II. Pathophysiology
- Teratogens cause birth defects, Stillbirths, IUGR
III. Risk Factors: General Teratogen Susceptibility
- Week 0-2: Pre-organogenesis
- Not Sensitive to malformation
- Significant exposure is lethal
- Week 3-8: Embryonic Period
- Greatest sensitivity to environmental exposures
- Fetal mass increases 2.5 Million fold first trimester
- Major malformations occur
- Week 9-38: Fetal Period
- Decreasing sensitivity
- Functional defects and minor malformations occur
IV. Causes: Occupational Exposures
-
General
- Household products also present Teratogen Exposure risk (Heavy Metals, solvents, Pesticides)
- High risk industries for Teratogen Exposure include laboratory work, dry cleaning, printing, manufacturing and agriculture
- Lead Exposure
- Gestational Hypertension
- Placenta Previa
- Preterm delivery
- Fetal loss
- Fetal Growth Retardation
- Fetal neurodevelopmental conditions
- Birth defects
-
Mercury Exposure
- See Mercury Content in Fish
- Preterm birth
- Fetal neurodevelopmental conditions (potent Neurotoxin)
- Solvents (Trichloroethylene, Chloroform, Benzene)
- Ensure adequate ventilation if at risk of exposure
- Associated with risk of Miscarriage, Stillbirth, preterm birth and IUGR
- Plastics (Vinyl Chloride)
- Pollutants (Polychlorinated or Polybrominated Biphenyl)
- Pesticides (Organophosphates)
- Gases (Carbon Monoxide, Inhalation Anesthetics)
- Radiation (e.g. XRay)
V. Causes: Home Exposures
- Medications
- See Medications in Pregnancy
- Reevaluate all OTC and prescribed medications
- Substances
- See Substance Abuse in Pregnancy
- Tobacco Cessation
- Tobacco associated with 4600 U.S. perinatal deaths per year
- Alcohol Abstention
- Marijuana
- Associated with low birth weight and NICU admission
- Heavy use is associated with Cannabinoid Hyperemesis and Preterm Labor
- Avoid in pregnancy
- Foods
- See Nutrition in Pregnancy
- See Mercury Content in Fish
- Avoid excessive large fish intake (e.g. shark, swordfish, tilefish or king mackerel) due to mercurcy contamination
- Vitamins
-
Herbals associated with Miscarriage
- Devil's claw root
- Barberry
- Dong Quai
- High concentrations of Ruta, Hydrastis or Oregano
- Other Herbal Teratogens
- See Herbal Remedy
- Exercise caution regarding overall risks of herbal contamination and lack of standardization
- Ginkgo
- Ephedra
- Ginseng
- See Herbal Remedy
- Other home exposures
- Avoid hot tubs and saunas in first trimester
- Associated with Neural Tube Defects and Miscarriages
- Avoid hair dyes and treatments in first trimester
- May be associated with childhood Acute Leukemia
- Couto (2013) Chem Biol Interact 205(1): 46-52 [PubMed]
- Avoid hot tubs and saunas in first trimester
VI. Resources
- CDC Medications in Pregnancy
- Vaccines and Medications in Pregnancy Surveillance System (VAMPSS)
- MotherToBaby Fact Sheets (from Organization of Teratology Information Specialists or OTIS)