Diagnosing preterm labour for women with intact membranes

Question 1

If the clinical assessment suggests that the woman is in suspected preterm labour and she is 30+0 weeks pregnant or more, consider transvaginal ultrasound measurement of cervical length as a diagnostic test to determine likelihood of birth within 48 hours. Act on the results as follows:

Answer 1

• If cervical length is more than 15 mm, explain to the woman that it is unlikely that she is in preterm labour
• If cervical length is 15 mm or less, view the woman as being in diagnosed preterm labour
• Consider fetal fibronectin testing (+ if >50ng/ml) as a diagnostic test to determine likelihood of birth within 48 hours if transvaginal ultrasound measurement of cervical length is indicated but is not available or not acceptable