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At least 19 recordsLinked to original sources
PubMed1991

A comparative study of X-ray pelvimetry and CT pelvimetry.

In this study 24 patients who had conventional erect lateral X-ray pelvimetry had a CT pelvimetry done after delivery to complete the pelvimetry views. The erect lateral pelvimetry was read independently by a Consultant Radiologist, Consultant Obstetrician and a Medical Officer training in Obstetrics and Gynaecology. Using CT pelvimetry as the 'gold standard' (as the error of measurement was known with the machine used) the 3 readings were compared. There was no statistical difference in the values suggesting that X-ray pelvimetry is comparable to CT pelvimetry. However CT pelvimetry is preferred, if available, because of the lower dose of radiation involved, more comfort for the patient and shorter time in performing the procedure. Measurements done are easily read directly from the CT console.

Adolescent↗
PubMed1993

Computed tomography pelvimetry: accuracy and radiation dose compared with conventional pelvimetry.

Several publications in the past few years have indicated that computed tomography (CT) pelvimetry is preferable to conventional pelvimetry when considering accuracy and radiation dose. Many of the previous publications have, however, compared state of the art CT pelvimetry with outmoded conventional pelvimetry techniques. This study compared both the accuracy and the radiation dose of CT pelvimetry with conventional pelvimetry as practised in two large teaching obstetric hospitals in Melbourne. The study did not demonstrate any significant difference in the accuracy between the two methods. The radiation dose to the fetal gonads was also similar. The radiation dose using CT pelvimetry could be significantly lowered if the axial CT section through the ischial spines were excluded from the CT technique.

Female↗
PubMed1980

Radiologic low-dose pelvimetry. Indications and pelvimetry data.

In large patient populations from Karolinska Sjukhuset, radiologic pelvimetry data including mean values and correlation of the pelvic diameters have been defined. Overall incidence of contraction and borderline pelvic measurements and the efficacy of selecting by palpation the patients with a narrow pelvis have been evaluated. The indications for pelvimetry were related to an earlier period. By re-evaluation of the clinical application of pelvimetry a modified routine low-dose pelvimetry is proposed. From measurement of the transverse outlet diameters on an orthodiagraphic a.p. film the sum of the outlet diameters is estimated and a supplementary lateral film is exposed in selected cases. Employing pelvimetry in all primigravidae by the orthodiagraphic a.p. film would still result in a lower total population dose than does the presently used routine of complete pelvimetry, consisting of the same a.p. and lateral films, in selected cases.

Female↗
PubMed1980

An evaluation of the usefulness of x-ray pelvimetry: comparison of the Thoms and modified Ball methods with manual pelvimetry.

One hundred studies by x-ray pelvimetry of cephalic presentations were retrospectively analyzed. The Thoms method of interpretation was compared to the modified Ball technique, and both were then contrasted with manual assessment of the pelvis, as prognostic indicators for safe vaginal delivery. Uneventful nonoperative vaginal deliveries occurred in 28.6% of patients with either inlet or midpelvic disproportion by the Thoms method, and in 22.5% of women with absolute disproportion in either plane by the modified Ball method. Neither of the two pelvimetric techniques was significantly more accurate than manual assessment of the pelvis in predicting obstetric outcome. The modified Ball technique offered no improvement over the Thoms method. In view of the high rate of false positives in this series, and the potential oncogenic risk of fetal irradiation, argument is presented for a full trial of labor in vertex presentations, except in the most clinically obvious cases of cephalopelvic disproportion (CPD). The data from this study suggest that there is no significant role for x-ray pelvimetry in the diagnosis and management of CPD in cephalic presentations.

Adolescent↗
PubMed1997

X-ray pelvimetry--which is the best technique?

AIM: To provide definitive data on the radiation doses given to both mother and fetus using different pelvimetry techniques at a number of centres. This data was combined with an assessment of image quality, to determine the optimum technique. PATIENTS AND METHODS: Multiple thermoluminescent dosimeters (TLDs) were used to measure patient and fetal doses inside an anthropomorphic phantom of a pregnant women at full term. Measurements were made at twenty hospitals that routinely perform pelvimetry using techniques including computed tomography (CT), conventional radiography, conventional radiography using an air-gap technique, and digital fluorography. To assess image quality the images obtained by the different techniques were reviewed by a panel of two radiologists and a senior radiographer. RESULTS: A wide range of absorbed doses and relative risks to mother and fetus was observed. The largest and smallest doses encountered in the study differed by a factor of approximately forty. CT pelvimetry was seen to give an average of 25% of the dose of conventional pelvimetry, and at some centres dose savings of over 90% would be possible by performing lateral CT scanograms in preference to plain film pelvimetry. However, a surprisingly wide variation in doses was observed between centres performing CT pelvimetry, and in some cases the potential dose saving would be small. An air-gap technique practised by one of the centres in the survey was found to give absorbed doses and relative risks comparable to average CT scanograms. A digital fluorography technique also gave a very low dose at one centre. However, a similar technique performed at another of the centres conferred little benefit over conventional pelvimetry. There was no observable correlation between the dose administered to the patient and image quality for any of the techniques, and CT and conventional pelvimetry both gave similar image quality. CONCLUSION: While CT deserves its reputation as a low dose technique for pelvimetry, in some cases there may be little dose saving over conventional techniques. The total mAs from the CT examination should be kept as low as possible. Low absorbed doses with good image quality may also be achieved without specialized equipment using an air gap technique. This method is highly recommended as an alternative to CT, for example if no CT scanner is available.

Female↗
PubMed2002

Postpartum X-ray pelvimetry. Its use in calculating the fetal-pelvic index and predicting fetal-pelvic disproportion.

OBJECTIVE: To determine whether postpartum x-ray pelvimetry can be used to calculate the fetal-pelvic index (FPI) in future pregnancies. STUDY DESIGN: In stage I of the study, 10 gravid women, after 36 completed weeks' gestation, underwent x-ray pelvimetry before delivery. Pelvimetry was repeated within two days after delivery. Comparisons between antepartum and postpartum measurements were made using paired t tests and correlation coefficients. In stage II, 25 gravid women, after 36 completed weeks' gestation, underwent fetal ultrasound for biometry. X-ray pelvimetry was performed within two days after delivery. FPI was calculated for each pregnancy using antepartum fetal ultrasound and postpartum pelvimetry measurements. FPI calculations were correlated with the incidence of fetal-pelvic disproportion (FPD), as indicated by the requirement for cesarean section for arrest of active labor. Sensitivity, specificity and predictive value of FPI were assessed. RESULTS: In stage I, mean anteroposterior and transverse diameters of the pelvic inlet, midpelvis and pelvic outlet did not differ significantly. In stage II, the sensitivity of FPI for detecting FPD was 100%, specificity 95%, positive predictive value 80%, and negative predictive value 100%. CONCLUSION: Postpartum pelvimetry has the same association with FPD as antepartum pelvimetry. The strategy of using postpartum pelvimetry and antepartum fetal biometry to calculate FPI successfully identified 100% of the patients who ultimately required cesarean section for FPD, with a false positive rate of 5%. Pelvimetry performed postpartum in an index pregnancy may be used in future pregnancies, in combination with antepartum fetal ultrasound, to calculate FPI and predict the likelihood of FPD.

Adult↗
PubMed1990

Pelvimetry by magnetic resonance imaging in breech presentation.

Evaluation of the pelvis by pelvimetry plays an important role in selecting patients with term breech presentation for possible vaginal delivery. X-ray pelvimetry involves the disadvantage of fetal exposure to ionizing radiation. Computed tomography reduces the amount of radiation markedly, but there is still a risk. Ten patients with breech presentation at term underwent antepartum pelvimetry with magnetic resonance imaging, following by postpartum magnetic resonance pelvimetry and x-ray pelvimetry. Measurements with magnetic resonance imaging are as reliable as those obtained with x-ray pelvimetry and the contrast of the magnetic resonance images is even better. The advantages of magnetic resonance pelvimetry are clear: no ionizing radiation and reliable pelvimetry results in cases of term breech presentation in which a normal pelvis is a prerequisite for safe vaginal delivery.

Breech Presentation↗
PubMedDate not supplied

Randomised controlled trial of magnetic-resonance pelvimetry in breech presentation at term.

BACKGROUND: Pelvimetry is widely used in women with breech presentation at term to select those for whom planned vaginal delivery is appropriate. However, its clinical value has never been established. We evaluated pelvimetry in a randomised controlled trial. The main outcome measures were the elective and emergency caesarean-section rates and the early condition of the neonate. METHODS: Magnetic-resonance (MR) pelvimetry was done on 235 women. The women were then randomly assigned to two groups--for the study group (n = 118), the pelvimetry results were reported to the responsible obstetricians, who used them as the basis for decisions on whether to schedule elective caesarean or trial of labour; for the control group (n = 117), the pelvimetry results were not disclosed until 8 weeks post partum, and decisions about obstetric management were made on the basis of clinical factors only. FINDINGS: 35 women (15 [13%] study group, 20 [17%] control group) had abnormalities on pelvimetry. The overall caesarean-section rates did not differ significantly between the study and control groups (50 [42%] vs 59 [50%], p = 0.24) but the emergency caesarean-section rate was significantly lower in the study group than in the control group (22 [19%] vs 41 [35%], p = 0.0052). The mean 1 min Apgar scores in the study and control groups were 8.1 and 8.0 (p = 0.93) and the mean 3 min scores 9.5 and 9.4, respectively (p = 0.28). There were no significant differences in the early neonatal outcome for infants born vaginally, by emergency caesarean section, or by elective caesarean section in the two groups, except for a significantly lower Apgar score in the six infants born vaginally to control-group women who had pelvic abnormalities. INTERPRETATION: The use of MR pelvimetry in breech presentation at term did not significantly reduce the overall caesarean-section rate. However, it allowed better selection of the delivery route, with a significantly lower emergency caesarean-section rate. Neonatal outcome was not compromised by use of the pelvimetry data.

Apgar Score↗
PubMed1984

Radiographic pelvimetry--its use and possible radiation risk.

Radiographic pelvimetry is widely used in obstetrics. Every fourth primapara in Sweden is submitted to this radiographic examination. The frequency of the examination in the United States is estimated to a mean of 6% of all deliveries. The use of radiographic pelvimetry is now under intense debate and the missing argument in this discussion is a prospective study of an unselected group of parturients where progress and outcome of labour is referred to known pelvic dimension. Since the value of the method is questioned the frequent use of radiographic pelvimetry is justified only by an almost negligible radiation risk to the mother and her baby. Such a low risk is also an indispensable condition to allow the correct scientific evaluation of radiographic pelvimetry mentioned above. This paper presents the measurement results of absorbed radiation dose with the only radiographic pelvimetry method used in Sweden. The estimated radiation risk of the method, based on these figures, is 1 case of childhood malignancy in 50 000 pelvimetries. This corresponds to 4 years routine use of radiographic pelvimetry in Sweden. The annual incidence of childhood malignancy in Sweden is 220. The maternal risk is estimated to one tenth of the fetal risk.

Female↗
PubMedDate not supplied

An appraisal of computed tomography pelvimetry in patients with previous caesarean section.

This study was conducted to determine the value of computed tomography (CT) pelvimetry in patients with previous caesarean section. Of 219 pregnant women with one previous caesarean section, 100 had antenatal CT pelvimetry and a control group of 119 women had no CT pelvimetry. In the CT pelvimetry group, 51.0% delivered by caesarean section, 28.0% underwent elective caesarean section for contracted pelvis based on the findings of CT pelvimetry and 23% underwent emergency caesarean section after a trial labour. In the control group, 21.8% underwent emergency caesarean section. The differences in birth weight and Apgar scores between the groups were not statistically significant. CT pelvimetry increased the rate of caesarean delivery, suggesting that CT pelvimetry before a vaginal birth after a previous caesarean delivery is of limited value.

Adult↗
PubMed1990

Vaginal breech delivery: a five-year prospective evaluation of a protocol using computed tomographic pelvimetry.

In 1983 a protocol was established at our institution that used computed tomographic pelvimetry to evaluate patients presenting with a singleton term frank breech fetus for an attempt at vaginal delivery. The criteria for a trial of labor were singleton fetus, term gestation (37 to 42 weeks' gestation from the first day of the last menstrual period), frank breech presentation, estimated fetal weight 2000 to 4000 gm, non-extended fetal head, and adequate computed tomographic pelvimetry. Two digital radiographs and a tomographic cross-section were taken of each patient, i.e., an anteroposterior view, a lateral view, and an axial section through the femoral head at the level of the fovea capitalis. Adequate pelvimetry was defined as: anteroposterior diameter of the inlet greater than or equal to 10.0 cm, transverse diameter of the inlet greater than or equal to 11.5 cm, transverse (interspinous) diameter of the midpelvis greater than or equal to 9.5 cm, and posterior sagittal diameter of the midpelvis greater than or equal to 4.0 cm. The purpose of this prospective analysis was to determine the obstetric and perinatal outcome of those breech fetuses that were evaluated with these criteria during the study period of January 1984 through July 1989. During this period the incidence of breech deliveries at our institution was 2.71% (394/14,542). Of these 394 breech deliveries, 122 patients underwent computed tomographic pelvimetry. Eighty-five patients had adequate pelvimetry, fulfilling the protocol criteria, and formed the study group. Eighty-one percent (69/85) of the study group had successful vaginal deliveries (group 1). Nineteen percent (16/85) required cesarean delivery after a trial of labor (group 2) (10 with fetal distress and six with arrested labor disorders). Of the 37 patients who had inadequate computed tomographic pelvimetry and underwent cesarean delivery without a trial of labor (group 3), 54% (20/37) had an extended fetal head, 21.6% (8/37) had an inadequate transverse diameter of the inlet, 13.5% (5/37) had an inadequate midpelvic posterior sagittal measurement, and 10.8% (4/37) had an inadequate interspinous diameter. Perinatal outcome including Apgar scores, cord gases, length of hospital stay, neonatal complications, was evaluated. No difference in infant complications was noted between the group delivered vaginally and the groups delivered abdominally. The only maternal complications in our study group were chorioamnionitis, endomyometritis, and postpartum anemia. There were no significant differences in the incidence of chorioamnionitis among the three groups of patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1998

Trends in the use of pelvimetry techniques.

Assessment of maternal pelvic dimensions is usually considered necessary where vaginal delivery is contemplated in a breech presentation or if reduced pelvic dimensions are suspected in a current or previous pregnancy. Pelvimetry techniques include computed tomography (CT), conventional radiography, digital fluorography and magnetic resonance imaging (MRI). The first three techniques result in a radiation dose to mother and fetus which, depending on how the technique is performed, can vary by up to 40-fold. Of the techniques using X-rays, CT pelvimetry with a lateral scanogram generally gives the lowest radiation dose and conventional radiography using an air gap technique with a single lateral view is a relatively low-dose alternative where CT is not available. A questionnaire was sent to 227 hospitals during 1993 and 1996 to assess whether there was a move towards lower dose techniques of pelvimetry. The results show a trend away from conventional pelvimetry (48.4% in 1993 to 28% in 1996) with a small proportion of centres using MRI (4%) in 1996. Of the centres still using conventional pelvimetry, relatively few were using a low-dose air-gap technique (2.1% in 1993 to 10.9% in 1996). An increasing majority of centres were using one-view CT (69.3% in 1993 and 80.4% in 1996) but a significant proportion were still performing more than one view. This study shows that there was a move towards lower dose techniques of pelvimetry but that there were still many hospitals that had not implemented a policy of reducing radiation exposure in these patients.

Female↗
PubMed1994

[Pelvimetry in Norwegian maternity departments].

A questionnaire was sent to 39 maternity departments in Norway. We asked about indications for and use of pelvimetry in the department. 36 departments returned the filled in questionnaire. This paper presents the results of the survey together with a brief discussion of possible harmful effects of pelvimetry. The results show that in Norway every pregnant woman has access to pelvimetry, but there is wide variation as regards the indications and which limits to use. Many obstetricians doubt the value of pelvimetry, especially in vertex presentation. Some are still concerned about the possible harmful effect of ionising radiography. All maternity departments should critically discuss their use of pelvimetry. In the future other methods should replace pelvimetry so that mother and foetus will no longer be exposed to ionising radiography.

Female↗
PubMed1998

A study of the use of radiological pelvimetry in a Chinese population.

BACKGROUND: To audit the use of radiological pelvimetry in a teaching obstetric unit in a Chinese population. METHODS: A prospective observational study included all radiological pelvimetries performed in one obstetric unit over 8 months. All pelvimetries were assessed by one of the authors, and the outcome of pregnancy was reviewed. RESULTS: Among 5576 women delivered in that period, 298 (5.3%) had a pelvimetry. The anteroposterior diameter of the outlet (APO) was on average 9.3 mm smaller than the obstetric conjugate (OC), and was below the definition of pelvic contraction in more than 70% of cases. Previous Cesarean sections accounted for 90.9% of the antenatal radiological pelvimetries. The result of this investigation affected the clinical management in more than 80% of these patients. The chance of successful vaginal delivery was directly related to the pelvic dimensions. CONCLUSIONS: Radiological pelvimetry may provide additional information which could facilitate the counseling of patients with a history of previous Cesarean section.

Asian People↗
PubMed2001

Pelvimetry: changing trends and attitudes.

Review of the literature regarding pelvimetry shows conflicting views as to its value. This study shows the decline in the use of pelvimetry in a teaching hospital obstetric unit over two time periods (1993 and 199798) and the change of views of the clinicians working in this unit. The number of pelvimetries performed fell from 56 per 1000 births to 4 per 1000 over this period. Most pelvimetries in 1993 (55.3%) were performed postpartum following caesarean section. However, in 199798, the majority (over 75%) were performed antepartum in breech presentation. The trend towards a more reluctant use of pelvimetry was mirrored by changes in clinicians' views. Recent publications and RCOG guidelines have effected a dramatic change in the use of pelvimetry over the last decade, largely restricting its use to a small selected group of patients.

Journal Article↗
PubMed2000

Pelvimetry for fetal cephalic presentations at term.

BACKGROUND: Pelvimetry assesses the size of a woman's pelvis by clinical examination, or by conventional X-rays, computerised tomography scanning, or magnetic resonance imaging. OBJECTIVES: The objective of this review was to assess the effects of pelvimetry (performed antenatally, intrapartum or postpartum) on the method of delivery, and on perinatal mortality and morbidity, and on maternal morbidity. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched. SELECTION CRITERIA: Acceptably randomised comparisons of the use of pelvimetry in cephalic presentations. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted by one author. MAIN RESULTS: Four trials of over 1000 women were included. The trials were generally not of good quality. Women undergoing pelvimetry were more likely to be delivered by caesarean section (odds ratio 2.17, 95% confidence interval 1.63 to 2.88). No significant impact was detected on perinatal outcome. REVIEWER'S CONCLUSIONS: There is not enough evidence to support the use of X-ray pelvimetry in women whose fetuses have a cephalic presentation.

Cesarean Section↗
PubMed1997

Low-field MRI pelvimetry.

The purpose of this study was to evaluate the usefulness of low-field MRI pelvimetry and to correlate the results with X-ray pelvimetry. A total of 19 women underwent low-field MRI pelvimetry. Mediosagittal and transverse planes were used to measure the diameters of the minor pelvic cavity. Correlations between MRI and X-ray pelvimetry were 0.96 for the sagittal inlet, 0.94 for the sagittal outlet, 0.93 for the transverse diameter (diameter transversa, DT) and 0.94 for the bispinous distance (interspinous distance, IS). The repeatability of the measurements was good. For fetuses with cephalic presentation it was also possible to determine the biparietal diameter (BPD). Low-field MRI pelvimetry was well accepted by the patients. The scanning time was less than 6 min, which is comparable with the time of X-ray examination with two planes. Magnetic resonance imaging provides a reliable method to image pelvic structures and soft tissue without ionizing radiation.

Adult↗