Asynclitism: a literature review of an often forgotten clinical condition

Asynclitism is defined as the “oblique malpresentation of the fetal head in labor”. Asynclitism is a clinical diagnosis that may be difficult to make; it may be found during vaginal examination. It is significant because it may cause failure of progress operative or cesarean delivery. We reviewed all literature for asynclitism by performing an extensive electronic search of studies from 1959 to 2013. All studies were first reviewed by a single author and discussed with co-authors. The following studies were identified: 8 book chapters, 14 studies on asynclitism alone and 10 papers on both fetal occiput posterior position and asynclitism. The fetal head in a laboring patient may be associated with some degree of asynclitism; this is seen as usual way of the fetal head to adjust to maternal pelvic diameters. However, marked asynclitism is often detected in presence of a co-existing fetal head malposition, especially the transverse and occipital posterior positions. Digital diagnosis of asynclitism is enhanced by intrapartum ultrasound with transabdominal or transperineal approach. The accurate diagnosis of asynclitism, in an objective way, may provide a better assessment of the fetal head position that will help in the correct application of vacuum and forceps, allowing the prevention of unnecessary cesarean deliveries.     

Is intrapartum translabial ultrasound examination painless?

Objectives: To find out whether intrapartum translabial ultrasound examination is painless by comparing pain score of ultrasound-based versus digital vaginal examination of foetal head station.

Methods: In 94 women carrying uncomplicated-term singleton pregnancies, labour progress was assessed by translabial ultrasound, followed immediately by conventional digital vaginal examination. Pain scores (0–10) using visual analogue pain scale were obtained for both examinations. Forty-eight and forty-six sets of data were obtained in first and second stage of labour, respectively. The difference in pain scores between digital vaginal examination and translabial ultrasound was analysed.

Results: The median pain score for translabial ultrasound was 0 (range 0–8), while that for vaginal examination was 4.5 (range 0–10), p?<?0.05. There was no significant difference in pain scores between first and second stages of labour for translabial ultrasound (p?=?0.123) and for vaginal examination (p?=?0.680). The pain score for vaginal examination was higher than that of translabial ultrasound in 81.9%, similar in 13.8% and lower in 4.3% of cases. There was no statistically significant difference in pain scores obtained for digital vaginal examination by clinicians with different experience (p?=?0.941).

Conclusions: Intrapartum translabial ultrasound is generally better tolerated than digital vaginal examination for assessment of labour progress, making it an acceptable adjunctive assessment tool during labour.     

The feasibility and accuracy of ultrasound assessment in the labor room

Objective: Vaginal examination is widely used to assess the progress of labor; however, it is subjective and poorly reproducible. We aim to assess the feasibility and accuracy of transabdominal and transperineal ultrasound compared to vaginal examination in the assessment of labor and its progress.

Methods: Women were recruited as they presented for assessment of labor to a tertiary inner city maternity service. Paired vaginal and ultrasound assessments were performed in 192 women at 24–42 weeks. Fetal head position was assessed by transabdominal ultrasound defined in relation to the occiput position transformed to a 12-hour clock face; fetal head station defined as head-perineum distance by transperineal ultrasound; cervical dilatation by anterior to posterior cervical rim measurement and caput succedaneum by skin-skull distance on transperineal ultrasound.

Results: Fetal head position was recorded in 99.7% (298/299) of US and 51.5% (154/299) on vaginal examination (p?¹). Bland–Altman analysis showed 95% limits of agreement, ?5.31 to 4.84 clock hours. Head station was recorded in 96.3% (308/320) on vaginal examination (VE) and 95.9% (307/320) on US (p?=?.79¹). Head station and head perineum distance were negatively correlated (Spearman’s r?=??.57, p?p?p?p?Conclusions: We describe comprehensive ultrasound assessments in the labor room that could be translated to the assessment of women in labor. Fetal head position is unreliably determined by vaginal examination and agrees poorly with US. Head perineum distance has a moderate correlation with fetal head station in relation to the ischial spines based on vaginal examination. Cervical dilatation is not reliably assessed by ultrasound except at dilatations of less than 4?cm. Caput is readily quantifiable by ultrasound and its presence is associated with lower fetal head station. Transabdominal and transperineal ultrasound is feasible in the labor room with an accuracy that is generally greater than vaginal examinations.     

A longitudinal study investigating cervical changes during labor using a wireless ultrasound device

Purpose: Cervical assessment during digital vaginal examination (DVE) includes assessing cervical dilatation, effacement, position and consistency. Only cervical dilatation during labor has been previously researched. We investigated cervical changes, including cervical dilatation and effacement, using a wireless ultrasound (US) device.

Materials and methods: This was a longitudinal study investigating cervical changes during labor using a wireless US device. Twenty-five women in labor participated in a serial comparison of cervical dilatation, length and thickness measured during intrapartum transperineal sonography using a wireless mobile US device (SONON) with measurements of cervical dilatation and effacement obtained during serial DVEs.

Results: Intrapartum sonography showed strong correlation with DVE in assessing cervical changes during labor including the measurement of cervical dilatation and thickness (p?Conclusions: We developed a new technique for evaluating effacement with cervical thickness. Cervical dilation and thickness using a transperineal intrapartum US demonstrated significant correlation with DVE findings. The use of a wireless US device is convenient and may be advantageous in the labor ward; however, further research is needed to define the role of this wireless device.     

Intrapartum sonography to determine fetal head position

Objective: To investigate the accuracy of intrapartum transvaginal digital examination in defining the position of the fetal head. Patients and methods: In 496 singleton pregnancies in labor at term, the fetal head position was determined by routine transvaginal digital examination by the attending midwife or obstetrician. Immediately before or after the clinical examination, the fetal head position was determined using transabdominal ultrasound by an appropriately trained sonographer who was not aware of the clinical findings. The digital examination was considered to be correct if the fetal head position was within 45° of the ultrasound finding. The accuracy of the digital examination was examined in relation to maternal characteristics and the progress of labor. Results: The position of the fetal head was determined by ultrasound examination in all 496 cases examined. Digital examination failed to define the fetal head position in 166 (33.5%) cases and, in 330 cases where the position was determined, the findings of the digital and sonographic examinations were in agreement in only 163 (49.4%) cases. The rate of correct identification of the fetal position by digital examination increased with cervical dilatation, from 20.5% at 3–4 cm to 44.2% at 8–10 cm, and was higher if the examination was carried out by an obstetrician than a midwife (50% versus 30%) and if there was absence rather than presence of caput (33% versus 25%). Conclusions: Routine digital examination during labor fails to identify the correct fetal position in the majority of cases.     

Transabdominal ultrasound assessment of the fetal head and the accuracy of vacuum cup application.

OBJECTIVE: To investigate whether the accuracy of vacuum cup placement can be improved by intrapartum ultrasound assessment of the fetal head position during the second stage of labor prior to vacuum extraction for prolonged second stage. METHODS: 50 women undergoing vacuum extraction for prolonged second stage were randomly allocated to either digital examination (n=25) or digital examination together with transabdominal intrapartum ultrasound (n=25) prior to vacuum extraction by the attending obstetrician. The distance between the centre of the chignon and the flexion point was then measured by a midwife immediately after delivery. The flexion point was defined as 6 cm posterior to the anterior fontanelle or 3 cm anterior to the posterior fontanelle. RESULTS: There were no statistically significant differences in the demographic data, duration of labor, incidence of induction/augmentation, and intrapartum complications between the two groups. The mean distance between the centre of the chignon and the flexion point was 2.1+/-1.3 cm in the group with digital examination and ultrasound assessment and 2.8+/-1.0 cm in the group with digital examination alone. The difference in the mean distance between the two groups was statistically significant (p=0.039). CONCLUSION: Intrapartum transabdominal ultrasound assessment of the fetal head position during the second stage of labor improves the accuracy of vacuum cup placement during vacuum extraction for prolonged second stage.     

Vaginal versus ultrasound examination of fetal occiput position during the second stage of labor

OBJECTIVE: The purpose of this study was to determine whether ultrasonography is more accurate than vaginal examination in the determination of fetal occiput position in the second stage of labor. STUDY DESIGN: Eighty-eight patients in the second stage of labor were evaluated by vaginal examination and by combined transabdominal and transperineal ultrasound examination to determine occiput position. These predictions of position were compared with the actual delivery position at vaginal delivery after spontaneous restitution or at cesarean delivery. Different examiners performed the vaginal examinations and the ultrasound examinations. Each examiner was blinded to the determination of the other examiner. RESULTS: Vaginal examination determined fetal occiput position correctly 71.6% of the time; ultrasound examination determined fetal occiput position correctly 92.0% of the time (P=.018). CONCLUSION: Ultrasound examination is more accurate than vaginal examination in the diagnosis of fetal occiput position in the second stage of labor.     

Levels of agreement between clinical examination and transabdominal ultrasound evaluation of fetal head position in the second stage of labor

Aim: To compare transvaginal digital examination performed by residents and attending physicians to transabdominal suprapubic ultrasound in the evaluation of fetal head position in the second stage of labor.

Methods: A prospective study was conducted at a tertiary center and included pregnant women at term, with normal singleton cephalic presentation fetuses. All patients had ruptured membranes and were evaluated during the second stage of labor. Fetal head position was assessed consecutively by two clinicians (one resident and one attending physician). Afterwards, transabdominal suprapubic ultrasound was performed by another observer. Examiners were blinded to each other’s findings. Cohen’s kappa test was used to assess the degree of agreement between the evaluation methods.

Results: One-hundred sixty-one women were included. Transvaginal examination was consistent with the ultrasound in 45.0% of cases (95% CI: 37–53%) when the examination was performed by residents (k?=?0.349) and in 67% (95% CI: 60–74%) if the attending physician carried out the evaluation (k?=?0.604). When considering only the anterior positions, the Cohen’s kappa test was 0.426 and 0.709, respectively.

Conclusion: Transabdominal suprapubic ultrasound improved the accuracy of the evaluation of fetal head position, namely when transvaginal digital examination was performed by residents. This may be important especially when instrumental deliveries are considered.     

Fetal head position during the second stage of labor: comparison of digital vaginal examination and transabdominal ultrasonographic examination

OBJECTIVE: To study the correlation between digital vaginal and transabdominal ultrasonographic examination of the fetal head position during the second stage of labor. METHODS: Patients (n = 110) carrying a singleton fetus in a vertex position were included. Every patient had ruptured membranes and a fully dilated cervix. Transvaginal examination was randomly performed either by a senior resident or an attending consultant. Immediately afterwards, transabdominal ultrasonography was performed by the same sonographer (OD). Both examiners were blind to each other's results. Sample size was determined by power analysis. Confidence intervals around observed rates were compared using chi-square analysis and Cohen's Kappa test. Logistic regression analysis was performed. RESULTS: In 70% of cases, both clinical and ultrasound examinations indicated the same position of the fetal head (95% confidence interval, 66-78). Agreement between the two methods reached 80% (95% CI, 71.3-87) when allowing a difference of up to 45 degrees in the head rotation. Logistic regression analysis revealed that gestational age, parity, birth weight, pelvic station and examiner's experience did not significantly affect the accuracy of the examination. Caput succedaneum tended to diminish (p = 0.09) the accuracy of clinical examination. The type of fetal head position significantly affected the results. Occiput posterior and transverse head locations were associated with a significantly higher rate of clinical error (p = 0.001). CONCLUSION: In 20% of the cases, ultrasonographic and clinical results differed significantly (i.e., >45 degrees). This rate reached 50% for occiput posterior and transverse locations. Transabdominal ultrasonography is a simple, quick and efficient way of increasing the accuracy of the assessment of fetal head position during the second stage of labor.     

Sonographic assessment of fetal occiput position during the second stage of labor: how reliable is the transperineal approach?

Objective: To compare the accuracy of transperineal (TP) ultrasound with transabdominal (TA) approach in the sonographic assessment of fetal occiput position during the second stage of labour.

Methods: A series of low-risk women at term attending the labour ward of three university hospitals were prospectively recruited for the purpose of this study. During the second stage of labor patients were evaluated first by TP and than by TA ultrasound to determine the fetal position. The occiput position was labelled as DOA (direct occiput anterior), ROA (right occiput anterior), LOA (left occiput anterior), DOP (direct occiput posterior), ROP (right occiput posterior), LOP (left occiput posterior), ROT (right occuput transverse) and LOT (left occiput transverse). The agreement between the two techniques was assessed.

Results: Overall 80 patients were recruited in the study group. Ultrasound examination was performed at 21(±8) minutes from the beginning of the active pushing. The ultrasound findings of the fetal occiput position were recorded. In all cases TA ultrasound confirmed the fetal occiput position as determined at TP approach except in one case of ROA that had been recorded as ROT using TP ultrasound.

Conclusions: Ultrasound TP examination is accurate in the diagnosis of fetal occiput position during the second stage of labor.     

Relationship between intrapartum transperineal ultrasound measurement of angle of progression and head–perineum distance with correlation to conventional clinical parameters of labor progress and time to delivery

Objective: To assess whether angle of progression (AOP) and head–perineum distance (HPD) measured by intrapartum transperineal ultrasound (ITU) correlate with clinical fetal head station (station); and whether AOP versus HPD varies during uterine contraction and relaxation. In a subset of primipaorus women, whether these ITU parameters correlate with time to normal spontaneous delivery (TD).

Methods: We evaluated prospectively 100 primiparous and multiparous women at term in active labor. Transabdominal and transperineal ultrasound (sagittal and transverse plane) were used to measure fetal head position and ITU parameters, respectively. Digitally palpated station and cervical dilatation were also noted. The results were compared using regression and correlation coefficients.

Results: Station was moderately correlated with AOP (r?=?0.579) and HPD (r?=??0.497). AOP was highly correlated with HPD during uterine contraction (r?=??0.703) and relaxation (r?=??0.647). In the subgroup of primiparous women, natural log of TD has the highest correlation with HPD and AOP during uterine contraction (r?=?0.742), making prediction of TD similar to that of using cervical dilatation.

Conclusion: ITU parameters were moderately correlated with station. There was constant high correlation between AOP and HPD. Prediction of TD in primiparous women using ITU parameters was similar to that of using cervical dilatation.     

Intrapartum fever at term: clinical characteristics and placental pathology

Objectives: To investigate the association between clinical characteristics and placental histopathology in women with intrapartum fever (IPF) at term. Methods: Maternal characteristics, intrapartum parameters, neonatal outcome and placental pathology were compared between 120 patients with IPF (≥380C) and a control group matched for mode of delivery. Placental lesions were classified as consistent with maternal circulation abnormalities or fetal thrombo-occlusive disease or inflammatory responses of maternal (MIR) or fetal (FIR) origin. Results: Compared to controls the study group was characterized by significantly higher rates of nulliparity, extra-amniotic balloon induction of labor, and epidural anesthesia, higher gestational age, higher white blood cell count, and more vaginal examinations. On multivariate logistic regression analysis, multiple vaginal examinations were independently associated with IPF. MIR was detected in 71% of the study group compared to 21% of controls (p < 0.001), and FIR, in 32.5% and 7.5%, respectively (p < 0.001). IPF was independently associated with inflammation of maternal origin (adjusted odds ratio (OR) 8.0, 95% CI 4.2–15.2, p < 0.001) and fetal origin (adjusted OR 5.2, 95% CI 2.07–13.4, p < 0.001). Neonatal outcome was similar in the two groups. Conclusions: Multiple vaginal examinations are a significant risk factor for the development of IPF. IPF at term is independently associated with placental inflammatory lesions.     

Transvaginal ultrasound and digital examination in predicting successful labor induction.

OBJECTIVE: To compare transvaginal ultrasound and digital cervical examination in predicting successful induction in post-term pregnancy. METHODS: Transvaginal ultrasound and digital vaginal examinations were performed on 122 women at 41 or more weeks' gestation, immediately before labor induction. Ultrasound assessments of cervical length, dilatation, and presence of funneling were compared with the components of the Bishop score. The primary outcome was the rate of vaginal delivery. Secondary outcomes assessed included the rates of active labor in 12 hours, vaginal delivery in 12 and 24 hours, mean duration of latent phase, and induction to vaginal delivery interval. Linear and multiple logistic regression models were generated to identify factors independently associated with successful induction. RESULTS: No ultrasound characteristic predicted primary or secondary outcomes. Bishop score (odds ratio [OR] 2.98, 95% confidence interval [CI] 1.71, 5.20), cervical position (OR 4.35, 95% CI 1.41, 12.50), and maternal age (OR 1.15, 95% CI 1.01, 1.30) independently predicted vaginal delivery. Maternal weight (OR 0.96, 95% CI 0.94, 0.98), cervical dilatation (OR 6.08, 95% CI 1.70, 21.68), and effacement (OR 2.34, 95% CI 1.16, 4.73) independently predicted active labor in 12 hours. Independent predictors of vaginal delivery in 12 hours were induction method (P <.001), cervical dilatation (OR 11.16, 95% CI 3.17, 39.29), gravidity (OR 2.06, 95% CI 1.13, 3.77), and maternal weight (OR 0.96, 95% CI 0.93, 0.99). Cervical effacement (OR 2.70, 95% CI 1.59, 4.57) and parity (OR 7.10, 95% CI 2.22, 22.72) independently predicted vaginal delivery in 24 hours. Maternal weight, cervical position, and cervical dilatation were independently associated with latent phase labor duration. Factors independently associated with length of induction to delivery interval were parity, cervical effacement, and maternal weight. CONCLUSION: Transvaginal ultrasound does not predict successful labor induction in post-term pregnancy as well as digital cervical examination.     

Clinical and sonographic diagnosis of occiput posterior position: a prospective study of 350 deliveries

OBJECTIVE: To evaluate clinical reliability compared to intrapartum ultrasound as a tool to diagnose occiput posterior position and to investigate the proportion of rotations occurring during labour. PATIENTS AND METHODS: 350 women in labor with a singleton fetus in a vertex position were prospectively studied using ultrasound and obstetrical examination. Outcome of labor was also monitored. RESULTS: Reliability of clinical examination is 85,7%, initial occiput posterior position represented 40,2% and most rotated in an anterior position (84, 8%) while only 0,6% of initial anterior positions delivered in occiput posterior position. Logistic regression did not allow to find significant predictor of occiput posterior position rotation. DISCUSSION AND CONCLUSION: Clinical examination is relatively reliable for posterior position diagnosis and in most cases, initially occipitoposterior positions rotate anteriorly.     

The Fetal vermis,pons and brainstem: normal longitudinal development as shown by dedicated neurosonography

Abstract

Objective: To describe the normal appearance and the growth of the fetal vermis, pons and midline brainstem by ultrasound from 18 weeks of gestation to term in order to produce developmental nomograms.

Methods: Serial ultrasound examinations of the fetal brain were performed in 21 fetuses between 18 and 39 weeks of gestation every two weeks. A total of 173 examinations were done, 8.2?±?5.2 examinations per fetus. A mid-sagittal plain of the brain was obtained either by transvaginal or transabdominal sonography. Antero-posterior, cranio-caudal diameters, and surface area of the pons and the vermis were measured. The surface area of the brain stem was also measured. Nomograms were produced according to Royston and Wright.

Results: The pons, vermis and brain stem grow in a linear fashion throughout pregnancy. The growth pattern correlates well with gestational age, biparietal diameter, head circumference and the cerebellar transverse diameter.

Conclusions: We have provided nomograms for assessment of the fetal brainstem. The present information supplies tools for the accurate identification of fetal mid-hindbrain anomalies providing a solid basis for a multidisciplinary approach, management and counseling of these conditions.     

Comparison of elastosonography and digital examination of cervix for consistency to predict successful vaginal delivery after induction of labor with oxytocin

Objective: To compare elastosonography and digital examination of cervix for consistency in the prediction of successful vaginal delivery.

Methods: A total of 64 pregnant women with the indication of induction of labor (IOL) were enrolled to the study. The uterine cervix is evaluated before and after the IOL with elastosonography and digital examination for consistency and sonography for length. Methods were compared in regard to the prediction of successful vaginal delivery.

Results: The median of gestational age was 41.00 (IQR?=?2.32). Out of 64 participants, 40 (62.5%) had vaginal delivery and 24 (37.5%) had cesarean delivery. The preinduction and postinduction elastosonographic indices were insignificant in delivery groups. The preinduction and postinduction evaluations of cervical consistency with digital examination were significant within vaginal delivery group (p?=?0.046), whereas it was insignificant within cesarean delivery group and between the delivery groups. The preinduction and postinduction Bishop scores were significant within vaginal delivery group (p?=?0.005), whereas it was insignificant within cesarean delivery group and between the delivery groups. Postinduction Bishop score was significant between the delivery groups.

Conclusion: Evaluation of cervix for consistency with either elastosonography or digital examination was found to be insignificant in prediction of successful vaginal delivery after IOL with oxytocin.     

Engagement de la tête fœtale : échographie transpérinéale,un nouvel outil diagnostique ?

ObjectiveAssessment of fetal head engagement by digital examination is highly subjective even though this method remains the gold standard. Ultrasonography could be helpful to determine fetal head engagement during the second stage of labor.Patients and methodsProspective unicentric study to compare the diagnostic of fetal head orientation and engagement between digital examination and ultrasonography. One hundred measurements were performed in 100 patients at complete cervical dilatation.ResultsIn 80 % of patients, abdominal ultrasound assessments were consistent with digital examinations in depicting fetal head position. We were not able to evaluate engagement by abdominal ultrasonography. Perineum to fetal head distance was measured between 12 and 83 mm by translabial ultrasonography. When the head was not engaged (?1), the mean distance was 66.4 ± 7.53 mm. The measure was 56.15 ± 10.86 mm when the head was at the upper part of the birth canal (+1), 46.47 ± 12.49 mm at the middle part (+2) and 35.81 ± 10.42 mm at the lower part (+3; +4). A threshold of 55 mm was associated with a sensibility and a negative predictive value of 100 % for vaginal birth.Discussion and conclusionAbdominal intrapartum ultrasound increases the accuracy of fetal head position assessment. Translabial ultrasound is a simple and easy method to define fetal head engagement by measuring the distance between perineum and fetal head. Ultrasound during the second stage of labor may serve as an educational tool for physicians in training.     

The Fetal Occiput Posterior Position: State of the Science and a New Perspective

Abstract: Background: The fetal occiput posterior position poses challenges in every aspect of intrapartum care—prevention, diagnosis, correction, supportive care, labor management, and delivery. Maternal and newborn outcomes are often worse and both physical and psychological traumas are more common than with fetal occiput anterior positions. The purpose of this paper is to describe nine prevailing concepts that guide labor and birth management with an occiput posterior fetus, and summarize evidence to clarify the state of the science. Methods: A search was conducted of the databases of PubMed and the Cochrane Library. Additional valuable information was obtained from obstetric and midwifery textbooks, books and websites for the public, conversations with maternity care professionals, and years of experience as a doula. Results: Nine prevailing concepts are as follows: (1) prenatal maneuvers rotate the occiput posterior fetus to occiput anterior; (2) it is possible to detect the occiput posterior fetus prenatally; (3) a fetus who is occiput anterior at the onset of labor will remain in that position throughout labor; (4) back pain in labor is a reliable sign of an occiput posterior fetus; (5) the occiput posterior fetus can be identified during labor by digital vaginal examination; (6) an ultrasound scan is a reliable way to detect fetal position; (7) maternal positions facilitate rotation of the occiput posterior fetus; (8) epidural analgesia facilitates rotation; (9) manual rotation of the fetal head to occiput anterior improves the rate of occiput anterior deliveries. Concepts 1, 2, 3, 4, 5, and 8 have little scientific support whereas concepts 6, 7, and 9 are supported by promising evidence. Conclusions: Many current obstetric practices with respect to the occiput posterior position are unsatisfactory, resulting in failure to identify and correct the problem and thus contributing to high surgical delivery rates and traumatic births. The use of ultrasound examination to identify fetal position is a method that is far superior to other methods, and has the potential to improve outcomes. Research studies are needed to examine the efficacy of midwifery methods of identification, and the effect of promising methods to rotate the fetus (simple positional methods and digital or manual rotation). Based on the findings of this review, a practical approach to care is suggested. (BIRTH 37:1 March 2010)     

Shock management in acute fetomaternal hemorrhage

Abstract

The determination of fetal head position can be useful in labor to predict the success of labor management, especially in case of malpositions. Malpositions are abnormal positions of the vertex of the fetal head and account for the large part of indication for cesarean sections for dystocic labor. The occiput posterior position occurs in 15–25% of patients before labor at term and, however, most occiput posterior presentations rotate during labor, so that the incidence of occiput posterior at vaginal birth is approximately 5–7%. Persistence of the occiput posterior position is associated with higher rate of interventions and with maternal and neonatal complications and the knowledge of the exact position of the fetal head is of paramount importance prior to any operative vaginal delivery, for both the safe positioning of the instrument that may be used (i.e. forceps versus vacuum) and for its successful outcome. Ultrasound (US) diagnosed occiput posterior position during labor can predict occiput posterior position at birth. By these evidences, the time requested for fetal head descent and the position in the birth canal, had an impact on the diagnosis of labor progression or arrested labor. To try to reduce this pitfalls, authors developed a new algorithm, applied to intrapartum US and based on suitable US pictures, that sets out, in detail, the quantitative evaluation, in degrees, of the occiput posterior position of the fetal head in the pelvis and the birth canal, respectively, in the first and second stage of labor. Authors tested this computer system in a settle of patients in labor.     

The effect of intrapartum clindamycin on vaginal group B streptococcus colony counts

Objective: To determine the temporal relationship between intrapartum clindamycin and vaginal Group B Streptococcus (GBS) colony counts. Methods: In this prospective observational study, women with GBS-positive, clindamycin-sensitive, antenatal rectovaginal cultures, intrapartum vaginal cultures were collected just before the first clindamycin dose (T₀) and then every 2?h for 8?h or until delivery. Colony counts were quantified using serial dilution. Results were standardized as percent of initial colony count and analyzed using sequential Friedman tests. Results: Twenty-one women had positive intrapartum vaginal GBS cultures at T₀. With T₀ colony counts standardized to 100%, subsequent percents-of-baseline fell rapidly and significantly by T₂ and fell further at each subsequent point, reaching 0% by T₆. For 12 women cultured for the full 8 hours, the decline in GBS was significant at p?<?0.001. Conclusions: Vaginal GBS colony counts fall rapidly after intrapartum clindamycin administration, similar to declines after penicillin. This represents a possible mechanism for efficacy of chemoprophylaxis.