I've recommended this a few times and you'll probably think I'm daft but almonds really helped me. They must be shelled (!) but still with their brown skins. Just nibble a few when the heartburn comes on. Seriously - my midwife recommended them and they worked for me
I too had Gaviscon, I used to keep it by the bed and drink it from the bottle my heartburn was so bad and Gaviscon did nothing! I then found the Rennie chews and they worked wonders, I would definitely recommend them!
I have suffered with stomach acid problems for years and so when I found out I was pregnant a couple of week ago, I booked an appointment with my gastroenterologist at the hospital. He advised that I stay of Rinitidine (Zantac) for the first 12 weeks, then after then, use it when required. I'm guzzling gaviscon like there's no tomorrow. Soda water helps me. I'm nearly 7 weeks pg.
Rennies do a liquid heartburn cure (currently BOGOF at tesco) that I think is better than gaviscon. Avoid caffiene & chocolate :-(
my heartburn got so bad that I was having osophageal spasms and they thought I had angina. But oddly enough it seems to have improved... I have a puppodum addiction and am loving soda scones - bothe have bicarb of soda in it which may be helping!