Prediction of preterm birth by second trimester cervical sonography in twin pregnancies

Authors

  • J.H. Yang,

    1. Department of Obstetrics and Gynecology, Samsung Cheil Hospital and Women's Healthcare Center, Sungkyunkwan University, Seoul, Korea
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  • K. Kuhlman,

    1. Department of Obstetrics and Gynecology, Jefferson Medical College of Thomas Jefferson University Hospital, Pittsburgh, PA, USA
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  • S. Daly,

    1. Department of Obstetrics and Gynecology, Jefferson Medical College of Thomas Jefferson University Hospital, Pittsburgh, PA, USA
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  • V. Berghella MD

    Corresponding author
    1. Department of Obstetrics and Gynecology, Jefferson Medical College of Thomas Jefferson University Hospital, Pittsburgh, PA, USA
    • Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, 834 Chestnut Street, Suite 400, Philadelphia, PA 19107, USA
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Abstract

Objectives

To determine the predictive value of sonographic cervical length and of funneling for spontaneous preterm delivery (PTD) in twin pregnancies under 26 weeks' gestation.

Methods

Women with twin pregnancies were studied prospectively with transvaginal or translabial ultrasound of the cervix from 18 to 26 weeks' gestation. Exclusion criteria were: signs of preterm labor, prophylactic cervical cerclage, placenta previa, or severe congenital fetal anomaly. The primary outcome was spontaneous preterm birth at < 35 weeks' gestation.

Results

Sixty-five twin pregnancies were analyzed, of which 23% (15/65) delivered preterm. Cervical ultrasound examination was performed by 22 weeks' gestation in 75% and by 24 weeks' gestation in 91% of women. Cervical length ≤ 25 mm and ≤ 30 mm was associated with sensitivities of 27% and 53%, respectively, and with 67% and 62% rates of PTD, respectively (R.R. 4.6, C.I. 2.0–10.3 and R.R. 3.6, C.I. 1.6–7.8, respectively). A cervical length > 35 mm was associated with only a 4% rate of PTD (R.R 0.13; C.I. 0.02–0.93). Of 10 women (15%) with any cervical funneling, 70% delivered preterm, all under 32 weeks' gestation. By logistic regression analysis, both short cervix ≤ 30 mm and any funneling were strongly predictive of PTD.

Conclusions

Both cervical length ≤ 30 mm and cervical funneling in twin pregnancies under 26 weeks' gestation are independently and strongly associated with high risk for preterm birth. A long cervix, of length > 35 mm, is associated with very low risk (4%) for preterm birth. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology

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