Another great report from Evidence Based Birth.
“In a very important study published in 2001, Smith looked at the length of pregnancy in 1,514 healthy women whose estimated due dates, as calculated by the last menstrual period, were perfect matches with estimated due dates from their first trimester ultrasound (Smith 2001).
“The researchers found that 50% of all women giving birth for the first time gave birth by 40 weeks and 5 days, while 75% gave birth by 41 weeks and 2 days.
“Meanwhile, 50% of all women who had given birth at least once before gave birth by 40 weeks and 3 days, while 75% gave birth by 41 weeks.
“This means that for both first-time and experienced mothers in Smith’s study, the traditional “estimated due date” of 40 weeks was wrong!”
from Agape Birth Doula Services http://ift.tt/2mJBS5Q