wht is the way to calculate EDD if someone have irregular periods history or dont know actual L.M.P. coz in ultrasound all the time EDD is different frm each other.
Re: estimated due date?
even if a lady knows her actual L.M.P ( whether regular cycle or irregular) still exact EDD can't be calculated what u get in the end is an estimated period of delivery
ultrasound practice is pretty common to calculate fetus age & EDD but still it's not 100% accurate .............. just like a born baby grows in different way , similarly each fetus grows in it's own way ( depending upon inherited genes , for instance a fetus with one or both tall parents probably grow more length wise ) , accuracy of ultrasound findings is more in first trimester and falls with every subsequent trimester ................ therefore noone could count the exact EDD , what u get in the end is estimated period when u're more likely to have a delivery ( roughly it's 37 ---- 42 weeks), hope it helps