Most of the Aromatherapy skincare on the market is safe to be used in pregnancy and for nursing mothers as the products can only  contain 1% of essential oils. 

Having said that,  it would be best to consult an aromatherapist so they can make a custom massage blend for you and can advice you which oils are best to be avoided. 

Overall, aromatherapy massage during pregnancy helps reduce fluid retention and aids deeper sleep. Mothers-to-be have also noticed that they develop fewer, if any stretch marks with regular massage. 

Essentials oil can be enormous help during labour, ask your Aromatherapist to make you a massage blend and an inhaler to prepare for the child birth. Essential oils, such as lavender, clary sage and roman chamomile can reduce pain and speed up the labour.  Geranium can help balance your hormones and rose and frankincense can both help with over breathing during labour. 

For the most, aromatherapy can soothe mother and baby during the birthing process, so you should defiantly consider purchasing good quality aromatherapy cosmetics.