Fetal distress

Trajectories of maternal D-dimer are associated with the risk of developing adverse maternal and perinatal outcomes: a prospective birth cohort study

OBJECTIVE

To assess the relationships of maternal D-dimer trajectories with the risk of developing adverse maternal and perinatal outcomes (AMPOs).

METHODS

A prospective birth cohort study was conducted in China, and 7,095 women who had singleton birth were included. The latent class growth model was used to determine the maternal D-dimer trajectory.

RESULTS

Three maternal D-dimer trajectories were identified: (1) slight increase (43.6%), (2) rapid rise (51.3%), (3) sustained high (5.1%). Compared to pregnant women with a slight increase in D-dimer trajectory, the risk of gestational diabetes mellitus, placenta previa, macrosomia, large for gestational age (LGA), and increased postpartum bleeding was significantly increased in those with a rapid rise trajectory (adjusted OR=1.22, 2.00, 1.80, and 1.56, adjusted β=15.92∼25.1ml, respectively, P<0.05), and women with a sustained high trajectory also demonstrated a relatively elevated risk of macrosomia and LGA (adjusted OR=2.11 and 1.82, respectively, P<0.05). While the odds of pregnancy-induced hypertension, low birth weight, and small for gestational age in pregnant women with the rapid rise D-dimer trajectory and fetal distress in those with sustained high trajectory exhibited a reduction (adjusted OR=0.62, 0.38, 0.54, and 0.64, respectively, P<0.05).

CONCLUSION

This study highlights the influence of inappropriate maternal D-dimer trajectories on the risk of AMPOs.

A Retrospective Review of Decision to Delivery Time Interval for Foetal Distress at a Central Hospital

PURPOSE

The aim of this study was to describe the trajectory of emergency caesarean deliveries for foetal distress at Chris Hani Baragwanath Academic Hospital (CHBAH).

PATIENTS AND METHODS

A retrospective, contextual, descriptive study, using consecutive convenience sampling was done reviewing all the records of emergency caesarean deliveries for foetal distress at CHBAH in February 2019 until a minimum sample size of 385 was reached.

RESULTS

During the study period, a total of 617 caesarean deliveries were done, of which 572 (92.7%) were emergencies. Foetal distress accounted for 395 (69.1%) of the emergency caesarean deliveries. No emergency caesarean delivery for foetal distress conformed to the 30-minute DDI and the mean (SD) DDI was 411 (291) minutes. The mean (SD) 5-minute and 10-minute Apgar scores were 8.4 (1.6) and 9.6 (1.3), respectively. There was a significant difference between the type of anaesthetic (general or neuraxial), with those receiving general anaesthesia having shorter anaesthetic start to cut time (p=0.0110). However, those delivered following neuraxial anaesthesia had better 5-minute (p=0.0002) and 10-minute (p=0.0175) Apgar scores.

CONCLUSION

This study showed that a DDI of 30-minutes, was not achieved at CHBAH during the study period. Most babies diagnosed with foetal distress pre-delivery had 5-minute and 10-minute Apgar scores inconsistent with this diagnosis. This over-diagnosis of foetal distress in some cases could have led to delays in delivery of babies who had actual foetal distress and where a 30-minute DDI could have improved outcome.

Does continuous cardiotocography during labor cause excessive fetal distress diagnosis and unnecessary cesarean sections?

OBJECTIVE

We aimed to evaluate the perinatal outcomes of patients who were continuously monitored by cardiotocography (CTG) during the labor and experienced cesarean operation with a diagnosis of fetal distress.

MATERIAL AND METHODS

This is a retrospective study in which records of the patients, who were diagnosed of fetal distress at Umraniye Training and Research Hospital, Department of Obstetrics and Gynecology, Istanbul, Turkey, between January 2015 and October 2020 were collated. The statistical analysis was done using the Statistical Packagefor Social Sciences version 22 software (SPSS Inc., Chicago IL, USA).

RESULTS

Of the 32,338 deliveries in this study period, 13,077 (40.4%) deliveries were through caesarean section. A total of 1504 (11.5%) of the 13,077 caesarean sections were due to fetal distress within the study period. A total of 1301 (86.5%) babies were born with ≥7 Apgar score at the1st min of delivery. NICU admission rate was 11.2% and perinatal mortality was 0.1%. More so, in the low-risk pregnancy group, the rate of the babies were born with ≥7 Apgar score at the1st min of delivery was 93.7% and NICU admission rate 2.1% and no perinatal mortality was seen. In the patient group in which pregestational and gestational diseases complicating pregnancy were excluded, newborns with meconium-stained amniotic fluid had statistically significantly lower 1st and 5th-min Apgar scores compared to the group without meconium and higher NICU admission (p = .000, p = .004 and p = .000, respectively).

CONCLUSION

The diagnosis of fetal distress should not be made only with fetal heart rate changes in CTG because this causes excessive fetal distress diagnosis and many unnecessary cesarean operations. We believe that rate of cesarean sections will decrease to the desired levels with the routine use of a method such as CTG which is easy to apply, but more sensitive and specific in the diagnosis of fetal distress.

DeepFHR: intelligent prediction of fetal Acidemia using fetal heart rate signals based on convolutional neural network

Background

Fetal heart rate (FHR) monitoring is a screening tool used by obstetricians to evaluate the fetal state. Because of the complexity and non-linearity, a visual interpretation of FHR signals using common guidelines usually results in significant subjective inter-observer and intra-observer variability. Objective: Therefore, computer aided diagnosis (CAD) systems based on advanced artificial intelligence (AI) technology have recently been developed to assist obstetricians in making objective medical decisions.

Methods

In this work, we present an 8-layer deep convolutional neural network (CNN) framework to automatically predict fetal acidemia. After signal preprocessing, the input 2-dimensional (2D) images are obtained using the continuous wavelet transform (CWT), which provides a better way to observe and capture the hidden characteristic information of the FHR signals in both the time and frequency domains. Unlike the conventional machine learning (ML) approaches, this work does not require the execution of complex feature engineering, i.e., feature extraction and selection. In fact, 2D CNN model can self-learn useful features from the input data with the prerequisite of not losing informative features, representing the tremendous advantage of deep learning (DL) over ML.

Results

Based on the test open-access database (CTU-UHB), after comprehensive experimentation, we achieved better classification performance using the optimal CNN configuration compared to other state-of-the-art methods: the averaged ten-fold cross-validation of the accuracy, sensitivity, specificity, quality index defined as the geometric mean of the sensitivity and specificity, and the area under the curve yielded results of 98.34, 98.22, 94.87, 96.53 and 97.82%, respectively

Conclusions

Once the proposed CNN model is successfully trained, the corresponding CAD system can be served as an effective tool to predict fetal asphyxia objectively and accurately.

Computer-Aided Diagnosis System of Fetal Hypoxia Incorporating Recurrence Plot With Convolutional Neural Network

Background: Electronic fetal monitoring (EFM) is widely applied as a routine diagnostic tool by clinicians using fetal heart rate (FHR) signals to prevent fetal hypoxia. However, visual interpretation of the FHR usually leads to significant inter-observer and intra-observer variability, and false positives become the main cause of unnecessary cesarean sections. Goal: The main aim of this study was to ensure a novel, consistent, robust, and effective model for fetal hypoxia detection. Methods: In this work, we proposed a novel computer-aided diagnosis (CAD) system integrated with an advanced deep learning (DL) algorithm. For a 1-dimensional preprocessed FHR signal, the 2-dimensional image was transformed using recurrence plot (RP), which is considered to greatly capture the non-linear characteristics. The ultimate image dataset was enriched by changing several parameters of the RP and was then used to feed the convolutional neural network (CNN). Compared to conventional machine learning (ML) methods, a CNN can self-learn useful features from the input data and does not perform complex manual feature engineering (i.e., feature extraction and selection). Results: Finally, according to the optimization experiment, the CNN model obtained the average performance using optimal configuration across 10-fold: accuracy = 98.69%, sensitivity = 99.29%, specificity = 98.10%, and area under the curve = 98.70%. Conclusion: To the best of our knowledge, this approached achieved better classification performance in predicting fetal hypoxia using FHR signals compared to the other state-of-the-art works. Significance: In summary, the satisfied result proved the effectiveness of our proposed CAD system for assisting obstetricians making objective and accurate medical decisions based on RP and powerful CNN algorithm.

Preeclampsia and ABO blood groups: a systematic review and meta-analysis

Preeclampsia (PE) is a multifactorial pregnancy-specific syndrome which represents one of the leading causes of maternal mortality worldwide. Inherited thrombophilia have been investigated as risk factor for the development of PE and it is currently known that ABO blood group may impact haemostatic balance, having the non-O blood groups (A, B or AB) subjects increased risk for thrombus formation, as compared to those of group O. We performed a systematic review of the literature for published studies investigating whether ABO blood groups could influence PE developing. A sensitive search of four databases identified 45 unique titles. The retrieved papers were assessed independently by authors and a rigorous process of selection and data extract was conduct. Methodological quality of the included studies was also evaluated. Two studies met eligibility criteria. As a main finding of our systematic review, an association between the AB blood group and the occurrence of PE was detected based on two original studies. Considering the role of ABO blood groups on the hemostatic process and thrombus formation, special attention should be given to pregnant patients carrying the AB blood group in order to prevent the syndrome and improve prognosis.

Perinatal outcomes associated with low birth weight in a historical cohort

OBJECTIVE

To identify perinatal outcomes associated with low birth weight (LBW).

METHODS

A retrospective cohort study in a tertiary maternity hospital. Analysis of the database on 43,499 liveborn infants delivered between 1986 and 2004 with low (n = 6,477) and normal (n = 37,467) birth weight. Outcomes associated with LBW were identified through crude and adjusted risk ratio (RR) and 95%CI with bivariate and multivariate analysis. The main outcomes were: onset of labor, mode of delivery, indication for cesarean section; amniotic fluid, fetal heart rate pattern, Apgar score, somatic gestational age, gender and congenital malformation.

RESULTS

LBW infants showed more frequently signs of perinatal compromise such as abnormal amniotic fluid volume (especially olygohydramnios), nonreassuring patterns of fetal heart rate, malformation, lower Apgar scores and lower gestational age at birth. They were associated with a greater risk of labor induction and cesarean delivery, but lower risk of forceps.

CONCLUSION

There was a clear association between LBW and unfavorable perinatal outcomes.

Ischemia-modified albumin levels in cord blood: A case-control study in uncomplicated and complicated deliveries

BACKGROUND

In the past few years ischemia modified albumin (IMA) has emerged as a new biomarker of ischemia in the area of monitoring acute coronary syndromes. We hypothesized that reduced blood flow, such as that resulting from vascular compression in complicated labors or placental ischemia, may increase IMA. IMA level in cord blood could then serve as an indicator of fetal hypoxia and fetal tissue ischemia and serve as a biomarker of the severity of these conditions.

METHODS

We performed a case-control study with 26 newborns (12 normal term deliveries, Apgar 8-9; and 14 complicated labors or pre-term deliveries, Apgar 5-8). Complications were: prematurity (3), fetal distress (6), premature rupture of membranes (6), intrauterine growth retardation (3), pre-eclampsia (1). We also studied 30 healthy adults. IMA was measured in serum from cord blood (or venous blood for adults) by the decrease in cobalt 2+ binding.

RESULTS

IMA levels in neonates from non-complicated deliveries are significantly higher (45%, p < 0.005) than those of an adult control population, suggesting that IMA may increase as a consequence of labor. This increased IMA in neonates could not be accounted for by the changes in albumin concentration. It is conceivable that a transient increase in IMA reflects, in part, transient localized tissue ischemia due to the external forces exerted on the fetus during the mechanism of labor. IMA levels in cord blood from neonates from complicated deliveries are 50% higher than in neonates from uneventful deliveries (p < 0.05) while their albumin values are not significantly different (32 +/- 3 vs. 33 +/- 2 g/l). Moreover, IMA seems to be responsive to hypoxic fetal distress, showing values more than 300% higher in cases of severe fetal hypoxia (Apgar 5 n = 2: 2.19 +/- 0.01 AU vs. 0.64 +/- 0.24 for controls). IMA values did not correlate significantly with either lipoperoxides or CRP levels.

CONCLUSIONS

This is the initial reporting of IMA levels in cord blood from normal deliveries compared to healthy adult ranges and neonates from complicated deliveries. Cord blood IMA levels may be an indicator of fetal ischemia and/or hypoxia. This test could become an additional biomarker to be used in conjunction with other markers and/or clinical scores aimed at determining risk of neurological complications of fetal distress.