Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants

Fetal Heart Rate Auscultation, 4th Edition

Intermittent auscultation (IA) is an evidence-based method of fetal surveillance during labor for birthing people with low-risk pregnancies. It is a central component of efforts to reduce the primary cesarean rate and promote vaginal birth (American College of Obstetricians and Gynecologists, 2019; Association of Women's Health, Obstetric and Neonatal Nurses, 2022a). The use of intermittent IA decreased with the introduction of electronic fetal monitoring, while the increased use of electronic fetal monitoring has been associated with an increase of cesarean births. This practice monograph includes information on IA techniques; interpretation and documentation; clinical decision-making and interventions; communication; education, staffing, legal issues; and strategies to implement IA.

Fetal Heart Rate Auscultation, 4th Edition

Intermittent auscultation (IA) is an evidence-based method of fetal surveillance during labor for birthing people with low-risk pregnancies. It is a central component of efforts to reduce the primary cesarean rate and promote vaginal birth (American College of Obstetricians and Gynecologists, 2019; Association of Women's Health, Obstetric and Neonatal Nurses, 2022a). The use of intermittent IA decreased with the introduction of electronic fetal monitoring, while the increased use of electronic fetal monitoring has been associated with an increase of cesarean births. This practice monograph includes information on IA techniques; interpretation and documentation; clinical decision-making and interventions; communication; education, staffing, legal issues; and strategies to implement IA.

The social organisation of decision-making about intrapartum fetal monitoring: An Institutional Ethnography

BACKGROUND

International guidelines recommend intrapartum cardiotocograph (CTG) monitoring for women at risk for poor perinatal outcome. Research has not previously addressed how midwives and obstetricians enable or hinder women's decision-making regarding intrapartum fetal monitoring and how this work is structured by external organising factors.

AIM

To examine impacts of policy and research texts on midwives' and obstetricians' work with labouring women related to intrapartum fetal monitoring decision-making.

METHODS

We used a critical feminist qualitative methodology known as Institutional Ethnography (IE). The research was conducted in an Australian tertiary maternity service. Data collection included interviews, observation, and texts relating to midwives' and obstetricians' work with the fetal monitoring system. Textual mapping was used to explain how midwives' and obstetricians' work was organised to happen the way it was.

FINDINGS

CTG monitoring was initiated predominantly by midwives applying mandatory policy. Midwives described reluctance to inform labouring women that they had a choice of fetal monitoring method. Discursive approaches used in a national fetal surveillance guideline, a Cochrane systematic review, and the largest randomised controlled trial regarding CTG monitoring in labour generated and reproduced assumptions that clinicians, not labouring women, were the appropriate decision-maker regarding fetal monitoring in labour.

DISCUSSION AND CONCLUSION

Guidelines structured midwives' and obstetricians' work in a manner that undermined women's participation in decisions about fetal monitoring method. Intrapartum fetal monitoring guidelines should be critically reviewed to ensure they encourage and enable midwives and obstetricians to support women to make decisions about intrapartum care.

[S3 guidelines on "full-term vaginal birth" from an anesthesiological perspective : Worthwhile knowledge for anesthesiologists]

The publication of the new S3 guidelines on "full-term vaginal birth" and the guidelines on cesarean section, also published in 2020, provide further steps towards the promotion of evidence-based medicine in obstetrics, even if the exact configuration of neonatal monitoring during birth, in particular, is still the subject of current discussions. The multiprofessionality in the medical supervision of a birth is also fundamentally well-represented in the compilation of the S3 guidelines by the participating actors and specialist societies. Important from an anesthesiological perspective is the fact that neuraxial procedures still represent the gold standard in obstetric analgesia. With remifentanil PCA an alternative option is available that enables a reliable analgesia to be accomplished, e.g. when there are contraindications to performing neuraxial methods, if this is appropriate under the prevailing circumstances (1:1 support and appropriate monitoring). During an uncomplicated birth the strict fasting rules are relaxed. Overall, the guidelines underline the importance of self-determination and self-control for the expectant mother and give the highest priority to the safety and well-being of mother and child; however, this presupposes that the expectant mother is sufficiently informed about the value of neuraxial analgesia. For this it appears to be of importance to initiate information proposals, which go beyond the usual information sessions for parents that are often organized exclusively by midwives.

Intrapartum cardiotocograph monitoring and perinatal outcomes for women at risk: Literature review

PROBLEM

Caesarean section rates have risen in high-income countries. One of the potential drivers for this is the widespread use of CTG monitoring.

BACKGROUND

Intrapartum cardiotocograph monitoring is considered to be indicated for women at risk for poor perinatal outcome.

AIM

This systematic literature review with meta-analysis examined randomised controlled trials and non-experimental research to determine whether cardiotocograph monitoring rather than intermittent auscultation during labour was associated with changes in perinatal mortality or cerebral palsy rates for high-risk women.

METHODS

A systematic search for research published up to 2019 was conducted using PubMed, CINAHL, Cochrane, and Web of Science databases. Non-experimental and randomised controlled trial research in populations of women at risk which compared intrapartum cardiotocography with intermittent auscultation and reported on stillbirth, neonatal mortality, perinatal mortality and/or cerebral palsy were included. Relative risks were calculated from extracted data, and meta-analysis of randomised controlled trials was undertaken.

FINDINGS

Nine randomised controlled trials and 26 non-experimental studies were included. Meta-analysis of pooled data from RCTs in mixed- and high-risk populations found no statistically significant differences in perinatal mortality rates. The majority of non-experimental research was at critical risk of bias and should not be relied on to inform practice. Cardiotocograph monitoring during preterm labour was associated with a higher incidence of cerebral palsy.

DISCUSSION

Research evidence failed to demonstrate perinatal benefits from intrapartum cardiotocograph monitoring for women at risk for poor perinatal outcome.

CONCLUSION

There is an urgent need for well-designed research to consider whether intrapartum cardiotocograph monitoring provides benefits.

No. 197b-Fetal Health Surveillance: Intrapartum Consensus Guideline

OBJECTIVE

This guideline provides new recommendations pertaining to the application and documentation of fetal surveillance in the intrapartum period that will decrease the incidence of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention. Pregnancies with and without risk factors for adverse perinatal outcomes are considered. This guideline presents an alternative classification system for antenatal fetal non-stress testing and intrapartum electronic fetal surveillance to what has been used previously. This guideline is intended for use by all health professionals who provide intrapartum care in Canada.

OPTIONS

Consideration has been given to all methods of fetal surveillance currently available in Canada.

OUTCOMES

Short- and long-term outcomes that may indicate the presence of birth asphyxia were considered. The associated rates of operative and other labour interventions were also considered.

EVIDENCE

A comprehensive review of randomized controlled trials published between January 1996 and March 2007 was undertaken, and MEDLINE and the Cochrane Database were used to search the literature for all new studies on fetal surveillance antepartum. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care (Table 1).

SPONSOR

This consensus guideline was jointly developed by the Society of Obstetricians and Gynaecologists of Canada and the British Columbia Perinatal Health Program (formerly the British Columbia Reproductive Care Program or BCRCP) and was partly supported by an unrestricted educational grant from the British Columbia Perinatal Health Program. RECOMMENDATION 1: LABOUR SUPPORT DURING ACTIVE LABOUR: RECOMMENDATION 2: PROFESSIONAL ONE-TO ONE CARE AND INTRAPARTUM FETAL SURVEILLANCE: RECOMMENDATION 3: INTERMITTENT AUSCULTATION IN LABOUR: RECOMMENDATION 4: ADMISSION FETAL HEART TEST: RECOMMENDATION 5: INTRAPARTUM FETAL SURVEILLANCE FOR WOMEN WITH RISK FACTORS FOR ADVERSE PERINATAL OUTCOME: When a normal tracing is identified, it may be appropriate to interrupt the electronic fetal monitoring tracing for up to 30 minutes to facilitate periods of ambulation, bathing, or position change, providing that (1) the maternal-fetal condition is stable and (2) if oxytocin is being administered, the infusion rate is not increased (III-B). RECOMMENDATION 6: DIGITAL FETAL SCALP STIMULATION: RECOMMENDATION 7: FETAL SCALP BLOOD SAMPLING: RECOMMENDATION 8: UMBILICAL CORD BLOOD GASES: RECOMMENDATION 9: FETAL PULSE OXIMETRY: RECOMMENDATION 10: ST WAVEFORM ANALYSIS: RECOMMENDATION 11: INTRAPARTUM FETAL SCALP LACTATE TESTING.

Fetal Heart Rate Auscultation, 3rd edition

The use of intermittent auscultation (IA) for fetal surveillance during labor decreased with the introduction of electronic fetal monitoring (EFM). The increased use of EFM is associated with an increase in cesarean births. IA is an evidence-based method of fetal surveillance during labor for women with low risk pregnancies and considered one component of comprehensive efforts to reduce the primary cesarean rate and promote vaginal birth. Many clinicians are not familiar with IA practice. This practice monograph includes information on IA techniques; interpretation and documentation; clinical decision-making and interventions; communication; education, staffing, legal issues, and strategies to promote implementation of IA into practice.

A prospective cohort study of fetal heart rate monitoring: deceleration area is predictive of fetal acidemia

BACKGROUND

Intrapartum electronic fetal monitoring is the most commonly used tool in obstetrics in the United States; however, which electronic fetal monitoring patterns predict acidemia remains unclear.

OBJECTIVE

This study was designed to describe the frequency of patterns seen in labor using modern nomenclature, and to test the hypothesis that visually interpreted patterns are associated with acidemia and morbidities in term infants. We further identified patterns prior to delivery, alone or in combination, predictive of acidemia and neonatal morbidity.

STUDY DESIGN

This was a prospective cohort study of 8580 women from 2010 through 2015. Patients were all consecutive women laboring at ≥37 weeks' gestation with a singleton cephalic fetus. Electronic fetal monitoring patterns during the 120 minutes prior to delivery were interpreted in 10-minute epochs. Interpretation included the category system and individual electronic fetal monitoring patterns per the Eunice Kennedy Shriver National Institute of Child Health and Human Development criteria as well as novel patterns. The primary outcome was fetal acidemia (umbilical artery pH ≤7.10); neonatal morbidities were also assessed. Final regression models for acidemia adjusted for nulliparity, pregestational diabetes, and advanced maternal age. Area under the receiver operating characteristic curves were used to assess the test characteristics of individual models for acidemia and neonatal morbidity.

RESULTS

Of 8580 women, 149 (1.7%) delivered acidemic infants. Composite neonatal morbidity was diagnosed in 757 (8.8%) neonates within the total cohort. Persistent category I, and 10-minute period of category III, were significantly associated with normal pH and acidemia, respectively. Total deceleration area was most discriminative of acidemia (area under the receiver operating characteristic curves, 0.76; 95% confidence interval, 0.72-0.80), and deceleration area with any 10 minutes of tachycardia had the greatest discriminative ability for neonatal morbidity (area under the receiver operating characteristic curves, 0.77; 95% confidence interval, 0.75-0.79). Once the threshold of deceleration area is reached the number of cesareans needed-to-be performed to potentially prevent 1 case of acidemia and morbidity is 5 and 6, respectively.

CONCLUSION

Deceleration area is the most predictive electronic fetal monitoring pattern for acidemia, and combined with tachycardia for significant risk of morbidity, from the electronic fetal monitoring patterns studied. It is important to acknowledge that this study was performed in patients delivering ≥37 weeks, which may limit the generalizability to preterm populations. We also did not use computerized analysis of the electronic fetal monitoring patterns because human visual interpretation was the basis for the Eunice Kennedy Shriver National Institute of Child Health and Human Development categories, and importantly, it is how electronic fetal monitoring is used clinically.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (CTG) records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic) to guide additional assessments of fetal wellbeing, or determine if the baby needs to be delivered by caesarean section or instrumental vaginal birth. This is an update of a review previously published in 2013, 2006 and 2001.

OBJECTIVES

To evaluate the effectiveness and safety of continuous cardiotocography when used as a method to monitor fetal wellbeing during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with no fetal monitoring, intermittent auscultation intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, quality and extracted data from included studies. Data were checked for accuracy.

MAIN RESULTS

We included 13 trials involving over 37,000 women. No new studies were included in this update.One trial (4044 women) compared continuous CTG with intermittent CTG, all other trials compared continuous CTG with intermittent auscultation. No data were found comparing no fetal monitoring with continuous CTG. Overall, methodological quality was mixed. All included studies were at high risk of performance bias, unclear or high risk of detection bias, and unclear risk of reporting bias. Only two trials were assessed at high methodological quality.Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, N = 33,513, 11 trials, low quality evidence), but was associated with halving neonatal seizure rates (RR 0.50, 95% CI 0.31 to 0.80, N = 32,386, 9 trials, moderate quality evidence). There was no difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, N = 13,252, 2 trials, low quality evidence). There was an increase in caesarean sections associated with continuous CTG (RR 1.63, 95% CI 1.29 to 2.07, N = 18,861, 11 trials, low quality evidence). Women were also more likely to have instrumental vaginal births (RR 1.15, 95% CI 1.01 to 1.33, N = 18,615, 10 trials, low quality evidence). There was no difference in the incidence of cord blood acidosis (RR 0.92, 95% CI 0.27 to 3.11, N = 2494, 2 trials, very low quality evidence) or use of any pharmacological analgesia (RR 0.98, 95% CI 0.88 to 1.09, N = 1677, 3 trials, low quality evidence).Compared with intermittent CTG, continuous CTG made no difference to caesarean section rates (RR 1.29, 95% CI 0.84 to 1.97, N = 4044, 1 trial) or instrumental births (RR 1.16, 95% CI 0.92 to 1.46, N = 4044, 1 trial). Less cord blood acidosis was observed in women who had intermittent CTG, however, this result could have been due to chance (RR 1.43, 95% CI 0.95 to 2.14, N = 4044, 1 trial).Data for low risk, high risk, preterm pregnancy and high-quality trials subgroups were consistent with overall results. Access to fetal blood sampling did not appear to influence differences in neonatal seizures or other outcomes.Evidence was assessed using GRADE. Most outcomes were graded as low quality evidence (rates of perinatal death, cerebral palsy, caesarean section, instrumental vaginal births, and any pharmacological analgesia), and downgraded for limitations in design, inconsistency and imprecision of results. The remaining outcomes were downgraded to moderate quality (neonatal seizures) and very low quality (cord blood acidosis) due to similar concerns over limitations in design, inconsistency and imprecision.

AUTHORS' CONCLUSIONS

CTG during labour is associated with reduced rates of neonatal seizures, but no clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing. However, continuous CTG was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed decision without compromising the normality of labour.The question remains as to whether future randomised trials should measure efficacy (the intrinsic value of continuous CTG in trying to prevent adverse neonatal outcomes under optimal clinical conditions) or effectiveness (the effect of this technique in routine clinical practice).Along with the need for further investigations into long-term effects of operative births for women and babies, much remains to be learned about the causation and possible links between antenatal or intrapartum events, neonatal seizures and long-term neurodevelopmental outcomes, whilst considering changes in clinical practice over the intervening years (one-to-one-support during labour, caesarean section rates). The large number of babies randomised to the trials in this review have now reached adulthood and could potentially provide a unique opportunity to clarify if a reduction in neonatal seizures is something inconsequential that should not greatly influence women's and clinicians' choices, or if seizure reduction leads to long-term benefits for babies. Defining meaningful neurological and behavioural outcomes that could be measured in large cohorts of young adults poses huge challenges. However, it is important to collect data from these women and babies while medical records still exist, where possible describe women's mobility and positions during labour and birth, and clarify if these might impact on outcomes. Research should also address the possible contribution of the supine position to adverse outcomes for babies, and assess whether the use of mobility and positions can further reduce the low incidence of neonatal seizures and improve psychological outcomes for women.

Electronic fetal monitoring, cerebral palsy, and caesarean section: assumptions versus evidence

Given evidence that cerebral palsy is not reduced by electronic fetal monitoring, Karin Nelson, Thomas Sartwelle, and Dwight Rouse ask why routine monitoring and related litigation continue to contribute to high rates of caesarean births

[Mode of delivery in spontaneous preterm birth]

OBJECTIVE

To evaluate the benefit/risk balance of way of birth according to fetal presentation, to assess monitoring during preterm labor, to discuss method of delivery and practice of delayed cord clamping in case of spontaneous preterm birth.

METHODS

Bibliographic research from the Pubmed database and recommendations issued by the main scientific societies, and assignment of a level of evidence and a recommendation grade.

RESULTS

In case of vertex presentation, no studies suggest that cesarean section improve neonatal outcome during spontaneous preterm birth (LE4). Nevertheless, cesarean is associated with higher maternal morbidity than vaginal delivery. Thus, routine cesarean is not recommended simply because of a spontaneous preterm labor (professional consensus). The available data do not allow specific recommendations about the choice of mode of delivery for preterm breech presentation in view of the low levels of proof (Professional consensus). Fetal rate monitoring is necessary during preterm labor (Professional consensus). Current data about second lines method for fetal surveillance (fetal scalp blood for pH or lactates) are insufficient to recommend their use before 34 WG (Professional consensus). Systematic assisted vaginal delivery is not recommended during preterm birth (Professional consensus). Use of vacuum is possible after 34 WG when cranial vertex ossification is considered satisfactory (Professional consensus). Systematic use of episiotomy in case of preterm birth is not recommended (Professional consensus). A delayed cord clamping is possible if the neonatal or maternal state so permits (Professional consensus). The available data are insufficient to recommend a systematic use of this procedure (LE3).

CONCLUSION

In case of preterm delivery, the available data do not allow specific recommendations about the choice of mode of delivery regardless of fetal presentation.

Planned caesarean section for women with a twin pregnancy

BACKGROUND

Twin pregnancies are associated with increased perinatal mortality, mainly related to prematurity, but complications during birth may contribute to perinatal loss or morbidity. The option of planned caesarean section to avoid such complications must therefore be considered. On the other hand, randomised trials of other clinical interventions in the birth process to avoid problems related to labour and birth (planned caesarean section for breech, and continuous electronic fetal heart rate monitoring), have shown an unexpected discordance between short-term perinatal morbidity and long-term neurological outcome. The risks of caesarean section for the mother in the current and subsequent pregnancies must also be taken into account.

OBJECTIVES

To determine the short- and long-term effects on mothers and their babies, of planned caesarean section for twin pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (18 November 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials comparing a policy of caesarean section with planned vaginal birth for women with twin pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, quality and extracted data. Data were checked for accuracy. For important outcomes the quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included two trials comparing planned caesarean section versus planned vaginal birth for twin pregnancies.Most of the data included in the review were from a multicentre trial where 2804 women were randomised in 106 centres in 25 countries. All centres had facilities to perform emergency caesarean section and had anaesthetic, obstetrical, and nursing staff available in the hospital at the time of planned vaginal delivery. In the second trial carried out in Israel, 60 women were randomised. We judged the risk of bias to be low for all categories except performance (high) and outcome assessment bias (unclear).There was no clear evidence of differences between women randomised to planned caesarean section or planned vaginal birth for maternal death or serious morbidity (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.67 to 1.11; 2844 women; two studies; moderate quality evidence). There was no significant difference between groups for perinatal or neonatal death or serious neonatal morbidity (RR 1.15, 95% CI 0.80 to 1.67; data for 5565 babies, one study, moderate quality evidence). No studies reported childhood disability.For secondary outcomes there was no clear evidence of differences between groups for perinatal or neonatal mortality (RR 1.41, 95% CI 0.76 to 2.62; 5685 babies; two studies, moderate quality evidence), serious neonatal morbidity (RR 1.03, 95% CI 0.65 to 1.64; 5644 babies; two studies, moderate quality evidence) or any of the other neonatal outcomes reported.The number of women undergoing caesarean section was reported in both trials. Most women in the planned caesarean group had treatment as planned (90.9% underwent caesarean section), whereas in the planned vaginal birth group 42.9% had caesarean section for at least one twin. For maternal mortality; no events were reported in one trial and two deaths (one in each group) in the other. There were no significant differences between groups for serious maternal morbidity overall (RR 0.86, 95% CI 0.67 to 1.11; 2844 women; two studies) or for different types of short-term morbidity. There were no significant differences between groups for failure to breastfeed (RR 1.14, 95% CI 0.95 to 1.38; 2570 women, one study; moderate quality evidence) or the number of women with scores greater than 12 on the Edinbugh postnatal depression scale (RR 0.95, 95% CI 0.78 to 1.14; 2570 women, one study; moderate quality evidence).

AUTHORS' CONCLUSIONS

Data mainly from one large, multicentre study found no clear evidence of benefit from planned caesarean section for term twin pregnancies with leading cephalic presentation. Data on long-term infant outcomes are awaited. Women should be informed of possible risks and benefits of labour and vaginal birth pertinent to their specific clinical presentation and the current and long-term effects of caesarean section for both mother and babies. There is insufficient evidence to support the routine use of planned caesarean section for term twin pregnancy with leading cephalic presentation, except in the context of further randomised trials.

Preterm cesarean delivery for nonreassuring fetal heart rate: neonatal and neurologic morbidity

OBJECTIVE

To compare the rates of neonatal morbidity and cerebral palsy among preterm neonates (less than 37 weeks of gestation) delivered by cesarean for a nonreassuring fetal heart rate (FHR) tracing compared with those who did not.

METHODS

This was a secondary analysis of a multicenter randomized trial of MgSO4 for the prevention of cerebral palsy. Newborns of women delivered by cesarean delivery for nonreassuring FHR were compared with a control group composed of the offspring of women who labored for 2 hours or longer but did not undergo cesarean delivery for nonreassuring FHR regardless of the mode of delivery. Using multivariable analysis to adjust for potential confounders, our objective was to compare two outcomes: 1) composite neonatal morbidity (Apgar score 3 or less at 5 minutes, seizure, sepsis, necrotizing enterocolitis grade II or III, intraventricular hemorrhage grade III or IV, or death before discharge) and 2) neurologic injury (cerebral palsy) at 2 years or more of corrected age between the groups.

RESULTS

Of the 1,291 preterm neonates who met the inclusion criteria, 177 (14%) were delivered by cesarean for nonreassuring FHR compared with 1,114 (86%) in the control group. Composite neonatal morbidity was similar between the groups (30.5 compared with 22.2%, adjusted odds ratio [OR] 1.4, 95% confidence interval [CI] 0.9-2.1). The rate of cerebral palsy of any severity (8.3 compared with 4.0%, adjusted OR 2.3, 95% CI 1.2-4.5) and moderate-to-severe cerebral palsy at 2 years of corrected age (6.0 compared with 2.2%, adjusted OR 3.2, 95% CI 1.4-7.1) was significantly higher in children born through cesarean delivery for nonreassuring FHR.

CONCLUSION

Nonreassuring fetal tracing deemed so serious as to require cesarean delivery is associated with an increased risk of cerebral palsy in preterm neonates.

LEVEL OF EVIDENCE

II.

The cascade of medical services and associated longitudinal costs due to nonadherent magnetic resonance imaging for low back pain

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare type, timing, and longitudinal medical costs incurred after adherent versus nonadherent magnetic resonance imaging (MRI) for work-related low back pain.

SUMMARY OF BACKGROUND DATA

Guidelines advise against MRI for acute uncomplicated low back pain, but is an option for persistent radicular pain after a trial of conservative care. Yet, MRI has become frequent and often nonadherent. Few studies have documented the nature and impact of medical services (including type and timing) initiated by nonadherent MRI.

METHODS

A longitudinal, workers' compensation administrative data source was accessed to select low back pain claims filed between January 1, 2006 and December 31, 2006. Cases were grouped by MRI timing (early, timely, no MRI) and subgrouped by severity ("less severe," "more severe") (final cohort = 3022). Health care utilization for each subgroup was evaluated at 3, 6, 9, and 12 months post-MRI. Multivariate logistic regression models examined risk of receiving subsequent diagnostic studies and/or treatments, adjusting for pain indicators and demographic covariates.

RESULTS

The adjusted relative risks for MRI group cases to receive electromyography, nerve conduction testing, advanced imaging, injections, and surgery within 6 months post-MRI risks in the range from 6.5 (95% CI: 2.20-19.09) to 54.9 (95% CI: 22.12-136.21) times the rate for the referent group (no MRI less severe). The timely and early MRI less severe subgroups had similar adjusted relative risks to receive most services. The early MRI more severe subgroup cases had generally higher adjusted relative risks than timely MRI more severe subgroup cases. Medical costs for both early MRI subgroups were highest and increased the most over time.

CONCLUSION

The impact of nonadherent MRI includes a wide variety of expensive and potentially unnecessary services, and occurs relatively soon post-MRI. Study results provide evidence to promote provider and patient conversations to help patients choose care that is based on evidence, free from harm, less costly, and truly necessary.

LEVEL OF EVIDENCE

N/A.

Pathology of perinatal brain damage: background and oxidative stress markers

PURPOSE

To review historical scientific background and new perspective on the pathology of perinatal brain damage. The relationship between birth asphyxia and subsequent cerebral palsy has been extensively investigated. The role of new and promising clinical markers of oxidative stress (OS) is presented.

METHODS

Electronic search of PubMed-Medline/EMBASE database has been performed. Laboratory and clinical data involving case series from the research group are reported.

RESULTS

The neuropathology of birth asphyxia and subsequent perinatal brain damage as well as the role of electronic fetal monitoring are reported following a review of the medical literature.

CONCLUSIONS

This review focuses on OS mechanisms underlying the neonatal brain damage and provides different perspective on the most reliable OS markers during the perinatal period. In particular, prior research work on neurodevelopmental diseases, such as Rett syndrome, suggests the measurement of oxidized fatty acid molecules (i.e., F4-Neuroprostanes and F2-Dihomo-Isoprostanes) closely related to brain white and gray matter oxidative damage.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (known also as electronic fetal monitoring), records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic), so additional assessments of fetal well-being may be used, or the baby delivered by caesarean section or instrumental vaginal birth.

OBJECTIVES

To evaluate the effectiveness of continuous cardiotocography during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 December 2012) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with (a) no fetal monitoring, (b) intermittent auscultation (c) intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, quality and extracted data from included studies.

MAIN RESULTS

Thirteen trials were included with over 37,000 women; only two were judged to be of high quality.Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n = 32,386, nine trials). There was no significant difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, n = 13,252, two trials). There was a significant increase in caesarean sections associated with continuous cardiotocography (RR 1.63, 95% CI 1.29 to 2.07, n = 18,861, 11 trials). Women were also more likely to have an instrumental vaginal birth (RR 1.15, 95% CI 1.01 to 1.33, n = 18,615, 10 trials).Data for subgroups of low-risk, high-risk, preterm pregnancies and high-quality trials were consistent with overall results. Access to fetal blood sampling did not appear to influence the difference in neonatal seizures nor any other prespecified outcome.

AUTHORS' CONCLUSIONS

Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed choice without compromising the normality of labour.

Correlation of arterial fetal base deficit and lactate changes with severity of variable heart rate decelerations in the near-term ovine fetus

OBJECTIVE

Recent guidelines classify variable decelerations without detail as to degree of depth. We hypothesized that variable deceleration severity is highly correlated with fetal base deficit accumulation.

STUDY DESIGN

Seven near-term fetal sheep underwent a series of graded umbilical cord occlusions resulting in mild (30 bpm decrease), moderate (60 bpm decrease), or severe (decrease of 90 bpm to baseline <70 bpm) variable decelerations at 2.5 minute intervals.

RESULTS

Mild, moderate, and severe variable decelerations increased fetal base deficit (0.21 ± 0.03, 0.27 ± 0.03, and 0.54 ± 0.09 mEq/L per minute) in direct proportion to severity. During recovery, fetal base deficit cleared at 0.12 mEq/L per minute.

CONCLUSION

In this model, ovine fetuses can tolerate repetitive mild and moderate variable decelerations with minimal change in base deficit and lactate. In contrast, repetitive severe variable decelerations may result in significant base deficit increases, dependent on frequency. Modified guideline differentiation of mild/moderate vs severe variable decelerations may aid in the interpretation of fetal heart rate tracings and optimization of clinical management paradigms.

Long-term child follow-up after large obstetric randomised controlled trials for the evaluation of perinatal interventions: a systematic review of the literature

BACKGROUND

Although the hope is that many perinatal interventions are performed with an ultimate aim to improve the long-term health and development of the child, long-term outcome is rarely used as a primary end-point in perinatal randomised controlled trials (RCTs).

OBJECTIVE

To evaluate how often and with which tools long-term follow-up is performed after large obstetric RCTs.

SEARCH STRATEGY

We searched the Cochrane Library for Cochrane reviews published by the Cochrane Pregnancy and Childbirth Group for reviews on interventions that aimed to improve neonatal outcome. Selection criteria  Reviews on perinatal interventions that were not performed to improve the condition of the neonate were excluded. We limited our review to RCTs with more than 350 participating women. For each included study, we checked in Web of Science as to whether the researchers had reported on follow-up in subsequent publications.

DATA COLLECTION AND ANALYSIS

Relevant information was extracted from these RCTs by two reviewers using a predefined data collection sheet. All information was analysed using SPSS 17.0 (SPSS Inc., Chicago, IL, USA).

MAIN RESULTS

We studied 212 reviews including 1837 RCTs on perinatal interventions, 249 (14%) of which included 350 participants. Only 40 of 249 RCTs (16%) followed the children after discharge from the hospital to evaluate the effect of a specific perinatal intervention. The number of RCTs with long-term follow-up remained stable, with 10 of 67 RCTs (15%) reporting follow-up before 1990, 17 of 115 (15%) between 1990 and 2000, and 13 of 67 (19%) after 2000 (P = 0.68).

CONCLUSIONS

Only a small minority of large perinatal RCTs report the long-term follow-up of the child. Future obstetric RCTs should consider performing long-term follow-up at the start of the trial.

Planned caesarean section for women with a twin pregnancy

BACKGROUND

Twin pregnancies are associated with increased perinatal mortality, mainly related to prematurity, but complications during birth may contribute to perinatal loss or morbidity. The option of planned caesarean section to avoid such complications must therefore be considered. On the other hand, randomised trials of other clinical interventions in the birth process to avoid problems related to labour and birth (planned caesarean section for breech, and continuous electronic fetal heart rate monitoring), have shown an unexpected discordance between short-term perinatal morbidity and long-term neurological outcome. The risks of caesarean section for the mother in the current and subsequent pregnancies must also be taken into account.

OBJECTIVES

To determine the short- and long-term effects on mothers and their babies, of planned caesarean section for twin pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011).

SELECTION CRITERIA

Randomised trials comparing a policy of caesarean section with planned vaginal birth for women with twin pregnancy.

DATA COLLECTION AND ANALYSIS

Two researchers independently assessed eligibility, quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

One small trial with unconfirmed allocation concealment compared caesarean section with planned vaginal birth in 60 women with vertex/non-vertex twin pregnancies. There were no differences in perinatal outcome. The trial was too small to exclude the possibility of clinically meaningful benefits of either approach. There is one additional trial currently ongoing.

AUTHORS' CONCLUSIONS

There is a lack of robust evidence to guide clinical advice regarding the method of birth for twin pregnancies. Women should be informed of possible benefits and risks of either approach, including short-term and long-term consequences for both mother and babies. Future research should aim to provide unbiased evidence, including long-term outcomes.

Neuroprotective approaches: before and after delivery

Infants born preterm are especially vulnerable to cerebral palsy, the risk of which is inversely proportional to gestational age at birth. The contribution of prematurity to the overall burden of cerebral palsy is substantial. This article reviews and discusses potential antenatal and postnatal neuroprotective approaches targeted at the numerous risk factors associated with cerebral palsy among preterm infants, including magnesium sulfate.

Electronic fetal monitoring: past, present, and future

Electronic fetal monitoring (EFM) using cardiotocography is a common tool used during labor and delivery for assessment of fetal well-being. It has largely replaced the use of intermittent auscultation and fetal scalp pH sampling. However, data suggesting improved clinical outcomes with the use of EFM are sparse. In this review, the history of EFM is revisited from its inception in the 1960s to current practice, interpretations, and future research goals.

Umbilical cord blood gas analysis in augmented labour

Labour augmentation with oxytocin may produce an excessive increase in frequency, duration or strength in uterine contractions which may result in fetal stress. Umbilical cord acid-base assessment provides an objective parameter in evaluating the neonatal condition immediately after delivery. We evaluated the neonatal condition in 235 deliveries where oxytocin was used for labour augmentation. The umbilical cord blood acid-base status was correlated with intrapartum cardiotocographic findings and Apgar scores. In two cases we noted umbilical artery pH <7.05 but the BDecF was not higher than 11 mmol/l and the 5-minute Apgar score was 8 in all cases. Our results indicate that the use of oxytocin for labour augmentation had no adverse effects on neonatal condition.

Epidemiology of stillbirth and fetal central nervous system injury

The epidemiology of stillbirth and fetal central nervous system (CNS) injury is described with some emphasis on maternal and feto-placental risk factors. To maximize utility of the discussion and because it also represents the classical manifestation of fetal CNS injury, we have selected cerebral palsy (CP) to illustrate the epidemiologic aspects of injury to the fetal CNS in general. While trends in stillbirth rates have modestly decreased over time, those of CP seem to be increasing. Interestingly, both stillbirth and CP share traditional as well as emerging risk factors lending credence to the hypothesis that fetuses that would previously have been stillborn are increasingly surviving albeit with some form of morbidity. The existence of shared risk factors also suggests that in some cases of stillbirth fetal CNS injury precedes the in utero fetal demise. Pregnant women bearing these risk indicators represent potential candidates for appropriate and tailored protocols for antenatal fetal testing.

Is cerebral palsy preventable?

PURPOSE OF REVIEW

To use evidence of good medical quality to update information on strategies for prevention of cerebral palsy, and on the success of these preventive efforts to date.

RECENT FINDINGS

Causes of cerebral palsy, and therefore promising approaches to prevention, differ by gestational age group and by clinical subtype. Neuroimaging and neuropathology indicate the importance of white matter disorders and of ischemic stroke in cerebral palsy; birth asphyxia, congenital malformations, placental pathology, and genetic variants also contribute to cerebral palsy risk. Multiplicity of risk factors markedly increases risk. Recent studies indicate that mild hypothermia lessens cerebral palsy risk in term infants with moderate neonatal encephalopathy, and the possibility that administration of magnesium sulphate to women in preterm labor may aid in primary prevention of cerebral palsy in very preterm infants.

SUMMARY

Past efforts to prevent cerebral palsy have not had the benefits sought, but recent results provide new hope and new challenges.

Long-term neurologic outcome of infants born by cesarean section

Prevention of neurologic injury to the fetus through skilled and attentive care during the peripartum period is designed to identify signs of fetal distress so that appropriate obstetric interventions can occur. The impact of mode of delivery on neurologic outcome varies depending on the clinical indication for cesarean delivery and the associated maternal and fetal conditions. This review summarizes current knowledge of the impact of mode of delivery on long-term neurologic outcome.

[Modality of fetal heart monitoring during labor (continuous or intermittent), telemetry and central fetal monitoring]

Fetal heart monitoring during labor is almost systematic today. Continuous monitoring decreases neonatal convulsions, but increases caesarean section and forceps deliveries without impact on long term neonatal prognosis. Overall, there is no proved impact of cardiac fetal monitoring (continuous or intermittent) on perinatal mortality. The most recent study shows neonatal benefits of continuous monitoring associated with an overall increase of caesarean section rate. Continuous fetal monitoring has a better sensitivity to detect acidosis. Many arguments for continuous fetal monitoring will be reported in this review. In specific conditions, intermittent fetal auscultation can be realised, but in current practice such conditions can rarely be applied. Telemetry has been poorly evaluated to date but experiences are currently undertaken. Central fetal monitoring does not improve neonatal issue but could increase caesarean section rate. Central of fetal monitoring could help in the organisation and the conservation of fetal heart monitoring.

[Fetal scalp blood sampling for pH and lactate measurement during labour]

The wide use of continuous of fetal heart rate monitoring (FHR) since the seventies has been accompanied by an increase in cesarean delivery rates, without any decrease in cerebral palsy rate. Second line methods of fetal monitoring have been developed in order to better identify fetuses truly at risk of intrapartum asphyxia. The use of fetal scalp blood sampling (FBS) for fetal monitoring seems logical since neonatal acidosis is one of the major criteria of birth asphyxia. Studies show that the use of FBS reduces the increase in cesarean deliveries associated with the use of continuous FHR monitoring. However, FBS is invasive, non continuous and technically uneasy, with a rather high rate of failed blood samplings. Fetal scalp lactates measurement by micromethod requires a much smaller volume of blood. Although a wider assessment is required, the predictive value of fetal blood lactates seems to be similar to that of fetal scalp blood pH.

WITHDRAWN: Continuous electronic heart rate monitoring for fetal assessment during labor

BACKGROUND

Electronic fetal monitoring (EFM) is used in the management of labor and delivery in nearly three of four pregnancies in the United States. The apparent contradiction between the widespread use of EFM and expert recommendations to limit routine use indicates that a reassessment of this practice is warranted.

OBJECTIVES

To compare the efficacy and safety of routine continuous EFM during labor with intermittent auscultation, using the results of published randomized controlled trials (RCTs).

SEARCH STRATEGY

We identified RCTs by searching MEDLINE and the register maintained by the Cochrane Pregnancy and Childbirth Group, and by contacting experts, and reviewing published references. Date of last search: January 2001.

SELECTION CRITERIA

Randomized controlled trials.

DATA COLLECTION AND ANALYSIS

Data were abstracted by one of us, and their accuracy was confirmed independently by a second person. A single reviewer assessed study quality based on criteria developed by others for RCTs. Data reported from similar studies were used to calculate a combined risk estimate for each of eight outcomes.

MAIN RESULTS

Our search identified 13 published RCTs addressing the efficacy and safety of EFM; no unpublished studies were found. Four trials that did not fulfil our selection criteria were excluded. The remaining nine trials included 18,561 pregnant women and their 18,695 infants in both high- and low-risk pregnancies from seven clinical centers in the United States, Europe, and Australia. Overall, a statistically significant decrease was associated with routine EFM for neonatal seizures (relative risk (RR) 0.51, 95% confidence interval (CI) 0.32-0.82). The protective effect for neonatal seizures was only evident in studies with high-quality scores. No significant differences were observed in 1-minute Apgar scores below four or seven, rate of admissions to neonatal intensive care units, perinatal deaths or cerebral palsy. An increase associated with the use of EFM was observed in the rate of cesarean delivery (RR 1.41, 95% CI 1.23-1.61) and operative vaginal delivery (RR 1.20, 95% CI 1.11-1.30).

AUTHORS' CONCLUSIONS

The only clinically significant benefit from the use of routine continuous EFM was in the reduction of neonatal seizures. In view of the increase in cesarean and operative vaginal delivery, the long-term benefit of this reduction must be evaluated in the decision reached jointly by the pregnant woman and her clinician to use continuous EFM or intermittent auscultation during labor.

Intrapartum fetal monitoring today

The literature on intrapartum fetal monitoring is reviewed emphasizing the pathophysiology, and current practice guidelines are discussed. FHR monitoring, ancillary tests, and investigational modalities are considered.

Intrapartum Electronic Fetal Heart Rate Monitoring and the Prevention of Perinatal Brain Injury

OBJECTIVE

Electronic fetal heart rate monitoring (EFM) is the most widely used method of intrapartum surveillance, and our objective is to review its ability to prevent perinatal brain injury and death.

DATA SOURCES

Studies that quantified intrapartum EFM and its relation to specific neurologic outcomes (seizures, periventricular leukomalacia, cerebral palsy, death) were eligible for inclusion. MEDLINE was searched from 1966 to 2006 for studies that examined the relationship between intrapartum EFM and perinatal brain injury using these MeSH and text words: "cardiotocography," "electronic fetal monitoring," "intrapartum fetal heart rate monitoring," "intrapartum fetal monitoring," and "fetal heart rate monitoring."

METHODS OF STUDY SELECTION

This search strategy identified 1,628 articles, and 41 were selected for further review. Articles were excluded for the following reasons: in case reports, letters, commentaries, and review articles, intrapartum EFM was not quantified, or specific perinatal neurologic morbidity was not measured. Three observational studies and a 2001 meta-analysis of 13 randomized controlled trials were selected for determination of the effect of intrapartum EFM on perinatal brain injury.

TABULATION, INTEGRATION, AND RESULTS

Electronic fetal monitoring was introduced into widespread clinical practice in the late 1960s based on retrospective studies comparing its use to historical controls where auscultation was performed in a nonstandardized manner. Case-control studies have shown correlation of EFM abnormalities with umbilical artery base excess, but EFM was not able to identify cerebral white matter injury or cerebral palsy. Of 13 randomized controlled trials, one showed a significant decrease in perinatal mortality with EFM compared with auscultation. Meta-analysis of the randomized controlled trials comparing EFM with auscultation have found an increased incidence of cesarean delivery and decreased neonatal seizures but no effect on the incidence of cerebral palsy or perinatal death.

CONCLUSION

Although intrapartum EFM abnormalities correlate with umbilical cord base excess and its use is associated with decreased neonatal seizures, it has no effect on perinatal mortality or pediatric neurologic morbidity.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (sometimes known as electronic fetal monitoring), records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic), so additional assessments of fetal well-being may be used, or the baby delivered by caesarean section or instrumental vaginal birth.

OBJECTIVES

To evaluate the effectiveness of continuous cardiotocography during labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (March 2006), CENTRAL (The Cochrane Library 2005, Issue 4), MEDLINE (1966 to December 2005), EMBASE (1974 to December 2005), Dissertation Abstracts (1980 to December 2005) and the National Research Register (December 2005).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with (a) no fetal monitoring, (b) intermittent auscultation (c) intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, quality and extracted data.

MAIN RESULTS

Twelve trials were included (over 37,000 women); only two were high quality. Compared to intermittent auscultation, continuous cardiotocography showed no significant difference in overall perinatal death rate (relative risk (RR) 0.85, 95% confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n = 32,386, nine trials) although no significant difference was detected in cerebral palsy (RR 1.74, 95% CI 0.97 to 3.11, n = 13,252, two trials). There was a significant increase in caesarean sections associated with continuous cardiotocography (RR 1.66, 95% CI 1.30 to 2.13, n =18,761, 10 trials). Women were also more likely to have an instrumental vaginal birth (RR 1.16, 95% CI 1.01 to 1.32, n = 18,151, nine trials). Data for subgroups of low-risk, high-risk, preterm pregnancies and high quality trials were consistent with overall results. Access to fetal blood sampling did not appear to influence the difference in neonatal seizures nor any other prespecified outcome.

AUTHORS' CONCLUSIONS

Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The real challenge is how best to convey this uncertainty to women to enable them to make an informed choice without compromising the normality of labour.

Prognostic value of 1H-MRS in neonatal encephalopathy

The aim of this study was to determine the prognostic value of proton magnetic resonance spectroscopy in neonatal encephalopathy. Studies were carried out in 11 consecutive term newborns with encephalopathy probably caused by hypoxic-ischemic injury. The clinical evaluation included pregnancy data, labor conditions, encephalopathy grade, presence of seizures, and necessity of antiepileptic drug therapy. Polygraphic recordings were obtained in all cases. Interest areas evaluated by spectroscopy were the basal ganglia and thalami. Among the cases, N-acetylaspartate/creatine, choline/creatine, and lactate/creatine ratios were calculated and related to the clinical variables, polygraphic recordings, and 6-month neurodevelopmental outcome. Abnormal follow-up occurred in 5 of 11 patients (45.4%) and was clearly related to an Apgar score <5 at 5 minutes (P = 0.003), encephalopathy grade (P = 0.02), early neonatal seizures (P = 0.02), and antiepileptic therapy (P = 0.01). No relationship was observed between spectroscopy results and polygraphic recordings profile. The lowest mean N-acetylaspartate/creatine ratio was observed in four of five patients with an adverse outcome and, although not statistically significant, demonstrated a clear trend to unfavorable follow-up (t test = 0.06). The choline/creatine ratios could not be related to follow-up in our sample. The most consistently observed abnormality on the spectra was the presence of the lactate peak in four of five patients with unfavorable outcome, with a high relative risk to determine evolution in the sample, relative risk 7.0 (chi2 = 0.01, 95% confidence interval = 1.1-42.9).

Critical illness during pregnancy: considerations for evaluation and treatment of the fetus as the second patient

When a critically ill woman is pregnant, clinical interventions for the mother can have a profound effect on fetal status. It is essential that the fetus be considered as the second patient when developing the plan of care. The most practical solution for providing comprehensive care to pregnant women in the intensive care unit (ICU) is a collaborative approach involving members of the ICU and the perinatal team, each contributing their unique knowledge and skills to the care of the mother and her unborn baby. The purpose of this article is to describe a collaborative approach to caring for a pregnant woman in the ICU along with a brief overview of fetal assessment for ICU care providers so they can become familiar with terms and methods used in assessing fetal status and common interventions that promote fetal well-being.

Cord gas analysis, decision-to-delivery interval, and the 30-minute rule for emergency cesareans

OBJECTIVE

Our primary objective was to examine the relationship between umbilical arterial gas analysis and decision-to-delivery interval for emergency cesareans performed for nonreassuring fetal status to determine if this would validate the 30-minute rule.

STUDY DESIGN

For this retrospective cohort study, all cesarean deliveries performed for nonreassuring fetal status from September 2001 to January 2003 were reviewed. A synopsis of clinical information that would have been available to the clinician at the time of delivery and the last hour of the electronic fetal heart rate tracing prior to delivery were reviewed by three different maternal-fetal medicine specialists masked to outcome, who classified each delivery as either emergent (delivery as soon as possible) or urgent (willing to wait up to 30 minutes for delivery) since immediacy of the fetal condition is the key factor affecting the type of anesthesia used.

RESULTS

Of 145 cesareans performed for nonreassuring fetal status during this period, 117 patients met criteria for entry, of which 34 were classified as emergent and 83 as urgent. Kappa correlation was 0.35, showing only fair/moderate agreement between reviewers. In the emergent group, general anesthesia was more common (35.3%, 10.8%, p=0.003), and the decision-to-delivery interval was 14 minutes shorter (23.0+/-15.3, 36.7+/-14.9 minutes, p<0.001). Linear regression showed a statistically significant relationship between increasing decision-to-delivery interval and umbilical arterial pH (r=0.22, p=0.02) and base excess (r=0.33, p<0.001) showing that delivery proceeded sooner for most of those with the worst cord gases, with a gradual improvement over time. For the 13 (11%) neonates with cord gases placing them at increased risk for long-term neurologic sequelae, the decision-to-delivery interval was 24.7+/-14.6 minutes (range 6 to 50 minutes), and 3/13 (23%) were classified as urgent rather than emergent.

CONCLUSION

Electronic fetal monitoring shows considerable variation in interpretation among maternal-fetal medicine specialists and is not a sensitive predictor of the fetus developing metabolic acidosis. There is no deterioration in cord gas results after 30 minutes, and most neonates delivered emergently or urgently for nonreassuring fetal status even when born after 30 minutes have normal cord gases. The 30-minute rule is a compromise that reflects the time it takes the fetus to develop severe metabolic acidosis, our imprecision in its identification, and its rarity in the presence of nonreassuring fetal monitoring.

Temporal and demographic trends in cerebral palsy--fact and fiction

The rate of cerebral palsy has not decreased in developed countries over the past 30 years, despite the widespread use of electronic fetal heart rate monitoring and a 5-fold increase in the cesarean delivery rate over the same period of time. However, neonatal survival has improved during these decades. These observations have lead to the hypothesis that increased survival of premature, neurologically impaired infants may have masked an actual reduction in cerebral palsy among term infants as a result of the use of electronic monitoring and the avoidance of intrapartum asphyxia. A review of the medical literature, as well as a demographic analysis of term and preterm birth rates in the United States, refutes this hypothesis on four grounds. First, cerebral palsy prevalence has been separately analyzed in term infants and shows no change over 30 years. Second, the prevalence of cerebral palsy is the same or lower in underdeveloped countries than in developed nations; in the former, the availability of emergency cesarean delivery based on electronic monitor data is limited or absent. Third, the increase in prevalence of cerebral palsy among low-birth-weight infants and the increase in cesarean sections based on presumed fetal distress were not simultaneous events-the former preceded the latter by a decade. Improved neonatal survival since the 1980s has been associated with a stable or decreasing rate of neurologic impairment and thus could not have obscured improvement from reduced term asphyxia. Finally, compared with the number of infants born by cesarean section for fetal distress, there are simply not enough infants born in the most vulnerable weight groups to make any impact on even a minimal improvement of outcome in the group delivered by cesarean section for presumed fetal distress. Except in rare instances, cerebral palsy is a developmental event that is unpreventable given our current state of technology.