Role of mid-trimester transvaginal cervical ultrasound in prediction of preterm delivery.
Ultrasonographic cervical length assessment is increasingly being utilized clinically to identify women at risk for spontaneous preterm delivery. In a randomised prospective longitudinal study involving 200 women, we measured cervical length and internal os diameter by transvaginal scan at 20 - 24 weeks and analysed their ability to predict preterm birth. The risk of spontaneous preterm delivery increased steeply as cervical length decreased. At cut off value of < or = 2.5cm, the cervical length measurements had sensitivity, specificity, positive predictive value and negative predictive value of 77%, 95%, 56% and 98% respectively. However, internal os diameter lacked sensitivity and specificity. Our data suggests that the duration of pregnancy is directly related to length of the cervix: the shorter the cervix, the greater the chance of preterm delivery.
Hebbar
S
S
Department of O and G, Melaka Manipal Medical College, Melaka, Postgraduate, Department of O.B.G., Kasturba Medical College, Manipal, Malaysia.
Samjhana
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K
D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000175:diagnosis*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography