Percentage of women who deliver on the expected date of delivery is

Based on Naegele&;s formula labor stas approximately onExpected date in 4%One week either side in 50%2 weeks earlier and 1 week later in 80%42 weeks in 10%43 plus weeks in 4%D.C.DUTTA&;S TEXTBOOK OF GYNECOLOGY, Pg no:113,7th edition