1000mg DHA is an optimum serving size for pregnancy.  In fact, higher amounts are also acceptable and pose no risk as you cannot overdose on natural DHA.  If the body has too much DHA, it will convert it into energy.

The reason you might find our recommendation is rather high is simply that many companies choose to recommend inadequate serving sizes. This way, by having more serves per bottle, their product looks better value. Serving sizes that all lower than necessary will not be effective and will not deliver results.  Unfortunately, many manufacturers are not bothered with that.