You should use some powder, antiperspirant, or deodorant in the creases of your skin and under your arms. Remember that deodorants do not prevent perspiration; their sole purpose is to make you smell pleasant. Excessive perspiration calls for the use of an antiperspirant. Make sure you carry it with you everywhere you go.  Also, deodorants containing aluminium, parabens, triclosan, phthalates, propylene glycol, or any other potentially harmful ingredients should be avoided during pregnancy.