What are critical periods in the development process of an embryo and fetus?

Which recommendation seems most appropriate for Catarina during her pregnancy?

Catarina should maintain a healthy diet and appropriate exercise regimen, and avoid unnecessary exposure to environmental contaminants. She should also keep taking her current antidepressants.
Catarina should definitely address the issues of a healthy diet and environment as well as exercise, but her physician should also explore whether to change to another dose or type of antidepressant.
Catarina has already exposed her unborn baby to some risk factors, so she should stop taking the antidepressant and try to control her depression through cognitive-behavioral therapy.
Catarina should definitely clean up her diet, but she might as well stay on her medication. What’s done is done, and the baby has already been exposed to antidepressants during critical periods.

Defend

After stating your decision, defend it.

Think about the factors that influenced your recommendation for Caterina. Why did you choose the option that you did? Include ALL of these issues in your response:

What are critical periods in the development process of an embryo and fetus? When do they occur and how might they be disrupted?
Which aspects of diet and exercise do you think are most critical during pregnancy?
What are the effects of alcohol, cigarette smoke, or e-cig vapors on a developing fetus?
What are the risks and benefits of Catarina remaining on antidepressants during her pregnancy, both for Caterina and for her baby?