Post-dates

A largely obsolete term, "post-dates" is used to further the idea that by creating an educated guess at when a child is conceived, you can then determine a date at which a baby is expected to be born. Then, this point is used as a center point where anything "before" that date is early and anything "after" that date is late or post-dates. This idea is largely fallacy even with the current rise of ultrasound dating for a variety of reasons:


 * No current form of testing can determine exactly when conception occurred in an ongoing pregnancy.
 * No current form of testing is consistent for dating exactly how long an individual pregnancy has been in existence.
 * No current form of testing knows how long a baby needs to continue developing before birth.

The technical definition of "post-dates" is a pregnancy that goes beyond 42 weeks or 294 days.

One of the most common usages for diagnosing a mother/baby dyad as "post-dates" is to then use induction to cause labor to occur. Given that individual practioners can choose to induce at 40 weeks 1 day or 42 completed weeks and it is largely dependent on personal opinion and not evidence-based science, post dates is not a reasonable measure for induction without other medical indication.