What things in my environment can cause problems in pregnancy? September 21, 2020 20:13 Updated A few chemicals are known to have harmful effects on a fetus. These include: Lead Mercury Certain pesticides Radiation Solvents Related articles What problems can use of substances like tobacco, alcohol, marijuana, illegal drugs, and prescription drugs taken for a nonmedical reason cause in pregnancy? What medical conditions affect pregnancy? What is preconception counseling/prepregnancy care?