Fetal heart rate response to cordocentesis and pregnancy outcome: a prospective cohort.

OBJECTIVE: To evaluate fetal cardiac response to cordocentesis and whether such changes may affect pregnancy outcome. METHODS: 117 singleton pregnant women requiring percutaneous trans-abdominal cordocentesis were prospectively included. Fetal heart rate was continuously evaluated by ultrasound for 1 min after completion of cordocentesis and intermittently for 20 min more. Fetal and pregnancy outcomes were analyzed by grouping fetal cardiac response to cordocentesis into bradycardia, normal heart rate and tachycardia groups. RESULTS: Women included in the study were 30.5+/-4.0 years old and had a gestational age of 23.7+/-2.0 weeks. Fetal blood sample obtained by cordocentesis was 3.1+/-0.8 ml. Fetal heart rate before cordocentesis was 149+/-8 beats per minute (bpm), ranging from 130 to 169 bpm. Fetal heart rate post-cordocentesis was 145+/-30 bpm (from 32 to 175 bpm). The incidence of bradycardia and tachycardia was 10.3% (n=12) and 6.0% (n=7), respectively. Fetal heart rate returned to normal levels in all cases at 相似文献   

Fetal heart rate response to running in midpregnancy and late pregnancy

Fetal heart rate was recorded at 20 and 32 weeks' gestation before and after 20 minutes of treadmill exercise. The intensity of the exercise was matched to each woman's current training level. On every occasion the fetal heart rate rose significantly after exercise.     

Predisposing factors and effects of fetal bradycardia following cordocentesis at mid-pregnancy

Objectives: To identify predisposing factors of fetal bradycardia following cordocentesis at mid-pregnancy and to compare the pregnancy outcomes to those without bradycardia. Methods: All cordocenteses performed at 18–22 weeks of gestation were prospectively enrolled. The inclusion criteria consisted of: (i) singleton pregnancies; (ii) no fetal structural or chromosomal abnormalities; (iii) the procedures done by experienced operators. They were divided into two groups; procedures with fetal bradycardia (Group 1) and those without bradycardia (Group 2). Factors related to bradycardia were identified and pregnancy outcomes between the two groups were also compared. Results: Of 6147 cordocenteses recruited, 2829 met the inclusion criteria. Of these,152 had fetal bradycardia whereas the remaining 2677 did not. The procedures involving placenta penetration, and umbilical cord bleeding were significantly related to a higher rate of fetal bradycardia. On the other hand, cordocenteses with fetal bradycardia had a significantly higher rate of fetal loss (11.8 vs. 1.9%, respectively, p = 0.001) as well as a higher rate of low birth weight and preterm birth. Conclusions: Cordocentesis with placenta penetration and umbilical cord bleeding carries a higher risk for fetal bradycardia and fetal bradycardia was an independent factor for a higher rate of fetal loss, preterm birth and low birth weight.     

Fetal electrocardiography: feasibility of long-term fetal heart rate recordings

The feasibility and accuracy of long-term transabdominal fetal electrocardiogram (fECG) recordings throughout pregnancy were studied using a portable fECG monitor. Fifteen-hour recordings of fetal heart rate (FHR) were performed in 150 pregnant women at 20–40 weeks of gestation and 1-hour recordings were performed in 22 women in labour and compared with simultaneous scalp electrode recordings. When ≥60% of fECG signals was present, the recording was defined as good. Eighty-two percent (123/150) of antenatal recordings were of good quality. This percentage increased to 90.7 (136/150 recordings) when only the night part (11 p.m.–7 a.m.) was considered. Transabdominal measurement of FHR and its variability correlated well with scalp electrode recordings ( r = 0.99, P < 0.01; r = 0.79, P < 0.01, respectively). We demonstrated the feasibility and accuracy of long-term transabdominal fECG monitoring.     

A comparison of cordocentesis outcomes between early and conventional procedures

Objective: To compare procedural outcomes between early cordocentesis (16–17 weeks) and those at 18–22 weeks. Materials and Methods: A prospective database of cordocentesis was assessed. The eligible criteria included are (1) singleton pregnancy; (2) no fetal abnormalities; (3) gestational age of 16–22 weeks and (4) procedures performed by experienced operators. The procedures performed during 16–17 weeks were defined as early cordocentesis (Study group). The Control group (conventional cordocentesis; 18–22 weeks) were selected by matching maternal age and years of procedures, with a ratio of 1:3. Results: Of 2942 eligible procedures, 103 procedures were undertaken during 16–17 weeks and 309 matched controls were selected. Baseline characteristics of both groups were comparable. Time used to complete the procedure was significantly longer in Study group (8.45 ± 9.91 vs. 6.07 ± 6.63 min; p value 0.007). Similarly, rate of difficult procedures was significantly higher in Study group (7.8 vs. 2.3%; p value 0.011). However, rates of fetal loss, low birth weight infants and preterm births were not significantly different, but there was a tendency to be higher in Study group. Conclusion: Early cordocentesis is more difficult but relatively safe when performed by experienced hands, although it has a tendency to increase rates of adverse outcomes. This information may be helpful in counseling the couples.     

Fetal heart rate and uterine contraction during automobile driving

OBJECTIVE: The purpose of this study was to clarify the influence of automobile driving in the third trimester of pregnancy on fetal heart rate and uterine contraction. METHODS: Twenty-nine pregnant women with singleton pregnancies after 28 weeks of gestation were monitored using a portable cardiotocogram during driving, and the results obtained before and after driving were compared. RESULTS: Baseline fetal heart rate and its variability, as well as periodic fetal heart rate patterns, showed no abnormal patterns during car driving. Automobile driving in late pregnancy was not a reinforcement factor for uterine activity. Maternal systolic and diastolic blood pressure and heart rate showed no specific characteristic or adverse change during driving. CONCLUSION: The results of this study suggest that automobile driving in the third trimester of pregnancy has no adverse influences on either pregnant women or fetuses.     

Antepartum fetal heart rate monitoring: III. Fetal movements and accelerations in fetal heart rate

This third part of the paper deals with the study of the relationships between fetal movements, fetal heart rate accelerations associated with such movements, fetal heart rate instability and neonatal outcome.No correlation has been found between absence of fetal movements and neonatal distress.A correlation has been found between the lack of fetal heart rate accelerations, the flatness of the record and poor neonatal outcome.In extreme situations (i.e. flatness in less than 10% of the record or in more than 80%) the presence or absence of accelerations does not add further useful information. Such information, however, is gained in the intermediary situations (the ‘combined’ recordings) and particularly when the record is between 51 and 80% flat where there appears to be an 85.6% risk to the fetus.Consequently, when trying to analyse an antenatal record it seems advisable to take primarily into account the percentage of flat recordings (providing the records are numerous enough and of sufficient length). Then, in records between 10 and 50% flat, the presence or the lack of spontaneous decelerations requires consideration whereas, when the record is between 51 and 80% flat, it is the presence or absence of fetal heart rate accelerations which is important.     

胎心中央监护及远程监护的评价

胎心中央监护及远程监护是胎儿电子监护和计算机网络技术相结合的结晶,通过网络将医院监护仪与家庭监护仪连接到产科中央监护站,经电脑处理后进行信息贮存和分析,以便更方便、更完善地评价胎儿状况,有效改善胎儿预后。     

Signal ambiguity resulting in unexpected outcome with external fetal heart rate monitoring

We report cases of unexpected adverse fetal outcome from monitored labors in which the fetal heart rate tracing was interpreted as reassuring. In these cases, portions from another signal source, usually maternal, were imperceptibly substituted into the fetal tracing in a way that masked the evidence of fetal compromise.     

Cross-over trial of fetal heart rate response to halogen light and vibroacoustic stimulation

Objective. The purpose of this study was to compare the effect of halogen light and vibroacoustic stimulation on fetal heart rate (FHR) responsiveness and on nonstress test (NST) results.

Methods. Sixty consecutively-chosen patients between 33 and 39 weeks of gestation underwent an NST on at least three weekly occasions. Each received halogen light (Vector Compact Sport Spot, Ft Lauderdale, FL, USA), vibroacoustic (SolaTone Artificial Larynx, Temecula, CA, USA), and no stimulation in a randomized order. The transabdominal light or vibroacoustic stimulation lasted for 10 seconds. If no initial FHR acceleration occurred, then the stimulus was repeated 10 minutes later up to a maximum of three times. The investigators who interpreted the FHR patterns were blinded as to the type of stimulus used.

Results. Reactive results were present in 171 tests (vibroacoustic: 98.3%; light: 96.6%; none: 93.3%). Compared with no stimulation, the mean difference in time from the onset of recorded ‘stimulation’ to the first FHR acceleration was shorter (p < 0.01) with either light (2.7 minutes, 95% confidence interval (CI) 0.9–4.5 minutes) or vibroacoustic stimulation (2.6 minutes, 95% CI 0.8–4.4 minutes). The mean time difference until a reactive result was also shorter (p < 0.05) with either light (2.7 minutes, 95% CI 0.1–4.9 minutes) or vibroacoustic stimulation (2.4 minutes, 95% CI 0.1–4.7 minutes) than with no stimulation. The need for repeated stimulation during each test was infrequent (light: 5.0%; vibroacoustic: 3.3%). No adverse effect from external stimulation was noted on the FHR tracing.

Conclusion. Halogen light stimulation is an acceptable alternative to vibroacoustic stimulation in provoking a more rapid fetal heart rate response and in shortening the time before a reactive nonstress test result.     

Fetal hepatic hemangioma representing non-reassuring pattern in fetal heart rate monitoring

To the best of our knowledge, this is the first report of a non-reassuring fetal pattern caused by a hepatic hemangioma that was found during fetal heart rate monitoring. A 37 weeks' gestation, a 32-year-old-woman was referred to our hospital for evaluation of a rapidly growing fetal abdominal tumor. Fetal heart rate monitoring revealed a non-reassuring pattern, and a cesarean section was performed as a result. Examination of the 2820 g female infant suggested a hepatic hemangioma accompanying an intratumor hemorrhage and coagulopathy. The infant died 2 days after birth. The autopsy confirmed that the cause of death was a result of a hepatic hemangioma. Frequent monitoring of fetuses and ultrasound examinations are necessary for determining the timing of delivery and for a favorable prognosis.     

Association between fetal myocardial performance index and fetal heart rate monitoring: a prospective observational cohort study

Objective: To evaluate whether the left myocardial performance index (MPI) changes in association with the fetal heart rate (FHR) tracing during labor.

Study design: Women with term, singleton pregnancies, in labor were recruited to this prospective cohort study. Primary outcome: difference in left MPI between Category of fetal heart rate tracings. Secondary outcomes: differences in left MPI by FHR characteristics. Participants underwent ultrasound examination, during which fetal MPI was measured.

Results: Twenty-four laboring patients were recruited. There were 13 patients with Category I FHR, 11 patients with Category II FHR, and 0 patients with Category III FHR. Demographics were similar between the groups. MPI was not significantly different between fetuses with Category I or Category II FHR (0.67 versus 0.65, p?=?.385). MPI was significantly higher in fetuses with accelerations versus those without (0.71 versus 0.59, p?=?.045). MPI was not significantly different for fetuses with or without decelerations (0.65 versus 0.68, p?=?.350), between deceleration type (0.50 versus 0.64 versus, 0.75, p?=?.421), or between variability type (0.56 versus 0.68, p?=?.113).

Conclusions: MPI of fetuses in term, laboring patients did not vary with differing FHR characteristics except for the presence or absence of accelerations.     

Antepartum fetal heart rate monitoring: I. A semi-quantitative evaluation of the ‘non-stressed’ fetal heart rate

1964 recordings (from 246 patients) were analysed on the basis of a semi-quantitative evaluation of base-line heart rate variability. All the tracings were obtained in the antepartum period, between the 20th wk of pregnancy and prior to the onset of labour. None of the recordings were made during labour or after induction of uterine activity so that a ‘non-stressed’ fetal heart rate test was obtained in every case. The percentage of flat tracing in each recording and the presence of sinusoidal patterns were compared with the neonatal outcome. When the tracings included a more than 50% flat pattern, 81.8% of the babies were distressed at birth. When a less than 50% flat recording was present only 11.4% of the neonates were distressed. Sinusoidal patterns were more frequently associated with abnormal tracings including those with more than 50% flat recordings. The presence of sinusoidal features did not significantly influence the neonatal outcome for tracings with a less than 50% anomaly: conversely sinusoidal patterns superimposed on a more than 50% flat tracing were predictive of fetal compromise and neonatal distress in 100% of the cases. These results allow to advocate the use of ‘non-stressed’ antepartum fetal heart rate monitoring, as a reliable test in the management of high risk pregnancies.     

Average acceleration and deceleration capacity of fetal heart rate in normal pregnancy and in pregnancies complicated by fetal growth restriction

Objective: To study fetal heart rate (FHR), its short term variability (STV), average acceleration capacity (AAC), and average deceleration capacity (ADC) throughout uncomplicated gestation, and to perform a preliminary comparison of these FHR parameters between small-for dates (SFD) and control fetuses. Methods: Prospective observational study of 7?h FHR-recordings obtained with a fetal-ECG monitor in the second half of uncomplicated pregnancies (n = 90) and pregnancies complicated by fetal SFD (n = 30). FHR and STV were calculated according to established analysis. True beat-to-beat FHR, recorded at 1?ms accuracy, was used to calculate AAC and ADC using Phase Rectified Signal Averaging (PRSA). Mean values of FHR, STV, AAC, and ADC derived from recordings in SFD fetuses were compared with the reference curves. Results: Compared with the control group the mean z-scores for STV, AAC, and ADC in SFD fetuses were lower by 1.0 SD, 1.5 SD, and 1.7 SD, respectively (p < 0.0001 for all comparisons). In SFD fetuses, both the AAC and ADC z-scores were lower than the STV z-scores (p < 0.02 and p < 0.002, respectively). Conclusions: Analysis of the AAC and ADC as recorded with a high resolution fECG recorder may differentiate better between normal and SFD fetuses than STV.     

Sinusoidal fetal heart rate

Two cases with sinusoidal fetal heart rates (SHR) with good perinatal outcome are reported. Since nonstress tests, oxytocin challenge tests and serum free estriols were normal, SHR was considered not indicative of fetal compromise. A SHR can occasionally be found in connection with reactive nonstress test. In those cases it may be of minor importance when compared to the situations when the tracing also shows a nonreactive nonstress test and the perinatal outcome is often poor.     

The INFANT trial of computer-assisted fetal heart rate pattern interpretation

Failure to correctly interpret fetal heart rate tracings in labour is a major cause of litigation. To investigate whether computer-assisted interpretation could prevent adverse outcomes, the United Kingdom Health Technology Assessment Program funded a prospective randomised controlled trial involving more than 46,000 women which commenced in 2010, completed in 2013 and reported in 2017. There was no evident effect of alarms based on computer assessment of abnormality in the fetal heart rate pattern on the outcome of labour for the mother or baby. Detailed assessment of 71 cases of adverse outcome (stillbirth, neonatal death and admission to neonatal intensive care with signs of asphyxia) revealed likely substandard care in 38% of cases. Potentially avoidable causes of adverse outcome included failure to interpret the tracing in the context of risk factors such as known fetal growth restriction, meconium staining of the amniotic fluid, pyrexia in labour, the use of oxytocics.     

Limitations of autocorrelation in fetal heart rate monitoring

Fetal heart rate monitors that use autocorrelation of the ultrasonic fetal signal usually produce a cleaner fetal heart rate record than that obtainable with conventional ultrasonic fetal monitors. However, since the autocorrelation function will emphasize any periodic signal originating from the fetus or the mother, in clinical situations the resultant fetal heart rate tracing may contain spurious data. To illustrate the limitations of the autocorrelation technique in fetal monitoring, we compared the autocorrelated ultrasound fetal heart rate records from 23 patients in active labor with the simultaneously recorded direct scalp fetal electrocardiogram tracings. The results indicate that every hour of recording contained, on the average, five instances in which data were missing (range, 0 to 13), four in which data were added (range, 0 to 23), and seven instances in which data were absent for greater than 1 minute (range, 0 to 26). The potential problem of misinterpretation of autocorrelated fetal heart rate data is discussed.