Alcohol, nicotine and cannabis when planning a baby, during pregnancy and while breastfeeding

Three stages, three separate questions

You may be a sperm donor looking to improve your test results. You may have a positive pregnancy test and be thinking about the previous weekend. Or you may be breastfeeding and wondering what could still enter your milk after using a substance. These situations are related, but the same rule cannot answer each one.

Before pregnancy

The focus is on fertility, sperm, hormones and sexual function, as well as a pregnancy that may already have begun. The person who hopes to become pregnant and your shared surroundings also need to be included in the planning.

During pregnancy

Some substances can reach the baby through the placenta. The pregnant person's health, the baby's supply through the placenta and additional exposure to smoke also play a role.

While breastfeeding

The relevant issues are substances in breast milk, smoke in the environment and safe care of the baby. The speed at which a substance leaves the body and the most suitable feeding arrangement depend on the substance involved.

A finding about a future father's alcohol consumption therefore does not establish that alcohol is safe in pregnancy. Similarly, a single evening before conception cannot give a reliable prediction about a child's health.

What substance use can tell us about sperm and fertility

Sperm are formed and mature over weeks. A semen analysis therefore does not simply indicate whether the previous day was healthy. Fever, the period without ejaculation before giving the sample, incomplete sample collection and differences between tests can all affect results. Sleep, illnesses and longer-term living circumstances also belong in the discussion.

Normal results are not a comprehensive certificate of health. Reference values in the WHO laboratory manual do not draw a definite line between fertile and infertile. If the results are abnormal, clinical assessment determines whether a repeat test is needed and when to do it.

In studies on substance use, the outcome being measured matters: sperm count and movement are different outcomes from a pregnancy or live birth. Other substances, illnesses and accompanying factors can influence the associations. Improved semen parameters therefore do not guarantee pregnancy.

Alcohol in men: consider both the quantity and the drinking pattern

Prolonged heavy alcohol consumption is particularly relevant to male fertility. It can be associated with changes in hormone regulation and testicular function. Findings for small amounts or occasional drinking are less conclusive. Claiming that one beer destroys sperm would be as inaccurate as saying regular binge drinking is harmless.

Alcohol can also interfere with trying to conceive in everyday ways, such as by affecting sleep, libido, erections or the ability to keep agreed appointments. A review of lifestyle and male fertility discusses these hormonal, sexual and reproductive connections.

For a doctor's appointment, the actual pattern is more useful than the word occasional: on how many days, approximately how much, and whether intoxication occurs repeatedly. If you plan to reduce consumption substantially, allow several weeks and observe changes in daily life and symptoms. Where dependence is present, this needs medical support.

Smoking, nicotine and fertility

There is evidence that cigarette smoke is associated with poorer sperm count, movement and shape, as well as damage to sperm DNA. This does not mean every man who smokes is infertile. Smoking is nevertheless a sensible starting point if you want to reduce avoidable exposure.

Tobacco smoke and nicotine should not be treated as identical. Cigarettes also deliver carbon monoxide and many combustion products. Evidence on vapes and nicotine pouches in human fertility is more limited; missing long-term data do not establish safety. The ASRM statement on tobacco, nicotine and cannabis explains these distinctions.

Smoking also matters for the person hoping to become pregnant: in women, tobacco use is associated with reduced fertility and poorer fertility treatment outcomes. Quitting smoking is therefore relevant to both people, including in private sperm donation. A smoke-free environment also reduces exposure to second-hand smoke.

Cannabis when trying to conceive: evidence without simple thresholds

Studies on cannabis and male fertility do not show a consistent pattern. Some find changes in semen parameters or hormones, while others do not find a clear association with the time taken to conceive. THC content, frequency, method of use and accompanying tobacco use differ substantially. ASRM therefore interprets these links more cautiously than the established risks of smoking.

If you are actively planning a pregnancy or have abnormal results, discuss cannabis openly and plan to stop. This can reduce a possible exposure without promising that everything returns to normal after a set number of days without use. If cannabis is mainly used for sleep or anxiety, appropriate help for those symptoms should be included.

Anyone who could become pregnant should not rely only on sperm studies. Recommendations to avoid cannabis in a possible early pregnancy apply before a positive pregnancy test as well.

Testosterone and anabolic steroids are a distinct issue

Testosterone supplied from outside the body can suppress the hormonal signals required by the testes to produce sperm. Sperm counts may fall considerably, or production may stop entirely. More muscle, increased sexual desire or a high testosterone level does not therefore automatically mean better fertility.

The AUA/ASRM guideline on male infertility advises against testosterone monotherapy when there is a current or future wish to have children. This applies to prescribed treatment as well as steroid cycles and self-medication for fitness.

Discuss the preparation, dose and duration with a urologist or andrologist. Recovery may take months and sometimes longer; this does not provide a fixed recovery period. Do not stop prescribed therapy on your own or try to restart sperm production with hormone combinations you select yourself.

Opioids, cocaine and other substances

The topic of drugs and sperm extends beyond cannabis. Opioids can affect hormonal signalling and, through that, libido and sexual function. Cocaine and other stimulants also carry serious risks for the heart, circulation and mental health. Research cannot provide a reliable ranking of doses that are safe for conception.

Prescribed pain treatment or treatment for opioid dependence differs from uncontrolled use. In pregnancy, methadone or buprenorphine can be part of recommended treatment for opioid dependence. Do not stop on your own: the CDC recommendations on opioid dependence during pregnancy stress the benefit of coordinated treatment. Newborns may develop withdrawal symptoms following opioid exposure, so the birth team should be informed early. This risk is not a reason to omit necessary treatment.

Severe drowsiness, slowed breathing, chest pain, seizures or unconsciousness require emergency medical care. Do not wait for the next fertility appointment with these symptoms.

Putting sugar and mixed substance use in context

Sugar does not belong to the same risk category as tobacco smoke or anabolic steroids. A dessert does not suddenly make sperm unusable. A persistently very high-calorie diet can affect weight and metabolism; this is a different issue from the direct effects of drugs. Marked tiredness or loss of libido should not be quickly attributed to sugar alone.

Mixed substance use, however, is directly relevant. Alcohol, tobacco and cannabis can overlap in daily life and make an abnormal result harder to explain. Combining alcohol with opioids or sedatives such as benzodiazepines is especially dangerous: their depressant effects may intensify and impair breathing. The FDA warning on opioids and sedating substances addresses this risk.

Record medicines too, including why you use them, for example for sleep difficulties or anxiety. Help with stopping substance use and treatment of these symptoms should go together. Supplements cannot compensate for the effects of substance use or replace treatment; see the guide to supplements when planning a pregnancy.

Alcohol during pregnancy: no proven safe limit

Alcohol can reach the embryo or foetus through the placenta. No safe amount, safe time or safe type of alcoholic drink has been established for pregnancy. The recommendation is therefore to avoid alcohol throughout pregnancy. This also applies when you want to conceive and pregnancy is already possible. The CDC information on alcohol during pregnancy explains this advice.

A safe threshold cannot be tested experimentally in pregnant people. Research therefore relies mainly on observational studies, where amounts and accompanying factors are not always fully recorded.

A large amount of alcohol in a short period produces high blood alcohol levels. Such binge drinking is particularly concerning, but repeated smaller amounts are not automatically safe. Beer, wine, sparkling wine and spirits differ in alcohol concentration, not in whether the alcohol can reach the baby.

Organs begin forming in the early weeks, while the brain develops throughout pregnancy. There is therefore no later point at which drinking becomes reliably harmless. At the same time, previous exposure does not mean harm has definitely occurred.

FASD and other possible effects of alcohol

Fetal alcohol spectrum disorders, or FASD, describe different possible effects of alcohol exposure before birth. Growth, physical development, learning, memory, attention, planning and impulse control may be affected. Behavioural difficulties and problems regulating emotions may only become apparent when everyday demands increase.

Physical features may include a smaller head circumference or growth problems. Some affected people have characteristic facial features, including short eye openings, a smooth groove between the nose and upper lip, and a thin upper lip. Their absence does not rule out alcohol-related developmental difficulties.

FAS and pFAS

Fetal alcohol syndrome and partial fetal alcohol syndrome are diagnostic terms within this spectrum.

ARND and ARBD

These terms refer to alcohol-related neurodevelopmental disorders and alcohol-related birth defects respectively. The diagnostic categories differ between guidelines.

The CDC overview of FASD explains the terminology; the AWMF guideline on FASD in children and adolescents is relevant to diagnosis in Germany. Diagnosis requires experienced professionals and cannot be inferred from an amount consumed or a single physical characteristic.

Alcohol consumption during pregnancy is also associated with miscarriage, preterm birth and other adverse pregnancy outcomes. A reassuring ultrasound is helpful, but cannot exclude all later effects on learning and development. An adverse outcome does not automatically mean previous alcohol use caused it either.

Use before a positive test: what you can do now

Many pregnancies are only recognised after a few weeks. If you drank alcohol, smoked or used cannabis before then, the first task is to prevent further exposure and discuss the situation during antenatal care. One earlier exposure does not prove permanent harm.

Note the timing, approximate quantities, repeated use or binge drinking, and any other substances involved as honestly as you can. You do not need a perfect calculation down to the millilitre. This information should help with counselling, rather than lead to an endless search for a guarantee about what has already happened.

A clear question for the consultation is which checks and support are appropriate now. If alcohol dependence or previous severe withdrawal may be involved, arrange medical help the same day for safe withdrawal. This specific situation should not be confused with advice to continue smoking cigarettes.

Smoking in pregnancy and after birth

Smoking involves several harmful exposures together. Carbon monoxide reduces oxygen transport in the blood; nicotine and other smoke constituents affect the pregnant person's body and the child's development. Well-established risks include growth problems, low birth weight and preterm birth. Placental complications are also among the risks.

Smoke remains relevant after birth: second-hand smoke raises infants' risks of sudden infant death syndrome, lower respiratory illnesses and middle ear problems, among others. The CDC overview of smoking and maternal and infant health summarises these associations.

Ideally, stop smoking before pregnancy. Stopping later still helps by preventing further exposure. One cigarette or a relapse does not make the previous smoke-free period worthless. What matters is returning to being smoke-free and addressing the trigger.

Vapes, hookah, snus and nicotine pouches

No combustion does not automatically mean no risk. At the same time, calling every product equally harmful would be inaccurate. Decisions require separate consideration of smoke constituents, nicotine, additives and the evidence available for each product.

E-cigarettes and vapes

They avoid some of the combustion products in cigarettes but can deliver nicotine and other substances in the aerosol. They are not established as safe alternatives during pregnancy. Nicotine-free liquids are not reliably tested pregnancy-safe products either.

Hookah

Water does not reliably filter away harmful exposure. Smoke and carbon monoxide remain relevant; long sessions may result in considerable exposure.

Snus and nicotine pouches

Snus contains tobacco, while nicotine pouches can be tobacco-free. Both can deliver nicotine. Being smoke-free therefore does not make them safe options in pregnancy or equivalent substitutes for a medically planned approach to quitting.

The CDC information on the health effects of vaping explains the risks and knowledge gaps. If you have already switched to another product, discuss a workable next step. Going back to cigarettes is not the answer. The aim is to become smoke-free and, if possible, nicotine-free, with support you can actually use.

Second-hand smoke: keep your home and car smoke-free

Even if you do not smoke, regular smoke in your surroundings matters. Risks from second-hand tobacco smoke in pregnancy and infancy are established. Cannabis smoke is also unsuitable around pregnant people or babies, and mixing it with tobacco combines both exposures.

An open window, sitting in another corner or briefly ventilating a room does not make a smoky indoor space reliably protective. Space is especially limited in a car. The practical rule is therefore not to smoke in the home or car, even when the baby is not present.

Partners, family members and visitors can follow this rule without discussing exceptions every day. Kindergesundheit-Info's guidance on second-hand smoke offers further practical advice.

Nicotine replacement and medicines to stop smoking

Counselling and everyday support are the foundation of quitting smoking during pregnancy. If these alone are not enough, medically supervised nicotine replacement, such as gum or patches, may be considered. It avoids cigarette combustion products, but needs appropriate selection and use. The IQWiG information on nicotine replacement therapy explains this assessment.

NICE NG209 also includes nicotine replacement together with behavioural support. Your doctor needs to assess which products suit your situation during pregnancy or breastfeeding; recommendations for nonpregnant adults cannot simply be applied. This includes prescription medicines for smoking cessation.

Cutting down may be an intermediate step but is not the same as being smoke-free. Harmful substance intake may not fall in proportion to the number of cigarettes if inhalation becomes stronger or deeper. A relapse is therefore a reason to review support and triggers.

Cannabis during pregnancy: what the studies show

THC, the main intoxicating component of cannabis, can cross the placenta. No safe dose has been established for pregnancy. Descriptions such as plant-based or only at weekends therefore do not establish that use is harmless.

A meta-analysis published in JAMA Pediatrics in 2025 found adverse associations even after accounting for important confounders such as tobacco use. The adjusted statistical comparisons, called odds ratios, were 1.75 for low birth weight, 1.52 for preterm birth and 1.57 for a baby being small for gestational age. These are not percentages of affected children or a personal prediction.

An evidence overview by Munn and colleagues including 89 studies and reviews also describes adverse associations with several growth and neonatal outcomes, including intensive care. The evidence on later development, learning, behaviour and mental health is less consistent in some respects.

The mainly observational studies do not prove that cannabis caused every difference found. The amount and timing of use, assessment through questionnaires or tests, and accompanying tobacco use affect the conclusions. Equally, a single study without adverse findings does not answer every question. Professional bodies therefore advise avoiding cannabis during pregnancy and breastfeeding.

Cannabis products: flowers, hashish, vapes, edibles and CBD

Cannabis includes a wide variety of products. Alongside frequency, discuss THC concentration, the route of use, possible additives and mixing with tobacco. A label that looks medical does not establish suitability for pregnancy or breastfeeding.

Flowers and hashish

The form and active ingredient content differ, but both can deliver THC. Smoking adds combustion exposure, and tobacco adds its own risks when mixed in.

Vapes, dabbing and concentrates

Less conventional combustion does not eliminate THC exposure. Concentrates can contain high amounts of active ingredients; additives and the actual composition create further uncertainty.

Edibles, drinks and capsules

After eating or drinking cannabis, effects may begin later and last longer. This increases the chance of taking another dose before the first has fully worked. Unexpectedly strong effects can contribute to anxiety, a racing heart and accidents. The CDC information on cannabis describes these immediate risks. Here too, avoiding smoke does not mean avoiding risk.

Oils, drops and CBD

CBD does not produce the same high as THC, but it has not been studied enough to establish safety during pregnancy and breastfeeding. Products sold without prescription may also contain unexpected THC or contaminants.

The FDA information on cannabis and CBD explains why CBD is not a proven safe alternative either. The form of the product changes specific risks, but cannot replace safety data.

Nausea, poor sleep and medical cannabis

Anyone using cannabis for nausea, pain, anxiety or insomnia needs a solution for those symptoms. Subjective short-term relief does not prove that the treatment is safe or appropriate during pregnancy. The 2025 ACOG recommendation advises better-studied alternatives.

This applies to prescribed medical cannabis too. Discuss plans for a pregnancy or an existing pregnancy early with the prescribing doctor and your gynaecology team, so that the underlying condition can continue to be treated. A prescription is not a general proof of safety during pregnancy or breastfeeding.

If you can hardly keep fluids down, are losing weight, pass very little urine or feel faint, seek prompt medical assessment. Severe pregnancy nausea should not be managed by experimenting with edibles or vapes.

When cannabis causes vomiting: cannabinoid hyperemesis

Regular cannabis use can trigger cannabinoid hyperemesis syndrome, or CHS: repeated severe vomiting and abdominal pain that may be confused with pregnancy nausea. Some people experience temporary relief from hot showers or baths. A case series on CHS during pregnancy describes this pattern.

Hot water is neither a reliable self-test nor a treatment recommendation. Persistent vomiting needs assessment for dehydration and other causes. Stopping cannabis is central to CHS management; continued use for the supposed nausea can keep the problem going. Improvement after stopping does not replace necessary acute care.

Breastfeeding: assess alcohol, nicotine and THC separately

After birth, the questions change. Apart from breast milk, a smoke-free environment and a consistently sober person caring for the baby also matter. Substance use does not automatically lead to the same breastfeeding decision for every substance.

Alcohol and breast milk

Avoiding alcohol is safest. Alcohol passes into breast milk; the level in milk falls as blood alcohol falls. Expressing and discarding milk does not speed up clearance. You may express milk for comfort or to maintain milk production when needed, but this does not allow you to breastfeed sooner.

As a guide, the US public health agency CDC advises waiting at least two hours per standard drink before breastfeeding. Here a standard drink contains 14 grams of alcohol, roughly 150 millilitres of wine at 12% alcohol by volume; a large glass can contain substantially more. More alcohol requires more time, and actual clearance varies. Plan previously expressed milk or suitable infant formula if needed. Premature babies, unwell babies or repeated drinking require individual advice. This timing does not apply to cannabis or other drugs.

Smoking, nicotine and breastfeeding

Nicotine and other substances can reach the baby through milk, while smoke adds exposure through the surroundings. If quitting has not yet been possible, breastfeeding is not automatically ruled out for that reason alone. Practical support and reducing exposure matter: smoke outdoors, keep the home and car smoke-free, and wash your hands and change smoke-exposed clothes before contact with the baby. The CDC recommendations on tobacco and breastfeeding emphasise this distinction.

Cannabis, THC and breastfeeding

THC is fat-soluble and can enter breast milk. Clearance varies widely; a urine test measures neither the THC concentration in milk nor the safety of breastfeeding. A fixed waiting period or expressing once therefore cannot reliably establish safety. ACOG recommends avoiding cannabis, but does not regard ongoing use as an automatic reason to stop breastfeeding. Discuss the product, frequency, last use and the baby's feeding with your doctor.

Other drugs and prescribed treatment

During current non-prescribed use of opioids, stimulants such as cocaine or sedating sleep medicines, the Academy of Breastfeeding Medicine recommends temporarily avoiding breastfeeding. Ensure suitable feeding for the baby and get advice about when breastfeeding can resume. Stable, medically supervised substitution treatment, such as methadone, needs a different assessment and may be compatible with breastfeeding. Medicines, dose, other substance use and the baby's condition should all inform the decision.

Sober care and protection from accidental ingestion

An intoxicated or very drowsy person cannot safely care for a baby alone. Arrange for a sober adult. After alcohol, cannabis or medicines that cause drowsiness, do not sleep with the baby in the same bed or on a sofa. A separate cot is also important if a caregiver smokes. The BIÖG guidance on the sleep environment explains these risks.

Keep cannabis products, e-liquids and medicines locked away and out of children's sight and reach. Cannabis edibles can be mistaken for sweets in particular; nicotine-containing liquids can also cause serious poisoning. Read more about feeding choices in Breastfeeding or not breastfeeding.

Tests, private sperm donation and medical assessment

A period without substance use replaces neither semen analysis nor infection testing. A home sperm test also cannot establish that a donation is medically safe. In private sperm donation, verifiable health records, suitable examinations and clear agreements remain separate responsibilities.

Semen analysis and further assessment when appropriate are useful when pregnancy has not occurred, known risks are present or the history raises concerns. The WHO guideline on infertility describes a structured approach to diagnosis. Abnormal results should not be attributed to lifestyle alone without proper assessment.

Early assessment by a urologist or andrologist is sensible after anabolic steroid use, or if you have persistent erection problems, a significant loss of libido or abnormal testicular findings. Sudden severe testicular pain, swelling or pain with fever need urgent assessment. A new lump or repeated blood in semen should also be investigated. The guide to semen and sperm explains the basic terms.

A practical plan for the next few weeks

For men planning conception, eight to twelve weeks can be a manageable period to change habits and arrange follow-up. This is not a biological guarantee or advice to postpone a necessary examination. During pregnancy, the priority is to avoid further exposure as soon as possible, with medical help where dependence is involved.

1. Record substance use, medicines and the situations in which you use them. Include vapes, nicotine pouches, cannabis oils, steroid cycles and mixed substance use.
2. Choose concrete next steps: support to quit smoking, an appointment for assessment, or treatment for sleep problems, anxiety, pain or nausea.
3. Agree on smoke-free rules for your home and car and arrange support from those around you. Plan suitable drinks for celebrations and ways to manage triggers for use.
4. Choose alternative actions for recurring triggers, such as a coffee break, a drive or an evening after an argument.
5. Fix a time to review what works and what further help you need. Discuss relapses in that review without abandoning the whole plan.

A booked counselling appointment or a plan for the next difficult situation helps more than resolving to do everything perfectly from now on.

Celebrations, alcohol-free drinks and support from others

At gatherings, order a suitable drink immediately or bring one along. Ask people you trust not to refill your glass or suggest exceptions. A brief refusal is enough; you do not have to explain your pregnancy or medical history publicly.

An alcohol-free label does not mean every product is completely without alcohol. Check the specific label. If drinks resembling beer or wine trigger cravings, choose another kind of drink.

Partners, family and friends can avoid pressure to use substances, help with tasks and support smoke-free rules. Blame or comments that minimise the issue make open conversations harder. Support remains important after birth, when lack of sleep and stress can bring back old habits.

When to get help and where to start

Seek support if you continue using despite your plans, cannot control the quantity, use secretly or need alcohol or cannabis to sleep or get through the day. Severe restlessness, panic, depressive symptoms or repeated vomiting also need medical assessment.

If alcohol dependence is possible, unsupervised withdrawal is dangerous, especially after previous shaking, sweating or seizures. The WHO recommendations on alcohol withdrawal stress supervised treatment. Benzodiazepines taken regularly should also not be stopped abruptly, because severe withdrawal symptoms may occur. For seizures, breathing problems, confusion or impaired consciousness, call 112 in Germany.

A family doctor, gynaecology clinic, midwife or addiction counselling service can help you take the first step. In Germany, the BIÖG addiction and drugs helpline offers initial guidance, while rauchfrei-info provides help with quitting smoking during pregnancy.

Four details help during the consultation: what you take, how often, why you use it and what happens when you take a break. Also mention whether you are pregnant, breastfeeding, or planning sperm donation or treatment. This can turn a general warning into a concrete treatment plan.

Legal status does not replace the health assessment. Germany's Consumer Cannabis Act has applied since 1 April 2024; the German Federal Ministry of Health information on the Cannabis Act explains the legal framework. Legal permission does not amount to medical approval during pregnancy or breastfeeding.

Common myths that make decisions harder

One instance of use proves that everything is already damaged.

Exposure is not definite proof of harm. An honest assessment, avoiding further exposure and suitable support are what matter.

A normal semen analysis makes any further substance use harmless.

It assesses specific semen parameters. It is not a comprehensive health check or a statement about the safety of a later pregnancy.

Plant-based, smoke-free or prescribed automatically means safe.

These features answer different questions. None replaces data about the specific use before conception, during pregnancy or while breastfeeding.

A few cigarettes or use only on weekends is guaranteed harmless.

Less exposure can be progress, but it is not an established safe limit. The amount, product and situation remain important.

Testosterone improves masculinity and therefore sperm production.

Testosterone supplied from outside the body can suppress sperm production. Plans to have children should therefore be discussed early when planning treatment.

Expressing milk removes alcohol or THC from the body faster.

Expressing does not speed alcohol clearance or make THC elimination reliably predictable.

A relapse means quitting will not work anyway.

A relapse shows where more support is needed. The next step without smoking or substance use is still worthwhile.

Conclusion

Alcohol, nicotine and cannabis need different answers at different stages. Starting to quit early, avoiding further exposure and seeking professional help for dependence are useful steps. Earlier use is not definite evidence of harm; a normal test does not mean continued use is safe. A specific plan and suitable support matter most.