The role of non-stress test as a method to evaluate the outcome of high-risk pregnancy: a tertiary care center experience

Background: Non-stress test (NST) is a graphical recording of changes in fetal heart activity and uterine contraction along with fetal movement when uterus is quiescent. NST is primarily a test of fetal condition and it differs from contraction stress test which is a test of uteroplacental function. The present study aimed at evaluating the efficacy and diagnostic value of NST for antenatal surveillance in high-risk pregnancy and comparing the mode of delivery with test results.Methods: A clinical study of NST was done between November 2014 to October 2015. NST was used for their surveillance from 32 weeks of gestation and NST was recorded weekly, biweekly, on alternate days or even on daily basis depending on high risk factors and were followed up.Results: A total of 100 cases were enrolled in the study. The mean age of patients was 25.09±3.78 years. In all 14 cases (23.3%) with reactive NST underwent lower caesarean section (LSCS) whereas 36 cases (90%) with non-reactive NST underwent LSCS. The mean NST delivery interval with reactive NST was 9.8±7.1 hours and in cases with non-reactive NST it was 9.2±8.6 hours, the difference was statistically not significant (p=0.70).Conclusions: NST tells about acute fetal hypoxia and decision to delivery time can be made for those patients with fetal distress so that a major improvement in the outcome among parturient can be achieved with abnormal NST results. An abnormal NST should alert the clinician of fetal compromise and has to be followed up by other biophysical tests.

The pattern of variations in the first trimester fetal heart rate in Indian population: a pilot study

Background: Fetal heart rate is an indicator of fetal viability. During third trimester and labour the normal range of fetal heart rate is between 110-160 bpm as recommended by the international guidelines. Unlike this, the first trimester embryonic heart rate does not lie in the same range. During the first trimester the normal embryonic heart rate varies between each week of gestation, as determined by a few western studies. Indian studies on the same are not available. Objective of this study was to determine the trend of the fetal heart rate in first trimester of pregnancy in South Indian women.Methods: Transvaginal scan was done in 51 pregnant women with singleton pregnancy attending the antenatal clinic in a medical college hospital. Crown rump length and fetal heart rate were measured and plotted on a graph. Also, the fetal heart rate at different gestational age of our study was compared with the fetal heart rates at the same gestational age from the studies in the western population.Results: The range of fetal heart rate at different weeks of gestation was comparable to the heart rate variations as seen in the western population. The maximum heart rates at 9 weeks of gestation in our study was higher than the heart rate in the western population.Conclusions: Possibility of variation in the fetal heart rates in the first trimester in different populations cannot be ruled out until confirmed by studies with large sample size.

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.

Study of Oligohydramnios and its perinatal outcome

Background: Importance of amniotic fluid volume as an indicator of fetal status is being appreciated relatively recently. Around 3% to 8% of pregnant women are presenting with low amniotic fluid at any point of pregnancy. The present study was undertaken to study the outcome of pregnancies with Oligohydramnios [(amniotic fluid index) AFI≤5cm] at or beyond 34 weeks.Methods: This study consists of 50 cases of antenatal patients with oligohydramnios (AFI≤5) at or beyond 34 weeks of gestation compared with age and gestation matched 50 normal liquor (AFI≥5 and ≤25). The outcome measures recorded were labor, gestational age at delivery, amniotic fluid index (AFI), mode of delivery, indication for cesarean section or instrumental delivery, APGAR score and birth weight.Results: In the present study, AFI was significantly decreased in cases (3.74±1.2) compared (12.54±2.5) with controls. Variable deceleration was noted in 14 (28%) and late deceleration in 5 (10%) cases. In control group, 2 (4%) had late deceleration. In cases induced labor is in 14 (28%), spontaneous labor 36 (72%). In cases, term normal vaginal delivery was in 15 (30%), PVD in 6 (12%), LSCS in 28 (56%) and instrumental vaginal delivery in 1 (2%). In controls, full term normal vaginal delivery was in 41 (82%), PVD in 5 (10%), LSCS in 4 (8%). APGAR score <7 at 1 minute was in 19 (38%) and at 5 minutes was in 5 (10%) in cases. Birth weight is reduced in cases. IUGR was reported in 9 (18%) in cases.Conclusions: Pregnancies with Oligohydramnios (AFI≤5) is associated with increased rate of non-reactive NST. Routine induction of labor for Oligohydramnios is not recommended. It is preferable to allow patients to go into spontaneous labor with continuous FHR monitoring. Antepartum diagnosis of Oligohydramnios warrants close fetal surveillance.

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)

Optimal template selecting combined with non-liner template matching for Doppler fetal heart rate extraction / 生物医学工程学杂志

The ultrasound Doppler fetal heart rate measurement is the gold standard of fetal heart rate counting. However, the existing fetal heart rate extraction algorithms are not designed specifically to suppress the high maternal interference during the second stage of labor, and false detection occurrences are common during labor. With this background, a method combining time-frequency frame template library optimal selecting and non-linear template matching is proposed. The method contributes a template library, and the optimal template can be selected to match the signal frame. After the short-time Fourier transform of the signal, the difference between the signal and the template is optimized by leaky rectified linear unit (LReLU) function frame by frame. The heart rate was calculated from the peak of the matching curve and the heart rate was calculated. By comparing the proposed method with the autocorrelation method, the results show that the detection accuracy of the proposed method is improved by 20% on average, and the non-linear template matching of 23% samples is at least 50% higher than the autocorrelation method. This paper designs the algorithm by analyzing the characteristics of the interference and signal mixing. We hope that this paper will provide a new idea for fetal heart rate extraction which not only focuses on the original signal.

Intelligent fetal state assessment based on genetic algorithm and least square support vector machine / 生物医学工程学杂志

Cardiotocography (CTG) is a commonly used technique of electronic fetal monitoring (EFM) for evaluating fetal well-being, which has the disadvantage of lower diagnostic rate caused by subjective factors. To reduce the rate of misdiagnosis and assist obstetricians in making accurate medical decisions, this paper proposed an intelligent assessment approach for analyzing fetal state based on fetal heart rate (FHR) signals. First, the FHR signals from the public database of the Czech Technical University-University Hospital in Brno (CTU-UHB) was preprocessed, and the comprehensive features were extracted. Then the optimal feature subset based on the -nearest neighbor (KNN) genetic algorithm (GA) was selected. At last the classification using least square support vector machine (LS-SVM) was executed. The experimental results showed that the classification of fetal state achieved better performance using the proposed method in this paper: the accuracy is 91%, sensitivity is 89%, specificity is 94%, quality index is 92%, and area under the receiver operating characteristic curve is 92%, which can assist clinicians in assessing fetal state effectively.

Anti-disturbance Fetal Heart Rate System Based on Combined Maternal-fetal Monitoring / 中国医疗器械杂志

The existing fetal monitor is prone to false detection in the case of high maternal interference in the second stage of labor. With this background, the article designs and implements a combined maternal-fetal fetal heart monitoring system. The system obtains the Doppler signal of the abdominal fetal heart and the blood oxygen signal of the mother's finger, and estimates the maternal interference degree in the fetal heart rate Doppler signal according to the maximum correlation value between the maternal finger blood oxygen signal and the abdominal fetal heart Doppler signal, and switches the fetal heart rate extraction algorithm between the autocorrelation method suitable for lower interference and improved template method suitable for higher interference according to the maternal interference degree. The accuracy of our method is 9.2% which is higher than that of the improved template matching method and 6.1% higher than that of the autocorrelation method.

Evaluation of clinical application value of remote fetal heart monitoring / 中国实用妇科与产科杂志

Remote fetal heart monitoring technology is an open-distributed monitoring system,which is the supplement of inpatient fetal heart rate monitoring and the outpatient extension of perinatal health care.It has enriched the connotation of family self-monitoring and is a strong guarantee of fetal safety.It opens up an effective,practical and feasible new way for the pregnancy management of high-risk pregnancy and fetus with umbilical cord factors.Scientific management and quality control are the preconditions for the development and promotion of remote fetal heart monitoring.

Intrapartum management of category Ⅱ fetal heart rate tracings / 中国实用妇科与产科杂志

The category Ⅱ fetal heart rate(FHR)tracings,which have various forms,are the common patterns of electronic fetal monitoring(EFM)during labor.The correct identification and assessment of categoryⅡ FHR tracings,as well as the targeted intervention according to specific clinical conditions,can reduce the occurrence of adverse pregnancy outcomes.This article introduces the intrapartum management process of categoryⅡFHR tracings according to the three-tier system for the categorization of intrapartum EFM,and expounds the causes and intervention measures of different types of categoryⅡFHR tracings,so as to guide clinical practice.

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.

Fetal heart rate monitoring: from Doppler to computerized analysis

The monitoring of fetal heart rate (FHR) status is an important method to check well-being of the baby during labor. Since the electronic FHR monitoring was introduced 40 years ago, it has been expected to be an innovative screening test to detect fetuses who are becoming hypoxic and who may benefit from cesarean delivery or operative vaginal delivery. However, several randomized controlled trials have failed to prove that electronic FHR monitoring had any benefit of reducing the perinatal mortality and morbidity. Also it is now clear that the FHR monitoring had high intra- and interobserver disagreements and increased the rate of cesarean delivery. Despite such limitations, the FHR monitoring is still one of the most important obstetric procedures in clinical practice, and the cardiotocogram is the most-used equipment. To supplement cardiotocogram, new methods of computerized FHR analysis and electrocardiogram have been developed, and several clinical researches have been currently performed. Computerized equipment makes us to analyze beat-to-beat variability and short term heart rate patterns. Furthermore, researches about multiparameters of FHR variability will be ongoing.

Effect of Music Intervention on Maternal Anxiety and Fetal Heart Rate Pattern During Non-Stress Test

PURPOSE: The purpose of this cross-over experimental study was to examine effects of music intervention on maternal anxiety, fetal heart rate pattern and testing time during non-stress tests (NST) for antenatal fetal assessment. METHODS: Sixty pregnant women within 28 to 40 gestational weeks were randomly assigned to either the experimental group (n=30) or control group (n=30). Music intervention was provided to pregnant women in the experimental group during NST. Degree of maternal anxiety and fetal heart rate pattern were our primary outcomes. State-trait anxiety inventory, blood pressure, pulse rate, and changes in peripheral skin temperature were assessed to determine the degree of maternal anxiety. Baseline fetal heart rate, frequency of acceleration in fetal heart rate, fetal movement test and testing time for reactive NST were assessed to measure the fetal heart rate pattern. RESULTS: The experimental group showed significantly lower scores in state anxiety than the control group. There were no significant differences in systolic blood pressure and pulse rate between the two groups. Baseline fetal heart rate was significantly lower in the experimental group than in the control group. Frequency of acceleration in fetal heart rate was significantly increased in the experimental group compared to the control group. There were no significant differences in fetal movement and testing time for reactive NST between the two groups. CONCLUSION: Present results suggest that music intervention could be an effective nursing intervention for alel viating anxiety during non-stress test.

Exercise stress test through brisk walking: A complimentary way to assess fetal well-being in term pregnancy / Philippine Journal of Obstetrics and Gynecology

OBJECTIVE: To determine the effect of exercise stress test (EST) through brisk walking on the cardiotocogram tracings (CTGs) and the association of the tracings to neonatal outcomes. METHODOLOGY: This one-group pretest-post test experimental study involved 65 term pregnant women (mean age = 25.94 + 4.66 years) who underwent brisk walking exercise using a motorized treadmill for 30 minutes, following American College of Obstetricians and Gynecologists (ACOG) guidelines for exercise among pregnant women. Pre- and post- walk CTGs were assessed, with presence of post-walk decelerations taken to mean a positive EST. Sensitivity (positive EST in sick / meconium-stained / cord coil babies), specificity (negative EST in well babies), positive predictive value (PPV) (probability of sick / meconium-stained / cord coil babies given positive EST) and negative predictive value (NPV) (probability of well babies given negative EST) were computed. RESULTS: A significant difference in the proportion of subjects with pre- and post- walk decelerations was noted (p-value = 0.000) wherein 18 subjects (28.13%) without decelerations in the baseline CTG had decelerations in the post-walk CTG. These decelerations were significantly associated to having sick, meconium-stained, or cord coil babies (p-values CONCLUSION: Exercise stress testing is a complementary way of assessing fetal well-being due to manifestation of decelerations in the post-walk CTG which could have gone undetected if only the resting CTG was done. The EST had high sensitivity for detecting sick / meconium-stained / cord coil babies and has the advantage of reinforcing a reassuring fetal condition due to its high NPV for detecting well babies.

To compare intrapartum cardiotocographic (CTG) recording with conventional intermittent auscultation during labor.

Standard evaluation of fetal well-being during labor includes the periodic assessment of the fetal heart rate (FHR), its pattern and response to intrapartum stimuli and events. Effective methods of evaluation and meaningful interpretation of FHR data range from non-invasive techniques like Intermittent Auscultation, continuous electronic fetal heart rate (FHR) monitoring to invasive techniques of fetal blood gas analysis and fetal ECG.

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. .

Fetal Heart Rate Regresses toward the Mean in the Third Trimester

The purpose of this study was to investigate the feasibility of different fetal heart rate (FHR) ranges in the nonstress test (NST) and to better understand the meaning of mild bradycardia and/or tachycardia without non-reassuring patterns. We employed the heredity to show that mild bradycardia (100-119 beats per minute, bpm) and mild tachycardia (161-180 bpm) regressed to the normal FHR range (120-160 bpm). We used linear regression to analyze FHR data from FHR tracings recorded 10 min before (NST, as the predictor) and 10 min after vibroacoustic stimulation testing (as the dependent variable). Acceleration for 15 bpm-15 seconds (Acc1515) and deceleration for 15 bpm-15 seconds (Dec1515) in the NST were also analyzed for each group. The slope of the best-fit line was the largest in the mild bradycardia group and the smallest in the normal range group. Dec1515 was most prominent in mild tachycardia and both the mild bradycardia and tachycardia groups regressed towards the mean FHR range. Therefore, we propose that both mild bradycardia and tachycardia of FHR in non-acute situations (range between 100 and 180 bpm) are not regarded a pathologic signal for clinical use.

Second stage fetal heart rate patterns and neonatal acid-base status

Background: Fetal surveillance in labour is performed mostly to identify fetuses at risk of hypoxia in order to reduce neonatal morbidity and mortality by initiating timely intervention. While normal and abnormal fetal heart rate (FHR) patterns have been well recognised and characterized for the first stage of labour, FHR patterns during the second stage of labour commonly showed some forms of abnormalities leading to problems in interpretation, particularly in predicting fetal hypoxia and acidosis. This study aims to identify patterns of FHR tracing during the second stage of labour associated with neonatal acidosis. Methods: A prospective cross sectional study was conducted in the Labour Ward of a state referral hospital. The study population were patients with low-risk singleton pregnancies between 37 to 42 weeks gestation who had normal cardiotocograph (CTG) tracing in the first stage of labour. CTG was recorded during the second stage of labour and neonatal umbilical cord blood was obtained for acid-base analysis immediately after birth prior to the delivery of placenta. FHR patterns were grouped according to modified Melchior and Barnard’s classification and matched with neonatal acid-base status. Patients with normal FHR pattern in the second stage acted as control. Results: A total of 111 matched pairs were analysed. Ninety nine (89.2%) second stage FHR tracings showed abnormal features when compared to control. There were significantly more neonatal acidosis and hypercapnia in type 1b, type 2a, type 2b and type 3 CTG patterns compared to control, in increasing order of severity. In addition, types 2b and 3 showed significant difference in the base excess. Conclusion: Certain second stage fetal heart rate patterns were found to be associated with neonatal acidosis.

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...