Legal Definitions - teratogen

A teratogen is any substance or agent that can cause developmental abnormalities or birth defects in a fetus when a pregnant individual is exposed to it. These agents interfere with the normal growth and development of the embryo or fetus, leading to structural or functional problems that are present at birth.

• Example 1: Prescription Medication

  A pregnant woman is prescribed a new medication for a severe skin condition. Unbeknownst to her or her doctor at the time, this specific drug is later found to interfere with fetal bone development, leading to significant skeletal deformities in babies whose mothers took it during the first trimester. In this scenario, the prescription medication acts as a teratogen because it directly caused birth defects in the developing fetus.

• Example 2: Environmental Toxin

  Workers at a manufacturing plant are exposed to a newly introduced industrial solvent. Several female employees who became pregnant while working with this solvent later gave birth to children with a rare type of congenital heart defect. Investigations revealed a strong correlation between exposure to the solvent and the heart defects. Here, the industrial solvent is identified as a teratogen due to its ability to cause specific birth defects in the fetuses of exposed individuals.

• Example 3: Viral Infection

  During a widespread outbreak, a pregnant woman contracts the Zika virus. The virus crosses the placental barrier and infects the developing fetus, leading to severe microcephaly (a condition where the baby's head is much smaller than expected) and other brain abnormalities. In this case, the Zika virus functions as a teratogen because it is an agent that directly causes significant developmental injuries and birth defects to the fetus.