Postterm Pregnancy: Incidence & Prevalence Worldwide & US

[nomadreid]

TL;DR

perhaps I am parsing Wikipedia's phrasing incorrectly; if not, is there really such a difference? (7% and 0.4%) I could not find the 0.4% figure elsewhere (and I do not have access to the article cited after the 0.4%), although I found the 7% figure elsewhere.

"In the Wikipedia article https://en.wikipedia.org/wiki/Postterm_pregnancy#Epidemiology I read:
Prevalence of postterm pregnancy ... The incidence is approximately 7%. Postterm pregnancy occurs in 0.4% of pregnancies approximately in the United States according to birth certificate data."
This seems to say that postterm preganancies are 7% of pregnancies worldwide (a figure I also found in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3991404/), and then that it is 0.4% in the US (although the link just mentioned gives higher figures). Is this what it is saying and if so, is it correct, and if so, why the discrepancy?

 

[Ryan_m_b]

How common is induced birth in the US? In some countries it is quite common to schedule induced births within 2 weeks of being overdue. In those countries you’d expect the percentage of post term births to be much lower than the global average.

 

[berkeman]

How common is induced birth in the US? In some countries it is quite common to schedule induced births within 2 weeks of being overdue.

That is probably the key point. From my limited experience, it is pretty common. From the wikipedia article that was posted in the OP:

Postterm pregnancy
Other names	Post-term, postmaturity, prolonged pregnancy, post-dates pregnancy, postmature birth
Specialty	Obstetrics

Postterm pregnancy is the condition of a woman who has not yet delivered her baby after 42 weeks of gestation, two weeks beyond the median duration of a human pregnancy of about 40 weeks (mean duration of pregnancy varies by parity).[1] Post-mature births can carry risks for both the mother and the infant, including fetal malnutrition. After the 42nd week of gestation, the placenta, which supplies the baby with nutrients and oxygen from the mother, starts aging and will eventually fail.

 

[nomadreid]

Ryan_m_b, that is a good point. It appears that the statistics for induced labor in the US are a bit fuzzy: in http://www.nationalpartnership.org/...ternity/quick-facts-about-labor-induction.pdf the estimates go from 23% to 30% of all pregnancies in the US.
berkeman: so, yes, induced labor in the US is quite common, especially for postterm pregnancy due to the dangers you listed.
However, whereas this could account for some discrepancy, I am not sure that this could account for the discrepancy between the figures of 7% or 4% down to 0.4%.