GREAT THREAD!
I did not change my regimen drastically. Off of the top of my head, here are some slight hair and diet related changes:
Of course, we all know to keep up with pre-natals and iron. However I had a hard time keeping the vits up. They made me hella nauseous, with every pregnancy. So I would increase my diet in healthy foods, veggies, low fat, etc... The prenatals contain folic acid, which help prevent malformations of spinal cord and brain. However, dark leafy greens, citrus fruits, dried beans, and whole grains all are high in folic acid...so I increased these in my diet heavily.
Water: the cure for everything. I try to sip on water throughout the day. If you have slight cramps or a headache, before you take pain medication, most times it is due to a lack of water, try that first.
Experts say it is safe to use commercial hair dyes, however I would avoid synthetic chemical colors that emit strong fumes during the process. Permanent dye is said to be unsafe as well. Also, if you visit a salon that uses a heat lamp for certain chemical treatments, avoid this. In general, if you go to a salon that has poor ventilation, avoid that too. I use henna to color my hair, which is all natural and considered very safe. (Also fumes in general are harmful: ie. Paint, cigarette smoke, etc.)
The oils you use on your hair ideally should be natural virgin oils. However there are a few oils to avoid (or at least use sparingly or cautiously):
Rosemary oil (or any products containing rosemary oil)
Basil Extract (or any products containing it)
Sage Oil ...
Dill Seed Oil ...
Hyssop Oil (“) ...
Most of us shampoo often, and in our showers. Keep the water at room temp, not steaming hot (for those of us that are lobsters). High temps draw blood away from the fetus. Stay away from hot tubs all together. Heating pads set on low or on normal are okay, but stay away from placing them directly on your belly, and do not use it for too long.
Limit your intake of certain types of fish (those with mercury, ie. Shark, Mackerel, Swordfish, and some others). No need to cut out fish all together, simply limit. Large consumptions of mercury can lead to brain malformations. My doc said to cut back to no more than 2 times per week to be safe.
I would stay away from raw fish (sushi) the entire pregnancy. Since we are on the topic of raw, I would stay away from rare, uncooked beef. If you normally take your steaks/beef rare or medium, stop this during pregnancy.
I have read that soft cheeses have harmful bacteria, such as cambmambert, brie, and certain Latin white cheeses.
Aromatherapy: avoid massage oils, pillow sprays, and bath products. Use the natural oils instead, i.e.: lavender, citrusoils, and chamomile.
Coffee and Tea: I cut out coffee while pregnant because I am severely anemic, but you can keep it in your diet, and limit it to only 300 mg per day. Also, tea is safe, but limit to 300 mg per day as well.
Peanut Butter – may increase baby's chance of developing a nut allergy (esp if you have a history of allergies in your family). I did not cut out, but I did cut back, just in case.
If you get sick or suffer nasal allergies, try to stay away from antihistamines, and look for alternatives from your doc/pharm.
Off topic, if you're spotting, never use a tampon, use a pad instead, until you see your doc.
I try not to live in a bubble while I am pregnant, but it is good to be AWARE. Lastly, I do not use pregnancy as an excuse to overeat. The baby does not need you to eat an exaggerated amount of food. Increase your calorie intake by about 500-750 cals per day (healthy cals though). But on the other hand, please do not diet, that is just plain selfish, in my opinion. Eat often, but try to avoid having extremely large and unhealthy meals at once. Be sensible.
Good luck.