Risk Of Cephalopelvic Disproportion Research Articles

The Relation between Head Circumference and Mid-Pelvic Circumference: A Simple Index for Cephalopelvic Disproportion Evaluation

Introduction: Cephalopelvic disproportion (CPD) is one of the most common obstetric complications. Since CPD is the disproportion between the fetal head and maternal bony pelvis, evaluation of the head circumference (HC) relative to the maternal bony pelvis may be a useful adjunct to pre-labor CPD evaluation. The aim of the present study was a proof-of-concept evaluation of the ratio between HC and pelvic circumference (PC) as a predictor of CPD. Methods: Of 11,822 deliveries, 104 cases that underwent an abdominopelvic CT for any medical indication and who underwent normal vaginal deliveries (NVDs) (n = 84) or cesarean deliveries (CD) due to CPD (n = 20) were included retrospectively. Maternal pelvis dimensions were reconstructed and neonatal HC, as a proxy for fetal HC, was measured. The correlation between cases of CPD and cephalopelvic circumference index (CPCI), which represents the ratio between the HC and PC in percentage (HC/PC × 100), was evaluated. Results: The mid-pelvis CPCI (MP-CPCI) was larger in CD groups as compared to the NVD group: 103 ± 11 versus 97 ± 8%, respectively (p = 0.0003). In logistic regression analysis, the MP-CPCI was found to be independently associated with CD due to CPD: each 1% increase in MP-CPCI increased the likelihood of CD for CPD by 11% (adjusted odds ratio [aOR] 1.11, 95% CI, 1.03–1.19, p = 0.004). The aOR for CD due to CPD increased incrementally as the MP-CPCI increased, from 3.56 (95% CI, 1.01–12.6) at MP-CPCI of 100 to 5.6 (95% CI, 1.63–19.45) at 105, 21.44 (95% CI, 3.05–150.84) at 110, and 28.88 (95% CI, 2.3–362.27) at MP-CPCI of 115. Conclusions: The MP-CPCI, representing the relative dimensions of the fetal HC and maternal PC, is a simple tool that can potentially distinguish between parturients at lower and higher risk of CPD. Prospective randomized studies are required to evaluate the feasibility of prenatal pelvimetry and MP-CPCI to predict the risk of CPD during labor.

Three-dimensional camera anthropometry to assess risk of cephalopelvic disproportion-related obstructed labour in Ethiopia.

Cephalopelvic disproportion (CPD)-related obstructed labour requires delivery via Caesarean section (C/S); however, in low-resource settings around the world, facilities with C/S capabilities are often far away. This paper reports three low-cost tools to assess the risk of CPD, well before labour, to provide adequate time for referral and planning for delivery. We performed tape measurement- and three-dimensional (3D) camera-based anthropometry, using two 3D cameras (Kinect and Structure) on primigravida, gestational age ≥ 36 weeks, from Addis Ababa, Ethiopia. Novel risk scores were developed and tested to identify models with the highest predicted area under the receiver-operator characteristic curve (AUC), detection rate (true positive rate at a 5% false-positive rate, FPR) and triage rate (true negative rate at a 0% false-negative rate). For tape measure, Kinect and Structure, the detection rates were 53%, 61% and 64% (at 5% FPR), the triage rates were 30%, 56% and 63%, and the AUCs were 0.871, 0.908 and 0.918, respectively. Detection rates were 77%, 80% and 84% at the maximum J-statistic, which corresponded to FPRs of 10%, 15% and 11%, respectively, for tape measure, Kinect and Structure. Thus, tape measurement anthropometry was a very good predictor and Kinect and Structure anthropometry were excellent predictors of CPD risk.

A safe, low-cost, easy-to-use 3D camera platform to assess risk of obstructed labor due to cephalopelvic disproportion.

Cephalopelvic disproportion (CPD)-related obstructed labor is accountable for 3–8% of the maternal deaths worldwide. The consequence of CPD-related obstructive labor in the absence of a Caesarian section (C/S) is often maternal or perinatal mortality or morbidity to the mother and/or the infant. Accurate and timely referral of at-risk mothers to health facilities where C/S is a delivery option could reduce maternal mortality in the developing world. The goal of this work was to develop and test the feasibility of a safe, low-cost, easy-to-use, portable tool, using a Microsoft Kinect 3D camera, to identify women at risk for obstructed labor due to CPD. Magnetic resonance imaging (MRI) scans, 3D camera imaging, anthropometry and clinical pelvimetry were collected and analyzed from women 18–40 years of age, at gestational age ≥36+0 weeks with previous C/S due to CPD (n = 43), previous uncomplicated vaginal deliveries (n = 96), and no previous obstetric history (n = 148) from Addis Ababa, Ethiopia. Novel and published CPD risk scores based on anthropometry, clinical pelvimetry, MRI, and Kinect measurements were compared. Significant differences were observed in most anthropometry, clinical pelvimetry, MRI and Kinect measurements between women delivering via CPD-related C/S versus those delivering vaginally. The area under the receiver-operator curve from novel CPD risk scores base on MRI-, Kinect-, and anthropometric-features outperformed novel CPD risk scores based on clinical pelvimetry and previously published indices for CPD risk calculated from these data; e.g., pelvic inlet area, height, and fetal-pelvic index. This work demonstrates the feasibility of a 3D camera-based platform for assessing CPD risk as a novel, safe, scalable approach to better predict risk of CPD in Ethiopia and warrants the need for further blinded, prospective studies to refine and validate the proposed CPD risk scores, which are required before this method can be applied clinically.

Study on the cephalopelvic relationship with cephalic presentation in nulliparous full-term Chinese pregnant women by MRI with three-dimensional reconstruction.

To analyze the relationship between fetal head size and maternal pelvis size using magnetic resonance imaging (MRI) with a 3-D reconstruction technique. A total of 301 nulliparous full-term Chinese pregnant women with cephalic presentation were enrolled and received MRI examinations before labor onset. Data were collected and imported into Mimics software to reconstruct the maternal pelvis and fetus. Of 301 pregnant women, 212 underwent vaginal delivery and 32 received cesarean section. The body mass index (BMI) was significantly different between the vaginal delivery group and the suspected cephalopelvic disproportion (CPD) group; the larger the BMI, the higher was the risk of CPD. The transverse diameter of the pelvic inlet and the posterior sagittal diameter of the midpelvis were significantly larger in the vaginal delivery group, compared with the suspected CPD group. Fetal weight > 3.5kg could be used as a diagnostic indicator for CPD. BMI is a risk factor for CPD, and fetal weight < 3.5kg is an important diagnostic indicator for natural delivery in Chinese pregnant women.

Three-dimensional magnetic resonance pelvimetry: A new technique for evaluating the female pelvis in pregnancy

ObjectiveTo describe three-dimensional (3D) magnetic resonance imaging (MRI) pelvimetry methods and to establish the pelvimetric reference in a large population of Chinese females at term pregnancy. MethodsThree-hundred one pregnant women at term who underwent MRI were included. Three-dimensional pelvic models were reconstructed using Mimics. 10.0 software based on MRI data sets, and measurements of these models were made. Pelvimetric results according to delivery modality were presented. Additionally, the previously described CT 3D pelvimetry method for predicting cephalopelvic disproportion (CPD) was used to validate its accuracy. ResultsTwo hundred ten women underwent vaginal delivery, and 13 underwent caesarean delivery for CPD. 3D modelling of the pelvis of pregnant women was feasible using MR data sets. Pelvimetric parameters in the vaginal delivery group were as follows: transverse diameter, 134.7 mm ± 7.5; obstetric conjugate, 126.9 mm ± 8.3; interspinous distance, 113.4 mm ± 8.2; sagittal midpelvis, 117.8 mm ± 8.1; intertuberous distance, 127.1 mm ± 10.4; sagittal outlet, 110.2 mm ± 8.9, and posterior sagittal outlet, 59.7 mm ± 8.1. According to the previously described CT 3D pelvimetry method for predicting CPD, 67.6% (142/210) of women in the vaginal delivery group were diagnosed with CPD. Conclusion3D MR pelvimetry is a novel method for determining pelvic dimensions at term pregnancy. A prospective trial is needed to establish a useful value for predicting CPD in Chinese females at high risk of CPD.

Age, Anthropometric Measurements and Mode of Delivery among Primigravidae Women at Addis Ababa Governmental Hospitals, Ethiopia

Background: In developing countries, a significant number of maternal deaths are attributable to the complications of obstructed labor. Identifying women at risk for Cephalopelvic Disproportion (CPD) prepares physicians for on time treatment and enables them to minimize maternal-fetal trauma that accompanies this midwifery emergency. The study aims to identify diagnostic accuracy of maternal age and anthropometric measurements to predict CPD among Primigravidae women visiting Addis Ababa Governmental Hospital. Methods: Hospital based prospective cohort study was carried out at Governmental Hospitals in Addis Ababa. The sample size was 384 mothers. Five hospitals were selected from Addis Ababa governmental hospitals by using simple random sampling (lottery method). Data was entered into EPI data version 3.3 and analyzed using SPSS version 23 statistical package. Results: The current study shows as the most predictive variable is maternal height with Positive Predictive Value percentage of 64.9, sensitivity of 85.4% and specificity of 96.4% followed by Michaelis rhomboid transverse diameter with Positive Predictive Value of 14.8%, sensitivity of 51.3%, and specificity of 89.4%. Conclusions: Age and maternal anthropometric measurements can predict CPD to some extent. Combining some of maternal anthropometric measurements with each other enhances the predictive value to a relatively modest degree. In this study when height is combined with other anthropometric measurements it doesn’t show increment in predictive value.

Short stature as an independent risk factor for cephalopelvic disproportion in a country of relatively small-sized mothers

ObjectiveTo clarify the relationship between maternal height and cesarean rate due to cephalopelvic disproportion (CPD) in singleton pregnancies among ethnic groups of relatively short stature.MethodsA retrospective cohort study was performed on Thai singleton pregnancies at gestational age of more than 34 weeks. Logistic regression analysis was performed to correlate the maternal height and a risk for CPD. The short stature was defined by a cut-off value at 5th percentile ranking. Odds ratio for CPD was determined.ResultsOf 11,026 recruited, 9,198 were available for analysis. Considering cut-off value of 145 cm, short stature was significantly associated with higher rate of CPD with odds ratio of 2.4 (95% CI 1.8–3.0). The odds = exp(4.048 − 0.042 × Ht). After control of other variables, the relationship between maternal height and rate of CPD was still high.ConclusionMothers with short stature were significantly correlated with a higher rate of CPD, even after control of birth weight, parity and type of attendance. Clinical points could be drawn from this study including (1) definition of short statue must be developed for particular geographic or ethnic groups. In Thai population, using 145 cm as a cut-off value, odds of CPD is 2.4; (2) Probability of CPD may be estimated by maternal height as a single variable or multiple variables using logistic regression equations.

A simple clinical formula for predicting fetal weight in labour at term--derivation and validation.

To derive and validate a simple formula for birth weight based on symphysis-fundal height (SFH) measurement during labour, and to determine a useful SFH cut-off value for prediction of birth weight > or = 4000 g. In a derivation study, SFH was measured in women at term in the active phase of labour. A simplified formula for birth weight was derived from a regression equation. The best cut-off SFH measurement was obtained for prediction of birth weight > or = 4000 g. After this, a similar study was done to validate these findings. In the derivation study (N = 504), birth weight was predicted by the equation: birth weight in g = 301 + 78 (SFH in cm). This was transformed to the simplified formula: birth weight in g = 100 ([SFH in cm]-5). Using this formula for the data set, 68.1% of birth weight estimates were correct to within 10% of the birth weight. For prediction of birth weight > or = 4000 g, an SFH measurement of 40 cm had a sensitivity of 82% and a specificity of 80%. In the validation study (N = 294), the derived simplified formula gave 65.0% of estimates correct to within 10% of the birth weight. The predictive values of the 40 cm SFH cut-off were similar to those in the derivation study. The derived simplified formula was validated in the second study. The formula may be useful for intrapartum use in term pregnancies. A cut-off SFH measurement of 40 cm may identify labours at risk for cephalopelvic disproportion or shoulder dystocia.

Sagittal Suture Overlap in Cephalopelvic Disproportion: Blinded and Non-Participant Assessment

Perinatal death and morbidity occur with cephalopelvic disproportion (CPD) as a consequence of the complications of obstructed labor. It is unclear whether overlap of fetal skull bones (molding) is a sign of normal labor, or is associated with and predictive of CPD. CPD is common in sub-Saharan Africans, who are considered to be at greater risk for CPD than Caucasians. A previous prospective study in the 1970s involving African women showed that overlap of skull bones at the sagittal suture and to a lesser degree at the lambdoid suture were associated with CPD and could be predictive. However, these findings were questioned for possible bias because of the absence of investigator blinding. In addition, the study lacked statistical analysis to adjust for confounding. In this prospective blinded cross-sectional study, the authors examined 505 women of at least 37 weeks' gestation in the active phase of labor with singleton live fetuses and vertex presentations, and no history of cesarean delivery. The authors defined CPD as cesarean section for poor progress in labor in the presence of adequate uterine activity; CPD occurred in 113 of the 505 women (22%). The investigators had no prior knowledge of the parity of the index women or previous clinical findings, and did not participate in their obstetric care. Multivariate logistic regression analysis revealed that sagittal suture overlap was independently associated with CPD. Lambdoid suture overlap could be determined in only 66.5% of examinations primarily because of frequent head deflexion, and intrapartum assessment of the Lambdoid suture was not predictive of CPD. The findings were not affected by parity. The authors conclude that overlap at the sagittal suture, although not necessarily diagnostic, is useful for prediction of CPD. Lambdoid suture overlap appears to be a normal intrapartum phenomenon and of little predictive value.

Effect of a clinical practice guideline on physician compliance.

To evaluate the effect of a clinical practice guideline for cesarean section due to dystocia on physician compliance, pregnancy outcome, and cesarean delivery rates, and to identify factors associated with physician non-compliance. A cross-sectional study. A university hospital, Southern Thailand. All 719 medical records of women undergoing a cesarean section due to dystocia (failure to progress; cephalopelvic disproportion) before and after implementation of the guideline, from 1 January 1998 to 31 December 2000. A clinical practice guideline for cesarean section due to dystocia was implemented on 1 June 1999. Physician compliance, pregnancy outcomes, and cesarean section rates. Multivariate logistic regression was used to identify factors associated with physician non-compliance. Independent variables consisted of maternal age, height, parity, type of service, and birthweight. Physician compliance with the guideline was 89.2%. Maternal complications were less in the period after implementation of the guideline. Fetal outcomes were not different between the two periods. The cesarean section rates due to dystocia decreased after implementation of the guideline, from 10.7% in 1999 to 8.6% in 2002. Private practice, maternal short stature, and birthweight > or = 3500 g were significant predictors of physician non-compliance. Physician compliance was high. A clinical practice guideline can reduce the cesarean section rates due to dystocia without increasing adverse outcomes. Physician non-compliance was more common in women with well known risk for cephalopelvic disproportion, and private practice.

Maternal height, birthweight and cephalo pelvic disproportion in urban Nigeria and rural Malawi.

Cephalo pelvic disproportion (CPD) has been attributed to short stature. It has been suggested that nutritional supplementation to promote linear growth would increase birthweight and the risk of CPD. The objective of this study was to examine the factors associated with CPD, with particular reference to birthweight, stature, parity and maternal age. Factors associated with CPD were analyzed using data abstracted from a detailed early hospital report from Ibadan, Nigeria and from a recent rural pregnancy study conducted in the Shire Valley, Malawi. In Nigeria, of 107 CPD cases admitted to hospital in Ibadan during 1953-54, 79% were women > 20 years. Birthweight values increased significantly with age and parity. In 19.6% of cases, the baby had a low birthweight (< 2500 g). In Malawi, among the 1523 women delivering, the incidence of CPD was 2.3%. Of the 35 cases of CPD, only four were adolescents. Birthweights increased with increasing parity, age and height (p < 0.001). In 6.4% of CPD cases, the baby had a low birthweight. Nulliparity (OR 4.0; CI 1.7-9.3; p = 0.0001), birthweight >or= 3400 g (OR 4.6; CI 2.1-10.0; p = 0.0001) and height <or= 154 cm (OR 3.8; CI 1.8-7.9; p = 0.0003) were associated with an increased risk of CPD. Adolescent mothers were less likely to experience CPD (OR 0.3; C.I. 0.8-0.9; p = 0.03). Adolescents are not at high risk of CPD. Nutritional supplementation of girls and adolescents should not be discouraged for fear of increasing the risk of CPD by improving birthweight. When CPD is present, it may result from childhood rickets and calcium deficiency.

Maternal height and external pelvimetry to predict cephalopelvic disproportion in nulliparous African women: a cohort study.

To assess external pelvimetry and maternal height, as predictors of cephalopelvic disproportion. Prospective cohort study. Four hospitals in Zaire. Six hundred and five nulliparous women. Maternal height and external pelvimetry were assessed during the third trimester antenatal visit. Cut off values for considering women at risk for cephalopelvic disproportion were height < 150 cm and external pelvic distances < 10th centile for the population. Logistic regression analysis, combining height and pelvic measurements, was performed to predict women at risk for cephalopelvic disproportion. Cephalopelvic disproportion was considered when there was caesarean section for failure to progress, vacuum or forceps delivery or intrapartum stillbirth. Cephalopelvic disproportion was present in 42 women. In univariate analysis, height, intertrochanteric diameter and the transverse diagonal of Michaelis sacral rhomboid area were found to be associated with cephalopelvic disproportion. Logistic regression analysis showed that maternal height < 150 cm and/or transverse diagonal < 9.5 cm were the variables most associated with cephalopelvic disproportion. The adjusted odds ratios were 2 x 2 (95% CI 0.9 to 5.4) and 6.5 (95% CI 3.2 to 13.2), respectively. The positive predictive value and likelihood ratio were 24% and 4.0 (95% CI 2.8 to 5.8), respectively. The addition of transverse diagonal to maternal height increased the sensitivity in predicting cephalopelvic disproportion from 21% to 52%. In addition to height, transverse diagonal measurement is able to predict one out of two cases of cephalopelvic disproportion in nulliparous women. After validation in a separate cohort, this simple predictive method may be used in peripheral centres for timely referral of pregnant women at risk for cephalopelvic disproportion.

Maternal height and age: risk factors for cephalopelvic disproportion in Zimbabwe.

Maternal age and stature are among several factors used to screen pregnant women for potential risk of labour complications. In a population-based case-control study in Harare, Zimbabwe, multivariate analysis was carried out to evaluate the importance of maternal age and height as risk factors for cephalopelvic disproportion (CPD). Using data abstracted from the medical records of 203 women with operative deliveries due to CPD and 299 women with normal unassisted vaginal deliveries, multiple logistic regression models were developed. Although maternal age < 18 years was not a significant risk factor in this study (perhaps because there were few women in this age group), advanced maternal age (> or = 35 years) was associated with a relative risk of 2.7 compared to women 20-34, after adjusting for other demographic and obstetric factors. Maternal height < 160 cm was associated with a twofold increased risk of CPD as compared to taller women.

Pelvimetry revisited

To describe three-dimensional (3D) magnetic resonance imaging (MRI) pelvimetry methods and to establish the pelvimetric reference in a large population of Chinese females at term pregnancy.Three-hundred one pregnant women at term who underwent MRI were included. Three-dimensional pelvic models were reconstructed using Mimics. 10.0 software based on MRI data sets, and measurements of these models were made. Pelvimetric results according to delivery modality were presented. Additionally, the previously described CT 3D pelvimetry method for predicting cephalopelvic disproportion (CPD) was used to validate its accuracy.Two hundred ten women underwent vaginal delivery, and 13 underwent caesarean delivery for CPD. 3D modelling of the pelvis of pregnant women was feasible using MR data sets. Pelvimetric parameters in the vaginal delivery group were as follows: transverse diameter, 134.7 mm ± 7.5; obstetric conjugate, 126.9 mm ± 8.3; interspinous distance, 113.4 mm ± 8.2; sagittal midpelvis, 117.8 mm ± 8.1; intertuberous distance, 127.1 mm ± 10.4; sagittal outlet, 110.2 mm ± 8.9, and posterior sagittal outlet, 59.7 mm ± 8.1. According to the previously described CT 3D pelvimetry method for predicting CPD, 67.6% (142/210) of women in the vaginal delivery group were diagnosed with CPD.3D MR pelvimetry is a novel method for determining pelvic dimensions at term pregnancy. A prospective trial is needed to establish a useful value for predicting CPD in Chinese females at high risk of CPD.