What is the cardinal rule regarding medications and herbal remedies during pregnancy?

• A. All drugs cross placenta and may affect the fetus
• B. No medications cross placenta
• C. Herbal remedies are always safe
• D. Only hormones cross placenta

Answer: (A)

The main idea here is that the placenta does not provide an absolute shield; most medications and many herbal remedies can cross to the fetus and potentially influence development or cause neonatal effects. Transfer depends on properties like small size, fat-loving (lipophilic) nature, and how tightly the substance binds to proteins; exposure at any stage of pregnancy can have consequences because the fetus has limited ability to metabolize drugs. That’s why any medication or herbal product used during pregnancy should be discussed with a healthcare provider, weighing benefits against potential risks. It’s not true that nothing crosses the placenta, or that herbal remedies are always safe, and hormones aren’t the only substances that can cross—many non-hormonal drugs do as well.