(1160) Optimal gestational age at cervical length measurement for predicting preterm birth in low-risk women

Friday, February 10, 2023

3:30 PM – 5:00 PM

Objective: To determine which gestational age at cervical length measurement more accurately predicts preterm birth in asymptomatic women without prior preterm birth.

Study Design: This retrospective cohort study included women without prior preterm birth who had cervical lengths checked routinely from 16 weeks of gestation until preterm labor or birth. Women who gave birth before 24 weeks of gestation, multiple pregnancies, iatrogenic preterm birth, and women who received cerclage operation were excluded. Cervical lengths were measured serially at two periods for all women; 16-24 weeks and 24-32 weeks of gestation. Receiver-operating characteristics curves were generated, and the area under the curves (AUCs) were compared for the performance of cervical length between two periods for predicting preterm birth. In addition, the time at cervical length measurements was divided into sub-periods (16-20, 20-24, 24-28, and 28-32weeks), and the AUCs were calculated.

Results: The study population included 2,725 (95.6%), 110 (3.9%), and 15 (0.5%) women with term birth, late preterm birth, and early preterm birth, respectively. For preterm birth and late preterm birth, the predictive value of cervical length at 24-32 weeks was significantly higher than that of cervical length at 16-24 weeks (Figure, p< 0.05). The AUCs of cervical length at sub-periods for preterm birth were 0.615 at 16-20 weeks, 0.598 at 20-24 weeks, 0.612 at 24-28 weeks, and 0.645 at 28-32 weeks, respectively. The best-cut-off value of cervical length at 24-32weeks to predict preterm birth was 2.78cm (sensitivity of 45.6%, specificity of 82.2%, positive likelihood ratio of 2.56, and negative likelihood ratio of 0.66).

Conclusion: Cervical length measurement after 24 weeks, especially after 28 weeks, appears to be a significant predictor of preterm birth. Further studies are necessary on methods to prevent preterm birth for women with short cervical length after the second trimester.

Coauthor(s)

Subeen Hong, MD
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul, Seoul-t'ukpyolsi, Republic of Korea
OK
Oyoung Kim, MD
Obstetrics and gynecology
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul St. Mary's Hospital / Seoul, Seoul-t'ukpyolsi, Republic of Korea
BK
Byung Soo Kang, MD
Obstetrics and gynecology
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul, Seoul-t'ukpyolsi, Republic of Korea

Presenting Author(s)

Seon Ui Lee, MD
Obstetrics and gynecology
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul, Seoul-t'ukpyolsi, Republic of Korea

Coauthor(s)

HH
Hyesung Hwang, MD
Catholic University of Korea
Seocho-Gu, South Korea, Republic of Korea
HK
Hyun Sun Ko, MD, PhD
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul, Seoul-t'ukpyolsi, Republic of Korea

Primary Author(s)

In Yang Park, MD, PhD
Obstetrics and gynecology
Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea
Seoul, Seoul-t'ukpyolsi, Republic of Korea