The value of ultrasonographic examination of the uterine cervix in predicting post-term pregnancy

Gestational diabetes mellitus: The optimal time of delivery

Gestational diabetes mellitus (GDM) is a common pregnancy complication strongly associated with poor maternal-fetal outcomes. Its incidence and prevalence have been increasing in recent years. Women with GDM typically give birth through either vaginal delivery or cesarean section, and the maternal-fetal outcomes are related to several factors such as cervical level, fetal lung maturity, the level of glycemic control still present, and the mode of treatment for the condition. We categorized women with GDM based on the latter two factors. GDM that is managed without medication when it is responsive to nutrition- and exercise-based therapy is considered diet- and exercise-controlled GDM, or class A1 GDM, and GDM managed with medication to achieve adequate glycemic control is considered class A2 GDM. The remaining cases in which neither medical nor nutritional treatment can control glucose levels or patients who do not control their blood sugar are categorized as class A3 GDM. We investigated the optimal time of delivery for women with GDM according to the classification of the condition. This review aimed to address the benefits and harms of giving birth at different weeks of gestation for women with different classes of GDM and attempted to provide an analytical framework and clearer advice on the optimal time for labor.

Can ultrasound predict the delivery time of patients with previous cesarean section in the 37th gestational week? A prospective cross-sectional study

BACKGROUND

The aim was to investigate factors that predict when patients with previous cesarean section will undergo cesarean section (CS) using ultrasonography in the 37th gestational week.

MATERIAL AND METHODS

In this prospective cross-sectional study, a total of 166 patients with previous CS who presented to the hospital for routine checks at the 37^0/7th gestational week were included in the study. Uterine-related, fetus-related, and patient-related factors that affect labor time were analyzed by the same physician at admission, and the patients were then divided into two groups as those having CS at early term (37^0/7 to 38^{6/7 weeks} of gestation) and full-term (39^0/7 to 40^{6/7 weeks} of gestation). Ninety-four patients underwent CS at full-term and 72 patients underwent CS at the early term in the study.

RESULTS

There was no significant difference for age (years), parity, weight gain, previous cesarean number, cervical length, myometrial thickness, estimated fetal weight, and full lower uterine segment thickness between the groups (p>.05). In the full-term group, 58% had a history of vaginal birth, whereas, in the early-term group, 42% had a history of vaginal birth (p < .05). Vaginal birth history was found to be independently associated with reaching full-term (respectively, OR: 2.876, 95% CI: [1.227-6.738]; p = .015) in all patients. Two different regression models were created to predict different CS times after the 37th week of pregnancy. Weight gain was found to be independently associated with CS time within the first seven days after admission (OR: 1.267, 95% CI: [1.003-1.599]; p = .047). Vaginal birth history and estimated fetal weight were found to be independently associated with CS time in the 8th day and further after admission (OR: 0.244, 95% CI: [0.089-0.675]; p = .007 and OR: 1.002, 95% CI: [1.000-1.003]; p = .047).

CONCLUSION

Vaginal birth history can be useful to predict reaching full-term in patients with previous CS. Determination of such risk factors is important in terms of reducing the frequency of emergency cesarean delivery.

The value of measuring cervical length between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy

OBJECTIVE

The aim of this study was to investigate the value of measuring cervical length (CL) between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy.

METHODS

In this prospective longitudinal study, pregnant women whose CL was measured between 24 and 28 weeks were followed until delivery. The CL was adjusted for confounders and the results are presented using odds ratio and receiver operating characteristic curve (ROC).

RESULTS

A total of 874 women met the inclusion criteria. The median value of CL measured between 24 and 28 weeks was 34.0 mm (30.0-38.0 25%, 75% interquartile range). The risk of late and post-term pregnancy was 5.8 times higher in pregnant women with a CL above 35 mm between the 24 and 28 weeks of gestation (95% CI: 2.65-12.94 adjusted OR = 5.8, p < .001). For pregnancies exceeding the 38th week, it was observed that the duration of the gestation increases as CL values increase.

CONCLUSIONS

In this study, it has been demonstrated that measuring the CL between 24 and 28 weeks of gestation can predict late and post-term pregnancy. Prolonged pregnancy may cause neonatal and fetal complications and anxiety. CL measurement performed in these weeks can help prepare pregnant women for a possible prolonged pregnancy and cope with prolonged pregnancy anxiety.

Is Unfavourable Cervix prior to Labor Induction Risk for Adverse Obstetrical Outcome in Time of Universal Ripening Agents Usage? Single Center Retrospective Observational Study

Cervical assessment on the Bishop scale prior to induction of labor (IOL) is one of the strongest prognostic criteria in relation to the success of the procedure. The commonly used preinduction methods are mainly aimed at reducing the percentage of cesarean sections. Our study has analyzed obstetric results of patients who had unripe cervix (Bishop score <7) before IOL and used preinduction (Foley catheter or misoprostol vaginal insert releasing 7 mcg of misoprostol per hour for 24 hours) with obstetric results of patients in whom, due to favourable cervix, only a low-dose infusion of oxytocin was used. We reviewed the medical records of 1010 single pregnancies in whom IOL was performed. We divided the patients into two groups: group A (where preinduction was used) and group B (Bishop score ≥7 points) where preinduction was not used. Patients in group A were more likely to complete the delivery by caesarean section (OR = 4.58, 95% CI 3.22-6.51), and more likely to have events that were indications for operative delivery: unreassuring fetal heart rate trace (OR = 3.29, 95% CI 2.07-5.23) and arrested labor or failed induction (OR = 3.4, 95% CI 2.06-5.62). The groups did not differ in the percentage of vacuum extraction, postpartum haemorrhage, and meconium stained amniotic fluid. In group B, more infants were born with umbilical cord blood pH <7.1 (1.38% vs. 0%), both groups included no deliveries of newborns with Apgar score ≤3 points, the groups did not differ in terms of the percentage of newborns with Apgar score between 4 and 7 at birth (OR = 0.66, 95% CI 0.29-1.49). The immature cervix and the need to use labor preinduction is a risk factor for caesarean section. The necessity of preinduction does not impair neonatological results.

Cervical length measurement in nulliparous women at term by ultrasound & its relationship to spontaneous onset of labour

Background & objectives:

Data on serial cervical length (CL) measurements in pregnancy at term to predict spontaneous labour onset are scarce and conflicting. This study was conducted to observe CL changes preceding spontaneous onset of labour, by serial transvaginal sonography (TVS) and transabdominal sonography (TAS), in nulliparous Indian women near term.

Methods:

Only nulliparous women with a singleton foetus in cephalic presentation and who confirmed their gestational age were recruited. Sonographic CL measurements were taken at weekly intervals from 36 wk gestation onwards by a single ultrasonologist. Transabdominal and transvaginal measurements were undertaken using the suitable transducer probes with the women in the supine position.

Results:

A total of 104 women with spontaneous onset of labour were evaluated. There was substantial variation in CL measurements, both by TVS and by TAS, from 36 to 40 wk gestation, although the two sets of measurements correlated closely. Mean CL changed significantly over the last three weeks before delivery. However, only one-third of the women showed CL change of >5 mm per week in the last three weeks. There was poor correlation between gestational age at delivery and the last measured CL, either by TVS or TAS. Length >3.1 mm, measured by TVS at 38 wk gestation, predicted post-dated pregnancy to a limited extent.

Interpretation & conclusions:

Inter-individual variations in CL and in CL changes were large. Thus, it was not practical to predict spontaneous onset of labour by sonographic CL measurement near term. Post-dated pregnancy may be predicted with limited success. Further studies should explore other parameters, in addition to CL.

Ultrasound cervical length measurement in prediction of labor induction outcome

Induction of labor is one of the most common procedures in modern obstetrics, with an incidence of approximately 20% of all deliveries. Not all of these inductions result in vaginal delivery; some lead to cesarean sections, either for emergency reasons or for failed induction. That's why, It seems necessary to outline strategies for the improvement of the success rate of induced deliveries. Traditionally, the identification of women in whom labor induction is more likely to be successful is based on the Bishop score. However, several studies have shown it to be subjective, with high variation and a poor predictor of the outcome of labor induction. Transvaginal sonography for cervical measurement can be a more objective criterion in assessing the success of labor induction. Many studies have been done recently to compare cervical measurement and Bishop Score in labor induction.This paper reviewed the literature that evaluated sonographic cervical length measurement to predict induction of labor outcome.

Use of the angle of progression on ultrasonography to predict spontaneous onset of labor within 7 days

OBJECTIVE

To investigate the relationship between angle of progression (AoP) on ultrasonography at 37-40 weeks' gestation and delivery within 7 days.

METHODS

This prospective study was conducted between January 2013 and May 2013 at Korea University Guro Hospital, Korea. Nulliparous women between 37/0 and 40/3 weeks' gestation with a singleton fetus, intact membrane, and cephalic presentation from January 2013 to May 2013 were enrolled. To evaluate the cervical parameters of cervical length and AoP, transvaginal and transperineal ultrasonography were performed, respectively. We then assessed the relationship between cervical parameters and onset of labor within 7 days by multivariate logistic regression analysis.

RESULTS

Women who underwent spontaneous onset of labor within 7 days had a significantly shorter cervical length and AoP than those who underwent labor after 7 days. Logistic regression analysis showed that a larger AoP was an independent predictor of spontaneous labor within 7 days.

CONCLUSIONS

A larger AoP was significantly associated with spontaneous onset of labor within 7 days. These findings may be useful for counseling patients regarding the management of term pregnancies.

Sonographic longitudinal cervical length measurements in nulliparous women at term: prediction of spontaneous onset of labor

OBJECTIVE

The aim of this study was to predict spontaneous onset of labor by serial transvaginal ultrasound measurement of cervical length (CL) in a homogeneous population of nulliparous women at term.

METHODS

162 nulliparous women with singleton fetuses in cephalic presentation were examined at weekly intervals from 36 weeks' gestation to delivery. CL was measured by transvaginal ultrasound in the supine and upright positions.

RESULTS

There was a significant decrease in CL in the last 12 days prior to delivery. However, this decrease was small with substantial variation between individuals. Women with spontaneous onset of labor could be divided into three different groups: those with unchanged CL before delivery; those with a fall in CL in the last 2 weeks prior to delivery; and those with a gradual change in CL starting before the last 2 weeks prior to delivery. A single CL measurement below 30 mm between 37 and 38 weeks of gestation predicted spontaneous onset of labor before 41 weeks' gestation with a sensitivity of 46%, specificity of 78%, positive predictive value (PPV) of 82%, negative predictive value (NPV) of 40% in the supine position; and sensitivity of 53%, specificity of 72%, PPV of 81%, NPV of 40% in the upright position.

CONCLUSION

Between 37 and 38 weeks' gestation, spontaneous onset of labor before 41 weeks can be predicted by a CL measurement, but with low sensitivity and NPV. Inter-individual variations in CL and in CL changes are large, which hampers the value of single and repeated CL measurements for the prediction of spontaneous onset of labor at term.

Cervical length and maternal factors in expectantly managed prolonged pregnancy: prediction of onset of labor and mode of delivery

OBJECTIVE

To examine the value of combining cervical length and maternal characteristics in a prolonged-pregnancy clinic in the prediction of the probability of firstly, spontaneous onset of labor within the subsequent 10 days and secondly, the need for Cesarean section.

METHODS

This was a prospective study of women with singleton pregnancies attending an ultrasound-based prolonged-pregnancy clinic at 40 + 4 to 41 + 6 weeks of gestation. The policy was to delay induction of labor by 7-10 days unless there was evidence of a specific medical or obstetric indication or the mother wanted earlier delivery. The measurement of cervical length was not given to the obstetrician, midwife or patient. Regression analysis was used to determine which of the following factors had a significant contribution in predicting induction of labor: maternal age, body mass index (BMI), ethnic origin, parity and cervical length. Regression analysis was also used to determine which of the factors amongst the maternal characteristics, onset of labor and cervical length provided significant prediction of Cesarean section.

RESULTS

We examined 2316 pregnancies but we excluded from further analysis 452 (19.5%) cases because iatrogenic delivery was carried out within the subsequent 6 days, including 427 cases of induction of labor (340 at the request of the mother and 87 for medical indications) and 25 cases of Cesarean section. In the remaining 1864 cases there was spontaneous onset of labor and delivery within 10 days in 1536 (82.4%) and induction of labor in 7-10 days in 328 (17.6%). The rate of Cesarean section was 15.2% (233 of 1536) in those with spontaneous onset of labor and 36.0% (118 of 328) in those whose labor was induced. Regression analysis demonstrated that in the prediction of induction of labor there were significant contributions from cervical length, BMI, parity and gestational age, and in the prediction of Cesarean section there were significant contributions from onset of labor, cervical length, BMI, parity and ethnicity.

CONCLUSION

Ultrasonographic measurement of cervical length at 41 weeks together with maternal factors can define the patient-specific probability of spontaneous onset of labor in the subsequent week and the risk of Cesarean section.

Ultrasound assessment of cervical length in prolonged pregnancy: prediction of spontaneous onset of labor and successful vaginal delivery

OBJECTIVES

To evaluate the usefulness of sonographic assessment of cervical length in the prediction of spontaneous onset of labor and of vaginal delivery.

METHODS

Two hundred and six women who attended a dedicated postdates clinic at 41 + 3 weeks of pregnancy and agreed to the assessment of cervical length using transvaginal ultrasound imaging were included in the study. Those who had not delivered at 42 weeks were offered induction of labor. The labor details were recorded prospectively, and the onset of spontaneous labor and mode of delivery were correlated with cervical length data.

RESULTS

Women who underwent spontaneous onset of labor (n = 112) had a significantly shorter cervical length (mean (SD) 25.0 (8.3) mm) than had women whose labor was induced (n = 67; mean (SD) 29.7 (8.5) mm). Logistic regression analysis showed that cervical length was an independent predictor of the likelihood of spontaneous labor in nulliparous women, and of vaginal delivery in both nulliparous and parous women. Parity had no independent effect on the onset of spontaneous labor, but was an independent predictor of the likelihood of vaginal delivery.

CONCLUSIONS

Sonographic assessment of cervical length is a significant independent predictor of the likelihood of the onset of spontaneous labor in nulliparous women, and of successful vaginal delivery in both nulliparous and parous women with prolonged pregnancy.

Cervical length and the risk of spontaneous labor at term

OBJECTIVE

To investigate the relationship between cervical length (CL) at 37 to 40 weeks and delivery within 7 days and delivery by 41 weeks.

STUDY DESIGN

We performed transvaginal ultrasound to measure CL in women with singleton gestations at 37 to 40 weeks. We then used a receiver operating characteristic curve (ROC) to assess the relationship between CL and delivery within 7 days and delivery by 41 weeks.

RESULT

For the 120 women included in the analysis, the mean CL (+/-s.d.) was 25.3+/-9.8 mm. The logistic regression model to predict each of the outcomes includes gestational age at ultrasound (GA-US) and CL. Neither birthweight, nor parity seems to affect the probability of delivery within 7 days. The ROC curve was used to assess the probability of spontaneous labor within 7 days at each CL measurement. The likelihood ratio of delivery within 7 days when CL is < or = 10 mm is 12.

CONCLUSION

CL measurement at 37-40 weeks is an independent predictor of delivery within 7 days and delivery by 41 weeks regardless of GA-US. This information can be utilized when counseling patients regarding the management of term pregnancies.

Prediction of prolonged pregnancy in nulliparous women by transvaginal ultrasonographic measurement of cervical length at 20-24 weeks and 37 weeks

This study was done to evaluate transvaginal ultrasonographic measurement of cervical length at 20 to 24 weeks and 37 weeks as a predictor of prolonged pregnancy (defined as a pregnancy that extended beyond 41+2 weeks of gestation [289 days]) in nulliparous women. This prospective observational study enrolled 149 consecutive nulliparous women with singleton gestation at 37 weeks. Cervical length was measured by transvaginal ultrasonography at 20 to 24 weeks and 37 weeks. Cervical length at 37 weeks, but not at 20 to 24 weeks, was significantly longer in women delivered at >41+2 weeks than in those delivered at <or=41+2 weeks (p<0.005). There was a significant correlation between cervical length at 37 weeks and gestational age at delivery (Pearson correlation coefficient, r=0.387, p<0.0001). In the receiver operating curve, the best cut-off value of cervical length at 37 weeks for the prediction of prolonged pregnancy was 30 mm, with a sensitivity of 78% and a specificity of 62%. Cervical length assessed by transvaginal ultrasonography at 37 weeks can predict the likelihood of prolonged pregnancy in nulliparous women. However, there is no association between cervical length at 20 to 24 weeks and the occurrence of prolonged pregnancy.

Bishop score and ultrasound assessment of the cervix for prediction of time to onset of labor and time to delivery in prolonged pregnancy

OBJECTIVES

To determine the ability of Bishop score and sonographic cervical length to predict time to spontaneous onset of labor and time to delivery in prolonged pregnancy.

METHODS

Ninety-seven women underwent transvaginal ultrasound examination and palpation of the cervix at 291-296 days' gestation according to ultrasound fetometry at 12-20 weeks' gestation. Sonographic cervical length and Bishop score were recorded. Multivariate logistic regression analysis was used to determine which variables were independent predictors of the onset of labor/delivery < or = 24 h, < or = 48 h, and < or = 96 h. Receiver-operating characteristics (ROC) curves were drawn to assess diagnostic performance.

RESULTS

In nulliparous women (n = 45), both Bishop score and sonographic cervical length predicted the onset of labor/delivery < or = 24 h and < or = 48 h (area under ROC curve for the onset of labor < or = 24 h 0.79 vs. 0.80, P = 0.94; for delivery < or = 24 h 0.81 vs. 0.85, P = 0.64; for the onset of labor < or = 48 h 0.73 vs. 0.74, P = 0.90; for delivery < or = 48 h 0.77 vs. 0.71, P = 0.50). Only Bishop score discriminated between nulliparous women who went into labor/delivered < or = 96 h or > 96 h. A logistic regression model including Bishop score and cervical length was superior to Bishop score alone in predicting delivery < or = 24 h (area under ROC curve 0.93 vs. 0.81, P = 0.03) and superior to Bishop score alone and cervical length alone in predicting the onset of labor < or = 24 h (area under ROC curve 0.90 vs. 0.79, P = 0.06; and 0.90 vs. 0.80, P = 0.06). In parous women (n = 52), Bishop score and sonographic cervical length predicted the onset of labor/delivery < or = 24 h (area under ROC curve for the onset of labor 0.75 vs. 0.69, P = 0.49; for delivery 0.74 vs. 0.70, P = 0.62), but only Bishop score discriminated between women who went into labor/delivered < or = 48 h and > 48 h. Three parous women had not gone into labor and six had not given birth at 96 h. In parous women logistic regression models including both Bishop score and cervical length did not substantially improve prediction of the time to onset of labor/delivery.

CONCLUSIONS

In prolonged pregnancy Bishop score and sonographic cervical length have a similar ability to predict the time to the onset of labor and delivery. In nulliparous women the use of logistic regression models including Bishop score and cervical length is likely to offer better prediction of the onset of labor/delivery < or = 24 h than the use of the Bishop score alone.

Three-dimensional ultrasound assessment of the cervix for predicting time to spontaneous onset of labor and time to delivery in prolonged pregnancy

OBJECTIVES

To determine whether three-dimensional (3D) ultrasound including power Doppler examination of the cervix is useful for predicting time to spontaneous onset of labor or time to delivery in prolonged pregnancy.

METHODS

A prospective study was conducted in 60 women who went into spontaneous labor. All underwent transvaginal 3D power Doppler ultrasound examination of the cervix immediately before a prolonged-pregnancy check-up at > or = 41 + 5 gestational weeks. Univariate and multivariate logistic regression analysis was used to determine which of the following variables predicted spontaneous onset of labor > 24 h and > 48 h and vaginal delivery > 48 h and > 60 h: length, anteroposterior (AP) diameter and width of the cervix and of any cervical funneling; cervical volume (cm3); vascularization index (VI); flow index (FI); vascularization flow index (VFI); parity; and Bishop score. Multivariate logistic regression analysis was carried out both with and without Bishop score as a predictive variable. Receiver-operating characteristics (ROC) curves were used to describe the diagnostic performance of the tests.

RESULTS

The areas under the ROC curves for Bishop score, cervical length, and logistic regression models did not differ significantly (areas ranging from 0.72 to 0.82). If Bishop score was not included in the logistic regression model, cervical length, VI and FI independently predicted delivery > 48 h, the likelihood increasing with increasing cervical length, decreasing VI and increasing FI.

CONCLUSIONS

In prolonged pregnancy cervical vascularization as estimated by 3D power Doppler ultrasound is related to time to delivery > 48 h, but the likelihood of delivery > 48 h can be predicted equally well using Bishop score alone or sonographic cervical length alone.