2022年 · 第04卷第02期

Objective: This study investigates the efficacy of analyzing fetal heart rate (FHR) signals based on Artificial Intelligence to obtain a baseline calculation and identify accelerations/decelerations in the FHR through electronic fetal monitoring during labor. Methods: A total of 43,888 cardiotocograph(CTG) records of female patients in labor from January 2012 to December 2020 were collected from the NanFang Hospital of Southern Medical University. After filtering the data, 2341 FHR records were used for the study. The ObVue fetal monitoring system, manufactured by Lian-Med Technology Co. Ltd., was used to monitor the FHR signals for these pregnant women from the beginning of the first stage of labor to the end of delivery. Two obstetric experts together annotated the FHR signals in the system to determine the baseline as well as accelerations/decelerations of the FHR. Our cardiotocograph network (CTGNet) as well as traditional methods were then used to automatically analyze the baseline and acceleration/deceleration of the FHR signals. The results of calculations were compared with the annotations provided by the obstetric experts, and ten-fold cross-validation was applied to evaluate them. The root-mean-square difference (RMSD) between the baselines, acceleration F-measure (Acc.F-measure), deceleration F-measure (Dec.F-measure), coefficient of synthetic inconsistency (SI) and the morphological analysis discordance index (MADI) were used as evaluation metrics. The data were analyzed by using a paired t-test. Results: The proposed CTGNet was superior to the best traditional method, proposed by Mantel, in terms of the RMSD.BL (1.7935 ± 0.8099 vs. 2.0293 ± 0.9267, t=-3.55 , P=0.004), Acc.F-measure (86.8562 ± 10.9422 vs. 72.2367 ± 14.2096, t= 12.43, P <0.001), Dec.F-measure (72.1038 ± 33.2592 vs. 58.5040 ± 38.0276, t= 4.10, P <0.001), SI (34.8277±20.9595 vs. 54.8049 ± 25.0265, t=-9.39, P <0.001), and MADI (3.1741 ± 1.9901 vs. 3.7289 ± 2.7253, t= -2.74, P= 0.012). The proposed CTGNet thus had significant advantages over the best traditional method on all evaluation metrics. Conclusion: The proposed Artificial Intelligence-based method CTGNet delivers good performance in terms of the automatic analysis of FHR based on cardiotocograph data. It promises to be a key component of smart obstetrics systems of the future.

Objective: To investigate the efficacy of in-phase and quadrature (IQ) demodulation in electronic fetal heart rate monitoring (EFM) to reduce false reports of fetal heart rate (FHR) doubling or halving. Methods: This is a prospective cohort study. A total of 263 full-term pregnant women who delivered at Peking University Shenzhen Hospital between August 2019 and July 2020 were prospectively enrolled in the study. FHR monitoring began when the cervix was dilated to 2-3 cm and continued until delivery. Raw fetal Doppler audio signals and internal and external cardiotocography curves from internal electrode monitoring, EFM with conventional demodulation (external), and EFM with IQ demodulation (external) were acquired to compare FHR doubling and halving time. In cohort 1, FHR was compared between IQ demodulation and conventional demodulation. In cohort 2, FHR was compared between IQ demodulation, conventional demodulation, and internal FHR monitoring. Count data were statistically analyzed using the Chi-squared test, and measurement data were statistically analyzed using t-test for correlation coefficients, and Bland-Altman analysis for concordance ranges. Results: To compare IQ demodulation and conventional demodulation, 225 pregnant women were monitored for a total of 835,870 seconds. The beat-to-beat interval of FHRs in raw fetal Doppler audio signals was used as the reference. The results showed a doubling time of 3401 seconds (0.407%, 3401/835,870) and a halving time of 2918 seconds (0.349%, 2918/835,870) with conventional demodulation, compared to 241 seconds (0.029%, 241/835,870) and 589 seconds (0.070%, 589/835,870), respectively, with IQ demodulation. IQ demodulation reduced FHR doubling by approximately 93% (3160/3401) and FHR halving by approximately 80% (2329/2918) compared to conventional demodulation (P < 0.01). To compare IQ demodulation, conventional demodulation, and internal FHR monitoring, 38 pregnant women were monitored for a total of 98,561 seconds. FHR from internal electrode monitoring was used as the reference. The results showed a doubling time of 238 seconds (0.241%, 238/98,561) and a halving time of 235 seconds 0.238%, 235/98,561) with conventional demodulation, compared with 30 seconds (0.030%, 30/98,561) and 81 seconds (0.082%, 81/98,561), respectively, with IQ demodulation (P < 0.05). No significant difference was observed in doubling or halving time between IQ demodulation and internal FHR monitoring (P > 0.05). IQ demodulation was more closely correlated with internal FHR monitoring than conventional demodulation (0.986 vs. 0.947). The Bland-Altman analysis showed that the concordance range of IQ demodulation vs. internal FHR monitoring was significantly narrower than that of conventional demodulation vs. internal FHR monitoring ((-5.32,6.01) vs. (-10.87,11.46)). Conclusion: EFM with IQ demodulation significantly reduces false FHR doubling and halving, with an efficacy similar to that of internal FHR monitoring.

Objective: To investigate the safety and efficacy of internal electronic fetal heart rate (FHR) monitoring during labor. Methods: This was a retrospective case-control study, which was an analysis of monitoring FHR with a fetal scalp electrode or a Doppler probe (94 pregnant women per group). In the internal monitoring group, when the opening of the uterine orifice was ≥3 cm, the fetal scalp electrode was placed after natural or artificial rupture of the membrane. FHR was simultaneously monitored using a Doppler probe. In the external monitoring group, continuous FHR monitoring was performed using an ultrasound Doppler transducer fixed on the maternal abdomen. The toco transducer was used to record uterine contractions. Pathological examination of the placenta was performed prospectively in 49 and 48 cases in the internal electronic FHR monitoring group and control group, respectively. Maternal-infant outcomes (e.g. fever, puerperal infection, puerperal morbidity, delivery mode, Apgar score, and scalp injury) were recorded. Umbilical artery blood was extracted for blood gas analysis. Differences between the two groups were compared using the paired t-test, χ2 test, Yates corrected χ2 test or Fisher exact test. Results: Non-statistically significant differences between the internal and external monitoring groups were observed in the incidence of neonatal acidosis (1/94 (1.06%) vs. 3/94 (3.19%), respectively; χ2= 0.255, P= 0.613), cesarean section/operative vaginal delivery (8/94 (8.51%) vs. 15/94 (15.96%), respectively; χ2 = 2.427, P= 0.181), fever during labor (18/94 (19.15%) vs. 15/94 (15.96%), respectively; χ2=0.331, P= 0.565), puerperal morbidity (2/94 (2.13%) vs. 3/94 (3.19%), respectively; χ2= 0.000, P= 1.000), chorioamnionitis (9/49 (18.37%) vs. 7/48(14.58%), respectively; χ2= 0.252, P= 0.616), and neonatal asphyxia (0/94 (0.00%) vs. 1/94 (1.06%), respectively; χ2= 0.000, P= 1.000). There were no puerperal infections, neonatal scalp injuries, or scalp abscesses found in either group. Using the internal monitoring value as reference, the incidence of FHR false deceleration in external FHR monitoring was 20.21% (19/94 women). Conclusion: Internal FHR monitoring during labor does not increase the incidence of adverse perinatal outcomes. External monitoring was associated with FHR false decelerations.

Objective: To evaluate the agreement and reliability of intrapartum nonreasurring cardiotocography (CTG) interpretation and prediction of neonatal acidemia by obstetricians working in different centers. Methods: A retrospective cohort study involving two tertiary hospitals (The First Affiliated Hospital of Sun Yat-sen University and Perking University Third Hospital) was conducted between 30th September 2018 and 1st April 2019. Six obstetricians from two hospitals with three levels of experience (junior, medium, and senior) reviewed 100 nonreassuring fetal heart rate (FHR) tracings from 1 hour before the onset of abnormalities until delivery. Each reviewer determined the FHR pattern, the baseline, variability, and presence of acceleration, deceleration, sinusoidal pattern, and predicted whether neonatal acidemia and abnormal umbilical arterial pH < 7.1 would occur. Inter-observer agreement was assessed using the proportions of agreement (Pa) and the proportion of specific agreement (Pa for each category). Reliability was evaluated with the kappa statistic (k-Light’s kappa for n raters) and Gwet’s AC1 statistic. Results: Good inter-observer agreement was found in evaluation of most variables (Pa>0.5), with the exception of early deceleration (Pa= 0.39, 95% confidence interval (CI): 0.36,0.43). Reliability was also good among most variables (AC1 > 0.40), except for acceleration, early deceleration, and prediction of neonatal acidemia (AC1 = 0.17, 0.10, and 0.25, respectively). There were no statistically significant differences among the three groups, except in the identification of accelerations (Pa = 0.89, 95% CI: 0.83,0.95; Pa= 0.50, 95% CI: 0.41,0.60, and Pa= 0.35, 95% CI: 0.25,0.43 in junior, medium and senior groups, respectively) and the prediction of neonatal acidemia (Pa= 0.52, 0.52, and 0.62 in junior, medium and senior groups, respectively), where agreement was highest and lowest in the junior-level group, respectively. The accuracy and sensitivity of the prediction for umbilical artery pH < 7.1 were similar among the three groups, but the specificity was higher in the senior groups (93.68% vs. 92.53% vs. 98.85% in junior, medium and senior groups, P= 0.015). Conclusion: Although we found a good inter-observer agreement in the evaluation of the most basic CTG features and FHR category statistically, it was insufficient to meet the clinical requirements for "no objection" interpretation for FHR tracings. Further specialized training is needed for standardized interpretation of intrapartum FHR tracings.

Maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the second and third trimesters of pregnancy may impact fetal development via vertical transmission, complications of coronavirus disease 2019 (COVID-19), or placental injury. However, potential associations between prenatal SARS-CoV-2 infection and fetal loss are not well understood. This case series of thirteen second and third trimester fetal losses reported by local public health departments to California’s state public health surveillance included maternal clinical and demographic characteristics as well as placental pathology, fetal autopsy reports, and coroner report. There was no evidence that maternal COVID-19 disease severity, placental injury, or SARS-CoV-2 vertical transmission contributed to pregnancy loss. However, this case series is a limited sample; more research is needed to identify factors of prenatal SARS-CoV-2 that may contribute to fetal death in the second and third trimesters.

Cardiotocography measures the human fetal heart rate and uterine activity using ultrasound. While it has been a mainstay in antepartum care since the 1960s, cardiotocograms consist of complex signals that have proven difficult for clinicians to interpret accurately and as such clinical inference is often difficult and unreliable. Previous attempts at codifying approaches to analyzing the features within these signals have failed to demonstrate reliability or gain sufficient traction. Since the early 1990s, the Dawes-Redman system of automated computer analysis of cardiotocography signals has enabled robust analysis of cardiotocographic signal features, employing empirically-derived criteria for assessing fetal wellbeing in the antepartum. Over the past 30 years, the Dawes-Redman system has been iteratively updated, now incorporating analyses from over 100,000 pregnancies. In this review, we examine the history of cardiotocography, signal processing methodologies and feature identification, the development of the Dawes-Redman system, and its clinical applications.

Since the 1970s, electronic fetal monitoring (EFM) also known as cardiotocography (CTG) has been used extensively in labor around the world, despite its known failure to help prevent many babies from developing neonatal encephalopathy and cerebral palsy. Part of EFM’s poor performance with respect to these outcomes arises from a fundamental misunderstanding of the differences between screening and diagnostic tests, subjective classifications of fetal heart rate (FHR) patterns that lead to large inter-observer variability in its interpretation, failure to appreciate early stages of fetal compromise, and poor statistical modeling for its use as a screening test. We have developed a new approach to the practice and interpretation of EFM called the fetal reserve index (FRI) which does the following: (1) breaking FHR components down into 4 components, (heart rate, variability, accelerations, and decelerations); (2) contextualizing the metrics by adding increased uterine activity; (3) adding specific maternal, fetal, and obstetric risk factors. The result is an eight-point scoring metric that, when directly compared with current American College of Obstetricians and Gynecologists EFM categories, even in version 1.0 with equal weighting of variables, shows that the FRI has performed much better for identifying cases at risk before damage had occurred, reducing the need for emergency deliveries, and lowering overall Cesarean delivery rates. With increased data, we expect further refinements in the specifics of scoring that will allow even earlier detection of compromise in labor.

We present an unusual and, until now, unreported case of vesicoallantoic cyst associated with multiple malformations in a fetus. A differential diagnosis is discussed, including the hypothesis of a genetic disorder.

Uterus didelphys occurs in ~0.4% of females and is found in ~11%-20% of all uterus defects. It is a risk factor for cervical insufficiency, consequently contributing to late miscarriage or preterm birth. Thus far, only two prior cases of uterus didelphys accompanied by cervical insufficiency treated through laparoscopic cervical cerclage have been reported; however, livebirth only occurred in one hemiuterus. Herein, we report a case of uterus didelphys in a patient diagnosed with cervical insufficiency. Following the placement of a modified laparoscopic cervical cerclage, the patient had two successful livebirths through both hemiuteruses, respectively, with longer gestation age (ie, >36 weeks). The aim of this case report was to provide useful information for clinical practitioners to make better decisions on the management of cervical insufficiency in patients with uterus didelphys, and identify obstetric complications that clinicians should pay attention to during pregnancy.