I have just had an induced miscarriage at 13 weeks. It was seen on the 12 week scan last week that baby had acrania/anencephaly. I have a high BMI and was prescribed 5mg of folic acid at my 7 week midwife appointment. But by then the problem had already occurred. It is recommended that 5mg folic acid should be taken for 3 weeks before conception for people with:
A history of neural tube defects in their family (this applies to both the mother's and father's sides of the family)
Insulin-dependent diabetes
A previous pregnancy where neural tube defects were identified in their baby
Coeliac disease
A body mass index higher than 30
And also women taking anti-epilepsy medication.
I will be asking for 5mg of folic acid to be put on a repeat prescription from now on.
The higher dose wont mean that there is no chance of baby developing a neural tube defect but the chance is greatly reduced and at least you will feel you did everything you could. Unlike me right now.