What's all this talk about DHA?

You hear a lot about this from your doctor or midwife and are counseled to make sure you are taking it during pregnancy and while breastfeeding. But what exactly is it? This is a question I ask of any dietary recommendation through supplementation because I am not a huge fan of supplements (there are definitely times when they are necessary...pregnancy being one of those times).
What DHA is:
DHA stands for docosahexaenoic acid and it is an omega-3 fatty acid. Our bodies cannot not produce this fat on it's own, so it must come from food or supplementation.
Why we need it:
Why this nutrient is getting all the hype is because of it's important function in neural development and function development of the central nervous system, the brain and eyes. Many published studies have concluded that children whose mothers supplemented DHA scored higher on IQ tests and were more advanced than children whose mothers did not. There is also a benefit for the mother, reducing the risk of postpartum depression.
How we can get it:
Your developing fetus relies on you for all his/her nutritional requirements, so it is important that you are getting this nutrient in your diet either through diet or supplementation.
There is research that DHA can be formed in our bodies from another polyunsaturated, omega-3 fat ALA, but isn't a guarantee and it is somewhat inefficient. Flax seed, canola and soybean oils, and walnuts all are sources that may have this conversion. On the other hand, seafood has high levels of DHA, particularly fatty fish such as haddock, cod, and pollock (these are the "safe" fishes you can have in pregnancy). The reason for this is actually because of the fish's diet of algae. Therefore, supplementation of DHA, produced directly from the source of DHA, really is the best source of DHA. This is why our health professionals suggest supplementation during pregnancy and lactation.

Don't disregard this nutrient after pregnancy and lactation as it has also been shown to reduce risk of heart disease, breast cancer, and all-cause dementia.