Medications and vaccines
Always tell your physician if you are planning a pregnancy, so that your medication can be planned to be as safe as possible for the fetus even before you actually become pregnant.
Antibiotics
Most antibiotics can be used during pregnancy and breastfeeding. Although most antibiotics are excreted in breast milk only in minute quantities, the infant may sometimes experience bowel symptoms if the mother is on antibiotics.
Please do not use antibiotics in the tetracycline group (e.g. doxicycline, tetracycline and lymecycline) during pregnancy. Note, however, that adverse fetal impacts of tetracycline do not emerge unless used at or after week 15 of the pregnancy. In other words, if you have used tetracyclines at an early stage, before you were aware of being pregnant, no action is necessary, because such use is not expected to be harmful. Because tetracyclines accumulate heavily in bones, please avoid their use during breastfeeding unless there are no safer alternatives available. If you have to use tetracyclines during breastfeeding, do not exceed three weeks of use.
You may use eye drops containing cloramphenicol to treat an eye infection at any time during your pregnancy. If you administer the eye drops with the proper method (press down on the inner corner of the eye over the tear duct for 1–2 minutes after administering the drop), then only a minimal amount of the medication will enter the bloodstream. If you follow the dosage instructions, you can also breastfeed safely.
Fluoroquinolones (e.g. ciprofloxacin, norfloxacin) are not recommended, although they may be indicated if other, more familiar antibiotics are ineffective. Fluoroquinolones are not known to cause fetal injury in humans. A short course of fluoroquinolone treatment does not prevent breastfeeding.
You can use antibiotics of the macrolide group (e.g. azithromycin and roxithromycin) during pregnancy. However, you should avoid antibiotics in this group if breastfeeding a child under two weeks old. Exposure of a newborn infant via breast milk particularly to azithromycin may elevate the risk of the child developing pyloric stenosis (a narrowing of the opening from the stomach to the small intestine).
Metronidazole may be used as an antibiotic during pregnancy. Topical application is the primary option, but a course of the drug taken by mouth is also possible if the physician considers it necessary. The above also applies to the breastfeeding period. Metronidazole administered by mouth or intravenously is extracted into breast milk, but this medication is also used safely to treat newborn infants.
Contrary to what is said in the package leaflet, there is no reason to suspend breastfeeding if the mother is on a course of metronidazole.
Nitrofurantoiinia ja pivmesillinaamia (jälkimmäinen penisilliinijohdos) voit käyttää virtsatietulehduksen hoitoon raskauden kestosta riippumatta. Voit käyttää molempia lääkkeitä myös imetyksen aikana.
You can take nitrofurantoin and pivmecillinam (the latter being a penicillin derivative) to treat urinary tract infection at any time during your pregnancy. You can also use both of them while breastfeeding.
Please avoid using trimethoprim and trimethoprim-sulfamethoxazole preparations when planning for pregnancy and during the first trimester of pregnancy, because these medications may have an adverse impact on the folate balance in your body. Trimethoprim (and trimethoprim-sulfamethoxazole) can be safely used during the second and third trimesters of pregnancy. There is no contraindication to using them during breastfeeding.
Epilepsy medications
Please always inform your doctor if you are planning a pregnancy while on epilepsy medication. Some epilepsy medications are harmful to fetal development, and your medication should be planned to be as safe as possible well in advance, when you are planning your pregnancy.
Maintaining proper treatment of epilepsy is important during pregnancy, because seizures can subject the fetus to trauma and lack of oxygen. Please do not stop taking medication or change your dosage without consulting your physician.
Many epilepsy medications can impact the efficacy of hormonal birth control. If you use hormonal birth control, please check with your physician whether it is compatible with your epilepsy medication.
Breastfeeding is not only allowed but indeed recommended while taking epilepsy medication. However, some epilepsy medications may excrete into breast milk to the extent that the baby may develop a drug reaction. Infants under the age of 3 months in particular may have limited capacity to deal with a drug received via breast milk. It is therefore important to have the baby monitored at the child care clinic for any drug reaction symptoms, and the safety of breastfeeding must be reviewed with your attending physician on a case-by-case basis.
Folic acid supplement recommended for users of epilepsy medication
It is recommended that prospective mothers on epilepsy medication begin taking a folic acid supplement a couple of months before discontinuing birth control, the prescribed dosage is 0.4 mg.
Folic acid supplements are known particularly to reduce the risk of meningomyelocele (neural tube defect). However, it has not been conclusively proven that it could specifically protect against malformations caused by epilepsy medications.
Using carbamazepine in early pregnancy elevates the risk of birth defects, but not by as much as using valproate. Using this medication during pregnancy should be restricted to epilepsy treatment and to situations where safer options are not usable.
The risk depends on the dose and amounts to 5% to 9% (in other words, 5 to 9 children out of 100 born to mothers who took carbamazepine early in the pregnancy will be diagnosed with a birth defect). Carbamazepine elevates the risk of meningomyelocele (neural tube defect), but the risk is considerably smaller (about 4 in 1,000). If the use of carbamazepine is strongly indicated, the daily dose should be divided into several subdoses.
Carbamazepine use does not prevent breastfeeding. Monitoring the child at the child health clinic is sufficient.
There is very little experience of using eslicarbazepine during pregnancy, and the risk to the fetus cannot therefore be reliably estimated. It may be advisable to monitor drug levels.
Eslicarbazepine use does not prevent breastfeeding. However, because this is a new medication and there is not very much information about its use during breastfeeding, it is important to have the child monitored at the child health clinic.
Research findings on use of the medication during pregnancy are limited but do not indicate an elevated risk of birth defects. However, use of gabapentin should be limited to the treatment of epilepsy.
For treating chronic pain during pregnancy, medications in other drug groups are generally recommended (e.g. antidepressants with a long track record). In complicated situations, gabapentin use for pain management during pregnancy is allowable. Gabapentin use close to the time of delivery may cause the newborn infant to suffer from withdrawal symptoms. It may be necessary to monitor the infant’s condition at the hospital for a few days in such a case.
Gabapentin use does not prevent breastfeeding. However, it is important to monitor the infant at the child health clinic in case of any symptoms resulting from the medication (sleepiness). Monitoring is particularly important for breastfed infants under 3 months of age.
Lamotrigine is used not only to treat epilepsy but also as a mood stabilizer. Its use would not seem to elevate the risk of birth defects. It is often necessary to monitor levels of the drug in the blood, and the physician may be obliged to increase the dosage of lamotrigine as the pregnancy progresses, because lamotrigine metabolism accelerates during pregnancy. Similarly, after childbirth the dosage has to be reduced gradually to pre-pregnancy levels according to the physician’s instructions.
Lamotrigine use does not prevent breastfeeding. However, in individual cases relatively high drug levels have been found in breastfeeding infants. It is therefore important to have the child monitored at the child health clinic. If adverse impacts of the medication are suspected in the infant (e.g. fatigue, poor weight gain, rash), breastfeeding must be suspended and the infant’s drug levels controlled.
Levetiracetam use during pregnancy has not been found to elevate the risk of birth defects. It is often necessary to monitor levels of the drug in the blood, and the physician may be obliged to increase the dosage of levetiracetam as the pregnancy progresses.
Levetiracetam use does not prevent breastfeeding. Monitoring the child at the child health clinic is important, however.
Pregnancy: Experience of oxcarbazepine use during pregnancy is limited but does not indicate an elevated risk of birth defects.
Breastfeeding: Oxcarbazepine use does not prevent breastfeeding. Monitoring the child at the child health clinic is important, however.
Phenytoin is not much used nowadays because of its side effects; it interacts in many ways with other medications. Using phenytoin early in the pregnancy elevates the risk of birth defects somewhat: birth defects are found in 3 to 6 out of 100 children (3% to 6%).
Phenytoin use does not prevent breastfeeding. Monitoring the child at the child health clinic is sufficient.
Using topiramate early in the pregnancy elevates the risk of birth defects. Topiramate has been linked particularly to an elevated risk of cleft lip/palate. Using this medication during pregnancy should be restricted to epilepsy treatment and to situations where safer options are not usable.
Topiramate use does not prevent breastfeeding. Monitoring the child at the child health clinic is important, however.
Valproate significantly elevates the risk of birth defects and developmental delays. Please do not use it during pregnancy unless there is a particularly weighty reason for doing so. Valproate may only be used in exceptional situations where no other appropriate or effective medications for your epilepsy are available.
Valproate must not be prescribed for women who could become pregnant, unless they follow a specific birth control regime. However, if you are on valproate, do not discontinue taking it without consulting your attending physician. Epileptic seizures can be dangerous for both mother and fetus, so continue to manage your epilepsy treatment well during pregnancy.
The use of valproate during pregnancy is strictly restricted to situations where no other medication is effective for your epilepsy. If it is essential to take valproate, the daily dose should be divided into several subdoses.
Taking valproate in early pregnancy elevates the risk of birth defects, and the drug can have harmful impacts on the fetus throughout the pregnancy. The risk of birth defects increases as the dose increases and can exceed 20% (20 children out of a 100 developing a birth defect) if the daily dose exceeds 1500 mg. Valproate can cause many kinds of congenital malformations, most typically meningomyelocele (neural tube defect) (absolute risk 1% to 2%, meaning that 1 or 2 children out of 100 born to mothers who took valproate early in the pregnancy are diagnosed with neural tube defect), heart problems and cleft lip/palate.
Structural malformations in the kidneys and urinary tract, and limb malformations, are also possible. Exposure to valproate in the womb elevates the risk of the child experiencing developmental delays. The child may have trouble in school and require special support. There is also an elevated risk of autism.
A mother who takes valproate can breastfeed. Monitoring the child at the child health clinic is sufficient.
Medication applied to the skin or eyes
With topical medication (skin creams, eyedrops, etc.), drug levels absorbed into the body are generally lower than if the medication is administered orally.
Absorption of substances applied to the skin into the bloodstream may increase during pregnancy due to increased superficial circulation, and eyedrops unless applied appropriately may excrete significant levels of active agent into the system.
For any medication applied topically, please follow these basic instructions during pregnancy and breastfeeding:
- For topical medication, only apply to the area of skin requiring treatment, avoid covering with bandages, and use for as short a period as possible.
- With eyedrops, you can significantly reduce exposure by pressing down on the inner corner of the eye (over the tear duct) for 1 to 2 minutes after administering the drops. The medication will then be absorbed into the eye rather than flowing down to the pharynx and then being absorbed into the bloodstream.
Misoprostol
Misoprostol is used to treat stomach ulcers and also for drug-induced termination of pregnancies. Please do not take misoprostol during pregnancy.
Misoprostol causes contractions of the uterus and thus an elevated risk of miscarriage. The contractions of the uterus caused by the medication may cause the fetus to not get enough oxygen. This may lead to damage to the fetus, such as partial absence of distal digits or damage to the central nervous system.
You must have made a final decision to terminate your pregnancy before taking the drug. Once started, the termination must be completed. Please attend the agreed follow-up examinations so that termination can be confirmed.
Mood stabilizers
Remember to tell your physician if you are planning a pregnancy while taking a mood stabilizer, because some medications used for this purpose may be harmful to fetal development (e.g. valproate use is not permissible).
Carbamazepine is an epilepsy medication that is also used to treat bipolar disorder. Carbamazepine use during early pregnancy slightly elevates the risk of damaging the fetus to about double the ‘background risk’ (4% to 5% of live born infants) of a birth defect.
What the ‘background risk’ means is that out of all babies born alive about 4% will have significant malformations of some kind; in other words, 4 out of 1,000 babies born have a malformation. If carbamazepine use during early pregnancy doubles this risk, then about 8 out of 1,000 babies born to mothers who used carbamazepine during early pregnancy have a malformation. Therefore in the case of bipolar disorder a safer medication should be chosen as a mood stabilizer.
Lamotrigine is an epilepsy medication. Lamotrigine does not elevate the risk of birth defects, at least not at small dosages (less than 325 mg per day), and it is the primary mood stabilizer option during pregnancy. With higher dosages, the risk of birth defects may be somewhat elevated, but this may have to do with the mother’s epilepsy just as well.
Lamotrigine and changes in dose while using combination birth control pills and during pregnancy:
- When you are on combination birth control pills, the estrogen input may accelerate lamotrigine metabolism in the liver, and the lamotrigine dose may have to be increased. Similarly, your lamotrigine dose must be reviewed when you stop taking combination birth control pills and begin to plan a pregnancy.
- Due to physiological changes in your body during pregnancy, your lamotrigine dose may again have to be increased as the pregnancy progresses. After childbirth the dosage has to be reduced gradually to pre-pregnancy levels. Please discuss your dosage with your physician.
Lithium is a mood stabilizer used to treat bipolar disorder. Discuss lithium use with your physician well in advance, when you are planning your pregnancy. Lithium treatment must always be discontinued gradually. Do not just stop the treatment unless there are grave medical reasons for doing so.
Lithium use during early pregnancy may elevate the risk of a structural birth defect in the heart. The risk is slight, however, being about twice that of the ‘background risk’ for heart defects. What the ‘background risk’ means that out of all babies born alive about 0.8% will have a congenital heart defect. In other words, 8 out of 1,000 babies born have a heart problem of some kind. If lithium is assumed to double the risk of a heart defect, then 16 out of 1,000 babies born to mothers taking lithium during early pregnancy have a heart problem. For mothers who have taken lithium during early pregnancy, an ultrasound examination of the fetus’s heart is recommended around week 20 of the pregnancy.
Good treatment of bipolar disorder during pregnancy is important. Untreated bipolar disorder is a greater risk for both mother and child than the slight risk involved in lithium use. Drug levels in the blood must be carefully monitored if using lithium during pregnancy. The mother’s overall blood volume increases during pregnancy, and lithium levels in the blood may thus vary even if the dose is not changed. Towards the end of the pregnancy, it may be necessary to measure lithium levels in the blood on a weekly basis.
Valproate must not be prescribed for women who may become pregnant. Please follow a specific birth control regime. Valproate must not be taken during pregnancy except when there are particularly weighty reasons for using it to treat epilepsy and other medications are not usable. Valproate must not be prescribed as a mood stabilizer during pregnancy.
Valproate multiplies the risk of birth defects from the ‘background risk’ level of (4% to 5% of live born infants, so that up to 25 out of 100 babies born to mothers who have taken valproate during early pregnancy may have a malformation of some kind. Valproate use during pregnancy also elevates the risk of developmental delays in the child.
Painkillers
The primary medication for pain and fever relief during pregnancy is paracetamol.
The primary medication for pain and fever relief during pregnancy is paracetamol. However, it must be used sparingly – only when there is an evident need for it. Paracetamol is subject to the same restrictions as all other medications during pregnancy: take it for the shortest possible treatment period and in the smallest possible dose.
Long-term and regular use of paracetamol during pregnancy must be discussed with your physician. Long-term use of paracetamol during pregnancy has been associated in certain studies with an elevated risk of ADHD and other behavioral disturbances in children.
Use of non-steroidal anti-inflammatory drugs (NSAIDs)
Non-steroidal anti-inflammatory drugs (NSAIDs) should only be used occasionally or for short periods of time in early pregnancy. If paracetamol is ineffective for pain relief, you may try taking an NSAID (primarily ibuprofen) for a short period. It is suspected that using an NSAID for more than two weeks near and after the time of conception may elevate the risk of miscarriage.
When you are planning your pregnancy, avoid repeated use of NSAIDs if possible, because they may also prevent ovulation.
Avoid taking NSAIDs after week 28 of your pregnancy.
Avoid taking NSAIDs after week 28 of your pregnancy. Repeated use, even if for short periods of time, during late pregnancy may have an adverse impact on circulation in the heart of the fetus and compromise the fetus’s kidney function. However, it is permissible to take individual doses of an NSAID occasionally even beyond week 28 of your pregnancy if paracetamol is ineffective. Please always discuss this at the maternity clinic.
Acetylsalicylic acid is not recommended as a painkiller during pregnancy. A low dosage as prescribed by a physician (50 to 100 mg per day) is safe, however.
Use of pain gels containing NSAIDs must be limited to the smallest possible skin area and the shortest possible treatment period. Although the amount of drug absorbed through the skin is very small, significant levels can accumulate in the blood stream through absorption if gel is used over large areas of skin and/or for a long time.
Also avoid using bandages, because drug absorption from the gel through the skin may be enhanced under a bandage. If you use topical NSAIDs, only use them for as short a period as possible, particularly beyond week 28 of your pregnancy.
Also avoid using tiger balm and other natural products used on the skin that contain large quantities of ethereal oils.
You can take pain medication while breastfeeding without harming your infant. Paracetamol use is safe, and among NSAIDs ibuprofen is a safe option. Using medications such as naproxen, ketoprofen, and diclofenac for brief periods of time is also permissible.
Acetylsalicylic acid is not recommended as pain or fever relief while breastfeeding. A small dosage as prescribed by a physician (50 mg to 100 mg per day) is safe, however.
Small quantities of active agent from a pain gel are absorbed through the skin into the bloodstream; the levels in breast milk will thus also be low. You can use pain gels during breastfeeding as long as you follow the instructions. Avoid using tiger balm and other natural products used on the skin that contain large quantities of ethereal oils.
Treatment of acne
Acne medication by mouth (isotretinoin) is absolutely prohibited during pregnancy. Please stop using such medication well in advance before your pregnancy.
Adapalene and tretinoin
Topical acne treatment involves preparations used externally, i.e. applied directly to the skin in the affected areas. Adapalene and tretinoin, used in topical treatment products, belong to the retinoid group like isotretinoin. Medications in this group if administered by mouth can cause birth defects. Although only low levels of adapalene and tretinoin are absorbed through the skin, significant levels may accumulate if you treat large areas of skin. You must not use retinoids even in topical treatments during pregnancy. Please stop using any such preparations when you are planning your pregnancy.
Benzoyl peroxide, azelaic acid, and clindamycin
During pregnancy, you may use topical acne creams that contain benzoyl peroxide, azelaic acid or clindamycin. However, only apply these to the area of skin that actually requires treatment.
Isotretinoin is a medication used to treat severe acne. Using it during early pregnancy significantly elevates the risk of severe birth defects in the heart and the central nervous system.
If you have been prescribed isotretinoin, remember this:
If the drug is used when the pregnancy has already begun, there may be up to a 25% to 40% risk of the fetus developing a severe birth defect (i.e. out of 100 mothers taking isotretinoin in early pregnancy, 25 to 40 will give birth to a child with a severe birth defect).
- Please use reliable birth control and observe a withholding period before pregnancy.
- Isotretinoin lingers in the body for a considerable period of time, so while you are on the medication and for one month after stopping, please use a birth control method at least as reliable, such as the pill or an IUD. We also recommend making doubly sure by using a condom as well.
- Perform a pregnancy test before beginning treatment and repeatedly during treatment, and also after stopping the treatment, so that the possibility of pregnancy while on the medication can be excluded.
- Never start taking a previously prescribed medication again unless you are specifically instructed to do so. Always follow your physician’s instructions exactly.
- Never give your medications to anyone else or take medication prescribed to anyone else.
All synthetic vitamin A derivatives are teratogens. A teratogen is any external factor (such as the rubella virus, certain chemical compounds, and certain medications) that may cause damage to the fetus. This damage may present as a birth defect, fetal death, or failure of an organ in the infant.
The withdrawal period is different for each type of medication. For acitretin, for instance, used in the treatment of psoriasis, the withdrawal period is 3 years.
Please also stop using topical synthetic vitamin A derivatives (skin creams for treating acne) when you are planning your pregnancy.
Sex hormones
Progesterone products: mini pill, capsule, IUD, injection
Accidental exposure to a birth control device containing progesterone during early pregnancy will not elevate the risk of damage to the fetus. If you get pregnant while you are still using a hormonal IUD, remove the IUD as soon as possible after you find out you are pregnant. Leaving the IUD in situ will elevate the risk of premature birth.
If you need to use hormonal birth control during breastfeeding, please primarily select a preparation that contains progesterone. Progesterone only excretes into breast milk in small quantities, and it does not affect the secretion or composition of breast milk. You can start using mini pills or a birth control capsule at any time, generally at your follow-up examination. A hormonal IUD can usually not be installed until at the follow-up examination (8 to 12 weeks from childbirth).
Combination birth control products: birth control pills, vaginal rings, patches)
Combination birth control products contain both estrogen and progesterone. Accidental exposure to a combination birth control product during early pregnancy will not elevate the risk of damage to the fetus, and the pregnancy may be monitored normally.
We recommend that you do not resume the use of combination birth control products until 6 months after childbirth. Estrogen intake may reduce the secretion of breast milk and elevate the risk of deep vein thrombosis if begun too soon after childbirth. Studies have shown a correlation between the use of combination birth control pills and early onset bottle feeding, the recommended 6 months of breastfeeding not being completed. Please do not use any products containing cyproterone acetate during breastfeeding.
Levonorgestrel
- Take within 72 hours of unprotected intercourse.
- Will not terminate a pregnancy that has already begun.
- Will not elevate the risk of damage to the fetus if the pregnancy continues.
- You should wait 3-4 hours after taking the medicine, before you start breastfeeding
Ulipristal
- Take within 120 hours of unprotected intercourse.
- Principally works by inhibiting ovulation.
- Research findings are limited, but experiences suggest that the risk of damage to the fetus is not elevated.
- You should wait 24 hours after taking the medicine, before you start breastfeeding. Nevertheless, withholding from breastfeeding this long is not necessary.
For women of a fertile age, there is usually no indication to prescribe hormone replacement therapy, which is intended for menopause symptoms. However, if you get pregnant while on such a therapy, please stop taking the medication. This also applies to estrogen replacement therapy administered locally via the vagina.
You may safely use estrogen products administered via the vagina during breastfeeding. To be used as a course of treatment. Do not begin the course of treatment until the physician says so after your follow-up examination after childbirth.
Intermittent courses of progesterone treatment (dydrogesterone, medroxyprogesterone, noretisterone, lynestrenol, etc.) are often used to stabilized the menstrual cycle. Accidentally becoming pregnant during such a course of treatment does not constitute a risk and does not warrant special fetal examinations. However, you should stop using the medication immediately once you find out you are pregnant.
Short-term use of progesterone products designed for delaying your period (noretisterone, lynestrenol) is possible during breastfeeding.
Vaccines
Pregnant women are vaccinated when they are at high risk of being exposed to the disease, when an infection would be harmful for the mother or the fetus, and when the vaccine in itself will probably not cause harm. Inactive vaccines do not contain live pathogens and are thus safe to administer during pregnancy. Please take any vaccinations you may need for travel when you are only just planning your pregnancy.
- You can take the coronavirus vaccine in any stage of pregnancy.
- Research data and experience of coronavirus vaccine use during pregnancy have not shown any safety concerns.
- The newest research data shows that the coronavirus vaccine is effective to prevent pregnancy outcomes such as preterm birth or still birth linked to severe COVID-19 infection.
- Pregnant people has a higher risk of severe COVID-19 infection than non-pregnant people, especially in the las trimester.
- The coronavirus vaccine can cause general symptoms, such as fatigue and fever. If you get a fever above 38 degrees celsius it is recommended to take paracetamol.
- You can be vaccinated while breastfeeding.
Further information about the coronavirus vaccine and its safety: www.thl.fi.
Influenza vaccines are safe and are recommended during the epidemic season for all pregnant women regardless of where they are in their pregnancy. The influenza vaccines used in Finland do not contain live pathogens. If you have influenza while pregnant, you will have a considerably elevated risk of developing a serious illness (e.g. pneumonia). An influenza infection with high fever may also be detrimental to the development of the fetus.
Pregnant women are commonly vaccinated when already exposed (e.g. hepatitis B), when going to travel to a high-risk region (e.g. hepatitis A), or if the mother has an underlying condition and thus belongs to a medical risk group that requires vaccination to protect against pneumococcus, for instance.
Pregnant women may also be given a diphtheria, tetanus and whooping cough vaccine booster if necessary. Other vaccines not containing live pathogens may also be given to a pregnant women on a case-by-case basis at the physician’s discretion.
You should avoid vaccines containing live pathogens (e.g. rubella, chicken pox, and MPR vaccines) for a period of 1 month before your pregnancy and during pregnancy. Yellow fever vaccine contains live, weakened viruses, but administering it during pregnancy may be indicated if the pregnant woman has a compelling reason to travel to an endemic region.
Exception: A yellow fever vaccination can be given during breastfeeding only for medically compelling reasons, if you cannot postpone or cancel travel to an endemic region. Infants under the age of 6 months may be harmed by the vaccine through breast milk. Remember to mention to the physician that you are breastfeeding if you need a yellow fever vaccine.
For more information on vaccines: Finnish Institute for Health and Welfare (THL), vaccinations for pregnant women
Warfarin
Warfarin is used as a blood thinner, to prevent and treat blood clots in veins.
Warfarin passes through the placenta and can cause hemorrhaging in the fetus, resulting in damage particularly to the central nervous system. Exposure from week 6 of the pregnancy onwards (calculated from your last period) may also cause developmental defects to cartilage and bone.
If you are taking warfarin, remember to discuss pregnancy plans with your physician well in advance before you stop birth control. If you miss a period or perform a pregnancy test that shows a positive result, contact your attending physician immediately.
The general aim is to replace warfarin with heparin before week 6 of your pregnancy. In certain rare cases for patients with an artificial heart valve, warfarin use may be essential during the second and third trimester of the pregnancy.