Reflux or gastric irritation in pregnancy is usually considered to be hormone related where the sphincter or valve becomes relaxed and therefore allows the gastric contents to flow backwards into the oesophagus. However any mechanical restrictions throughout the abdomen, chest or pelvis may also affect the bodies ability to cope with the expanding uterus and therefore causing the reflux to occur. Tension in the upper neck may irritate the vagus nerve which is in charge of the abdominal organs, therefore worsening symptoms. In my experience i've had a lot of success at decreasing or eliminating such symptoms with osteopathic treatment. Hope this is helpful!