Table 2.
Diagnostic Indices of Sonographic Cervical Length in Low-risk, Asymptomatic Pregnant Women According to Different Cervical Length Cutoffs.
| Author | Year | N | Gestation (wk) |
Cutoff (mm) |
Definition of PTD (wk) |
Prevalence of PTD (%) |
Sensitivity (%) |
Specificity (%) |
PPV (%) |
NPV (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| Andersen et al.76 | 1990 | 113 | <30 | <39 | <37 | 15 | 76 | 59 | 25 | 93 |
| Tongsong et al.81 | 1995 | 730 | 28–30 | ≤35 | <37 | 12 | 66 | 62 | 20 | 93 |
| Iams et al.49 | 1996 | 2915 | 24 | <20 | <35 | 4 | 23 | 47 | 26 | 97 |
| Taipale and Hiilesmaa67 | 1998 | 3694 | 18–22 | ≤25 | <37 | 2 | 6 | 100 | 39 | 99 |
| Heath et al.151 | 1998 | 2702 | 23 | ≤15 | ≤32 | 1.5 | 58 | 99 | 52 | 99 |
| Hassan et al.70 | 2000 | 6877 | 14–24 | ≤15 | ≤32 | 3.6 | 8 | 99 | 47 | 97 |
NPV, negative predictive value; PPV, positive predictive value.
Source: Reproduced with permission from Gervasi M–T, Romero R, Maymon E, Pacora P, Jeanty P. Ultrasound examination of the uterine cervix during pregnancy. In: Fleischer AC, Manning FA, Jeanty P, Romero R, eds. Sonography in Obstetrics and Gynecology: principles and practice, 6th ed. New York: McGraw-Hill, 2001:821–41.