There is no definitive answer to this question. Manufacturers of HA fillers advise against it. While HA is a substance naturally found in the body, the commonly used pre-filled syringes also contain lidocaine for numbing purposes. Lidocaine is contraindicated during pregnancy and breastfeeding. The same applies to Hylase, which would need to be administered in case of emergency. It is also contraindicated. It is therefore prudent not to have filler treatments during pregnancy and breast-feeding.