The period of maximum fetal vulnerability for women using drugs is?

The period of maximum fetal vulnerability for women using drugs is typically during the first trimester of pregnancy, specifically from the time of conception through the 12th week. During this critical development phase, the fetus is forming essential organs and systems, making it particularly susceptible to teratogenic effects of drugs. Exposure to harmful substances during this time can lead to congenital anomalies or developmental issues. It's important for women to avoid drug use during this stage to minimize risks to fetal health.