Prenatal predictors of cesarean section due to labor arrest

Predictors of emergency cesarean section in women with preexisting diabetes

OBJECTIVE

Preexisting diabetes in pregnancy is associated with a high risk of emergency cesarean section (CS), which is associated with increased risk of maternal and neonatal complications. Thus, the aim of this study was to identify possible predictors of emergency CS in women with preexisting diabetes.

STUDY DESIGN

This is a secondary analysis of a prospective observational study of 204 women with preexisting diabetes (118 with type 1 diabetes and 86 with type 2) with singleton pregnancies recruited at Rigshospitalet, Copenhagen, Denmark from August 2015 to February 2018. Mode of delivery (trial of labor or planned CS) was individually planned in late pregnancy based on clinical variables reflecting maternal and fetal health including glycemic control and ultrasonically estimated fetal weight. Univariate and multivariable analyses were performed to identify possible predictors of in labor emergency CS.

RESULTS

Trial of labor was planned in 79 % (n = 162) of the women of whom 65 % (n = 105) were delivered vaginally and 35 % (n = 57) by an emergency CS, while the remaining 21 % (n = 42) were offered a planned CS. Nulliparity (adjusted odds ratio (aOR) 5.6 95 % CI 1.7-18.8), presence of a hypertensive disorder (aOR 2.8, 95 % CI 1.2-6.7) and previous CS (aOR 6.7, 95 % CI 1.5-28.9) were independently associated with an emergency CS. Maternal height was inversely associated with emergency CS (aOR 0.6 95 %, CI 0.5-0.9 per 5 cm decrease). Neither maternal HbA1c nor ultrasonically estimated fetal size in late pregnancy were associated with emergency CS. Women scheduled for a planned CS were characterized by poorer glycemic control and higher estimated fetal size than those offered a trial of labor.

CONCLUSION

Nulliparity, presence of a hypertensive disorder, previous CS and shorter maternal height were predictors of emergency CS in women with a planned trial of labor, whereas this not was the case for late pregnancy maternal Hba1c or fetal size estimated by ultrasound.

Echogenicity of puborectalis muscle, cervix and vastus lateralis muscle in pregnancy in relation to mode of delivery

OBJECTIVES

To confirm our previous observation that levator hiatal dimensions and mean echogenicity of the puborectalis muscle (MEP) are significantly different at 12 weeks' gestation in women who delivered by Cesarean section due to failure to progress compared with those who delivered vaginally. The secondary objective was to assess the association between the echogenicity of the cervix and vastus lateralis muscle and mode of delivery.

METHODS

In this prospective multicenter study, 306 nulliparous women with a singleton pregnancy underwent ultrasound assessments of the pelvic floor at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver, of the cervix and of the vastus lateralis muscle at 12 weeks' gestation. Dimensions of the levator hiatus, MEP and mean echogenicity of the cervix and vastus lateralis muscle were measured and compared according to mode of delivery.

RESULTS

Two hundred and forty-nine women were included in the analyses. We were unable to confirm our previous finding that MEP and levator hiatal transverse diameter and area at 12 weeks' gestation are associated significantly with mode of delivery. In addition, we could not demonstrate a significant association between echogenicity of the cervix or vastus lateralis muscle and mode of delivery. Overall, MEP was a mean of 20 points lower in women in the new database as compared with the previous study, despite the use of the same ultrasound equipment.

CONCLUSION

In a second, independent multicenter dataset, we were unable to confirm our previous finding that levator hiatal dimensions and MEP on pelvic floor muscle contraction are associated significantly with mode of delivery. We also found no association between echogenicity of the cervix or vastus lateralis and mode of delivery. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Maternal height and risk of caesarean section in singleton births in Sweden-A population-based study using data from the Swedish Pregnancy Register 2011 to 2016

Caesarean section (CS) has short and long term adverse health consequences, and should therefore only be undertaken when necessary. Risk factors such as maternal age, maternal body mass index (BMI) and fetal weight have been extensively investigated in relation to CS, but the significance of maternal height has been less explored in Sweden. The aim was to investigate the significance of maternal height on risk of CS in a representative, population-based sample from Sweden, also taking into account confounders. Data on singleton births in the Swedish Pregnancy Register 2011 to 2016 were collected, including women with heights of 140 cm and above, constituting a sample of 581,844 women. Data were analysed with epidemiological and biostatistical methods. Mean height was 166.1 cm. Women born outside Sweden were significantly shorter than women born in Sweden (162.8 cm vs. 167.1 cm, p<0.001). There was a decreasing risk of CS with increasing maternal height. This effect remained after adjustment for other risk factors for CS such as maternal age, BMI, gestational age, parity, high birth weight and country of birth. Frequency of CS was higher among women born outside Sweden compared with Swedish-born women (17.3% vs. 16.0%), however, in a multiple regression model country of birth outside Sweden diminished as a risk factor for CS. Maternal height of 178-179 cm was associated with the lowest risk of CS (OR = 0.76, CI95% 0.71-0.81), whereas height below 160 cm explained 7% of CS cases. BMI and maternal age are established factors involved in clinical assessments related to birth, and maternal height should increasingly enjoy a similar status in these considerations. Moreover, when healthcare professionals are counselling pregnant women, taller stature should be more emphasized as a positive indicator for successful vaginal birth to increase pregnant women's confidence in giving birth vaginally, with possible positive impacts for lowering CS rates.

Association between levator hiatal dimensions on ultrasound during first pregnancy and mode of delivery

OBJECTIVES

To determine the association between levator hiatal dimensions, measured using transperineal ultrasound, in women during their first pregnancy and the subsequent mode of delivery, stratified by the indication for intervention.

METHODS

In this prospective observational study, 280 nulliparous women with a singleton pregnancy were invited for transperineal ultrasound examination at 12 and 36 weeks' gestation. Their levator hiatal dimensions were measured at rest, on pelvic floor muscle contraction and on Valsalva maneuver. The subsequent mode of delivery was classified into five categories: spontaneous vaginal delivery, instrumental vaginal delivery owing to fetal distress, instrumental vaginal delivery owing to failure to progress, Cesarean section owing to fetal distress and Cesarean section owing to failure to progress. Levator hiatal dimensions according to mode of delivery were compared by analysis of variance and Tukey's post-hoc test. Since multiple comparison tests were performed, the statistical significance level was corrected using the Bonferroni method.

RESULTS

Of the 252 women included, those who delivered by Cesarean section because of failure to progress had a significantly smaller levator hiatal transverse diameter on pelvic floor contraction at 12 weeks' gestation than did women who had a spontaneous vaginal delivery (Tukey's post-hoc test, P < 0.001). There was also a trend towards a smaller hiatal area on pelvic floor contraction at 12 weeks' gestation in women who delivered by Cesarean section because of failure to progress compared to women who had a spontaneous vaginal delivery (Tukey's post-hoc test, P = 0.005). In women who had an instrumental vaginal delivery because of failure to progress there was a trend towards a smaller levator hiatal anteroposterior diameter on pelvic floor contraction at 36 weeks' gestation compared with women who had a spontaneous vaginal delivery (Tukey's post-hoc test, P = 0.033).

CONCLUSIONS

Smaller levator hiatal dimensions on pelvic floor contraction during first pregnancy are associated with a subsequent instrumental vaginal delivery or a Cesarean section owing to failure to progress.

A clinical prediction model to assess the risk of operative delivery

OBJECTIVE

To predict instrumental vaginal delivery or caesarean section for suspected fetal distress or failure to progress.

DESIGN

Secondary analysis of a randomised trial.

SETTING

Three academic and six non-academic teaching hospitals in the Netherlands.

POPULATION

5667 labouring women with a singleton term pregnancy in cephalic presentation.

METHODS

We developed multinomial prediction models to assess the risk of operative delivery using both antepartum (model 1) and antepartum plus intrapartum characteristics (model 2). The models were validated by bootstrapping techniques and adjusted for overfitting. Predictive performance was assessed by calibration and discrimination (area under the receiver operating characteristic), and easy-to-use nomograms were developed.

MAIN OUTCOME MEASURES

Incidence of instrumental vaginal delivery or caesarean section for fetal distress or failure to progress with respect to a spontaneous vaginal delivery (reference).

RESULTS

  375 (6.6%) and 212 (3.6%) women had an instrumental vaginal delivery or caesarean section due to fetal distress, and 433 (7.6%) and 571 (10.1%) due to failure to progress, respectively. Predictors were age, parity, previous caesarean section, diabetes, gestational age, gender, estimated birthweight (model 1) and induction of labour, oxytocin augmentation, intrapartum fever, prolonged rupture of membranes, meconium stained amniotic fluid, epidural anaesthesia, and use of ST-analysis (model 2). Both models showed excellent calibration and the receiver operating characteristics areas were 0.70-0.78 and 0.73-0.81, respectively.

CONCLUSION

  In Dutch women with a singleton term pregnancy in cephalic presentation, antepartum and intrapartum characteristics can assist in the prediction of the need for an instrumental vaginal delivery or caesarean section for fetal distress or failure to progress.

The relationship of ethnicity, maternal height and shoe size, and method of delivery

In a bid to determine the relationship of ethnicity, maternal height and shoe size as predictors of cephalopelvic disproportion, we conducted a prospective comparative study of primigravidas at term with singleton pregnancies, who had undergone spontaneous labour. A total of 208 primigravidas were studied; 151 (62.9%) achieved vaginal delivery and 57 (37.1%) had emergency caesarean section for failure-to-progress. We found a statistically significant positive correlation between maternal height and vaginal delivery (p = 0.04), but no correlation with maternal shoe size was found (p = 0.24). This study also showed that Caucasian women were significantly more than twice as likely to achieve vaginal delivery compared with Africans (p = 0.02). Maternal height of at least 162.5 cm, has a sensitivity of 74% and a specificity of 43% for predicting vaginal delivery. We concluded that the most predictive anthropometric measurement for vaginal delivery is maternal height.

Transvaginal ultrasonographic cervical measurement in predicting failed labor induction and cesarean delivery for failure to progress in nulliparous women

The aim of this study was to evaluate the value of transvaginal sonographic cervical measurement in predicting failed labor induction and cesarean delivery for failure to progress in nulliparous women. One hundred and sixty-one women scheduled for labor induction underwent transvaginal ultrasonography and digital cervical examinations. Logistic regression demonstrated that cervical length and gestational age at induction, but not the Bishop score, significantly and independently predicted failed labor induction. According to the receiver operating characteristic curves analysis, the best cut-off value of cervical length for predicting failed labor induction was 28 mm, with a sensitivity of 62% and a specificity of 60%. In terms of the likelihood of a cesarean delivery for failure to progress as the outcome variable, logistic regression indicated that maternal height and birth weight, but not cervical length or Bishop score, were significantly and independently associated with an increased risk of cesarean delivery for failure to progress. Transvaginal sonographic measurements of cervical length thus independently predicted failed labor induction in nulliparous women. However, the relatively poor predictive performance of this test undermines its clinical usefulness as a predictor of failed labor induction. Moreover, cervical length appears to have a poor predictive value for the likelihood of a cesarean delivery for failure to progress.

Fetal weight, maternal age and height are poor predictors of the need for caesarean section for arrest of labor

Retrospective data on 228 patients was analyzed in order to develop a predictive model of operative delivery, caesarean section for arrest of labor. The ANOVA, discriminant analysis and the Fisher discriminant function of SPSS were used. Birth weight, maternal age and maternal height were statistically significant risk factors, but only 10.9% of caesarean sections could be predicted with these variables. Seven percent of patients who delivered vaginally were predicted as needing a caesarean section for arrest of labor.

Risk factors for arrest of descent during the second stage of labor

OBJECTIVE

To define obstetrical risk factors for arrest of descent during the second stage of labor and to determine perinatal outcome.

STUDY DESIGN

All singleton, vertex, term deliveries with an unscarred uterus, between the years 1988 and 1999 were included. Univariable and multivariable analysis were performed to investigate independent risk factors associated with arrest of descent during the second stage of labor and the perinatal outcome.

RESULTS

The study included 93266 deliveries, of these 1545 (1.7%) were complicated with arrest of descent during the second stage of labor. Using a multivariable analysis, the following obstetric risk factors were found to be significantly associated with arrest of descent: nulliparity (OR=7.8, 95% CI=6.9-8.7; P<0.001), birth weight >4 kg (OR=2.3, 95% CI=1.9-2.8; P<0.001), epidural analgesia (OR=1.8, 95% CI=1.6-2.0; P<0.001), hydramnios (OR=1.6, 95% CI=1.3-2.0; P<0.001), hypertensive disorders (OR=1.5, 95% CI=1.3-1.8; P<0.001), gestational diabetes A1 and A2 (OR=1.5, 95% CI=1.2-1.8; P<0.001), male gender (OR=1.4, 95% CI=1.2-1.5; P<0.001), premature rupture of membranes (PROM, OR=1.3, 95% CI=1.04-1.6; P=0.021), and induction of labor (OR=1.2, 95% CI=1.02-1.4; P=0.030). Deliveries complicated by arrest of descent resulted in cesarean section in 20.6%, vacuum extraction in 74.0%, and forceps delivery in 5.4%. Newborns delivered after arrest of descent during the second stage of labor had significantly higher rates of low Apgar scores (<7) at 1 and 5 min, as compared to the controls (12.7 vs. 2.1%, P<0.001; and 0.9 vs. 0.2%, P<0.001, respectively). Nevertheless, no significant differences were noted between the groups regarding perinatal mortality (0.38 vs. 0.44%; P=0.759).

CONCLUSIONS

Major risk factors for arrest of descent during the second stage of labor were nulliparity, fetal macrosomia, epidural analgesia, hydramnios, hypertensive disorders and gestational diabetes mellitus. These risk factors should be carefully evaluated during pregnancy in order to actively manage high-risk pregnancies.

Maternal height as a risk factor for Caesarean section due to failure to progress in labour

We examined for a regional sample of the New Zealand population, the relationship between maternal height and an increased risk of emergency Caesarean section due to arrested labour, to identify a height below which the risk of Caesarean section increases markedly and to quantify the risk of a Caesarean section for a range of maternal heights. The data of nulliparous singleton pregnancies over the period 1994-1998 was sorted into 2 study groups, one resulting in emergency Caesarean section for arrested labour and the other a group of women who had normal vaginal delivery requiring no intervention. The means and standard deviations of these 2 groups were found and 99% confidence intervals calculated. They were analysed for statistical difference and then a logistical regression calculation tried to identify a height at which the risk of a Caesarean section increased suddenly. There were 81 women in the Caesarean section group and 997 in the normal vaginal delivery group. Mean heights and confidence intervals were 161.0 cm (158.9-163.1) and 164.6 cm (164.0-165.2) respectively. There was a statistically significant difference between these means (p<0.001) but logistic regression analysis showed that risk of Caesarean section increased gradually with decreasing height, and even then did not reach more than 30% risk until a height of less than 140 cm. Low maternal height was associated with increased risk of Caesarean section due to labour arrest. Because the likelihood of having a normal vaginal delivery was still very good (>80 %) at modest degrees of short stature, this risk factor alone is unlikely to affect management. However the combination of other risk factors with maternal height may be of clinical use.