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。     

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.     

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.     

Assessment of left ventricular function using the Myocardial Performance Index in term fetuses that develop intrapartum compromise

Objective: To investigate the relationship between the prelabour left ventricular Myocardial Performance Index (LVMPI) and intrapartum fetal compromise (IFC) in low-risk term pregnancies.

Methods: A blinded, prospective observational cohort study at the Mater Mother’s Hospital, Brisbane, Australia. A cohort of 284 women with uncomplicated singleton pregnancies underwent fortnightly ultrasound from 36 weeks until delivery. The LVMPI was assessed by conventional Doppler ultrasound and correlated with intrapartum outcomes. The LVMPI was also correlated with other Doppler indices of fetal wellbeing.

Results: Two hundred and seventy-three women were included in the final analysis, the median LVMPI was higher in fetuses that required any emergency operative delivery for IFC (0.56, 0.52–0.60 versus 0.54, 0.50–0.58, p?=?.007). The left ventricular cardiac output (LVCO) and cerebroplacental ratio (CPR) were lower in fetuses that required any emergency operative delivery for IFC compared to those that did not (164?±?19?ml/min/kg versus 181?±?30?ml/min/kg, p?p?r?=??0.20, p?r?=??0.29, p?r?=??0.22, p?Conclusions: Higher global LVMPI is associated with a higher risk for IFC and poorer condition of the newborn.     

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.     

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 ??5 minutes post-cordocentesis. In the tachycardia group, 6 cases had normal pregnancy outcome and one patient was lost to follow-up. In the bradycardia group, we observed two pregnancy terminations, one patient was lost to follow-up and nine were normal outcomes. In the group with normal heart rate (n?=?98), we observed one intrauterine fetal death, nine adverse fetal outcomes, eight pregnancy terminations and nine patients were lost to follow-up.

Conclusions.?Transient fetal tachycardia and bradycardia were uncommon and were not associated with adverse fetal or pregnancy outcomes.     

Fetal scalp stimulation (FSS) versus fetal blood sampling (FBS) for women with abnormal fetal heart rate monitoring in labor: a prospective cohort study

Objective: To evaluate the performance of fetal scalp stimulation (FSS) compared to fetal blood sampling (FBS) as a second line test of fetal wellbeing in labor.

Study design: A prospective cohort study was conducted including 298 fetal blood sampling procedures performed due to abnormal fetal cardiotocography (CTG). Two independent observers interpreted the CTG following stimulation. The FSS test was classified as normal when an elicited acceleration and/or provoked fetal heart rate variability was recorded. The FBS was classified as normal (pH?≥7.25), borderline (pH 7.21–7.24), and abnormal (pH?≤7.20).

Results: Of the 298 procedures, 249 (84%) had a normal scalp pH result, 199 (67%) had an acceleration in response to FSS and 255 (86%) had an acceleration or normal variability in response to FSS. All 11 of the neonates classified as normal by FSS, but abnormal by FBS were born with normal Apgar scores and cord pH results. The consistency between FSS and FBS was “fair” (kappa 0.28) while the consistency between either test and cord arterial pH was “poor”.

Conclusions: This study suggests that FSS has the potential to be a reliable alternative to FBS. The findings require evaluation in a well-designed randomized controlled trial.     

产时Ⅱ类胎心监护的流程管理

Ⅱ类胎心监护是产程中常见的胎心监护图形，其形式多样，正确识别和评估Ⅱ类胎心监护，并根据具体临床情况进行针对性干预，可降低不良妊娠结局的发生。文章根据产时胎心监护三级评估系统，介绍产时Ⅱ类胎心监护的处理流程，并对不同类型Ⅱ类胎心监护的病因及干预措施进行了阐述，以指导临床实践。     

Association of non-reassuring fetal heart rate and fetal acidosis with placental histopathology

Objective

To investigate the association between different placental lesions and non-reassuring fetal heart rate (NRFHR) pattern and fetal acidosis in labor.

Study design

Placentas from 213 women who underwent cesarean section because of NRFHR with or without fetal acidosis (pH < 7.2) were classified by histopathologic findings: consistent with maternal circulation abnormalities i.e., namely, marginal or retroplacental hemorrhage (M0), maternal underperfusion, vascular (M1) or villous changes (M2), and those consistent with fetal thrombo-occlusive disease due to vascular (F1) or villous (F2) changes. Lesions were also analyzed by maternal (MIR) or fetal (FIR) origin of inflammatory responses.

Results

Cord blood pH was normal in 169 neonates (7.29 ± 0.04; control group) and <7.2 in 44 (7.10 ± 0.07; study group). The study group had higher rates of histologic chorioamnionitis; MIR was detected in 34.1% compared to17.8% of controls (p = 0.018), and FIR, in 18.2% compared to 6.5% (p = 0.016). Neonates in the study group had lower Apgar scores and longer hospitalization.

Conclusions

Placental MIR and FIR are associated with cord blood acidosis in neonates delivered by cesarean section for NRFHR tracings in labor.     

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.     

Intrapartum fetal heart rate monitoring in cases of cytomegalovirus infection

OBJECTIVE: Several studies have shown that abnormal intrapartum fetal heart rate patterns are the results from pre-existing fetal brain damage. We evaluated intrapartum fetal heart rate pattern of cytomegalovirus-infected fetuses and correlated the patterns with neurologic outcomes. STUDY DESIGN: Between 1991 and 2001, there were 20 cytomegalovirus-infected fetuses. We selected 40 fetuses as control subjects that were matched for gestational age and birth weight. Fetal heart rate was interpreted according to the guidelines of the National Institute for Child and Human Development. The incidence of abnormal fetal heart rate pattern and umbilical blood gases were compared between both groups. We also investigated the factors that contributed to abnormal fetal heart rate pattern in the cytomegalovirus group. RESULTS: Nonreassuring fetal heart rate patterns (prolonged deceleration and recurrent late deceleration) were observed in 8 of 20 fetuses (prolonged deceleration, 7 fetuses; recurrent late deceleration, 1 fetus) in the cytomegalovirus group and in 3 of 41 fetuses (prolonged deceleration, 1 fetus; recurrent late deceleration, 2 fetuses) in the control group (P<.05, Fisher test). Baseline fetal heart rate variability was minimal in 4 of the 7 prolonged deceleration cases in the cytomegalovirus group. Umbilical pH <7.1 was found for 1 fetus in the cytomegalovirus group. The average umbilical arterial pH values were similar in both the groups. In the cytomegalovirus group, there were no differences in the incidence of contributing factors between 8 fetuses with abnormal fetal heart rate pattern (prolonged deceleration and recurrent late deceleration) and 8 fetuses with no change. There were 3 fetuses with cerebral palsy: 2 fetuses in the no change group and 1 fetus in the prolonged deceleration group. Antigenemia was positive exclusively in 4 cases with abnormal fetal heart rate pattern (P<.05). CONCLUSION: Cytomegalovirus-infected fetuses are more likely to show abnormal intrapartum fetal heart rate patterns than low-risk control fetuses, which suggests that the perinatal detection of cytomegalovirus is necessary to distinguish hypoxic-ischemic encephalopathy.     

First trimester fetal heart rate as a predictor of newborn sex

Objective: To predict the sex of newborns using first trimester fetal heart rate (FHR).

Methods: This was a retrospective review of medical records and ultrasounds performed between 8 and 13 weeks of gestation. Continuous variables were compared using Student’s t-tests while categorical variables were compared using Chi-square test.

Results: We found no significant differences between 332 (50.7%) female and 323 (49.3%) male FHRs during the first trimester. The mean FHR for female fetuses was 167.0?±?9.1?bpm and for male fetuses 167.3?±?10.1?bpm (p?=?0.62). There was no significant difference in crown rump length between female and male fetuses (4.01?±?1.7 versus 3.98?±?1.7?cm; p?=?0.78) or in gestational age at birth (38.01?±?2.1 versus 38.08?±?2.1 weeks; p?=?0.67). The males were significantly heavier than females (3305.3?±?568.3 versus 3127.5?±?579.8?g; p?<?0.0001) but there were no differences in the proportion of small for gestational age (SGA), average for gestational age (AGA) and large for gestational age (LGA) infants.

Conclusions: We found no significant difference between the female and male FHR during the first trimester in contrast to the prevailing lay view of females having a faster FHR. The only statistically significant difference was that males weighed more than female newborns.     

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.     

第一产程胎心监护异常226例的相关因素分析

目的探讨第一产程胎心监护异常的相关因素，提示处理措施。方法2004年1月1日。12月31日对我院226例第一产程胎心监护异常的相关因素进行回顾性分析。结果第一产程胎心监护异常为综合因素所致，胎儿高危因素为91.59％，母体高危因素为65．49％，产程处理因素为42．92％。结论第一产程胎心监护异常主要与胎儿因素、母体因素有关，提高产前检查质量、加强产程监护、正确选择分娩方式极为重要。     

Antepartum nonstress fetal heart rate monitoring: systematic analysis of baseline patterns and decelerations as an adjunct to reactivity in the prediction of fetal risks

A total of 1552 antepartum nonstress tests performed during the week before delivery are analyzed with respect to both reactivity and the presence of pathologic baseline patterns (tachycardia, bradycardia, diminished beat-to-beat variability) or decelerations. Correlation with mode of delivery and condition of the newborn infant shows that, irrespective of nonstress test reactivity, the presence of baseline anomalies and/or decelerations is associated with significantly increased perinatal morbidity and mortality. Nonstress test analysis, if systematic, that is, not restricted to reactivity alone, makes it possible to better detect fetuses at high perinatal risk, in which case closer surveillance would be indicated.     

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.