Ginger has been demonstrated to relieve pregnancy nausea and vomitting, and other symptoms that goes with "morning sickness". A lot of women swear by it, but before you go and buy a dietary supplement of fix yourself a ginger tea, do consult your doctor. On one hand, there have been scientific studies touting its efficacy; on the other hand, there are studies indicating that when used at large doses or at extensive periods, the use of ginger during pregnancy may contribute to risks of spontaneous abortions or mutations. There have been no conclusive data, though, but it's better to err on the side of precaution.