Uterine contraction may not be an independent risk factor for spontaneous preterm birth before 35 weeks in women with cervical shortening

• Published in: International journal of gynecology and obstetrics Vol. 161; no. 3; pp. 894 - 902
• Main Authors: Horie, Kenji, Takahashi, Kayo, Mieno, Makiko, Nagayama, Shiho, Aoki, Hiroaki, Nagamatsu, Takeshi, Kanatani, Ayumi, Hyodo, Hironobu, Terada, Kayoko, Hayashi, Masako, Nakai, Akihito, Yoneda, Noriko, Saito, Shigeru, Matsuda, Yoshio, Matsubara, Shigeki, Ohkuchi, Akihide, Hirose, Noriko, Sato, Mariko, Sato, Takuma, Matsuoka, Tomona, Taketani, Yuuki, Nakazato, Norihiko, Saitou, Etsuko, Funakura, Midori, Inoue, Tomoko, Miura, Shiho, Kikuchi, Eriko, Yoshie, Masaki, Otsuki, Katsufumi
• Format: Journal Article
• Language: English
• Published: United States 01.06.2023
• Subjects: cervical incompetence; Cervical Length Measurement; cervical shortening; Cervix Uteri - diagnostic imaging; Female; Humans; Infant, Newborn; Pregnancy; Premature Birth - etiology; Retrospective Studies; Risk Factors; spontaneous preterm birth; threatened abortion; threatened preterm labor; Uterine Cervical Incompetence; Uterine Hemorrhage - epidemiology; threatened abortion; cervical incompetence; spontaneous preterm birth; threatened preterm labor; cervical shortening
• ISSN: 0020-7292; 1879-3479
• DOI: 10.1002/ijgo.14578

Objective To compare the risk of spontaneous preterm birth (SPTB) before 35 weeks in symptomatic and asymptomatic women with cervical shortening at 16–34 weeks under mid‐trimester universal screening of cervical length (CL). Method Multicenter retrospective cohort study involving six secondary/tertiary perinatal centers was planned in 2016. Primary outcomes were SPTB before 35 weeks. In all, 407 women were analyzed using multivariable logistic regression analysis for predicting SPTB before 35 weeks while adjusting for presence/absence of uterine contraction, gestational weeks, vaginal bleeding, and CL classification (1–9, 10–14, 15–19, and 20–24 mm) at admission, the execution of cervical cerclage, and the presence/absence of past history of preterm delivery. Results SPTB before 35 weeks of pregnancy occurred in 14.5%. Presence of uterine contraction was not an independent risk factor for SPTB before 35 weeks (adjusted odds ratio [aOR] 1.22, 95% confidence interval [CI] 0.67–2.20). CL of 1–9 mm, CL of 10–14 mm, and vaginal bleeding at admission were independent risk factors for SPTB before 35 weeks (aOR 5.35, 95% CI 2.11–13.6; aOR 2.79, 95% CI 1.12–6.98; and aOR 2.37, 95% CI 1.12–5.10, respectively). Conclusion In women with a cervical shortening at 16–34 weeks, presence of uterine contractions at admission may not be an independent risk factor for the occurrence of SPTB before 35 weeks. Synopsis In women with cervical shortening at 16–34 weeks, presence of uterine contractions may not be risk factor for spontaneous preterm birth before 35 weeks.