it is critical to apply statistics to medical problems

you need to evaluate the probabilities of competing diseases before you take a solution. A women may have 10+% chance to suffer from breast cancer in her life time. It varies from person to person depending on family history and other risk factors. Do you want to remove yours irregardless your risk factors? Your baby may suffer from hundereds of genetic diseases each with a tiny possibility. Do you want to test all these possibilities before you give birth to a baby?

In fact, treating a medical problem has no difference than other problems in life, you maximize your expected return within your acceptable risk.