Analysis of fetal heart rate fluctuations in women diagnosed with preeclampsia during the latent phase of labor.

Introduction: Fetal heart rate variability (fHRV) is a tool used to investigate the functioning of the fetal autonomic nervous system. Despite the significance of preeclampsia, fHRV during the latent phase of labor has not been extensively studied. This study aimed to evaluate fetal cardiac autonomic activity by using linear and nonlinear indices of fHRV analysis in women diagnosed with preeclampsia without hypertensive treatment during gestation, compared to normotensive women during the latent phase of labor. Methods: A cross-sectional and exploratory study was conducted among pregnant women in the latent phase of labor, forming three study groups: normotensive or control (C, 38.8 ± 1.3 weeks of pregnancy, n = 22), preeclampsia with moderate features (P, 37.6 ± 1.4 weeks of pregnancy n = 10), and preeclampsia with severe features (SP, 36.9 ± 1.2 weeks of pregnancy, n = 12). None of the participants received anti-hypertensive treatment during their pregnancy. Linear and nonlinear features of beat-to-beat fHRV, including temporal, frequency, symbolic dynamics, and entropy measures, were analyzed to compare normotensive and preeclamptic groups. Results: Significantly lower values of multiscale entropy (MSE) and short-term complexity index (Ci) were observed in the preeclamptic groups compared to the C group (p < 0.05). Additionally, higher values of SDNN (standard deviation of R-R intervals) and higher values of low-frequency power (LF) were found in the P group compared to the C group. Conclusion: Our findings indicate that changes in the complexity of fetal heart rate fluctuations may indicate possible disruptions in the autonomic nervous system of fetuses in groups affected by undiagnosed preeclampsia during pregnancy. Reduced complexity and shifts in fetal autonomic cardiac activity could be associated with preeclampsia's pathophysiological mechanisms during the latent phase of labor.

Uterine activity modifies the response of the fetal autonomic nervous system at preterm active labor.

Background: The autonomic nervous system of preterm fetuses has a different level of maturity than term fetuses. Thus, their autonomic response to transient hypoxemia caused by uterine contractions in labor may differ. This study aims to compare the behavior of the fetal autonomic response to uterine contractions between preterm and term active labor using a novel time-frequency analysis of fetal heart rate variability (FHRV). Methods: We performed a case-control study using fetal R-R and uterine activity time series obtained by abdominal electrical recordings from 18 women in active preterm labor (32-36 weeks of gestation) and 19 in active term labor (39-40 weeks of gestation). We analyzed 20 minutes of the fetal R-R time series by applying a Continuous Wavelet Transform (CWT) to obtain frequency (HF, 0.2-1 Hz; LF, 0.05-0.2 Hz) and time-frequency (Flux0, Flux90, and Flux45) domain features. Time domain FHRV features (SDNN, RMSSD, meanNN) were also calculated. In addition, ultra-short FHRV analysis was performed by segmenting the fetal R-R time series according to episodes of the uterine contraction and quiescent periods. Results: No significant differences between preterm and term labor were found for FHRV features when calculated over 20 minutes. However, we found significant differences when segmenting between uterine contraction and quiescent periods. In the preterm group, the LF, Flux0, and Flux45 were higher during the average contraction episode compared with the average quiescent period (p<0.01), while in term fetuses, vagally mediated FHRV features (HF and RMSSD) were higher during the average contraction episode (p<0.05). The meanNN was lower during the strongest contraction in preterm fetuses compared to their consecutive quiescent period (p=0.008). Conclusion: The average autonomic response to contractions in preterm fetuses shows sympathetic predominance, while term fetuses respond through parasympathetic activity. Comparison between groups during the strongest contraction showed a diminished fetal autonomic response in the preterm group. Thus, separating contraction and quiescent periods during labor allows for identifying differences in the autonomic nervous system cardiac regulation between preterm and term fetuses.

Incidencia de alteraciones de la frecuencia cardíaca fetal tras la inducción de analgesia del parto neuroaxial / Incidence of fetal heart rate abnormalities after neuroaxial labor analgesia induction

OBJECTIVE: To assess changes in fetal heart rate variability (FHR) after induction of neuraxial labor analgesia. MATERIALS AND METHODS: Prospective analytical cohort clinical trial conducted between July 2020 and July 2021, with fifty-nine pregnant women from the Pereira Rossell Hospital Center (CHPR) who met the inclusion criteria. Analgesic technique (epidural/spinal epidural) was randomly assigned. FHR, maternal blood pressure (BP), intensity of uterine contraction in Montevideo Units (UM) and pain using a verbal numerical scale (VAS) were monitored for 20 minutes. RESULTS: No statistically significant differences were observed for FHR at each of the times, and there were no cases of fetal bradycardia. In PA and UM, no statistically significant differences were observed. No statistically significant differences were observed for VAS at each of the times, except immediately after receiving analgesia, p value = 0.046. CONCLUSIONS: CSE was not associated with a higher risk of FHR alterations. Intrathecal fentanyl at a maximum dose of 15 mcg is safe and effective in relieving labor pain. Pain relief was similar for the two groups. No episodes of hypotension were observed. Both techniques are effective for pain relief with a similar safety profile when low doses of intraspinal fentanyl are used.

OBJETIVO: Valorar las alteraciones de la variabilidad de la frecuencia cardíaca fetal (FCF) luego de la inducción de analgesia del parto neuroaxial. MATERIALES Y MÉTODOS: Ensayo clínico prospectivo analítico de cohortes realizado entre julio de 2020 y julio de 2021, con 59 embarazadas del Centro Hospitalario Pereira Rosell (CHPR) que cumplieron con los criterios de inclusión. Se asignó de forma aleatoria la técnica analgésica (epidural/espinal-epidural). Se monitorizó durante 20 minutos la FCF, presión arterial materna (PA), intensidad de la contracción uterina en Unidades Montevideo (UM) y dolor mediante escala numérica verbal (EVA). RESULTADOS: Para la FCF en cada uno de los tiempos no se observaron diferencias estadísticamente significativas, ni hubo casos de bradicardia fetal. En la PA y UM no se observaron diferencias estadísticamente significativas. Para la EVA en cada uno de los tiempos no se observaron diferencias estadísticamente significativas, excepto inmediatamente a recibir la analgesia, valor p = 0,046. CONCLUSIONES: La CSE no se asoció a mayor riesgo de alteraciones de la FCF. El fentanil intratecal a dosis máxima de 15 mcg es seguro y efectivo para calmar el dolor del trabajo de parto. El alivio del dolor fue similar para los 2 grupos. No se observaron episodios de hipotensión. Ambas técnicas son eficaces para el alivio del dolor con similar perfil de seguridad cuando se usan dosis bajas de fentanil intrarraquídeo.

Differences in the Asymmetry of Beat-to-Beat Fetal Heart Rate Accelerations and Decelerations at Preterm and Term Active Labor.

The fetal autonomic nervous system responds to uterine contractions during active labor as identified by changes in the accelerations and decelerations of fetal heart rate (FHR). Thus, this exploratory study aimed to characterize the asymmetry differences of beat-to-beat FHR accelerations and decelerations in preterm and term fetuses during active labor. In an observational study, we analyzed 10 min of fetal R-R series collected from women during active preterm labor (32-36 weeks of pregnancy, n = 17) and active term labor (38-40 weeks of pregnancy, n = 27). These data were used to calculate the Deceleration Reserve (DR), which is a novel parameter that quantifies the asymmetry of the average acceleration and deceleration capacity of the heart. In addition, relevant multiscale asymmetric indices of FHR were also computed. Lower values of DR, calculated with the input parameters of T = 50 and s = 10, were associated with labor occurring at the preterm condition (p = 0.0131). Multiscale asymmetry indices also confirmed significant (p < 0.05) differences in the asymmetry of FHR. Fetuses during moderate premature labor may experience more decaying R-R trends and a lower magnitude of decelerations compared to term fetuses. These differences of FHR dynamics might be related to the immaturity of the fetal cardiac autonomic nervous system as identified by this system response to the intense uterine activity at active labor.

Fetal deaths in pregnancies with SARS-CoV-2 infection in Brazil: A case series.

BACKGROUND: There are few reports of miscarriages or stillbirths in women infected with SARS-CoV-2. We present five consecutive cases of fetal death (≥12 weeks) without other putative causes in women with laboratory-confirmed (RT-PCR) COVID-19 managed in a single Brazilian institution. CASE SERIES: All five women were outpatients with mild or moderate forms of COVID-19 and were not taking any medication. Four were nulliparous, all were overweight or obese, and none had any comorbidities or pregnancy complications that could contribute to fetal demise. Fetal death occurred at 21-38 weeks of gestation, on COVID-days 1-22. SARS-Cov-2 was detected by RT-PCR in amniotic fluid in one case and in placental specimens in two cases. All five women had acute chorioamnionitis on placental histology, massive deposition of fibrin, mixed intervillitis/villitis, and intense neutrophil and lymphocyte infiltration. One fetus had neutrophils inside alveolar spaces, suggestive of fetal infection. CONCLUSIONS: These five cases of fetal demise in women with confirmed COVID-19 without any other significant clinical or obstetric disorders suggest that fetal death can be an outcome of SARS-CoV-2 infection in pregnancy. The intense placental inflammatory reaction in all five cases raises the possibility of a direct effect of SARS-CoV-2 on the placenta.

Comparison of fetal heart rate variability by symbolic dynamics at the third trimester of pregnancy and low-risk parturition.

Fetal heart rate variability (fHRV) is an essential source of information to monitor fetal well-being during pregnancy. This study aimed to apply a nonlinear approach, known as symbolic dynamics (SD), for comparing human fHRV in the third trimester of pregnancy during active fetal state (TT) and active labor at term (P). We performed a longitudinal, prospective, descriptive, and comparative study composed of 42 longitudinal recordings of 5-minutes of fetal heartbeat interval series. Recordings were collected from 21 low-risk, healthy, pregnant women attending the Maternal and Child Research Center (CIMIGen), Mexico City. We calculated relevant linear parameters of fHRV between TT and P stages, such as the percentage of differences between adjacent RR intervals >5 ms (PRR5, related to vagal modulations) and other SD parameters such as the percentage of no variations between three successive symbols (%0V, reflects sympathetic modulations) and the probability of low variability with a threshold of 4 ms (POLVAR4, associated with a low variability). We identified statistical differences for PRR5 between TT and P (37.13% [28.47-47.60%] vs. 28.84% [19.36-36.76%], p = 0.03), respectively. Also, for 0V% (65.66% [59.01-71.80%] vs. 71.14% [65.94-75.87%], p = 0.03) and for POLVAR4 values (0.06 [0.04-0.11] vs. 0.15 [0.09-0.24], p = 0.002), respectively. Our results indicate that during parturition, the short-term fetal fHRV is decreased, showing a decreased vagal modulations and higher adrenergic response of the heart. These autonomic modifications may result from the fetal response to the stressful inflammatory challenge of labor. We thus confirmed that the analysis of the SD applied to fHRV time series could be a potential clinical biomarker to differentiate the fetal autonomic cardiac condition at different stages of pregnancy.

A Proxy for Detecting IUGR Based on Gestational Age Estimation in a Guatemalan Rural Population.

In-utero progress of fetal development is normally assessed through manual measurements taken from ultrasound images, requiring relatively expensive equipment and well-trained personnel. Such monitoring is therefore unavailable in low- and middle-income countries (LMICs), where most of the perinatal mortality and morbidity exists. The work presented here attempts to identify a proxy for IUGR, which is a significant contributor to perinatal death in LMICs, by determining gestational age (GA) from data derived from simple-to-use, low-cost one-dimensional Doppler ultrasound (1D-DUS) and blood pressure devices. A total of 114 paired 1D-DUS recordings and maternal blood pressure recordings were selected, based on previously described signal quality measures. The average length of 1D-DUS recording was 10.43 ± 1.41 min. The min/median/max systolic and diastolic maternal blood pressures were 79/102/121 and 50.5/63.5/78.5 mmHg, respectively. GA was estimated using features derived from the 1D-DUS and maternal blood pressure using a support vector regression (SVR) approach and GA based on the last menstrual period as a reference target. A total of 50 trials of 5-fold cross-validation were performed for feature selection. The final SVR model was retrained on the training data and then tested on a held-out set comprising 28 normal weight and 25 low birth weight (LBW) newborns. The mean absolute GA error with respect to the last menstrual period was found to be 0.72 and 1.01 months for the normal and LBW newborns, respectively. The mean error in the GA estimate was shown to be negatively correlated with the birth weight. Thus, if the estimated GA is lower than the (remembered) GA calculated from last menstruation, then this could be interpreted as a potential sign of IUGR associated with LBW, and referral and intervention may be necessary. The assessment system may, therefore, have an immediate impact if coupled with suitable intervention, such as nutritional supplementation. However, a prospective clinical trial is required to show the efficacy of such a metric in the detection of IUGR and the impact of the intervention.

Is moderate intensity exercise during pregnancy safe for the fetus? An open clinical trial / Exercício de intensidade moderada durante a gravidez é seguro para o feto? Ensaio clínico aberto

Abstract Objective To determine the effect of treadmill walking on maternal heart rate (MHR) and cardiotocographic parameters (basal fetal heart rate [FHR], active fetal movements [AFM], number of accelerations and decelerations, and short-term variation [STV] and long-term variation [LTV] of fetal heart rate) in pregnant women at 36 weeks. Methods A nonrandomized, open clinical trial involving 88 healthy pregnant women submitted to moderate intensity walking and computed cardiotocography in 3 20- minute periods (resting, treadmill walking, and postexercise recovery). Results The mean FHR decreased during walking (resting: 137 bpm; treadmill: 98 bpm; recovery: 140 bpm; p<0.001), with bradycardia occurring in 56% of the fetuses in the first 10minutes of exercise, and in 47% after 20minutes. Bradycardia was not detected in the other phases. The mean STV and HV were 7.9, 17.0, and 8.0 milliseconds (p<0.001) and 7.6, 10.8 and 7.6 bpm (p=0.002) in the resting, walking and recovery phases, respectively. Themean number of fetalmovements in 1 hour was 29.9, 22.2 and 45.5, respectively, in the 3 periods (p<0.001). In overweight/obese women, the mean FHR was lower (p=0.02). Following the logistic regression analysis, two variables remained significantly associated with bradycardia: maternal fitness in the 28th week of pregnancy (protective effect) and maternal weight (increased risk). Conclusion In healthy fetuses, physical exercise proved to be safe, since, although FHR and AFM decreased during treadmill walking, an increase in SVT and LTV was observed.

Resumo Objetivo Determinar o efeito da caminhada em esteira sobre a frequência cardíaca materna (FCM) e parâmetros cardiotocográficos (batimentos cardiofetais basais [BCFs], movimentos ativos fetais [MAFs], número de acelerações e desacelerações e variabilidade de curta [STV] e longa [LTV] duração da frequência cardíaca fetal) em gestantes na 36a semana. Métodos Foi realizado umensaio clínico não randomizado e aberto com 88 gestantes saudáveis submetidas a caminhada de moderada intensidade na esteira e a cardiotocografia computadoriza em 3 momentos de 20 minutos (antes, durante e após a caminhada). Resultados A média dos BCFs diminuiu durante a caminhada, retornando a níveis prévios (antes: 137 bpm; durante: 98 bpm; após: 140 bpm; p<0,001), com bradicardia ocorrendo em 56% dos fetos nos primeiros 10 minutos do exercício, e em 47% após 20 minutos. A bradicardia fetal não foi observada em outrosmomentos (antes ou depois). As médias da STV e da LTV foram 7,9, 17,0 e 8,0milissegundos (p<0,001) e 7,6, 10,7 e 7,6 bpm (p=0,002) antes, durante e após a caminhada, respectivamente. Amédia dos números dos MAFs em 1 hora foi 29,9, 22,2 e 45,5, respectivamente, nos três momentos (p<0,001). Nas mulheres com sobrepeso/obesidade, a média da FCM foi menor (p=0,02). Após a análise de regressão logística, duas variáveis permaneceram significativamente associadas a bradicardia: aptidão maternal na 28a semana de gravidez (efeito protetor) e peso materno (aumento do risco). Conclusão Em fetos saudáveis, o exercício físico mostrou-se seguro, uma vez que, embora os BCFs e osMAFs diminuam durante a caminhada na esteira, foi observado um aumento da SVT e da LTV.

Maternal, fetal and neonatal heart rate and heart rate variability in Holstein cattle / Frequência cardíaca e variabilidade da frequência cardíaca materna, fetal e neonatal em bovinos da raça Holstein

The aim of this study was to describe the normal values for maternal, fetal and neonatal heart rate (HR) and heart rate variability (HRV) indexes in the time domain (standard deviation of beat-to-beat interval - SDNN; root mean square of successive beat-to-beat differences - RMSSD) and the frequency domain (low frequency - LF; high frequency - HF; relationship between low and high frequency - LF/HF) in 23 Holstein cows, 23 fetuses and 18 neonates during the perinatal period. HR and HRV were calculated by fetomaternal electrocardiography (ECG). Fetomaternal measurements were taken six times prepartum (between days 234 and 279 of pregnancy) and measurements were taken in neonates six times after calving (after birth and five times weekly). HR, time and frequency domain were analyzed. No significant changes in maternal, fetal beat-to-beat interval (RR interval) or HR were found. In maternal variables, SDNN decreased significantly from 38.08±2.6ms (day 14 before calving) to 23.7±2.5ms (day 1 after calving) (p<0.05), but the RMSSD did not change significantly. HR and RR interval of calf differed statistically from the day before delivery (163±7.5bpm; 381±24.2ms) to the day after calving (131±5bpm; 472±16.2ms). Time variables (SDNN and RMSSD) and the frequency-domain variables (LF and HF) were significantly different (p<0.05) between fetal and neonatal stages. Reductions in the values of SDNN and RMSSD can reflect a sympathetic dominance. After calving, the increase in HF and decrease in LF variables can indicate activation of the vagal nerve followed by heart and respiratory modulation.(AU)

O objetivo deste estudo foi descrever os valores normais para os índices de frequência cardíaca (FC) materna, fetal e neonatal e de variabilidade da frequência cardíaca (VFC) no domínio do tempo (desvio padrão do intervalo batimento a batimento, SDNN; raiz quadrada média de sucessivas diferenças de batimento a batimento, RMSSD) e do domínio da frequência (baixa frequência, LF; alta frequência, HF; relação entre baixa e alta frequência, LF/HF) em 23 vacas Holandesas, 23 fetos e 18 neonatos durante o período perinatal. A FC e a VFC foram calculadas por eletrocardiografia materno-fetal. As medidas materno-fetais foram realizadas seis vezes antes do parto (entre os dias 234 e 279 de gestação) as medidas neonatais foram realizadas seis vezes após o parto (um dia após nascimento e semanalmente, durante cinco semanas). FC, e variáveis no domínio do tempo e de frequência foram analisadas. Não foram encontradas alterações significativas na FC e no intervalo de batimento para batimento (intervalo RR) materno e fetal. Nas variáveis maternas, o SDNN diminuiu significativamente de 38,08±2,6ms (dia 14 antes do parto) para 23,7±2,5ms (dia 1 após o parto) (p<0,05), mas o RMSSD não alterou significativamente. A FC e o intervalo e RR do bezerro diferiram estatisticamente a partir de um dia antes do parto (163±7,5bpm, 381±24,2ms) até o dia seguinte ao parto (131±5bpm, 472±16,2ms). As variáveis de tempo (SDNN e RMSSD) e as variáveis de domínio de frequência (LF e HF) foram significativamente diferentes (p<0,05) entre os momentos fetal e neonatal. As reduções nos valores de SDNN e RMSSD podem refletir domínio simpático. Após o parto, o aumento da HF e a diminuição das variáveis LF podem indicar a ativação do nervo vagal seguido de modulação cardíaca e respiratória.(AU)

Maternal, fetal and neonatal heart rate and heart rate variability in Holstein cattle / Frequência cardíaca e variabilidade da frequência cardíaca materna, fetal e neonatal em bovinos da raça Holstein

The aim of this study was to describe the normal values for maternal, fetal and neonatal heart rate (HR) and heart rate variability (HRV) indexes in the time domain (standard deviation of beat-to-beat interval - SDNN; root mean square of successive beat-to-beat differences - RMSSD) and the frequency domain (low frequency - LF; high frequency - HF; relationship between low and high frequency - LF/HF) in 23 Holstein cows, 23 fetuses and 18 neonates during the perinatal period. HR and HRV were calculated by fetomaternal electrocardiography (ECG). Fetomaternal measurements were taken six times prepartum (between days 234 and 279 of pregnancy) and measurements were taken in neonates six times after calving (after birth and five times weekly). HR, time and frequency domain were analyzed. No significant changes in maternal, fetal beat-to-beat interval (RR interval) or HR were found. In maternal variables, SDNN decreased significantly from 38.08±2.6ms (day 14 before calving) to 23.7±2.5ms (day 1 after calving) (p<0.05), but the RMSSD did not change significantly. HR and RR interval of calf differed statistically from the day before delivery (163±7.5bpm; 381±24.2ms) to the day after calving (131±5bpm; 472±16.2ms). Time variables (SDNN and RMSSD) and the frequency-domain variables (LF and HF) were significantly different (p<0.05) between fetal and neonatal stages. Reductions in the values of SDNN and RMSSD can reflect a sympathetic dominance. After calving, the increase in HF and decrease in LF variables can indicate activation of the vagal nerve followed by heart and respiratory modulation.(AU)

O objetivo deste estudo foi descrever os valores normais para os índices de frequência cardíaca (FC) materna, fetal e neonatal e de variabilidade da frequência cardíaca (VFC) no domínio do tempo (desvio padrão do intervalo batimento a batimento, SDNN; raiz quadrada média de sucessivas diferenças de batimento a batimento, RMSSD) e do domínio da frequência (baixa frequência, LF; alta frequência, HF; relação entre baixa e alta frequência, LF/HF) em 23 vacas Holandesas, 23 fetos e 18 neonatos durante o período perinatal. A FC e a VFC foram calculadas por eletrocardiografia materno-fetal. As medidas materno-fetais foram realizadas seis vezes antes do parto (entre os dias 234 e 279 de gestação) as medidas neonatais foram realizadas seis vezes após o parto (um dia após nascimento e semanalmente, durante cinco semanas). FC, e variáveis no domínio do tempo e de frequência foram analisadas. Não foram encontradas alterações significativas na FC e no intervalo de batimento para batimento (intervalo RR) materno e fetal. Nas variáveis maternas, o SDNN diminuiu significativamente de 38,08±2,6ms (dia 14 antes do parto) para 23,7±2,5ms (dia 1 após o parto) (p<0,05), mas o RMSSD não alterou significativamente. A FC e o intervalo e RR do bezerro diferiram estatisticamente a partir de um dia antes do parto (163±7,5bpm, 381±24,2ms) até o dia seguinte ao parto (131±5bpm, 472±16,2ms). As variáveis de tempo (SDNN e RMSSD) e as variáveis de domínio de frequência (LF e HF) foram significativamente diferentes (p<0,05) entre os momentos fetal e neonatal. As reduções nos valores de SDNN e RMSSD podem refletir domínio simpático. Após o parto, o aumento da HF e a diminuição das variáveis LF podem indicar a ativação do nervo vagal seguido de modulação cardíaca e respiratória.(AU)

Computerized Cardiotocography Analysis: Comparison among Several Parental Ethnic Origins / Análise de cardiotocografia computadorizada: comparação entre diversas origens étnicas

ABSTRACT Objective: We speculate that genetic racial disparity exists in fetal life and can be detected by modern computerized cardiotocography (cCTG) . Methods: This is a retrospective study comparing the results of the cCTG of pregnant patients at 37-42 weeks according to the parental ethnicity (black versus white). A cCTG was performed to analyze the variables of fetal heart rate (FHR). The cCTG variables analyzed were: percentage of signal loss; number of contractions; basal FHR; number of accelerations; number of decelerations; length of high variation episodes; short-term variability (STV); total trace duration time; and number of fetal active movements. Non-stress test (NST) parameters in the two groups were compared using the Mann-Whitney test for continuous data, and the Chi-square test for categorical variables. Results: We found a significantly lower number of active fetal movements (p 1/4 0.007) and longer periods of low variation (p 1/4 0.047) in the cCTG of black patients when compared with white patients. Conclusions: In conclusion, identifying the factors responsible for the variance in the objective analysis of CTG results is important to improve the outcomes of patients. Our study lends further evidence as to the importance of ethnicity in clinical cCTG interpretation.

RESUMO Objetivo: Especulamos que disparidade genética racial exist ana vida do feto, e que possa ser detectada por moderna cardiotocografia computadorizada (cCTG). Métodos: Estudo retrospective comparando resultados do cCTG de gestantes entre 37-42 semanas de gestação de acordo com etnicidade dos pais (negro vs. brancos). cCTG foi usado para analisar as variáveis a frequência cardíaca do feto (FHR). As variáveis abalizadas do cCTG foram o % de perda de sinal, número de contrações, basal FHR, número de acelerações, número de desacelerações, comprimento dos episódios de alta variação, viabilidade de curto prazo, tempo total de duração do rastreamento, e número de movimentos de atividade fetal. Os parâmetros do teste de não estresse (NST) em dois grupos foram comparados usando o teste de Mann-Whitney para dados contínuos e teste qui-square para variáveis categóricas. Resultados: Encontramos números significativamente mais baixos de movimentos de atividade fetal (p 1/4 0,007) e períodos mais longos de baixa variação (p 1/4 0,047) no cCTG de pacientes negros se comparados a pacientes brancos. Conclusões: Identificar fatores responsáveis pela variação na análise objetiva dos resultados de CTG é importante em resultados de pacientes que apresentam melhora. Nosso estudo fornece evidências adicionais à importância de estudos clínicos da etnicidade interpretada pelo cCTG.

Transient accelerations of fetal heart rate analyzed by computerized cardiotocography in the third trimester of pregnancy / Acelerações transitórias da frequência cardíaca fetal analisada pela cardiotocografia computadorizada no terceiro trimestre da gestação

Objective: the aim of this study was to investigate the patterns of transient FHR accelerations (10 bpm and 15 bpm) in the third trimester of pregnancy, comparing the occurrence of this event before and after the 32nd gestational week. Methods: This is a prospective study comparing the results of the computerized cardiotocography of 46 low-risk women with singleton pregnancies, maternal age between 18 and 40 years, gestational age between 28 and 40 weeks, absence of maternal morbidity and adequate fetal growth according to ultrasound. Computed Cardiotocography (8002 Sonicaid System and Fetal Care System) was performed for 30 minutes to analyze the variables of FHR. Results: twenty-three pregnant women underwent cardiotocography before 32 weeks (mean = 29.9 weeks, SD = 1.4 weeks) and were compared with 23 pregnant women who were examined after 32 weeks (mean = 36.3 weeks, SD = 2.5 weeks). Regarding the characteristics of FHR, fetuses evaluated between 32 1/7 weeks and 40 weeks showed a significantly greater number of accelerations above 15 bpm (median = 5, variation 0-18) than the group of pregnant women from 28 to 32 weeks (median = 4, variation 0 to 10; P = 0.048). There was a significant positive correlation between the number of accelerations above 15 bpm and the gestational age at examination (rho = 0.33; P = 0.026). Conclusion: computerized cardiotocography showed an association regarding the number of transient accelerations greater than 15 bpm in the assessment of both periods before and after 32 weeks of gestational age, suggesting the influence of the maturation of the fetal autonomic nervous system with pregnancy progression. .

Objetivo: o objetivo deste estudo foi investigar os padrões das acelerações transitórias da FCF (de 10 e 15 bpm) no terceiro trimestre da gestação, comparando a ocorrência desse evento antes e após a 32ª semana gestacional. Métodos: trata-se de estudo prospectivo comparando os resultados do exame de cardiotocografia computadorizada de 46 gestantes de baixo risco, com feto único, idade materna entre 18 e 40 anos, idade gestacional entre 28 e 40 semanas, ausência de morbidades maternas e crescimento fetal adequado pela ultrassonografia. Foi realizada a cardiotocografia computadorizada (Sonicaid System 8002 e Fetal Care System) por 30 minutos para análise das variáveis da FCF. Resultados: vinte e três gestantes que realizaram a cardiotocografia antes da 32ª semana (média = 29,9 semanas, DP = 1,4 semanas) foram comparadas com 23 que realizaram o exame após a 32ª semana (média = 36,3 semanas, DP = 2,5 semanas). Quanto às características da FCF, os fetos avaliados entre 32 1/7 semanas e 40 semanas apresentaram número significativamente maior de acelerações acima de 15 bpm (mediana = 5, variação 0 a 18) que o grupo de gestantes de 28 a 32 semanas (mediana = 4, variação 0 a 10; P = 0,048). Houve correlação significativa e positiva entre o número de acelerações transitórias acima de 15 bpm e a idade gestacional no momento do exame (rho = 0,33; P = 0,026). Conclusão: a cardiotocografia computadorizada revelou associação entre o número de acelerações transitórias acima de 15 bpm quando avaliados os períodos antes e após 32 semanas de idade gestacional, sugerindo influência da maturação do sistema nervoso autônomo fetal com a progressão da gestação. .

Análisis no lineal de la frecuencia cardíaca fetal / Nonlinear analysis of fetal heart rate

Evaluar el comportamiento de la frecuencia cardíaca fetal a través del análisis no lineal en fetos sanos y con restricción del crecimiento intrauterino. Unidad de Perinatología, Departamento Clínico Integral de la Costa, Escuela de Medicina y Departamento de Matemáticas, Facultad de Ciencias y Tecnología, Universidad de Carabobo. Se trata de una investigación observacional, analítica, de corte transversal; se analizaron 60 registros de la frecuencia cardíaca fetal de 40 fetos sanos y de 20 fetos con restricción del crecimiento intrauterino entre las 30 y 42 semanas de gestación. Cada registro de la frecuencia cardíaca fetal en papel se convirtió a formato digital; se estableció la complejidad de cada registro de la frecuencia cardíaca fetal obtenida a través de los métodos de la asimetría del tiempo de reverso y el máximo exponente de Lyapunov. Se utilizó la dimensión de correlación (D2) para cuantificar el comportamiento caótico. Se determinó la complejidad de los registros de la frecuencia cardíaca fetal obtenidos; la dimensión de correlación de los fetos con restricción del crecimiento intrauterino (0,90 ± 0,03) fue menor que la calculada en los fetos sanos (0,93 ± 0,02), probándose su significancia estadística (P = 0,012). La correlación de dimensión disminuidas en fetos con restricción del crecimiento nos indica que la regulación de su dinámica cardíaca es menos compleja, probablemente está limitada la integridad del control del sistema cardiovascular y por ende su capacidad de adaptación frente a noxas externas o internas, estableciendo que el análisis no lineal permite diferenciar los fetos sanos de los fetos con restricción del crecimiento intrauterino.

To evaluate the behavior of the fetal frequency cardiac through nonlinear analysis in healthy fetuses and with intrauterine growth restriction. Unidad de Perinatología, Departamento Clínico Integral de la Costa, Escuela de Medicina y Departamento de Matemáticas, Facultad de Ciencias y Tecnología, Universidad de Carabobo. This work is an observational, analytical investigation, of cross-section; 60 registries of the fetal heart rate of 40 normal fetuses and 20 intrauterine growth restricted fetuses between 30 and 42 gestation weeks were analyzed. Each registry in paper of the fetal heart rate became to digital format; in the search of the possible complex behavior of each monitoring records was applied the asymmetry of the reverse time and the maximum exponent of Lyapunov. The chaotic behavior of each one of them by means of the dimension of correlations was quantified (D2). Was given the complexity of the fetal heart rate records; the correlation dimension of intrauterine growth restricted fetuses (0.90 ± 0.03), was lower than of the normal fetuses (0.93 ± 0.02) proving its statistical significance (P = 0.002). The correlation dimension diminished in intrauterine growth restricted fetuses indicates that the regulation of its cardiac dynamics is less complex, probably is limited the integrity of the cardiovascular control and therefore its capacity of adaptation to external or internal noxas, establishing that the nonlinear analysis allows differentiating the healthy fetuses from intrauterine growth restricted fetuses.

Hemorragia fetomaterna masiva con patrón cardiotocográfico sinusoidal: presentación de un caso y revisión de la literatura / Massive fetomaternal hemorrhage with cardiotocographic sinusoidal rhythm: a case presentation and literature review

Introducción: la transfusión fetomaterna masiva (TFM) es una entidad con una elevada morbilidad y mortalidad fetal, suele cursar con una disminución en la percepción de los movimientos fetales por parte de la madre, y la presencia de un patrón cardiotocográfico sinusoidal fetal, asociado a la anemia fetal. No obstante, ambas situaciones tienen muy baja especificidad. Se presenta un caso clínico con el objetivo de revisar la exactitud del patrón sinusoidal en el diagnóstico de anemia fetal. Materiales y metodos: se presenta el caso de una gestante de 36 semanas que fue atendida en el Hospital Universitario La Paz (complejo hospitalario de tercer nivel que forma parte del conjunto de hospitales públicos en España), en la que tras presentarse un patrón cardiotocográfico no tranquilizador, se realizó una inducción del parto en el que las pruebas habituales de bienestar fetal resultaron insuficientes para el diagnóstico de sufrimiento fetal. Tras un parto eutócico se comprobó la presencia de una anemia neonatal grave, comprobándose la presencia de un gran volumen de sangre fetal en la sangre materna mediante el test de Kleihauer Betke. Se hace una revisión de los artículos publicados en los últimos 10 años en las base de datos Medline vía PubMed, en español e inglés.Conclusión: la monitorización fetal intraparto podría ser útil en el diagnóstico de la hemorragia fetomaterna masiva, aunque se deben hacer estudios más amplios para determinar la exactitud diagnóstica...

Introduction: massive fetomaternal transfusion (MFT) is an entity having high fetal morbidity and mortality; it usually involves the mother’s reduced perception of fetal movements and the presence of a cardiotocographic fetal sinusoidal rhythm, associated with fetal anemia. However, both situations have very low specificity. A clinical case is presented here to arouse interest in reviewing the precision of the sinusoidal rhythm when diagnosing fetal anemia. Materials and methods: the case of a 36-weeks pregnant mother is presented; she attended La Paz teaching hospital (a third-level hospital forming part of the Spanish public hospital system). After presenting a non-reassuring cardiotocographic heart rate pattern, birth was induced in which the usual fetal wellbeing tests proved insufficient for diagnosing fetal suffering. The presence of serious neonatal anemia was shown following a eutocic delivery, the Kleihauer-Betke test proving the presence of a large volume of fetal blood in the mother’s blood. Articles published in both Spanish and English during the last 10 years in the Medline database were reviewed via PubMed. Conclusion: intradelivery fetal monitoring could be useful in diagnosing massive fetal-maternal hemorrhage, even though broader studies should be carried out for determining diagnostic precision...

Sistema inteligente para auxílio ao diagnóstico no monitoramento fetal eletrônico por análise de cardiotocografias / A computer aided diagnostic intelligent system for electronic fetal monitoring based on cardiotocographies

A análise acurada da frequência cardíaca fetal (FCF) correlacionada com as contrações uterinas permite diagnosticar, e consequentemente antecipar, diversos problemas relativos ao bem estar fetal e à preservação de sua vida. O presente trabalho apresenta os resultados de um sistema híbrido, baseado em regras determinísticas e em um módulo de inferência nebuloso do tipo Mamdani, para análise de sinais coletados através de exames denominados cardiotocografias (CTG). As variáveis analisadas são: o valor basal da FCF, suas variabilidades de curto e de longo prazo, acelerações transitórias e desacelerações, sendo estas classificadas por seu tipo e número de ocorrências. São utilizados dois modelos de classificação. A saída do sistema, em qualquer dos modelos, é um diagnóstico de primeiro nível baseado nestas variáveis de entrada. O sistema inteligente para auxílio ao diagnóstico no monitoramento fetal eletrônico por análise de cardiotocografias (SISCTG) foi desenvolvido na linguagem de scripts do programa MATLAB® v.7. O projeto conta também com uma parceria multi-institucional entre o Brasil e a Alemanha, envolvendo o Departamento de Engenharia de Teleinformática (DETI) da Universidade Federal do Ceará (UFC), a Maternidade-Escola Assis Chateaubriand (MEAC), a Technische Universitãt München e a empresa alemã Trium GmbH, que fornece a base de dados utilizada neste trabalho. Os resultados apresentados pelo SISCTG mostram-se promissores, com um índice de acertos (comparando-se os dois modelos utilizados) variando de 83% a 100%, de acordo com o tipo de diagnóstico. Isto permite projetar o aprimoramento deste sistema com novas variáveis de entrada (como a entropia aproximada da FCF e da sua variabilidade). A validação do sistema contou com especialistas brasileiros e alemães na área obstétrica.

The accurate analysis of the fetal heart rate (FHR) and its correlation with uterine contractions (UC) allow the diagnostic and the anticipation of many problems related to fetal distress and the preservation of its life. This paper presents the results of a hybrid system based on a set of deterministic rules and fuzzy inference system developed to analyze FHR and UC signals collected by cardiotocography (CTG) exams. The studied variables are basal FHR, short and long-term FHR variability, transitory accelerations and decelerations, these lasts classified by their type and number of occurrences. Two classification models are used. For both models, the system output is a first level diagnostic based on those input variables. The system is developed using the MATLAB® v.7 script language. The project is also supported by a multi-institutional agreement between Brazil and Germany, among the DETI (Departamento de Engenharia de Teleinformática of the Universidade Federal do Ceará), the MEAC (Maternidade-Escola Assis Chateaubriand), the TUM (Technische Universitãt München), and the Trium GmbH, a German company who supplied the database used in this project. The results are very promising with a diagnostic accuracy (considering the two models used) varying from 83% to 100%, according to the type of diagnostic. These results allow the projection of refinements of the proposed system, inserting new input variables (such as the approximate entropy of the FHR and its variability). The system validation methodology was based on the knowledge of Brazilian and German obstetricians.

Fetal monitoring based on bioelectrical signals from maternal abdomen

Conventional fetal monitoring to evaluate fetal state is based on ultrasound Doppler technique. A new approach proposed in this work relies on analysis of bioelectrical signals recorded from maternal abdominal...

Using of a simple method of maternal ECG processing for fetal heart rate determination

Signals of electrical activity being recorded from maternal abdominal surface contain more information than currently used mechanical heart activity measurement based on ultrasound signals...