The simple answer is to stop all unnecessary medications before trying to get pregnant, but of course, this is not always feasible.
Some medications are known to be able to harm the fetus and should be stopped or replaced before conception: isotretinoin (for acne), warfarin and the other coumarin anticoagulants, tetracyclines, valproic acid (for epilepsy), methotrexate and ACE inhibitors (for high blood pressure). For other medications, such as certain migraine drugs or high-dose cortisone, the decision is individualized. Talk to your doctor before stopping any prescription medication you take.
Many pain-relieving medications are safe in small amounts. However, some nonsteroidal anti-inflammatory drugs (NSAIDs), or any medication containing ibuprofen, may affect ovulation and the endometrium.
The best advice is to talk with your doctor before taking any medication. For many drugs, there are equally safe alternatives for pregnant women. For example, if you need an anticoagulant for deep vein thrombosis, heparin is safe because it does not cross the placenta. Discuss these issues with your obstetrician before attempting to conceive.
What to do before you start trying
Book a preconception visit two to three months ahead and bring a list of everything you take: prescription medications, over-the-counter products, herbs and supplements. For most chronic conditions there is a pregnancy-compatible treatment, and the switch is best made before conception. Do not stop medications for epilepsy, thyroid disease, diabetes, high blood pressure, asthma or depression on your own: uncontrolled disease is often more dangerous for the pregnancy than the medication itself.
Medications that need to be stopped in advance
- Isotretinoin (for acne): stop at least one month before conception, with reliable contraception in the meantime.
- Methotrexate: usually three to six months before.
- Valproate: the neurologist changes the treatment before conception.
- Warfarin and other coumarin anticoagulants: replaced with low molecular weight heparin.
- ACE inhibitors and sartans (for high blood pressure): switch to a blood pressure medication suitable for pregnancy. Read more about high blood pressure in pregnancy.
These time frames are approximate and are set by your treating doctor.
Medications generally considered safe
- Acetaminophen (paracetamol) for pain and fever, at the lowest effective dose.
- Levothyroxine for hypothyroidism. The dose is often increased as soon as the pregnancy is confirmed.
- Insulin, and metformin where indicated.
- Most asthma inhalers.
- Antibiotics from the penicillin and cephalosporin groups.
Supplements and herbs
Folic acid, 400 micrograms a day, should be started at least one to three months before conception. Some women need a higher dose, which the doctor determines. Avoid products with high doses of vitamin A (retinol), and remember that "herbal" does not mean safe: for most herbs there are no data in pregnancy.
Your partner's medications
Testosterone and anabolic steroids suppress sperm production, while some hair loss medications, blood pressure drugs and chemotherapy agents also affect fertility. Read about male infertility.
You will find more practical advice for the time before conception in the article on how to get pregnant.
Why the timing of a medication matters so much
The same medication can be harmless at one stage and dangerous at another. The development of the fetus goes through stages with different sensitivity:
- First two weeks after conception: the "all or nothing" rule applies. Serious damage usually leads to early loss, while if the pregnancy continues, the embryo usually develops normally. That is why medications taken during this period rarely cause birth defects.
- From the 3rd to the 8th week after conception, that is, roughly the 5th to the 10th week of pregnancy: the organs form. This is the most sensitive period.
- After the first trimester: some medications affect the growth, kidney function or brain of the fetus.
The problem is that the most sensitive period begins before most women realize they are pregnant. This is why treatment is reviewed before conception, not when the test comes back positive.
Medications by condition when trying to get pregnant
The list below helps you prepare for the conversation with your doctors. It does not replace individualized advice, and no change should be made without your treating doctor.
Epilepsy
Valproate and topiramate are covered by special European pregnancy prevention programs because of the risk of birth defects and neurodevelopmental disorders. Lamotrigine and levetiracetam have more reassuring data. Women taking antiepileptic drugs usually need a higher dose of folic acid, set by their doctor.
Thyroid
Levothyroxine is safe and necessary. For hyperthyroidism, methimazole (thiamazole) is linked to a risk of birth defects in the first trimester, which is why switching to propylthiouracil before conception or as soon as the pregnancy is confirmed is often preferred.
Hypertension
Labetalol, nifedipine and methyldopa are widely used in pregnancy. The switch from ACE inhibitors or sartans is ideally made before conception, so that blood pressure is controlled from the start.
Diabetes, obesity and weight loss injections
Insulin is the reference treatment. Injectable GLP-1 agonists, such as semaglutide, are not recommended in pregnancy. For semaglutide, the product label calls for stopping at least two months before a planned conception. SGLT2 inhibitors are also stopped. If you are predisposed, also learn about gestational diabetes.
Mental health
Most selective serotonin reuptake inhibitors (SSRIs) have extensive experience of use in pregnancy. Lithium is often continued with close monitoring, after a careful discussion of benefits and risks. Some antipsychotics raise prolactin and can disrupt ovulation, which is worth checking if your periods have become infrequent.
Autoimmune and rheumatic diseases
Mycophenolate is stopped at least six weeks before conception. Leflunomide stays in the body for a long time and requires a special elimination procedure. In contrast, hydroxychloroquine, azathioprine and sulfasalazine in women are considered compatible with pregnancy. The right time to conceive is when the disease has been in remission for several months.
Skin and acne
Besides isotretinoin, acitretin for psoriasis requires avoiding pregnancy for three years after stopping. Topical retinoid creams are best stopped, and spironolactone, given for acne or excess hair growth in women with polycystic ovaries, is also stopped because of its antiandrogenic effect.
Cholesterol and anticoagulants
Statins are usually stopped when a pregnancy is planned, except in special high-risk cases. The newer oral anticoagulants are not recommended in pregnancy and are replaced with low molecular weight heparin.
Medications that make conception harder without harming the fetus
Not all problematic medications cause birth defects. Some simply lower the chances of conception:
- Medications that raise prolactin, such as certain antipsychotics and anti-nausea drugs, which can make ovulation infrequent or stop it.
- High doses of progestins or hormonal products given for other reasons that suppress the cycle.
- Nasal decongestants with pseudoephedrine or first-generation antihistamines, which in theory may reduce cervical mucus. The data are limited, but if you only need them occasionally, it is best not to take them on your fertile days.
- Long-term opioid use, which affects reproductive hormones in both sexes.
If you take any of these and your cycle has become irregular, tell your doctor. Also see how to tell whether you have regular ovulation.
Over-the-counter products we often forget
- Cold remedies: many contain a combination of a pain reliever, a decongestant and an antihistamine. Choose plain acetaminophen (paracetamol) and saline spray for your nose.
- "Herbal" sleep aids and sedatives: for most of them there are no safety data in pregnancy.
- General multivitamins: check the label for retinol. Prenatal vitamins have an appropriate formulation.
- Cosmetics with hydroquinone or high concentrations of salicylic acid: best stopped while you are trying.
- Antacids and mild laxatives: the usual products are generally considered safe for occasional use.
Which women need a higher dose of folic acid
The standard dose of 400 micrograms covers most women. A higher dose, determined by the doctor, is usually recommended when:
- there has been a previous pregnancy with a neural tube defect or there is a family history,
- the woman takes antiepileptic drugs,
- she has diabetes,
- her body mass index is 30 or higher,
- she has bowel conditions that reduce absorption.
Cannabis, alcohol and other substances
Cannabis has been linked to ovulation problems in women and poorer sperm parameters in men, and it is not recommended either while trying or during pregnancy. The same applies to gym "booster" supplements that contain hormones or unknown substances. For alcohol and coffee, see what applies to female fertility and lifestyle.
Preconception checklist
- Write down all the medications, supplements, herbs and creams you use, with doses.
- Ask each doctor who follows you to tell you whether their treatment is compatible with pregnancy.
- Start folic acid at the dose that is right for you.
- Ask whether a waiting period is needed after stopping a medication.
- Get the prenatal screening that is appropriate for your age and history.
- Keep the list on your phone so you have it at every visit or in an emergency.
For information, rely on the official package leaflet and your pharmacist rather than forums. Many stories online involve different doses or stages of pregnancy and cause needless fear.
If you get pregnant while taking a high-risk medication
It happens more often than you think, and it does not automatically mean the fetus has a problem. The steps are specific:
- Contact the doctor who prescribed the medication and your obstetrician on the same day.
- Do not abruptly stop medications for epilepsy, mental illness, thyroid disease or anticoagulant treatment without instructions. Stopping suddenly can be more dangerous than continuing.
- Write down the exact name, the dose and the dates you took it. The risk depends mainly on the week of pregnancy at the time of exposure.
- Accurate dating is done with a first trimester ultrasound. Where needed, the fetal anatomy is checked in a targeted way on the level II ultrasound.
In most cases, a detailed assessment leads to a reassuring conclusion and the pregnancy continues with appropriate monitoring.
For a personalized assessment of your case, book an appointment with Dr. Panagiotis Polyzos at his office in Athens or Volos.
Frequently Asked Questions
I took a medication before I knew I was pregnant. What should I do?
Don't panic. In the first two weeks after conception, most medications either do not affect the embryo or the pregnancy does not continue. Tell your doctor the medication, the dose and the dates.
Is ibuprofen allowed when I am trying to get pregnant?
It is best to avoid it around and after ovulation, because anti-inflammatory drugs can affect ovulation and implantation. Choose acetaminophen (paracetamol) instead.
Should I stop my antidepressants?
Not without medical guidance. Many antidepressants have extensive experience of use in pregnancy, and stopping abruptly carries a risk of relapse. The decision is made together with your psychiatrist and your obstetrician.
When should I start folic acid?
At least one month, ideally three, before conception, and continue it at least until the 12th week.
Are vaccines allowed when I am trying for a baby?
Yes, and it is the right time to check your immunity. Live virus vaccines, such as those for rubella and chickenpox, are given before pregnancy, with a one-month wait before conception.
Can I take antihistamines for allergies when I am trying to get pregnant?
Newer antihistamines, such as loratadine and cetirizine, have reassuring data and are often used. For nasal allergies, nasal corticosteroids at usual doses are also a good option. Tell your doctor that you use them.
Should I stop weight loss injections before trying for a baby?
Yes. GLP-1 agonists are not recommended in pregnancy. For semaglutide, stopping is advised at least two months before a planned conception. Discuss with your doctor how to maintain your weight during the transition.
Can I keep using retinol or retinoid creams?
Prescription retinoid creams are best stopped when you are trying to get pregnant. For acne, alternatives such as azelaic acid are considered more suitable. Ask your dermatologist.
My partner takes finasteride for hair loss. Should he stop it?
Finasteride can reduce sperm parameters in some men, and the effect usually reverses after stopping. If conception is delayed or the semen analysis is abnormal, discuss stopping it with a urologist.
Do antibiotics affect the chances of conception?
Common antibiotics do not appear to reduce fertility. What matters is choosing a product that is compatible with a possible early pregnancy, so tell your doctor that you are trying to conceive.
