while you're taking DHA supplements, don't forget about arachidonic acid. get those supplements which has both, like the milk formula. DHA and AA work hand in hand. many research papers did not include AA as part of the factor,

http://www.medicalnewstoday.com/articles/102011.php

not all fish oil contains the right ratio of O3 and O6, the process molecular distillation (used by many supplement companies) ensures that there is only DHA and EPA is left after the process. usually in health supplements, you can see in their labels that they don't contain any O6. (or if you compare the capsule size of let's say 500mg of fish oil, there's like 300mg EPA 200mg DHA, no room for O6 you see?)

can i point out something that you might missed out?
the O6 that we take from diet are mostly linolenic acid. studies show that we get about 10:1 omega6 to omega3, of which most are LA. however to made into AA, LA has to be converted to GLA and then converted again to AA. but the problem here is the rate of conversion of LA to AA is very low.

"Contrary to popular opinion, synthesis of AA from LA is not efficient either. Only a small percentage of LA intake is actually converted to AA in rats and even less in humans. Vegans generally have strongly reduced blood levels of both AA and DHA."
http://www.chiro.org/nutrition/FULL/Polyun...Disorders.shtml

imagine this, the mom's dietary LA, after conversion you already have very little AA. the only source of AA the baby can take is maternal's AA (LA in mom is useless for babies as their body cannot synthesize LA to AA). and how much maternal AA will be passing through the placenta barrier (or breast milk?). Therefore in order for the baby to have the most AA, mothers need to have high AA in their system. and like I already pointed out, AA should not rely entirely from LA conversion.