Anencephaly risk factors

As soon as my doctor told me that anencephaly is at least partially environmental, I heard "you could have prevented this.  This is your fault." Of course that's not entirely true, but I want to do everything in my control to make sure this does not happen again. So I started digging--what can I do next time? (If there is a next time.)

Okay, everyone knows some of the big risk factors: 

Folic acid insufficiency (take a folic acid supplement!)
Maternal diabetes
Obesity (again, it sucks to be fat)
Family history (there is some genetic component)
Teratogenic medications
High heat exposure (no hot tubs)

http://www.spinabifida.net/causes-of-neural-tube-defects/

But I have none of those risk factors and I still had this happen. So what else?

Drinking tea is a risk factor: http://www.ncbi.nlm.nih.gov/pubmed/21487294

The theory is that tea can affect your body's ability to absorb folic acid. Well, that sucks. I drink a lot of tea. (As in 2-3 cups a day.) I thought I was being healthy, but I might have been inadvertently contributing to my baby's death. Needless to say, I am throwing away all of my tea. 

Reoccurring miscarriages are a factor... Specifically a miscarriage right before the pregnancy:

http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC1777788&blobtype=pdf
http://onlinelibrary.wiley.com/doi/10.1002/ajmg.1320510203/abstract

The theory is that either the prior miscarriages could be prior neural tube defect pregnancies, and/or some tissue from the prior pregnancy (up to 12 months later) could remain and affect the development of the later pregnancy. 

Well, that really fucking sucks. My last miscarriage was in October, and I got pregnant this time in February. Maybe my prior miscarriages were because of neural tube defects, and maybe they actually contributed to this one. Sigh. 

But you know what the single biggest risk factor is for a neural tube defect baby? A prior neural tube defect baby. Booooooooooooooooooooo.