Pregnancy and Breast Feeding: Pregnancy and breast feeding could adversely affect your treatment result since your refractive error (glasses prescription) can fluctuate during this time. In addition, pregnancy and breast-feeding may affect your healing process, and some medications may pose a risk to the unborn or nursing child. Therefore, if you are pregnant or nursing, you should not undertake the LASIK procedure until after the pregnancy and breast-feeding period or with the resumption of your normal menstrual cycles.