Question

What situation occurs when drugs cross the placenta during pregnancy?

Answer 1

Explanation:

Illicit drugs:

Cocaine crosses the placenta, constricts the blood vessels reducing blood flow to the fetus. The reduced blood and oxygen supply to the fetus slows the growth of bones and intestine.

Answer 2

Answer:

The fact is that most drugs do cross the placenta in some amount.

1. drug to be teratogenic in pregnancy, it must be able to cross the placenta in early pregnancy in a concentration high enough to cause abnormal fetus development. Drug companies have known for a long time that there are certain characteristics of their drug that will determine how much of it crosses the placenta.
2. The primary determining factors of what type of drugs will cross the placental barrier are molecular weight, lipid (fat or fat-like) solubility, polarity (molecular charge), protein binding, and receptor mediation. Drugs that have low molecular weight, lipid (fat) solubility, nonpolarity, and no protein binding properties will quickly and easily cross the placenta.
3. Alcohol, for example, readily reaches the embryo in fairly high concentrations. On the other hand, high molecular-weight drugs like heparin (20,000 daltons) do not cross the placenta. It is therefore widely used to treat hypercoagulation during pregnancy.