Rooted in the Greek teratos, teratology “is the science that studies the causes, mechanisms and patterns of abnormal development” (Ujházy et al., 2012). As teratology is a subspecialty of medical genetics, genetic counselors are well equipped to step in when questions about teratogenic exposures arise; nonetheless, many genetic counselors feel these discussions are not within their purview. 

As genetic counselors with a combined 36 years of experience in reproductive medicine, and as graduate training program directors, we support teratology as a core component of professional education and practice. While we recognize that many training programs, including ours, have dedicated Teratology courses, and that many practicing GCs incorporate teratogen risk assessment and counseling in their practice, we have encountered many others who are resistant to this practice. In an ideal world, we would never again hear a student or colleague say: 

“I don’t do teratogen counseling.”

“Why is teratology part of the curriculum?” 

“Why is teratogen counseling part of our scope of practice?” 

We understand that the knowledge needed to grasp teratology is different from foundational medical genetics knowledge. Journal articles in this field can seem outside our comfort zones, and the topics can feel unfamiliar. Still, recognizing how important this area is, we want to highlight several key points that are often overlooked. 

1. There Is a High Prevalence of Medication and Other Exposures Making Teratology Essential Knowledge for Reproductive Counseling 
   All genetic counselors working with patients who are pregnant or planning pregnancy should understand medication and other exposure risks. About 90% of people who are pregnant take some form of medication (Balch, 2022). Beyond prescription medications, exposures can include herbal products, vaccines, radiation, infectious agents, underlying medical conditions, occupational exposures, cosmetics and body care products, substances including alcohol and tobacco, and environmental agents like air pollutants. Many of these exposures are common despite limited pregnancy safety data and not every exposure is a teratogen. It is crucial that patients (and providers) know the difference.  
2. Genetics Evaluations Are Incomplete Without Considering In-utero Exposures 
   Risk assessments in the genetics clinic are not thorough without considering whether teratogenic exposures contributed to a patient’s phenotype. Recent publications have identified a putative prenatal fentanyl exposure syndrome that mimics findings in Smith-Lemli-Opitz syndrome (Wadman et al., 2023). Risks can also persist beyond childhood, as seen with the association between in utero diethylstilbestrol exposure and clear cell adenocarcinoma of the vagina or cervix. Discussing potential teratogenic exposures and considering their impact can guide genetic testing strategies and assist with diagnosis. 
3. Patients Deserve Evidence-based Guidance 
   Genetic counselors must know how to find, evaluate and explain up-to-date, science-driven evidence, especially when misinformation and restrictive policies and laws make it challenging. For example, after the Dobbs decision, non-pregnant people have been blocked from critical medications for conditions unrelated to pregnancy or abortion (Matloff, 2023a; Matloff, 2023b). Recently there have been misconceptions about acetaminophen and SSRI exposures.  Counselors who understand teratology have the tools to advocate for patients and ensure equitable access to care. Skipping these conversations can make outcomes worse, and patients deserve guidance based on evidence, not fear, stigma or falsehoods. 
4. We Have the Psychosocial Skills 
   Genetic counselors can have difficult conversations with patients and help them address shame and guilt. If we do not bring these questions up, patients often will not either. We typically have more time for these conversations than other providers, allowing us to build trust and rapport. These conversations are opportunities to normalize parental guilt and permit disclosure of exposures that concern patients. In many cases, we are able to alleviate fears that are not supported by evidence. 
5. The Knowledge Translates Across Practice Settings 
   The ability to locate, critically assess and communicate current and accurate data is essential for all genetic counselors, regardless of practice setting. The practice of teratology strengthens risk assessment, literature review skills and patient-centered counseling. 

Practical Tips for Successful Teratogen Counseling 

• Take a deep breath – The patient is likely more nervous than you are. It helps to have a set of questions ready and to rehearse beforehand. Don’t forget to take it slow. 

• Know before you go – Know where to find and how to evaluate scientific evidence. Personally verify the resources you share and periodically review them for accuracy and accessibility. Identify your limitations and know when and how to refer for a teratology consultation. 

• Explain your why – “The reason I ask is because some exposures can increase risks to you or the fetus. This helps us know if there is anything else we need to think about.”  

• Normalize guilt – Patients who are pregnant have often already considered that an exposure could have led to an adverse outcome. Acknowledging this may open the door for them to share their concerns. For example: “The guilt switch often turns on as soon as we get a positive pregnancy test. Are there any medications or exposures that you are worried about?” This line of questioning becomes even more crucial when fetal anomalies are present, as one or both parents may have already assigned culpability to themselves, in most cases without scientific justification. 

• Give permission to tell you – Avoid questions that imply a correct answer, such as “you don’t drink alcohol, right?” Broad, nonjudgmental questions make disclosure easier. Try “how many drinks do you have per day?” 

• You only know what they tell you – Believe the patient and counsel accordingly. We are not there to impose morality or beliefs. If they are not ready to talk, remind them that your team is available when they are. 

Rising to the Challenge 

In genetics, most anomalies cannot be prevented, except those caused by teratogens. This is a rare opportunity to effect positive change by helping patients understand exposure risks and navigate them in future pregnancies. By addressing guilt and shame and providing evidence-based counseling, we improve both psychological well-being and clinical care. Teratogen counseling is not optional. It is time for genetic counselors to step confidently into this responsibility. 

Selected Teratology Resources  

• MotherToBaby - https://mothertobaby.org/  

• Reprotox - https://reprotox.org/ 

• TERIS - https://teris.com/ 

• The Society for Birth Defects Research and Prevention https://birthdefectsresearch.org/  

References 

• Ujházy, E., Mach, M., Navarová, J., Brucknerová, I., & Dubovický, M. (2012). Teratology - past, present and future. Interdisciplinary toxicology, 5(4), 163–168. https://doi.org/10.2478/v10102-012-0027-0 
• Genetic Alliance, & District of Columbia Department of Health. (2010). Understanding genetics: A District of Columbia guide for patients and health professionals (Appendix D: Teratogens/prenatal substance abuse). https://www.ncbi.nlm.nih.gov/books/NBK132140/ 
• Balch, B. (2022). Prescribing without data: Doctors advocate for the inclusion of pregnant people in clinical research. AAMC. https://www.aamc.org/news/prescribing-without-data-doctors-advocate-inclusion-pregnant-people-clinical-research 
• Matloff, E. (2023a). Supreme Court’s Dobbs decision blocks nonpregnant female patients from receiving treatment for lupus, rheumatoid arthritis, other diseases. Forbes. https://www.forbes.com/sites/ellenmatloff/2023/05/08/dobbs-v-jackson-scotus-decision-blocks-non-pregnant-female-patients-from-receiving-treatment-for-lupus-rheumatoid-arthritis-other-diseases/ 
• Matloff, E. (2023b). One year after Dobbs decision, women blocked from meds for conditions unrelated to abortion. Forbes. https://www.forbes.com/sites/ellenmatloff/2023/06/23/one-year-after-dobbs-decision-women-blocked-from-meds-for-conditions-unrelated-to-abortion/ 
• Wadman, E., Fernandes, E., Muss, C., Powell-Hamilton, N., Wojcik, M. H., Madden, J. A., Carreon, C. K., Clark, R. D., Stenftenagel, A., Chikalard, K., Kimonis, V., Brucker, W., Alves, C., & Gripp, K. W. (2023). A novel syndrome associated with prenatal fentanyl exposure. Genetics in medicine open, 1(1), 100834. https://doi.org/10.1016/j.gimo.2023.100834  

 

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