Classification | Relevant period | Postulated mechanisms |
---|---|---|
Acute | 3 Months before conception | Mutagenesis of germ cells |
First and second trimester of pregnancy | Toxin in seminal fluids, and mothers' contamination after intercourse | |
Home contamination (working clothes, equipment) leading to exposure of mother during pregnancy | ||
Non-acute | Lifelong before conception | Potential storage of chemicals |
Stem cell damage |