I'm a mother of 4 children my youngest it 10 months today i had a copper iud inserted the dr told me my cervix is still slightlyopen can iud fall out?

Very unlikely: It is not uncommon for the cervix to remain slightly open after multiple births. However, this slight opening of the cervix is not a known risk factor for expulsion (the IUD "falling out") Your risk for expulsion is not higher than average. The overall risk is low for all women but not zero, so be sure to check the strings daily to ensure that your IUD is still in place.