Meta-analysis of the predictive value of ultrasonic measurement of cervical internal orifice width and cervical length for premature delivery

Objective: To systematically assess the predictive value of ultrasonic measurement of cervical internal orifice width andcervical length for premature delivery.Method: The systematic review and meta-analysis comprised literature search on Cochrane Library, PubMed, Embase, Webof Science, China National Knowledge Infrastructure and other databases for clinical studies published between January 1,2000, and December 31, 2020, on the predictive value of ultrasonic measurement of cervical internal orifice width andcervical length for premature birth. Two researchers screened the literature, extracted data, and analysed the risk of biasindependently. Meta-analysis was performed using RevMan 5.3.Results: Of the 1,382 studies initially identified, 10(0.7%) were analysed. There were 242 patients in the study group and931 in the control group. Compared to the control group, the cervical length of the study group was smaller (p<0.0001),the width of the internal cervical orifice of the study group was larger (p<0.00001), and the cervical Bishop score of thestudy group was higher (p<0.00001). Preterm delivery patients with cervical length <10mm were significantly more thanthose with cervical length 10mm of more (p=0.0008). Preterm delivery patients with cervical internal orifice width <5mmwere significantly less than those with cervical internal orifice width greater than or equal to 5mm (p<0.00001).Conclusion: Ultrasonic measurement of cervical length and width of internal cervical orifice had significant clinical valuefor predicting premature delivery.Keywords: Ultrasound, Internal cervical orifice, Cervical length, Premature delivery, Meta-analysis.