannabis, heat, nutrition, sleep, medications, and medical conditions. Changes made several months before conception may be most relevant because sperm development takes time.
Is it safe to keep exercising while trying to conceive?
Usually yes. Moderate exercise is generally supportive. The concern is excessive high-intensity or high-volume training, especially with under-fueling, cycle changes, or persistent fatigue.
Are fertility supplements worth trying?
Some nutrients are important, such as folic acid or folate, but many fertility supplements have limited evidence and may contain hormonally active ingredients. Review products with a healthcare professional before use.
When should I seek fertility testing?
Many clinicians recommend evaluation after 12 months of trying if under 35, after 6 months if 35 or older, and sooner if there are irregular cycles, known reproductive conditions, recurrent pregnancy loss, or male-factor concerns.
Sources
- WebMD — Things Not to Do If You Want to Get Pregnant
- Healthline — 5 Foods to Avoid When Trying to Get Pregnant
- The Bump — 10 Things to Avoid When Trying to Get Pregnant
Disclaimer
This article is for informational purposes only and does not replace personalized medical advice, diagnosis, or treatment. Consult a qualified healthcare professional about medications, medical conditions, fertility concerns, and pregnancy planning.
