الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Preterm labor is defined as the presence of uterine contractions of sufficient frequency and intensity leading to progressive effacement and dilation of the cervix prior to term gestation. Occurring at 20-37 weeks of gestation. Premature birth may be iatrogenic or spontaneous. Iatrogenic premature birth is the result of a medical intervention due to a fetal and/or maternal condition (e.g., fetal growth restriction, preeclampsia) necessitating early delivery. By contrast, spontaneous premature birth often occurs despite best efforts to prolong the pregnancy. It is estimated that up to 80 percent of premature births fall into this category. The incidence of preterm birth is increasing. This may be for two reasons: the rising number of medically indicated deliveries in singleton pregnancies and a higher rate of multiple pregnancy due to more widespread use of assisted reproductive technologies. The ability to identify women who will deliver prematurely is important, as it allows targeted administration of effective treatments, such as vaginal progesterone, steroids, and magnesium sulfate for neuroprotection. Both progesterone pessaries and cervical cerclage have been shown to reduce the incidence of preterm birth and improve neonatal outcome. Prediction and prevention of preterm birth have come a long way. Methods used for predicting preterm birth include home uterine activity monitoring (HUAM), assessments of salivary estriol FFN, the presence of bacterial vaginosis, and cervical length assessment, and the most recent method is assessment of uterocervical angle. • Using transvaginal ultrasound, threshold of cervical length in 24 weeks of gestation for PB risk was defined as 25 mm (10th percentile), with 37.3% sensitivity and 92.2% specificity the risk of delivery prior to 35 weeks’ gestation increased by 6-fold. Also, within 3-week period, a shortening in cervical length >10% was found associated with increased risk of PB. A recent meta-analysis showed that the knowledge of cervical length had a reduced risk for PB before 37 weeks. A cervical length ≤15mm was reported as the most optimal cut-off point with 81% specificity and 83% positive predictive value for predicting the true preterm labor. UCA represents a novel ultrasonographic marker that is defined as the triangular segment measured between the lower uterine segment and the cervical canal. Several studies have investigated the potential value of UCA, especially the posterior cervical angle (PCA), as a mechanical barrier for the prediction of preterm birth, with few studies reporting the influence of PCA on labor progress. During the last years several studies investigated the potential impact of UCA for the prediction of preterm birth. The rationale behind the hypothesis of this association is based on the potential mechanical properties of this angle, which seems to act as a preventive barrier when it is acute. A wide uterocervical angle ≥95 and ≥105 degrees detected during the second trimester was associated with an increased risk for spontaneous preterm birth <37 and <34 weeks, respectively. A recent study showed that UCA had greater sensitivity of 80-81% than CL for prediction of PTB. This study aimed to evaluate the efficacy of combining both cervical length measurement and posterior utero cervical angle assessment using • transvaginal ultrasound at the period from 12th week to 14th week of gestation for prediction of preterm labor. This prospective cohort study was carried out on 60 well dated singleton pregnant women at the period from 12th week to 14th week of gestation and previous obstetric history of PROM or preterm labour. All pregnant women in the study were subjected to full history taking, complete clinical examination, laboratory investigation and cervical length assessment and posterior uterocervical angle assessment. Summary of our Results: • Demographic data (age, BMI, parity, educational level, and mode of delivery) were insignificantly different between both groups. All cases were multipara. • The risk factors (previous history of preterm labour, smoking, vaginitis, bleeding in early pregnancy and spontaneous abortion) of preterm labour were insignificantly different between both groups. • The cervical length was significantly lower in the preterm labor group compared to the term labor group (P value < 0.022). The posterior cervical angle degree was significantly higher in the preterm labor group compared to the term labor group (P value = 0.042). • Cervical length can significantly predict incidence of preterm labour with AUC of 0.784. At cut off ≤ 38.06, it‘s a significant predictor with 83.33 % sensitivity, 61.90 %specificity, 48.4 % PPV 89.7% NPV and 70.0% diagnostic accuracy. • Posterior cervical angle degree can significantly predict incidence of preterm labour with AUC of 0.711. At cut off >115.9, it‘s a significant predictor with 72.22 % sensitivity, 78.75 %specificity, 59.1 % PPV and 86.1% NPV, 76.7% diagnostic accuracy. • Cervical length with posterior cervical angle degree can significantly predict incidence of preterm labour with AUC of 0.583. At cut of ≤ ≤ 38.06 or >115.9 is a significant predictor with 55.6% sensitivity, 92.9% specificity, 76.9% PPV, 83.0% NPV and 81.7% diagnostic accuracy.