Repeated cervical length measurements for the verification of short cervical length.

Objective: To determine if the verification of short cervical length with a repeated measurement improved the identification of patients with short cervical length at increased risk of preterm delivery.

Methods: The present secondary analysis analyzed prospective cohort study data from patients with singleton pregnancies without a history of preterm delivery who presented for obstetric care in the Netherlands and delivered between November 18, 2009, and January 1, 2013. Cervical length was measured during standard anomaly scan and a second measurement was performed if the cervical length was 30 mm of shorter.