Universal cervical length screening for singleton pregnancies with no history of preterm delivery, or the inverse of the Pareto principle.

UNLABELLED: Ultrasound measurement of cervical length in the general population enables the identification of women at risk for spontaneous preterm delivery. Vaginal progesterone is effective in reducing the risk of preterm delivery in this population. This screening associated with treatment by vaginal progesterone is cost-effective. Universal screening of cervical length can therefore be considered justified. Nonetheless, this screening will not appreciably reduce the preterm birth prevalence: in France or UK, where the preterm delivery rate is around 7.4%, this strategy would make it possible to reduce it only to 7.0%. This small benefit must be set against the considerable effort required in terms of screening ultrasound scans.

TWEETABLE ABSTRACT: Universal ultrasound screening of cervical length is the inverse of Pareto's principle: a small benefit against a considerable effort.