 cytokines, CRH, C-reactive protein, fetal fibronectin ,... etc. are sufficiently sensitive or specific to be used alone or in combination to help decrease the rate of preterm births. Ozhan et al., 2007 Obviously, theres a need for an accurate method with high sensitivity and specificity for prediction of preterm labor. So that an appropriate management or referral to a higher center can be done to women likely to have PTB. Whereas unnecessary tocolytic therapy can be avoided in women who are unlikely to have PTB. Rengaraj et al., 2009 Convincing data have shown that 2-dimensional 2D ultrasound measurement of cervical length CL can identify women at risk for PTB. 