The medication causing birth defects that doctors still prescribe is not one drug but several, and the most dangerous among them is valproate, sold under the brand name Depakote. About 10 percent of babies exposed to valproate during the first trimester are born with a major birth defect — neural tube defects, heart malformations, cleft lip, craniofacial abnormalities, and limb deformities among them. Despite a boxed warning from the FDA and a 2023 statement from the World Health Organization urging that valproate not be prescribed to women of childbearing potential, a November 2025 report in ScienceDaily confirmed it remains widely used across the globe. For families navigating dementia care, where anticonvulsants and mood stabilizers are sometimes prescribed to manage behavioral symptoms, this is not an abstract concern. It is a concrete risk that touches multiple generations.
But valproate is far from the only offender. Isotretinoin, the powerful acne drug once sold as Accutane, carries a label that states in bold capital letters: “CAUSES BIRTH DEFECTS.” Topiramate, prescribed for epilepsy and migraines, raises the risk of cleft lip and palate by as much as 21 times. Even acetaminophen — the active ingredient in Tylenol, taken by a majority of pregnant women — is now the subject of hundreds of lawsuits alleging links to autism and ADHD, though the science remains contested. This article examines each of these medications in detail, explains why doctors continue to prescribe them despite known risks, and offers practical guidance for patients and caregivers who need to weigh these tradeoffs. The thread connecting all of these drugs is a painful reality of modern medicine: sometimes the treatments we rely on carry risks that are not fully communicated, not adequately monitored, and not equally distributed across populations. Understanding which medications pose the greatest dangers during pregnancy — and which warnings are backed by strong evidence versus preliminary findings — is essential for anyone making healthcare decisions for themselves or a loved one.
Table of Contents
- Which Medications Causing Birth Defects Are Doctors Still Prescribing Today?
- How Dangerous Is Valproate During Pregnancy, and Why Hasn’t It Been Banned?
- Topiramate and the Hidden Risk of Cleft Lip and Palate
- What Should Patients Do When Prescribed a Teratogenic Medication?
- The Acetaminophen Controversy and the Limits of Emerging Evidence
- SSRIs, Pregnancy, and the Risk of Doing Nothing
- What the Future Holds for Teratogenic Drug Regulation
- Conclusion
- Frequently Asked Questions
Which Medications Causing Birth Defects Are Doctors Still Prescribing Today?
The list is longer than most patients realize. At the top sits valproate, which the Journal of Clinical Psychiatry has called “psychiatry’s most teratogenic drug,” explicitly calling for stronger regulation. The FDA’s updated 2024 prescribing label now carries a boxed warning against its use during pregnancy for migraine prevention, and for epilepsy or bipolar disorder, the label states it should only be used when other medications have failed. Yet valproate remains a first-line treatment in many countries and clinical settings, particularly for older patients with seizure disorders or behavioral disturbances associated with dementia. Children exposed in utero score lower on IQ and cognitive tests compared to children whose mothers took other anti-seizure drugs, meaning the damage extends well beyond physical birth defects into lifelong neurodevelopmental impairment. Isotretinoin, the generic successor to Accutane (which Roche pulled from the market in 2009), is still widely prescribed for severe cystic acne. The FDA requires participation in the iPledge program — two negative pregnancy tests before prescribing, monthly pregnancy testing during treatment, and documented use of two forms of contraception. Yet compliance gaps persist.
A study published through Harvard Health found that less than one-third of teenage girls prescribed teratogenic medications, including isotretinoin, received birth control prescriptions or even basic counseling about pregnancy risks. The birth defects isotretinoin causes are severe: facial abnormalities including cleft palate and ear malformations, heart defects, brain and central nervous system malformations, and intellectual disabilities. Then there is thalidomide, the drug that caused the most infamous birth defect crisis in medical history during the 1950s and 1960s. What most people do not know is that the FDA re-approved thalidomide in 1998 for treating multiple myeloma, and it is still prescribed today under a strict Risk Evaluation and Mitigation Strategy program. Even a single dose during pregnancy can cause severe limb deformities, organ damage, or fetal death. The comparison between thalidomide’s tightly controlled distribution and valproate’s relatively loose prescribing patterns is striking — and troubling.
How Dangerous Is Valproate During Pregnancy, and Why Hasn’t It Been Banned?
The numbers on valproate are stark. A ten percent rate of major birth defects in first-trimester exposure makes it one of the most teratogenic commonly prescribed drugs in existence. To put that in perspective, the background rate of major birth defects in the general population hovers around three percent. Valproate roughly triples that risk. The types of defects are serious — spina bifida and other neural tube defects, cardiac malformations, and craniofacial abnormalities that may require multiple surgeries. Beyond structural birth defects, the cognitive effects are equally alarming. Studies referenced by the National Center for Biotechnology Information show that children exposed to valproate in utero consistently score lower on standardized IQ tests than children exposed to other anticonvulsants, with some studies documenting an average deficit of eight to ten IQ points. So why hasn’t it been pulled from the market? The answer lies in the drug’s effectiveness for conditions where alternatives are limited.
For certain types of epilepsy — particularly generalized seizures and Lennox-Gastaut syndrome — valproate remains among the most effective treatments available. For some patients with bipolar disorder who have not responded to lithium or other mood stabilizers, valproate may be the only medication that controls dangerous manic episodes. The FDA’s approach has been to restrict rather than ban: the 2024 label update prohibits its use for migraine prevention during pregnancy entirely, while allowing continued use for epilepsy and bipolar disorder only when other treatments have failed. However, if a woman of childbearing age is already stable on valproate for a seizure disorder, the decision to switch medications is itself risky — abrupt changes in anticonvulsant therapy can trigger status epilepticus, a life-threatening condition. The WHO’s May 2023 statement went further than the FDA, recommending that valproate should not be prescribed to any woman or girl of childbearing potential, full stop. But recommendations and enforcement are different things. In many healthcare systems, particularly in low- and middle-income countries, valproate is the most affordable and available anticonvulsant. The gap between what the evidence demands and what clinical reality allows remains wide.
Topiramate and the Hidden Risk of Cleft Lip and Palate
Topiramate, marketed as Topamax, occupies a different but equally concerning category. While its overall teratogenic risk is lower than valproate’s, the specific defect it causes — oral clefts — is dramatically elevated. Data from the Epilepsy Foundation show that the risk of cleft lip or cleft palate is 21 times greater when a woman takes topiramate during the first trimester of pregnancy. The prevalence of oral clefts in infants exposed to topiramate is approximately 1.4 percent, compared to 0.38 to 0.55 percent for other anti-epileptic drugs. And the risk is dose-dependent: at daily doses above 100 milligrams, the risk climbs to 5.2 times the baseline, according to research from Massachusetts General Hospital’s Center for Women’s Mental Health. The FDA required an updated boxed warning for topiramate in 2011, yet the drug continues to be prescribed not only for epilepsy and migraines but also off-label for weight loss — a use that disproportionately affects women of childbearing age.
This off-label prescribing pattern is particularly concerning because a woman taking topiramate for weight management may not be receiving the same level of pregnancy counseling as a woman being treated for epilepsy by a neurologist. The prescribing physician may be a primary care doctor or an endocrinologist who is less familiar with the drug’s teratogenic profile. A woman who becomes pregnant while taking topiramate for weight loss faces a risk she may never have been warned about. For families involved in dementia care, topiramate is occasionally encountered as a medication prescribed to younger family members for migraines or seizures. The relevance here is generational awareness: a daughter caring for a parent with Alzheimer’s disease who also manages her own migraine disorder with topiramate needs to understand the pregnancy risks before they become urgent. The time to have that conversation with a neurologist is before conception, not after a positive pregnancy test.
What Should Patients Do When Prescribed a Teratogenic Medication?
The first step is straightforward but too often skipped: ask your prescribing physician directly whether the medication carries any risk during pregnancy, and request that the answer be specific rather than vague. “There may be some risks” is not an adequate response when the drug in question is valproate with a ten percent birth defect rate. Patients and caregivers should request the FDA-approved prescribing label, which is publicly available online, and read the pregnancy section themselves. The tradeoff is not between taking the medication and feeling well versus not taking it and feeling poorly — it is between the known risk of the drug and the known risk of the untreated condition, and both sides of that equation deserve honest assessment. For valproate specifically, the conversation should include a concrete plan: are there alternative anticonvulsants or mood stabilizers that could be tried first? Lamotrigine, levetiracetam, and carbamazepine all carry lower teratogenic risks, though none is risk-free. The switch should happen well before pregnancy if possible, allowing time to confirm that seizures or mood episodes remain controlled on the new medication.
For isotretinoin, the iPledge program’s requirements — two forms of contraception, monthly pregnancy tests, and a mandatory waiting period after stopping the drug before attempting conception — are non-negotiable. But adherence to those requirements falls on both the prescriber and the patient, and the Harvard Health data showing that less than a third of teenage girls on teratogenic drugs received contraception counseling suggests the system is failing on the prescriber side. The comparison between how medicine handles isotretinoin versus valproate is instructive. Isotretinoin has an entire regulatory infrastructure — iPledge — designed to prevent pregnancies during treatment. Valproate has a boxed warning on a label that many patients never read. One might argue that the drug with the ten percent birth defect rate deserves at least as rigorous a prevention program as the acne medication.
The Acetaminophen Controversy and the Limits of Emerging Evidence
The case of acetaminophen illustrates how difficult it can be to separate genuine risk from statistical noise and litigation pressure. Beginning in September 2022, more than 500 lawsuits were filed alleging that prenatal acetaminophen use increases the risk of autism spectrum disorder and attention deficit hyperactivity disorder in children. An August 2025 study from Mount Sinai found that children with higher prenatal exposure were 2.26 times more likely to have ADHD and 2.14 times more likely to have ASD. Those numbers sound alarming in isolation. However, a judge dismissed the consolidated MDL cases in late 2024, ruling that the plaintiffs’ expert witnesses had failed to support their conclusions with sufficient scientific evidence. A comprehensive review published in The Lancet, analyzing 43 high-quality studies, found no link between acetaminophen use during pregnancy and autism or ADHD.
The Second U.S. Circuit Court of Appeals is preparing to hear oral arguments on an appeal that could revive the lawsuits, so the legal question is not settled. But the scientific question, as of early 2026, leans toward acetaminophen being safe at recommended doses during pregnancy. The limitation here is important: absence of proven harm is not the same as proof of safety, and pregnant women should still use the lowest effective dose for the shortest duration necessary. But the leap from “we should be cautious” to “Tylenol causes autism” is not currently supported by the weight of peer-reviewed evidence. For caregivers managing pain in elderly family members with dementia, the acetaminophen controversy is largely irrelevant to their immediate situation. But it serves as a useful case study in how to evaluate medication safety claims: look at the size and quality of the studies, check whether the findings have been replicated, and be wary of conclusions driven primarily by litigation rather than by clinical research.
SSRIs, Pregnancy, and the Risk of Doing Nothing
The debate over selective serotonin reuptake inhibitors during pregnancy captures a tension that runs through all teratogenic medication decisions: the risk of the drug versus the risk of the untreated disease. A meta-analysis of 18 cohort studies found that first-trimester SSRI use was linked to a 26 percent higher relative risk for cardiovascular malformations, with paroxetine (Paxil) carrying the highest concern and a possible slight increase in heart defects. The FDA held an expert panel on SSRIs and pregnancy on July 21, 2025, signaling continued regulatory attention to this question. But here is where context matters enormously.
That 26 percent increase in relative risk translates to only a few extra cases per 10,000 births in absolute terms. Meanwhile, untreated depression during pregnancy carries its own serious risks: preterm birth, preeclampsia, low birth weight, impaired maternal-infant bonding, and in severe cases, maternal suicide. The American College of Obstetricians and Gynecologists publicly criticized the FDA panel for focusing on SSRI risks while ignoring the well-documented dangers of untreated maternal depression. A 2025 article in the New England Journal of Medicine reinforced this point, noting that larger, well-controlled studies adjusting for confounding factors generally find little or no increased birth defect risk from SSRIs. For a woman with moderate to severe depression, stopping her SSRI because of a small and uncertain risk may create a much larger and more certain one.
What the Future Holds for Teratogenic Drug Regulation
The regulatory landscape is shifting, if slowly. The WHO’s 2023 statement on valproate, the FDA’s 2024 label updates, and the 2025 expert panels on SSRIs all point toward greater scrutiny of medications prescribed to women of childbearing age. The key question going forward is whether that scrutiny will translate into systemic changes — mandatory pregnancy prevention programs for high-risk drugs beyond isotretinoin, better integration of teratogenic risk into electronic prescribing systems, and more consistent counseling standards across specialties.
For the dementia care community, these developments matter in two ways. First, anticonvulsants like valproate and topiramate are sometimes prescribed to manage seizures or behavioral symptoms in dementia patients, and family caregivers should be aware of these drugs’ broader risk profiles. Second, the women most often serving as primary caregivers for elderly parents with dementia — daughters and daughters-in-law in their thirties and forties — are themselves of childbearing age and may be taking medications with teratogenic potential. The intersection of caregiving stress, personal health management, and reproductive planning is a space where better information can prevent irreversible harm.
Conclusion
The medications that cause birth defects while remaining on pharmacy shelves are not obscure or experimental. Valproate, with its ten percent birth defect rate and documented cognitive impacts, remains widely prescribed despite FDA boxed warnings and WHO directives. Isotretinoin’s strict iPledge program demonstrates that aggressive risk mitigation is possible, yet similar systems have not been implemented for other high-risk drugs. Topiramate’s 21-fold increase in cleft lip and palate risk continues alongside off-label weight loss prescribing. And the ongoing debates around acetaminophen and SSRIs remind us that the line between established danger and emerging concern is often blurred by litigation, media coverage, and incomplete data.
The practical takeaway is this: any woman of childbearing age who is prescribed an anticonvulsant, a retinoid, or a psychiatric medication should have an explicit, documented conversation with her prescriber about teratogenic risk before filling the prescription. That conversation should include the specific risk numbers, the available alternatives, and a contraception plan if the medication is medically necessary. For caregivers, the responsibility extends to ensuring that younger family members who may be prescribed these drugs understand the stakes. The information exists. The warnings have been issued. What remains is closing the gap between what we know and what patients are actually told.
Frequently Asked Questions
What is the most dangerous prescription medication for pregnancy?
Valproate (Depakote) carries one of the highest teratogenic risks of any commonly prescribed drug, with approximately 10 percent of first-trimester exposed babies born with major birth defects. The WHO has recommended it not be prescribed to women of childbearing potential.
Is Accutane still available even though it causes birth defects?
The brand-name Accutane was pulled from the market by Roche in 2009, but generic isotretinoin is still widely prescribed for severe acne. The FDA requires participation in the iPledge program, which mandates pregnancy testing and two forms of contraception during treatment.
Does Tylenol really cause autism?
The evidence remains contested. An August 2025 Mount Sinai study found a correlation between high prenatal acetaminophen exposure and increased ADHD and ASD risk, but a comprehensive Lancet review of 43 high-quality studies found no link. A federal judge dismissed the MDL lawsuits in late 2024, though an appeal is pending.
Are antidepressants safe during pregnancy?
Most SSRIs carry a small increase in relative risk for cardiovascular malformations, but the absolute risk increase amounts to only a few extra cases per 10,000 births. The American College of Obstetricians and Gynecologists has warned that the risks of untreated depression — including preterm birth and maternal suicide — often outweigh the small medication risks. Paroxetine (Paxil) carries the highest concern among SSRIs.
Can topiramate be taken during pregnancy?
Topiramate carries a significant risk of oral clefts, with risk elevated up to 21 times during first-trimester exposure. The FDA added a boxed warning in 2011. Women taking topiramate who may become pregnant should discuss alternative medications with their doctor before conception, not after.
Is thalidomide still prescribed?
Yes. The FDA re-approved thalidomide in 1998 for multiple myeloma treatment. It is prescribed under a strict Risk Evaluation and Mitigation Strategy program. Even a single dose during pregnancy can cause severe birth defects or fetal death.
