There are many routes of administration that can deliver drugs directly to the developing fetus. The direct fetal routes of drug administration are invasive in nature and should only be used when absolutely necessary. These routes should be employed for which of the following scenarios?
1. If passage through the placenta is adversely affected by fetal disease.
2. If the drug is not associated with maternal side effects.
3. If the drug easily crosses the placenta.
4. If rapid drug effects are required.

The correct answer is option - 1. If passage through the placenta is adversely affected by fetal disease. and 4. If rapid drug effects are required.

Explanation:

Normally the drug that is provided and administrated to the fetal is through the placenta of the mother. The direct delivery of medicine can be dangerous. However, with the advancement of the medical technology direct fetal drug administration is possible and it assists in the rapid uptake of the drug by the fetus.

If the fetus requires a rapid drug effect it can be provided by direct drug delivery. Also when the placental is not working properly and affected by the disease it is recommended to provide the fetus with the drug with the help of direct delivery.

Thus, the correct answer is : 1. If passage through the placenta is adversely affected by fetal disease. and 4. If rapid drug effects are required.