Question

A speech in which you try to convince your audience that smoking during pregnancy leads to complications at birth might best be organized into this pattern.

Answer 1

that type of speech could be organized in: cause-efect/efect-cause pattern.
This type of pattern is most commonly used as a persuasion method to attract the readers to do something.
In this case, the speaker want to convince the audience to stop smoking by telling how smoking (causes) is related to birth problems (effect)