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BACKGROUND: Little is known about how and why metabolic acidosis changes within the first six hours of life in intensive care unit neonates. OBJECTIVE: To determine changes in pH and base excess between paired umbilical cord arterial and neonatal arterial blood samples during the first 6 h of life, to identify factors associated with the direction and magnitude of change, and to examine morbidity and mortality in newborns with acidosis at birth or as neonates. STUDY DESIGN: Retrospective cohort study of all deliveries from a single institution between 2016-2020 with paired umbilical cord arterial and neonatal arterial samples obtained within 6 h of life meeting rigorous criteria to ensure sample integrity. The primary outcomes were the direction and magnitude of change of pH and base excess. Multiple factors were assessed for possible correlation with pH and base excess change. The secondary outcome was the association between a composite outcome of death or cerebral palsy and pathologic acidosis (pH ≤ 7.1) at birth or as a neonate. RESULTS: 102 patients met inclusion criteria. Newborn arterial gasses were obtained at a median of 1.5 h (74 % < 2 h). pH improved in 71 % of cases and worsened in 29 %, and base excess improved in 52 % and worsened in 48 %, with wide observed ranges in both parameters. The paired pH and base excess values were moderately (r = 0.38) and strongly (r = 0.63) positively correlated, respectively, but were not correlated with time since birth (r = 0.14). Low birth weight, prematurity or respiratory failure were associated with worsening or less improvement, while worse initial acidosis was associated with greater improvement. Death or survival with cerebral palsy was more common with pathologic acidosis in either cord or newborn sample as compared with those without acidosis (27.3 % vs 3.7 %, p = 0.003), and was more common in those with isolated neonatal acidosis as compared to those without acidosis (50 % vs 3.7 %, p = 0.016). CONCLUSIONS: Changes in pH and base excess occurred over a wide range between delivery and the first newborn blood gas in the first 6 h of life, and we identified several factors associated with direction of change. Metabolic acidosis at birth cannot reliably be inferred from neonatal arterial values. Neonatal acidosis, including acidosis following a normal pH and base excess at birth, was associated with morbidity and mortality.

Asunto(s)

Acidosis , Unidades de Cuidado Intensivo Neonatal , Humanos , Recién Nacido , Acidosis/sangre , Acidosis/epidemiología , Estudios Retrospectivos , Femenino , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Masculino , Concentración de Iones de Hidrógeno , Sangre Fetal/química , Arterias Umbilicales

RESUMEN

BACKGROUND: In clinical medicine, fetal heart rate (FHR) monitoring using cardiotocography (CTG) is one of the most commonly used methods for assessing fetal acidosis. However, as the visual interpretation of CTG depends on the subjective judgment of the clinician, this has led to high inter-observer and intra-observer variability, making it necessary to introduce automated diagnostic techniques. METHODS: In this study, we propose a computer-aided diagnostic algorithm (Hybrid-FHR) for fetal acidosis to assist physicians in making objective decisions and taking timely interventions. Hybrid-FHR uses multi-modal features, including one-dimensional FHR signals and three types of expert features designed based on prior knowledge (morphological time domain, frequency domain, and nonlinear). To extract the spatiotemporal feature representation of one-dimensional FHR signals, we designed a multi-scale squeeze and excitation temporal convolutional network (SE-TCN) backbone model based on dilated causal convolution, which can effectively capture the long-term dependence of FHR signals by expanding the receptive field of each layer's convolution kernel while maintaining a relatively small parameter size. In addition, we proposed a cross-modal feature fusion (CMFF) method that uses multi-head attention mechanisms to explore the relationships between different modalities, obtaining more informative feature representations and improving diagnostic accuracy. RESULTS: Our ablation experiments show that the Hybrid-FHR outperforms traditional previous methods, with average accuracy, specificity, sensitivity, precision, and F1 score of 96.8, 97.5, 96, 97.5, and 96.7%, respectively. CONCLUSIONS: Our algorithm enables automated CTG analysis, assisting healthcare professionals in the early identification of fetal acidosis and the prompt implementation of interventions.

Asunto(s)

Acidosis , Enfermedades Fetales , Femenino , Embarazo , Humanos , Acidosis/diagnóstico , Algoritmos , Cardiotocografía , Toma de Decisiones , Inteligencia Artificial

RESUMEN

OBJECTIVE: Baroreflex is a regulatory mechanism that slows the fetal heart rate. This study aimed to investigate the effects of lipopolysaccharide (LPS)-induced endotoxemia on fetal baroreceptor sensitivity in preterm fetal sheep. METHODS: The changes in fetal baroreceptor sensitivity were measured in seven chronically instrumented preterm fetal sheep. Fetal baroreceptor sensitivity was measured in three phases: (A) control phase, defined as the 24 h before the first injection of LPS; (B) acute phase, defined as the 24 h between the first and second injections of LPS; and (C) fetal acidosis phase, defined as the time from the second LPS injection until intrauterine fetal death. Histological examinations of the fetal membrane and umbilical cord were also conducted. RESULTS: Each fetus developed metabolic acidosis after the second injection of LPS. The fetuses died 24.7 (SD = 6.1) hours after the second injection of LPS. Both the umbilical cord and fetal membranes showed histological evidence of severe inflammation. In total, 163 fetal baroreceptor measurements were performed in this experiment (A, n = 77 times; B, n = 60 times; C, n = 26 times). Fetal baroreceptor sensitivity showed significant differences in all three phases (A: 2.7 [SD = 0.2]; B: 2.5 [SD = 0.2]; and C: 1.5 [SD = 0.2]). Post hoc tests showed that baroreceptor sensitivity in the acidosis phase had decreased significantly compared to that in the control and acute phases (p<.001 and p=.002, respectively). CONCLUSIONS: Fetal baroreceptor sensitivity decreased during fetal acidosis induced by LPSs.

Asunto(s)

Acidosis , Enfermedades Fetales , Embarazo , Femenino , Humanos , Ovinos , Animales , Lipopolisacáridos , Presorreceptores/metabolismo , Presorreceptores/patología , Feto/patología , Inflamación/inducido químicamente , Inflamación/patología , Frecuencia Cardíaca Fetal

RESUMEN

OBJECTIVE: To assess the association of fetal heart rate short-term variability (STV) pattern during term labor with both neonatal composite morbidity (cord blood pH ≤ 7.10 and/or neonatal intensive care unit admission and/or Apgar score at 5 min <7) and small for gestational age (SGA) status. STUDY DESIGN: Retrospective cohort in a single academic institution between January 2016 and December 2018. A total of 1896 women that delivered a singleton during labor in cephalic presentation after 37 weeks of gestation were included (948 women with SGA neonates and 948 women with appropriate weight for gestational age (AGA) neonates that were matched to women with SGA neonates based on maternal age, parity, induction of labor, gestational diabetes, gestational age at delivery and a history of one cesarean section using propensity score matching). STV was compared at labor onset (cervical dilation ≤ 4 cm), in the first stage of labor (cervical dilation = 6 cm) and in the second stage of labor (cervical dilation = 10 cm). A generalized linear mixed model was used to assess the association between SGA status, neonatal composite morbidity and STV. RESULTS: After adjustment for maternal origin, term, gestational diabetes, labor length, SGA status was not associated with any change in STV during labor (mean adjusted STV: -0.20 ms, 95 %CI[-0.58-0.17], p = 0.284 at labor onset, 0.29 ms, 95 %CI[-0.1- 0.68], p = 0.155, in the first stage of labor and 0.36 ms, 95 %CI[-0.02-0.74], p = 0.065 in the second stage of labor). In case of neonatal composite morbidity mean adjusted STV was lower in the first stage of labor (mean adjusted STV: -1.29 ms, 95 %CI[-2.1 - -0.43], p = 0.003) and in the second stage of labor (mean adjusted STV: -1.15 ms, 95 %CI[-1.96 - -0.34], p = 0.005). The results were similar with the addition of delivery mode and meconium-stained amniotic fluid in the model or non-reassuring fetal heart rate and meconium-stained amniotic fluid. CONCLUSIONS: This work suggests that STV decrease during term labor is associated with fetal well-being, independently of fetal weight. This suggests that further prospective studies should consider the evaluation of this parameter in the prediction of neonatal compromise.

Asunto(s)

Enfermedades del Recién Nacido , Trabajo de Parto , Recién Nacido , Embarazo , Femenino , Humanos , Cesárea , Edad Gestacional , Frecuencia Cardíaca Fetal , Estudios Retrospectivos , Estudios Prospectivos , Recién Nacido Pequeño para la Edad Gestacional , Retardo del Crecimiento Fetal , Morbilidad

RESUMEN

BACKGROUND: Calcium, a physiological ion, causes vasoconstriction and has a positive ionotropic action on heart. Its use to prevent post-spinal hypotension has been suggested but never formally evaluated for patients undergoing caesarean section. This study investigated the hemodynamic effects of calcium administration in parturients with the primary aim of comparing the incidence of post-spinal hypotension. METHODS: Sixty healthy full-term pregnant patients scheduled for caesarean section were randomly allocated to two equal groups to receive either calcium gluconate or normal Saline bolus over 20min by syringe infusion pump under electrocardiography monitoring immediately after the patient was turned supine following spinal anaesthesia. Blood pressure and heart rate were recorded at baseline, and at regular intervals following spinal. Maternal calcium levels were estimated before and after infusion. Neonatal blood gas analysis and calcium level were analyzed. Total mephentermine requirement was recorded in both groups. RESULTS: The heart rate values remained comparable to baseline value in group calcium gluconate while in group normal Saline, it decreased significantly at 8,12 and 16min. Blood pressure decreased significantly as compared to the baseline value from 4min onwards in both the groups. However, it was comparable in the two groups at all time points(0.622). Nineteen patients(63.33%) required mephentermine infusion in group calcium gluconate as compared to 23 patients(76.6%) in group normal Saline for maintenance of systolic blood pressure.(p=0.791) Umbilical venous pH (p=0.038) and partial pressure of carbon dioxide(p=0.038) were significantly better in group calcium gluconate. CONCLUSIONS: Calcium used for prophylaxis of hypotension in healthy parturients undergoing caesarean section reduced the vasopressor requirements and total mephenteramine dose, but the difference did not attain statistical significance.

Asunto(s)

Anestesia Obstétrica , Anestesia Raquidea , Hipotensión , Anestesia Obstétrica/efectos adversos , Anestesia Raquidea/efectos adversos , Calcio/uso terapéutico , Gluconato de Calcio/uso terapéutico , Cesárea/efectos adversos , Método Doble Ciego , Femenino , Humanos , Hipotensión/tratamiento farmacológico , Hipotensión/etiología , Hipotensión/prevención & control , Recién Nacido , Mefentermina/uso terapéutico , Nepal , Fenilefrina/uso terapéutico , Embarazo , Solución Salina/uso terapéutico

RESUMEN

BACKGROUND: Transition of clear amniotic fluid to meconium-stained fluid is a relatively common occurrence during labor. However, data regarding the clinical significance and the prognostic value of the presence of meconium-stained amnionic fluid (MSAF) are scarce. This study aimed to investigate delivery and neonatal outcomes according to the presence of MSAF and the timing of the meconium passage. METHODS: We used an historical cohort study at a single tertiary medical center in Israel between the years 2011 and 2018. Women were divided into two groups according to timing of meconium passage: primary MSAF (MSAF present at membrane rupture) and secondary MSAF (clear amnionic fluid that transitioned to MSAF during labor). Neonatal complication rates were compared between groups. Composite adverse neonatal outcome was defined as arterial cord blood pH <7.1, 5 min Apgar score ≤7, and/or neonatal intensive care unit admission. RESULTS: The study cohort included 56 863 singleton term births. Of these, 9043 (15.9%) were to women who had primary MSAF, and 1484 (2.6%) to those with secondary MSAF. Secondary MSAF compared with primary MSAF increased the risks of cesarean birth and operative vaginal delivery, increased the risks of low one- and five-minute Apgar scores and low arterial cord blood pH, and increased hospital stay duration. Multivariate analysis revealed that secondary MSAF was independently associated with an increased risk of composite adverse neonatal outcome (OR1.68, 95% CI 1.25-2.24, p < 0.001) compared with primary MSAF. CONCLUSIONS: In this sample, secondary MSAF was associated with more adverse neonatal outcomes than primary MSAF. Closer monitoring of fetal well-being may be prudent in these cases.

Asunto(s)

Enfermedades del Recién Nacido , Complicaciones del Embarazo , Recién Nacido , Embarazo , Femenino , Humanos , Meconio , Líquido Amniótico , Estudios de Cohortes , Puntaje de Apgar

RESUMEN

OBJECTIVE: Current guidelines provide little supporting literature for the definition of uterine tachysystole during labour and no distinction is made for optimal contraction frequency depending on the clinical situation. We hypothesize that fetal hypoxia is frequently caused by uterine tachysystole and that high uterine contraction frequencies are especially harmful when fetal heart rate (FHR) abnormalities are present. We studied the association between contraction frequency and fetal scalp pH values in women with an indication for fetal blood sampling (FBS) based on FHR abnormalities. STUDY DESIGN: A retrospective study including 762 women was performed in a tertiary teaching hospital in the Netherlands from January 2015 until January 2020. Women with a singleton pregnancy with a gestational age ≥ 34+0 weeks were included when FBS was performed because of suspicious or pathological FHR tracings. Exclusion criteria were maternal age < 18 years, failed fetal scalp pH values, lack of thirty minute registration by tocodynamometry prior to FBS, poor quality of uterine monitoring, intrauterine resuscitation in the thirty minutes prior to FBS, maternal body mass index ≥ 30 kg/m2 and neonatal birth weight < 10th percentile. Uterine contractions in the thirty minutes prior to FBS were manually annotated by a researcher who was blinded to FBS values, FHR and other obstetrical data. Linear and logistic analysis were used to explore the association between uterine contraction frequency and FBS results. RESULTS: Low fetal scalp pH values were significantly associated with contraction frequency prior to FBS. Fetuses of women with four to five contractions per ten minutes prior to FBS were 2.4 times more likely to have hypoxia as compared to fetuses of women with two to three contractions per ten minutes (aOR 2.4, 95% CI 1.1-5.4). With increasing contraction frequency, the risk of fetal hypoxia further increased. CONCLUSIONS: Contraction frequency above four per ten minutes prior to FBS is significantly associated with fetal hypoxia in women with FHR abnormalities. We suggest to aim for a maximum contraction frequency of four per ten minutes in these women.

Asunto(s)

Frecuencia Cardíaca Fetal , Contracción Uterina , Adolescente , Femenino , Feto , Frecuencia Cardíaca Fetal/fisiología , Humanos , Concentración de Iones de Hidrógeno , Lactante , Recién Nacido , Embarazo , Estudios Retrospectivos , Cuero Cabelludo

RESUMEN

Fetal acidosis is one of the main concerns during labor. Currently, fetal blood sampling (FBS) has become the most accurate measurement of acidosis detection. However, it is invasive and does not provide a real time measurement due to laboratory procedures. Delays in diagnosis of acidosis have caused serious injury to the fetus, especially for the brain and the heart. This paper reviews the new technique in diagnosis of acidosis non-invasively. Magnetic Induction Spectroscopy (MIS) has been proposed to be a new device for acidosis detection in recent years. This paper explains the basic principle of MIS and outlines the design specifications and design considerations for a MIS pH probe. It is expected that readers will gain a basic understanding of the development of a MIS pH probe from this review.

Asunto(s)

Acidosis , Sangre Fetal , Acidosis/diagnóstico , Femenino , Sangre Fetal/química , Frecuencia Cardíaca Fetal , Humanos , Concentración de Iones de Hidrógeno , Fenómenos Magnéticos , Embarazo , Cuero Cabelludo , Análisis Espectral

RESUMEN

OBJECTIVE: To investigate the predictive value of pre-induction digital examination, sonographic measurements and parity for the prediction of non-reassuring fetal status and cord arterial pH < 7.2 prior to the induction of labor (IOL). METHOD: This was a prospective observational study, including 384 term pregnancies undergoing IOL. Before the IOL, the Bishop score (BS) by digital examination, sonographic Doppler parameters and the estimated fetal weight (EFW) was assessed. The fetal cord arterial was sampled to measure the pH at delivery. Multivariate logistic regression analysis was performed to identify independent predictors of non-reassuring fetal status and low cord arterial pH. RESULTS: Forty four cases (11.5%) had non-reassuring fetal status, and 76 cases (19.8%) had fetal cord arterial pH < 7.2. In the non-reassuring fetal status group, the incidence of cord arterial pH < 7.2 was significantly higher than that in the normal fetal heart rate group (χ2 = 6.401, p = 0.011). Multivariate analysis indicated that significant independent predictors of non-reassuring fetal status were nulliparity (adjusted odds ratio [AOR]: 3.746, p = 0.003), EFW < 10th percentile (AOR: 3.764, p = 0.003) and cerebroplacental ratio (CPR) < 10th centile (AOR:4.755, p < 0.001). In the prediction of non-reassuring fetal status, the performance of the combination of nulliparity and EFW < 10th percentile was improved by the addition of CPR < 10th percentile (AUC: 0.681, (95%CI: 0.636 to 0.742) vs 0.756, (95%CI:0.713 to 0.795)), but the difference was not significant (DeLong test: z = 1.039, p = 0.053).. None of the above variables were predictors of cord arterial pH < 7.2. CONCLUSION: The risk of fetal acidosis has increased in cases of non-reassuring fetal status. Nulliparity, small for gestational age and CPR < 10th centile are independent predictors for non-reassuring fetal status in term fetuses, though the addition of CPR < 10th centile could not significantly improve the screening accuracy.

Asunto(s)

Acidosis/diagnóstico , Enfermedades Fetales/diagnóstico , Circulación Placentaria , Diagnóstico Prenatal/métodos , Ultrasonografía Prenatal/métodos , Acidosis/embriología , Adulto , Femenino , Peso Fetal , Feto/irrigación sanguínea , Feto/diagnóstico por imagen , Feto/embriología , Frecuencia Cardíaca Fetal , Humanos , Concentración de Iones de Hidrógeno , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Trabajo de Parto Inducido , Modelos Logísticos , Arteria Cerebral Media/diagnóstico por imagen , Arteria Cerebral Media/embriología , Arteria Cerebral Media/metabolismo , Análisis Multivariante , Oportunidad Relativa , Paridad , Valor Predictivo de las Pruebas , Embarazo , Tercer Trimestre del Embarazo/metabolismo , Estudios Prospectivos , Flujo Pulsátil , Ultrasonografía Doppler , Arterias Umbilicales/diagnóstico por imagen , Arterias Umbilicales/embriología , Arterias Umbilicales/metabolismo

RESUMEN

An increasing number of delivering women experience major morbidity and mortality. Limited work has been done on automated predictive models that could be used for prevention. Using only routinely collected obstetrical data, this study aimed to develop a predictive model suitable for real-time use with an electronic medical record. We used a retrospective cohort study design with split validation. The denominator consisted of women admitted to a delivery service. The numerator consisted of women who experienced a composite outcome that included both maternal (eg, uterine rupture, postpartum hemorrhage), fetal (eg, stillbirth), and neonatal (eg, hypoxic ischemic encephalopathy) adverse events. We employed machine learning methods, assessing model performance using the area under the receiver operator characteristic curve and number needed to evaluate. A total of 303,678 deliveries took place at 15 study hospitals between January 1, 2010, and March 31, 2018, and 4130 (1.36%) had ≥1 obstetrical complication. We employed data from 209,611 randomly selected deliveries (January 1, 2010, to March 31, 2017) as a derivation dataset and validated our findings on data from 52,398 randomly selected deliveries during the same time period (validation 1 dataset). We then applied our model to data from 41,669 deliveries from the last year of the study (April 1, 2017, to March 31, 2018 [validation 2 dataset]). Our model included 35 variables (eg, demographics, vital signs, laboratory tests, progress of labor indicators). In the validation 2 dataset, a gradient boosted model (area under the receiver operating characteristic curve or c statistic, 0.786) was slightly superior to a logistic regression model (c statistic, 0.778). Using an alert threshold of 4.1%, our final model would flag 16.7% of women and detect 52% of adverse outcomes, with a number needed to evaluate of 20.9 and 0.455 first alerts per day per 1000 annual deliveries. In conclusion, electronic medical record data can be used to predict obstetrical complications. The clinical utility of these automated models has not yet been demonstrated. To conduct interventions to assess whether using these models results in patient benefit, future work will need to focus on the development of clinical protocols suitable for use in interventions.

Asunto(s)

Reglas de Decisión Clínica , Registros Electrónicos de Salud , Hipoxia-Isquemia Encefálica/epidemiología , Aprendizaje Automático , Complicaciones del Trabajo de Parto/epidemiología , Preeclampsia/epidemiología , Mortinato/epidemiología , Adulto , Presión Sanguínea , Femenino , Humanos , Edad Materna , Obesidad Materna/epidemiología , Paridad , Hemorragia Posparto/epidemiología , Embarazo , Nacimiento Prematuro/epidemiología , Reproducibilidad de los Resultados , Estudios Retrospectivos , Datos de Salud Recolectados Rutinariamente , Factores de Tiempo , Rotura Uterina/epidemiología

RESUMEN

We aimed to examine the impact of a daily pro-inflammatory diet during pregnancy on intrapartum fetal acidemia using a large birth cohort study in Japan. We used data on singleton pregnancies in the Japan Environment and Children's Study (JECS) involving births from 2011 to 2014 through vaginal delivery to calculate the maternal dietary inflammatory index (DII). Participants were categorized according to DII quintiles. A multiple logistic regression model was used to estimate the risk of a pro-inflammatory diet on fetal umbilical artery pH. In total, 56,490 participants were eligible for this study. Multiple regression analysis showed that nulliparous women who had undergone vaginal delivery and were consuming a pro-inflammatory diet had an increased risk of pH < 7.10 (adjusted odds ratio [aOR]: 1.64, 95% confidence interval [CI]: 1.12-2.39). Among these women, the risk of pH < 7.10 was not affected by the duration of labor (aOR: 1.64, 95% CI: 1.11-2.42). In conclusion, following a pro-inflammatory diet during pregnancy is a risk factor for fetal acidosis among nulliparous women undergoing vaginal delivery. A high DII diet during pregnancy may modify the intrapartum fetal heart rate pattern via intrauterine inflammation.

Asunto(s)

Asfixia/epidemiología , Asfixia/fisiopatología , Dieta/efectos adversos , Inflamación/epidemiología , Inflamación/fisiopatología , Acidosis , Adulto , Estudios de Cohortes , Parto Obstétrico/estadística & datos numéricos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Japón/epidemiología , Modelos Logísticos , Fenómenos Fisiologicos Nutricionales Maternos , Oportunidad Relativa , Embarazo , Complicaciones del Embarazo/epidemiología , Resultado del Embarazo , Factores de Riesgo

RESUMEN

OBJECTIVE: To determine which parameter of umbilical arterial cord gas analysis, pH, base deficit, lactate concentration, ionogram values, or glucose level index is the best predictor of neonatal morbidity at term. DESIGN: We conducted a 15-month retrospective cohort study that included all nonanomalous, singleton, term births at a single center. The predictive ability of lactate concentration, base deficit, pH, ionogram values, and glucose level were compared using receiver-operating characteristic curves for global and neurological composite morbidity. Optimal cutoff values for lactate concentration, base deficit, and pH were estimated based on their maximum area under the curve. RESULTS: We included 5161 newborns: 52 (1.01 %) had global composite morbidity, and 17 had (0.33 %) neurological composite morbidity. Blood levels of potassium, calcium, natremia, glucose level, and HCO3- did not differ significantly between groups. pH, partial pressure of CO2, partial pressure of O2, base deficit, and lactate levels differed significantly between neonates in the groups with and without global composite morbidity. Nearly similar results were found for neurological composite morbidity. The predictive ability did not differ between arterial pH and arterial lactate concentration (P = .25) and base deficit (P = .79). Optimal cutoff values to predict global composite morbidity were arterial pH 7.144, venous pH 7.236, and arterial lactate concentration 6.5 mmol/L. CONCLUSIONS: Acid-base status analysis remains the best objective indicator for predicting neonatal morbidity and can be estimated using pH, lactate, or base deficit. Ionogram cord blood composition and glucose level do not appear to be useful for this purpose.

Asunto(s)

Gases , Cordón Umbilical , Sangre Fetal , Glucosa , Humanos , Concentración de Iones de Hidrógeno , Recién Nacido , Estudios Retrospectivos

RESUMEN

INTRODUCTION: Cardiotocography (CTG) is currently the most commonly used method for intrapartum fetal monitoring during labor. However, a high false-positive rate of fetal acidosis indicated by CTG leads to an increase in obstetric interventions. We developed a microdialysis probe that is integrated into a fetal scalp electrode allowing continuous measurement of lactate subcutaneously, thus giving instant information about the oxygenation status of the fetus. Our aim was to establish proof of concept in an animal model using a microdialysis probe to monitor lactate subcutaneously. MATERIAL AND METHODS: We performed an in vivo study in adult male wild-type Wistar rats. We modified electrodes used for CTG monitoring in human fetuses to incorporate a microdialysis membrane. Optimum flow rates for microdialysis were determined in vitro. For the in vivo experiment, a microdialysis probe was inserted into the skin on the back of the animal. De-oxygenation and acidosis were induced by lowering the inspiratory oxygen pressure. Oxygenation and heart rate were monitored. A jugular vein cannula was inserted to draw blood samples for analysis of lactate, pH, pco2 , and saturation. Lactate levels in dialysate were compared with plasma lactate levels. RESULTS: Baseline blood lactate levels were around 1 mmol/L. Upon de-oxygenation, oxygen saturation fell to below 40% for 1 h and blood lactate levels increased 2.5-fold. Correlation of dialysate lactate levels with plasma lactate levels was 0.89 resulting in an R2 of .78 in the corresponding linear regression. CONCLUSIONS: In this animal model, lactate levels in subcutaneous fluid collected by microdialysis closely reflected blood lactate levels upon transient de-oxygenation, indicating that our device is suitable for subcutaneous measurement of lactate. Microdialysis probe technology allows the measurement of multiple compounds in the dialysate, such as glucose, albumin, or inflammatory mediators, so this technique may offer the unique possibility to shed light on fetal physiology during the intrapartum period.

Asunto(s)

Monitoreo Fetal/instrumentación , Lactatos/análisis , Membranas Artificiales , Microdiálisis , Tejido Subcutáneo/química , Acidosis/diagnóstico , Animales , Femenino , Enfermedades Fetales/diagnóstico , Monitoreo Fetal/métodos , Modelos Animales , Oximetría , Embarazo , Ratas Wistar

Asunto(s)

Acidosis , Frecuencia Cardíaca Fetal , Femenino , Humanos , Concentración de Iones de Hidrógeno , Embarazo

RESUMEN

Purposes: The pH in the umbilical artery at delivery provides information on the fetal environment and is related to postnatal outcomes. The ability to predict fetal acidemia at delivery would improve clinical management and neonatal well-being. We hypothesized that an alteration in maternal immunity would accompany placental changes that precede a decrease in pH in the fetal circulation in twin gestations.Methods: Peripheral blood mononuclear cells (PBMCs), obtained from 86 women with twin pregnancies, were lysed and assayed for concentrations of T-cell immunoglobulin mucin domain 3 (Tim-3) and galectin-9 (gal-9) by ELISA. Tim-3-gal-9 interaction is a primary mechanism promoting immune suppression. At delivery, the pH of arterial cord blood was determined.Results: In eight women (9.3%), the pH in the placental arteries from both twins was <7.15, indicating fetal acidosis. In the remaining 78 women the arterial pH was ≥7.15 in both twins. The median Tim-3 level was 361 pg/ml when arterial pH was <7.15 and 199 pg/ml when pH was ≥7.15 (p = .003). Similarly, gal-9 was 31.2 versus 12.4 ng/ml when pH was <7.15 or ≥7.15, respectively (p = .001). A Tim-3 concentration >260 pg/ml predicted arterial pH <7.15 with a sensitivity of 87.5%, specificity of 79.5% and negative predictive value of 98.4%. A gal-9 level >18.4 predicted arterial pH <7.15 with a sensitivity of 100%, specificity of 73.8% and a negative predictive value of 100%.Conclusion: We conclude that elevations in Tim-3 and gal-9 in PBMCs during gestation predict the subsequent occurrence of a pH <7.15 in the fetal arteries at delivery in twin gestations.

Asunto(s)

Acidosis/diagnóstico , Sangre Fetal/química , Enfermedades Fetales/diagnóstico , Embarazo Gemelar/sangre , Acidosis/sangre , Adulto , Femenino , Galectinas/sangre , Receptor 2 Celular del Virus de la Hepatitis A/sangre , Humanos , Leucocitos Mononucleares/inmunología , Placenta/irrigación sanguínea , Placenta/metabolismo , Valor Predictivo de las Pruebas , Embarazo , Curva ROC

RESUMEN

BACKGROUND: Automated fetal heart rate (FHR) analysis removes inter- and intra-expert variability, and is a promising solution for reducing the occurrence of fetal acidosis and the implementation of unnecessary medical procedures. The first steps in automated FHR analysis are determination of the baseline, and detection of accelerations and decelerations (A/D). We describe a new method in which a weighted median filter baseline (WMFB) is computed and A/Ds are then detected. METHOD: The filter weightings are based on the prior probability that the sampled FHR is in the baseline state or in an A/D state. This probability is computed by estimating the signal's stability at low frequencies and by progressively trimming the signal. Using a competition dataset of 90 previously annotated FHR recordings, we evaluated the WMFB method and 11 recently published literature methods against the ground truth of an expert consensus. The level of agreement between the WMFB method and the expert consensus was estimated by calculating several indices (primarily the morphological analysis discordance index, MADI). The agreement indices were then compared with the values for eleven other methods. We also compared the level of method-expert agreement with the level of interrater agreement. RESULTS: For the WMFB method, the MADI indicated a disagreement of 4.02% vs. the consensus; this value is significantly lower (p<10-13) than that calculated for the best of the 11 literature methods (7.27%, for Lu and Wei's empirical mode decomposition method). The level of inter-expert agreement (according to the MADI) and the level of WMFB-expert agreement did not differ significantly (p=0.22). CONCLUSION: The WMFB method reproduced the expert consensus analysis better than 11 other methods. No differences in performance between the WMFB method and individual experts were observed. The method Matlab source code is available under General Public Licence at http://utsb.univ-catholille.fr/fhr-wmfb.

Asunto(s)

Monitoreo Fetal/métodos , Frecuencia Cardíaca Fetal/fisiología , Procesamiento de Señales Asistido por Computador , Programas Informáticos , Algoritmos , Femenino , Humanos , Embarazo

RESUMEN

BACKGROUND: All guidelines regarding electronic fetal heart monitoring (EFM) before 2008 were designed to avoid more hypoxia than acidosis. In addition, the results of the Cochrane meta-analysis of 2013 do not show a significant improvement in neonatal outcomes using EFM or intermittent auscultation (IA). OBJECTIVES: We retrospectively evaluated the results on delivery outcomes arising from a comparison between EFM and IA during labor of 2 specific and high-quality trials. We hypothesized that revisiting the delivery outcomes through the adoption of the recent National Institute of Child Health and Human Development (NICHHD) guidelines, the reported delivery outcomes would be different. MATERIAL AND METHODS: The study retrospectively evaluated the results on delivery outcomes arising from the comparison between EFM and IA during labor of the "Dublin trial" and "Vintzileos trial" published, respectively, in 1985 and 1993. A translational model was constructed to recalculate these results, applying a correction factor to estimate the number of pathological patterns using the NICHHD guidelines for EFM. RESULTS: After the reevaluation of the 2 trials using the proposed correction factor, the comparison of the recalculated cesarean section and operative delivery rates for fetal distress between EFM and IA group were no longer statistically significant, both in the Dublin trial and Vintzileos trial. Even the comparison of the recalculated incidence of the rate of non-reassuring fetal heart rate (FHR) patterns in the EFM and IA groups has not given any indication of significance for the Vintzileos trial. CONCLUSIONS: Our results lead to reconsidering the results of the Dublin trial and Vintzileos trial in terms of operational rates of births, hypothesizing that these results would have been significantly lower if FHR traces were interpreted using the current NICHHD guidelines, which aim to identify potential acidotic fetuses rather than hypoxic ones.

Asunto(s)

Cesárea , Sufrimiento Fetal/diagnóstico , Auscultación Cardíaca/métodos , Frecuencia Cardíaca Fetal , Guías de Práctica Clínica como Asunto , Niño , Femenino , Corazón Fetal , Humanos , National Institute of Child Health and Human Development (U.S.) , Embarazo , Estudios Retrospectivos , Estados Unidos

RESUMEN

OBJECTIVE: Nomograms are statistical models that combine variables to obtain the most accurate and reliable prediction for a particular risk. Fetal heart rate (FHR) interpretation alone has been found to be poorly predictive for fetal acidosis while other clinical risk factors exist. The aim of this study was to create and validate a nomogram based on FHR patterns and relevant clinical parameters to provide a non-invasive individualized prediction of umbilical artery pH during labour. STUDY DESIGN: A retrospective observational study was conducted on 4071 patients in labour presenting singleton pregnancies at >34 gestational weeks and delivering vaginally. Clinical characteristics, FHR patterns and umbilical cord gas of 1913 patients were used to construct a nomogram predicting an umbilical artery (Ua) pH <7.18 (10th centile of the study population) after an univariate and multivariate stepwise logistic regression analysis. External validation was obtained from an independent cohort of 2158 patients. Area under the receiver operating characteristics (ROC) curve, sensitivity, specificity, positive and negative predictive values of the nomogram were determined. RESULTS: Upon multivariate analysis, parity (p < 0.01), induction of labour (p = 0.01), a prior uterine scar (p = 0.02), maternal fever (p = 0.02) and the type of FHR (p < 0.01) were significantly associated with an Ua pH <7.18 (p < 0.05). Apgar score at 1, 5 and 10 min were significantly lower in the group with an Ua pH <7.18 (p < 0.01). The nomogram constructed had a Concordance Index of 0.75 (area under the curve) with a sensitivity of 57%, a specificity of 91%, a negative predictive value of 5% and a positive predictive value of 99%. Calibration found no difference between the predicted probabilities and the observed rate of Ua pH <7.18 (p = 0.63). The validation set had a Concordance Index of 0.72 and calibration with a p < 0.77. CONCLUSION: We successfully developed and validated a nomogram to predict Ua pH by combining easily available clinical variables and FHR. Discrimination and calibration of the model were statistically good. This mathematical tool can help clinicians in the management of labour by predicting umbilical artery pH based on FHR tracings.

Asunto(s)

Acidosis/diagnóstico , Frecuencia Cardíaca Fetal/fisiología , Trabajo de Parto , Arterias Umbilicales/fisiología , Acidosis/fisiopatología , Adulto , Cardiotocografía , Femenino , Humanos , Concentración de Iones de Hidrógeno , Modelos Teóricos , Nomogramas , Embarazo , Estudios Retrospectivos , Adulto Joven

RESUMEN

Fetoscopic myelomeningocele (MMC) repair is performed using intrauterine carbon dioxide (CO2 ) insufflation. Sheep experiments have shown that CO2 insufflation is associated with significant fetal acidemia; however, corresponding data for human pregnancy are not available. We performed umbilical venous cord blood sampling in three patients during fetoscopic MMC repair at 25 + 1, 25 + 3 and 24 + 0 weeks' gestation, respectively. Fetal venous pH at the beginning of CO2 insufflation was 7.36, 7.46 and 7.37, respectively in the three fetuses, and repeat values were 7.28, 7.35 and 7.36 after 181, 159 and 149 min, respectively. The partial pressure of oxygen and CO2 was maintained in the normal range during these times, and pH decrease was less in Patient 3 who received humidified CO2 insufflation. Our observations suggest that, in contrast to sheep experiments, CO2 insufflation during fetoscopic myelomeningocele repair does not cause acidemia in human fetuses. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Asunto(s)

Dióxido de Carbono/sangre , Sangre Fetal/química , Fetoscopía/métodos , Insuflación/métodos , Meningomielocele/cirugía , Animales , Análisis de los Gases de la Sangre , Femenino , Enfermedades Fetales/cirugía , Edad Gestacional , Humanos , Meningomielocele/sangre , Embarazo , Resultado del Embarazo , Ovinos

RESUMEN

OBJECTIVE: In case of abnormal fetal heart rate, there is no consensus on the decision threshold pH scalp leading to a rapid birth. The objective of this study was to compare neonatal issues and cesarean rate in two maternity using different decision thresholds of scalp pH. MATERIAL AND METHODS: A comparative retrospective study conducted in two level III maternity units between January 2013 and May 2014, one maternity unit used a decision threshold of 7.20 (maternity unit 7,20), and the other one a threshold of 7.25 (maternity unit 7,25). An adverse neonatal outcome was defined by a composite endpoint of neonatal morbidity. The risk of cesarean was assessed using a multivariate analysis. RESULTS: One hundred and four patients were included in the maternity unit 7,20 and 163 patients in the maternity 7,25. Adverse neonatal outcome was similar in both maternities (25% vs. 30,1%; P=0.4). The average pH at birth was similar in both maternities, as well as the Apgar score at 5minutes and neonatal transfer rates. However, BE<-12 was more frequent in maternity using 7,20 scalp pH threshold (7% vs. 0%; P<0.01). The cesarean rate was higher in maternity 7,25 (adjusted OR=2.23 95% CI [1.17-4.25]). CONCLUSION: It seems that a decisional threshold fixed to 7,20 could be used reasonably. It could allow to reduce cesarean rate. Other studies are, however, needed to confirm that such threshold of 7,20 does not increase the risk of severe acidosis.

Asunto(s)

Acidosis/diagnóstico , Cesárea , Monitoreo Fetal/métodos , Feto/química , Trabajo de Parto/fisiología , Cuero Cabelludo/química , Acidosis/congénito , Adulto , Cesárea/estadística & datos numéricos , Toma de Decisiones , Femenino , Sufrimiento Fetal/diagnóstico , Sufrimiento Fetal/cirugía , Francia , Humanos , Concentración de Iones de Hidrógeno , Embarazo , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven