Uterine contractions are routinely monitored by tocodynamometer (TOCO) at late stage of pregnancy to predict the onset of labor. However, TOCO reveals no information on the synchrony and coherence of ...contractions, which are important contributors to a successful delivery. The electrohysterography (EHG) is a recording of the electrical activities that trigger the local muscles to contract. The spatial-temporal information embedded in multiple channel EHG signals make them ideal for characterizing the synchrony and coherence of uterine contraction. To proceed, contractile time-windows are identified from TOCO signals and are then used to segment out the simultaneously recorded EHG signals of different channels. We construct sample entropy SamEn and Concordance Correlation based feature ψ from these EHG segments to quantify the synchrony and coherence of contraction. To test the effectiveness of the proposed method, 122 EHG recordings in the Icelandic EHG database were divided into two groups according to the time difference between the gestational ages at recording and at delivery (TTD). Both SamEn and ψ show clear difference in the two groups (p<10
) even when measurements were made 120 h before delivery. Receiver operating characteristic curve analysis of these two features gave AUC values of 0.834 and 0.726 for discriminating imminent labor defined with TTD ≤ 24 h. The SamEn was significantly smaller in women (0.1433) of imminent labor group than in women (0.3774) of the pregnancy group. Using an optimal cutoff value of SamEn to identify imminent labor gives sensitivity, specificity, and accuracy as high as 0.909, 0.712 and 0.743, respectively. These results demonstrate superiority in comparing to the existing SOTA methods. This study is the first research work focusing on characterizing the synchrony property of contractions from the electrohysterography signals. Despite the very limited dataset used in the validation process, the promising results open a new direction to the use of electrohysterography in obstetrics.
Objective Recent recommendations called for obstetricians to abandon the terms of “hyperstimulation” and “hypercontractility” in favor of the more rigidly defined term, “tachysystole” (TS). The aim ...of the current study is to describe incidence of and risk factors for TS, describe fetal heart rate (FHR) changes associated with TS, and investigate maternal and neonatal outcomes associated with TS. Study Design For this retrospective cohort study, we reviewed and analyzed the intrapartum FHR and tocometric characteristics of all patients with a singleton, nonanomalous fetus in term labor in a single hospital system over a 28-month period. Univariate association testing was done using χ2 and t tests, comparing demographics, pregnancy characteristics, outcomes, and TS events. Multivariable association testing between risk factors and TS events were tested using generalized estimating equations, adjusting for multiple pregnancies during the study period for the same woman. Results There were a total of 50,335 deliveries from 48,529 women during the 28-month period. Of these, there were a total of 7567 TS events in 5363 deliveries among 5332 women. Use of oxytocin or misoprostol, an epidural, hypertension, and induction of labor were associated with an increased risk of TS. We found a doubling of TS events with any oxytocin, a dose-response correlation between oxytocin and TS, FHR changes occurring in a quarter of TS events and, finally, that presence of TS increases the chance of composite neonatal morbidity. Conclusion TS is associated with specific risk factors and impacts FHR and neonatal morbidity.
Considerable evidence has accumulated on the association between pregnancy-specific stress and adverse birth outcomes with an increasing number of measures of pregnancy-specific stress being ...developed internationally. However, the introduction of these measures has not always been theoretically or psychometrically grounded, resulting in questions about the quality and direction of such research. This review summarizes evidence on the reliability and validity of pregnancy-specific stress measures identified between 1980 and October 2010. Fifteen pregnancy-specific stress measures were identified. Cronbach's alpha coefficient ranged from 0.51-0.96 and predictive validity data on preterm birth were reported for five measures. Convergent validity data suggest that pregnancy-specific stress is related to, but distinct from, global stress. Findings from this review consolidate current knowledge on pregnancy-specific stress as a consistent predictor of premature birth. This review also advances awareness of the range of measures of pregnancy-specific stress and documents their strengths and limitations based on published reliability and validity data. Careful consideration needs to be given as to which measures to use in future research to maximize the development of stress theory in pregnancy and appropriate interventions for women who experience stress in pregnancy. An international, strategic collaboration is recommended to advance knowledge in this area of study.
Uterine contractions can be registered by external tocodynamometry (ET) or, after rupture of the membranes, by internal tocodynamometry (IT). Monitoring of the frequency of contractions is important ...especially when intravenous oxytocin is used as excessive uterine activity (hyperstimulation or tachysystole) can cause fetal distress. During induction of labour as well as during augmentation with intravenous oxytocin, some clinicians choose to monitor frequency and strength of contractions with IT rather than with ET as an intrauterine pressure catheter measures intrauterine activity more accurately than an extra-abdominal tocodynamometry device. However, insertion of an intrauterine catheter has higher costs and also potential risks for mother and child.
To assess the effectiveness of IT compared with using ET when intravenous oxytocin is used for induction or augmentation of labour.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 April 2012) and PubMed (1966 to 7 March 2012).
We included all published randomised controlled trials with data from women in whom IT was compared with ET in induced or augmented labour with oxytocin. We excluded trials that employed quasi-randomised methods of treatment allocation. We found no unpublished or ongoing studies on this subject.
Two review authors independently assessed trial eligibility and risk of bias, and independently extracted data. Data were checked for accuracy. Where necessary, we contacted study authors for additional information.
Three studies involving a total of 1945 women were included. Overall, risk of bias across the three trials was mixed. No serious complications were reported in the trials and no neonatal or maternal deaths occurred. The neonatal outcome was not statistically different between groups: Apgar score less than seven at five minutes (RR 1.78, 95% CI 0.83 to 3.83; three studies, n = 1945); umbilical artery pH less than 7.15 (RR 1.31, 95% CI 0.95 to 1.79; one study, n = 1456); umbilical artery pH less than 7.16 (RR 1.23, 95% CI 0.39 to 3.92; one study, n = 239); admission to the neonatal intensive care unit (RR 0.34, 95% CI 0.07 to 1.67; two studies, n = 489); and more than 48 hours hospitalisation (RR 0.92, 95% CI 0.71 to 1.20; one study, n = 1456). The pooled risk for instrumental delivery (including caesarean section, ventouse and forceps extraction) was not statistically significantly different (RR 1.05, 95% CI 0.91 to 1.21; three studies, n = 1945). Hyperstimulation was reported in two studies (n = 489), but there was no statistically significant difference between groups (RR 1.21, 95% CI 0.78 to 1.88).
This review found no differences between the two types of monitoring (internal or external tocodynamometry) for any of the maternal or neonatal outcomes. Given that this review is based on three studies (N = 1945 women) of moderate quality, there is insufficient evidence to recommend the use of one form of tocodynamometry over another for women where intravenous oxytocin was administered for induction or augmentation of labour.
To evaluate the influence of maternal obesity on the performance of external tocodynamometry and electrohysterography.
In a 2-hour measurement during term labor, uterine contractions were ...simultaneously measured by electrohysterography, external tocodynamometry, and intra-uterine pressure catheter. The sensitivity was compared between groups based on obesity (non-obese/obese/morbidly obese) or uterine palpation (good/moderate/poor), and was correlated to maternal BMI and abdominal circumference.
We included 14 morbidly obese, 18 obese, and 20 non-obese women. In morbidly obese women, the median sensitivity was 87.2% (IQR 74-93) by electrohysterography and 45.0% (IQR 36-66) by external tocodynamometry (p < 0.001). The sensitivity of electrohysterography appeared to be non-influenced by obesity category (p = 0.279) and uterine palpation (p = 0.451), while the sensitivity of tocodynamometry decreased significantly (p = 0.005 and p < 0.001, respectively). Furthermore, the sensitivity of both external methods was negatively correlated with obesity parameters, being non-significant for electrohysterography (range p-values 0.057-0.088) and significant for external tocodynamometry (all p-values < 0.001).
Electrohysterography performs significantly better than external tocodynamometry in case of maternal obesity.
Objective
To evaluate the performance of external electronic fetal heart rate and uterine contraction monitoring according to maternal body mass index.
Design
Secondary analysis of prospective ...equivalence study.
Setting
Three US urban teaching hospitals.
Sample
Seventy‐four parturients with a normal term pregnancy.
Methods
The parent study assessed performance of two methods of external fetal heart rate monitoring (abdominal fetal electrocardiogram and Doppler ultrasound) and of uterine contraction monitoring (electrohystero‐graphy and tocodynamometry) compared with internal monitoring with fetal scalp electrode and intrauterine pressure transducer. Reliability of external techniques was assessed by the success rate and positive percent agreement with internal methods. Bland–Altman analysis determined accuracy. We analyzed data from that study according to maternal body mass index.
Main outcome measures
We assessed the relationship between body mass index and monitor performance with linear regression, using body mass index as the independent variable and measures of reliability and accuracy as dependent variables.
Results
There was no significant association between maternal body mass index and any measure of reliability or accuracy for abdominal fetal electrocardiogram. By contrast, the overall positive percent agreement for Doppler ultrasound declined (p = 0.042), and the root mean square error from the Bland–Altman analysis increased in the first stage (p = 0.029) with increasing body mass index. Uterine contraction recordings from electrohysterography and tocodynamometry showed no significant deterioration related to maternal body mass index.
Conclusions
Accuracy and reliability of fetal heart rate monitoring using abdominal fetal electrocardiogram was unaffected by maternal obesity, whereas performance of ultrasound degraded directly with maternal size. Both electrohysterography and tocodynamometry were unperturbed by obesity.
Non-invasive measurement of uterine activity using electrohysterogram (EHG) surface electrodes has been attempted to monitor uterine contraction. This study aimed to computationally compare the ...performance of acquiring EHG signals using monopolar electrode and three types of Laplacian concentric ring electrodes (bipolar, quasi-bipolar and tri-polar). With the implementation of dipole band model and abdomen model, the performances of four electrodes in terms of the local sensitivity were quantified by potential attenuation. Furthermore, the effects of fat and muscle thickness on potential attenuation were evaluated using the bipolar and tri-polar electrodes with different radius. The results showed that all the four types of electrodes detected the simulated EHG signals with consistency. That the bipolar and tri-polar electrodes had greater attenuations than the others, and the shorter distance between the origin and location of dipole band at 20 dB attenuation, indicating that they had relatively better local sensitivity. In addition, ANOVA analysis showed that, for all the electrodes with different outer ring radius, the effects of fat and muscle on potential attenuation were significant (all p < 0.01). It is therefore concluded that the bipolar and tri-polar electrodes had higher local sensitivity than the others, indicating that they can be applied to detect EHG effectively.
During labor mother and fetus are evaluated at intervals to assess their well-being and determine how the labor is progressing. These assessments require skillful physical diagnosis and the ability ...to translate the acquired information into meaningful prognostic decision-making. We describe a coordinated approach to the assessment of labor. Graphing of serial measurements of cervical dilatation and fetal station creates “labor curves,” which provide diagnostic and prognostic information. Based on these curves we recognize nine discrete labor abnormalities. Many may be related to insufficient or disordered contractile mechanisms. Several factors are strongly associated with development of labor disorders, including cephalopelvic disproportion, excess analgesia, fetal malpositions, intrauterine infection, and maternal obesity. Clinical cephalopelvimetry involves assessing pelvic traits and predicting their effects on labor. These observations must be integrated with information derived from the labor curves. Exogenous oxytocin is widely used. It has a high therapeutic index, but is easily misused. Oxytocin treatment should be restricted to situations in which its potential benefits clearly outweigh its risks. This requires there be a documented labor dysfunction or a legitimate medical reason to shorten the labor. Normal labor and delivery pose little risk to a healthy fetus; but dysfunctional labors, especially if stimulated excessively by oxytocin or terminated by complex operative vaginal delivery, have the potential for considerable harm. Conscientiously implemented, the approach to the evaluation of labor outlined in this review will result in a reasonable cesarean rate and minimize risks that may accrue from the labor and delivery process.
The partogram (sometimes known as partograph) is usually a pre-printed paper form on which labour observations are recorded. The aim of the partogram is to provide a pictorial overview of labour, to ...alert midwives and obstetricians to deviations in maternal or fetal wellbeing and labour progress. Charts often contain pre-printed alert and action lines. An alert line represents the slowest 10% of primigravid women's labour progress. An action line is placed a number of hours after the alert line (usually two or four hours) to prompt effective management of slow progress of labour.
To determine the effect of use of partogram on perinatal and maternal morbidity and mortality.To determine the effect of partogram design on perinatal and maternal morbidity and mortality.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2013).
Randomised and quasi-randomised controlled trials involving a comparison of partogram with no partogram, or comparison between different partogram designs.
Three review authors independently assessed eligibility, quality and extracted data. When one review author was also the trial author, the two remaining authors assessed the studies independently.
We have included six studies involving 7706 women in this review; two studies assessed partogram versus no partogram and the remainder assessed different partogram designs. There was no evidence of any difference between partogram and no partogram in caesarean section (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.24 to 1.70); instrumental vaginal delivery (RR 1.00, 95% CI 0.85 to 1.17) or Apgar score less than seven at five minutes (RR 0.77, 95% CI 0.29 to 2.06) between the groups. When compared to a four-hour action line, women in the two-hour action line group were more likely to require oxytocin augmentation (RR 1.14, 95% CI 1.05 to 1.22). When the three- and four-hour action line groups were compared, caesarean section rate was lowest in the four-hour action line group and this difference was statistically significant (RR 1.70, 95% CI 1.07 to 2.70, n = 613, one trial). When a partogram with a latent phase (composite) and one without (modified) were compared, the caesarean section rate was lower in the partograph without a latent phase (RR 2.45, 95% CI 1.72 to 3.50, n = 743, one trial).
On the basis of the findings of this review, we cannot recommend routine use of the partogram as part of standard labour management and care. Given the fact that the partogram is currently in widespread use and generally accepted, it appears reasonable, until stronger evidence is available, that partogram use should be locally determined. Further trial evidence is required to establish the efficacy of partogram use.
Objective: To compare various labour parameters in partogram among primiparous women and women with one previous caesarean section scar Study Design: Comparative cross-sectional study Place and ...Duration of Study: Gynaecology and Obstetrics Department, Pak Emirates Military Hospital, Rawalpindi Pakistan, from Oct 2021 to Sep 2022. Methodology: This study was conducted on primiparous women and women with one previous scar who were booked cases in our department for antenatal checkups and labour. Patients were divided into two groups for comparison. Group-I were primiparous, while Group-II had one previous scar. All women underwent detailed labour records via conventional partogram in the labour room. Duration of the active phase of labour, duration of the second stage, time to progress by 1 cm and time after the alert line were compared in partograms of both the study groups. Results: A total of 390 women who were either primiparous or had one previous caesarean section were recruited for this study. Of the study participants, 226(42.6%) were primiparous, while 164(57.4%) had one previous caesarean section scar. Statistical analysis revealed that the duration of the active phase of labour, time to progress by 1 cm and time after the alert line were statistically significant (p-value<0.05) in partograms of women in Group-I (primiparous) as compared to those in Group- II (women with one previous scar) (p-value<0.05). Conclusion: The main parameters of the partogram differ significantly among primiparous women and women with one previous caesarean section scar.
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