does pyridostigmine bromide affect embryo implantation & does it cause early abortion

I have a patient , 37 years old ,on pyridostigmine bromide for about eight years . she is newly married since January 2008 . she had 2-3 v.early spontaneous abortions .

she is on 60 mg daily of PB. does the drug affects ovulation ; implantation ;& does it has any relation with spontaneous abortion