Three-dimensional volumetric gray-scale uterine cervix histogram prediction of days to delivery in full term pregnancy

OBJECTIVE: Our aim was to figure out whether volumetric gray-scale histogram difference between anterior and posterior cervix can indicate the extent of cervical consistency. METHODS: We collected data of 95 patients who were appropriate for vaginal delivery with 36th to 37th weeks of gestational age from September 2010 to October 2011 in the Department of Obstetrics and Gynecology, Korea University Ansan Hospital. Patients were excluded who had one of the followings: Cesarean section, labor induction, premature rupture of membrane. Thirty-four patients were finally enrolled. The patients underwent evaluation of the cervix through Bishop score, cervical length, cervical volume, three-dimensional (3D) cervical volumetric gray-scale histogram. The interval days from the cervix evaluation to the delivery day were counted. We compared to 3D cervical volumetric gray-scale histogram, Bishop score, cervical length, cervical volume with interval days from the evaluation of the cervix to the delivery. RESULTS: Gray-scale histogram difference between anterior and posterior cervix was significantly correlated to days to delivery. Its correlation coefficient (R) was 0.500 (P = 0.003). The cervical length was significantly related to the days to delivery. The correlation coefficient (R) and P-value between them were 0.421 and 0.013. However, anterior lip histogram, posterior lip histogram, total cervical volume, Bishop score were not associated with days to delivery (P >0.05). CONCLUSION: By using gray-scale histogram difference between anterior and posterior cervix and cervical length correlated with the days to delivery. These methods can be utilized to better help predict a cervical consistency.

Prediction of delivery within 7 days after ultrasonographic measurement of the cervical angle and cervical length in term pregnancies / 대한산부인과학회지

OBJECTIVE: The study was to assess the value of the cervical angle (CA) and cervical length (CL) measurement by transvaginal ultrasonography (USG) in predicting delivery within 7 days after USG in low risk singleton term pregnancies. METHODS: This prospective study included 85 singleton low risk term pregnancies. The CA and the CL were measured at 36 weeks' gestation and each week thereafter. Seven cases were lost to follow-up and finally a total of 78 cases were analyzed. The number of days to delivery was recorded. The odds ratios of the CA and CL for predicting delivery within 7 days after USG at different weeks' gestation were calculated using the Cox proportional hazard model. Receiver-operation characteristic curves were drawn to determine the cutoff values of the CA and CL. RESULTS: CA measurement did not predict delivery within 7 days after USG. However, there was a significant relationship between the CL and the days to delivery at 37 weeks' gestation. The optimal cutoff value in predicting the delivery within 7 days was 10 mm at 37 weeks' gestation. We could not obtain proper cutoff points at other weeks' gestation. CONCLUSION: CA measurement by transvaginal USG may not have a significant clinical impact on predicting delivery within 7 days after USG. However, CL measurement USG at 37 weeks' gestation can help predict the delivery within 7 days after USG.

Prediction of an actual birth within one week by ultrasonographic examination at 38 weeks' of gestation / 대한산부인과학회지

OBJECTIVE: The aim of this study is to predict spontaneous labor onset delivery within 7 days in low risk pregnant women at 38 weeks' of gestation by ultrasonographic examination of cervical changes. MATERIAL AND METHODS: This prospective study included 110 singleton low risk pregnancies between 37(+0) and 37(+6) weeks of gestation. Fifteen cases were lost during follow-up and finally 95 pregnant women (58 nulliparous, 37 multiparous) were analysed. The study period was from Oct/2005 to May/2007. Four cervical changes (length, gland thickness, funneling and canal formation) were evaluated. Main outcome was remaining day to delivery after the examination. Remaining days to actual delivery with spontaneous labor onset were recorded and the pregnancies were divided into two groups according to remaining days (within 7 days, over 7 days) to compare predicting power of delivery within 7 days. ROC curves were drawn to find out cut-off values of cervical length and gland thickness. Sensitivity, specificity, positive predictive value and negative predictive value were extracted from four cervical changes. RESULTS: Mean cervical length of pregnant women at 38 weeks' of gestation was 25.8 (+/-10.0) mm and mean cervical gland thickness was 4.3 (+/-1.2) mm. Funnelings of uterine cervix were detected in 13 cases (13.7%), canal formations in 6 cases (6.3%). All four cervical changes were statistically valuable to predict delivery within 7 days and the cervical length showed highest sensitivity. When the cervical length was measured under 20 mm, the possibility of delivery within 7 days was 78.6% (p<0.001). The cervical gland thickness less than 4 mm could predict the delivery within 7 days with sensitivity of 57.1% (p<0.01). Sensitivities of funneling and canal formation for delivery within 7 days were 54.5%, 36.4% each. CONCLUSION: Ultrasonographic examination of the cervical changes in low risk singleton pregnancy at 38 weeks' of gestation are valuable for predicting spontaneous labor onset delivery within 7 days. Among four cervical changes, cervical length is most sensitive ultrasonographic marker.