Fish Oil & Pregnancy: Benefits, Risks & Mercury Concerns

Question
Age: 25
Children: None, currently 36 weeks pregnant.
First day of last menstrual period: November 15

Early in my pregnancy I found some information on the internet and from my doctor that DHA/EPA is good for healthy brain development, and they say that fish oil supplements are okay to take in pregnancy.  However, there is information to the contrary that certain fish can contain high levels of mercury and should be avoided or limited.  Well, I've been taking fish oil supplements for my entire pregnancy, and now I'm wondering how much, if any, mercury I could've exposed my unborn child to, and I'm scared that I could have damaged him rather than helped with brain development.  I have a feeling that if I ask my OB/GYN this question he will just blow me off and tell me not to worry, but I think this is a valid concern. Can you help?  

Answer
The fish oil supplements, DHEA, or Omega III will not cause any harm nor will they give too much mercury exposure. However, Mercury occurs naturally in the environment and can be released into the air and accumulate in streams and oceans. Fish absorb the mercury as they feed so it builds up in them. Some fish have more mercury than others. Avoid shark, swordfish, king mackerel, and tilefish. Fish that are low in murdury are shrimp, canned light tuna, salmon, pollock, and catfish. Albacore tuna has more mercury than canned light tuna. Therefore, eat up to 6 ounces of albacore una per week.