14 DAY TRIAL // According to a new study published in yesterday's issue of the journal Human Reproduction, just 4% of women give birth to their children on the due date.
70% have their babies up to ten days before or after the estimated due date, and the remaining become mothers roughly five weeks earlier or later than expected.
Oddly enough, these variations are natural ones. Otherwise put, they are not the result of errors made when calculating gestational age.
“We know that length of gestation varies among women, but some part of that variation has always been attributed to errors in the assignment of gestational age.”
“Our measure of length of gestation does not include these sources of error, and yet there is still five weeks of variability. It's fascinating,” researcher Dr. Anne Marie Jukic explains, as cited by EurekAlert.
By the looks of it, the older a woman is, the later she will deliver her baby. Interestingly enough, women whose own birth weight was higher than average also appear to have longer gestations.