Thesis statment :

The physiology of alcohol dependence causes physiological aspects of the obstetric and the effect of alcohol during pregnancy can cause mental retardation, facial deformity, and other neurological problems.

That's not a thesis statement.

Your thesis statement must include factual information (which you already have) plus your position/opinion/stance. Without your position on the topic, it isn't a true thesis statement. So think of this sentence as the angle you want to take on the topic and what you intend to prove by the end of your paper. (If your statement is simply factual, then there's nothing to prove!)

http://blog.eduify.com/index.php/2009/06/21/5-tips-on-how-to-write-a-strong-thesis-statement/
Read carefully and follow ALL directions.

http://leo.stcloudstate.edu/acadwrite/thesistatement.html
This is one of the very best places I've seen online to help students write good thesis statements. It shows you sentences that aren't thesis statements and how to turn each one into real thesis statements.

To create a thesis statement, start by identifying the main idea or argument of your paper. In this case, it seems like your main argument is that the physiology of alcohol dependence contributes to the physiological aspects of obstetric complications and also has negative effects on the developing fetus, which can lead to mental retardation, facial deformity, and other neurological problems.

With that in mind, here's a suggestion for a thesis statement:

"The physiology of alcohol dependence plays a significant role in the development of obstetric complications, and the detrimental impact of alcohol consumption during pregnancy can result in various neurological issues, facial deformities, and mental retardation in the unborn child."

Remember, a thesis statement should clearly state the main argument or point of your paper and provide a roadmap for the reader to understand what will be discussed in the subsequent paragraphs.

As for finding supporting evidence for your thesis statement, you can start by conducting research in reputable academic sources such as scientific journals, medical databases, or books on alcohol dependence, obstetric complications, and fetal alcohol spectrum disorders (FASDs). Additionally, you can also consult relevant studies, statistics, and reports from reputable organizations like the World Health Organization (WHO) or the National Institutes of Health (NIH) to gather evidence to support your thesis.