ACOG Practice Bulletin #70: Intrapartum Fetal Heart Rate Monitoring

Placental pathology in perinatal asphyxia: a case-control study

Introduction

Placentas of term infants with birth asphyxia are reported to have more lesion such as maternal vascular malperfusion (MVM), fetal vascular malperfusion (FVM) and chorioamnionitis with fetal response (FIR) than those of term infants without birth asphyxia. We compared the placental pathology of asphyxiated newborns, including those who developed hypoxic-ischemic encephalopathy (HIE), with non-asphyxiated controls.

Methods

We conducted a retrospective case-control study of placentas from neonates with a gestational age ≥ 35 weeks, a birthweight ≥ 1,800 g, and no malformations. Cases were asphyxiated newborns (defined as those with an umbilical artery pH ≤ 7.0 or base excess ≤ -12 mMol, 10-minute Apgar score ≤ 5, or the need for resuscitation lasting >10 min) from a previous cohort, with (n=32) and without (n=173) diagnosis of HIE. Controls were non-asphyxiated newborns from low-risk l (n= 50) or high-risk (n= 68) pregnancies. Placentas were analyzed according to the Amsterdam Placental Workshop Group Consensus Statement 2014.

Results

Cases had a higher prevalence of nulliparity, BMI>25, thick meconium, abnormal fetal heart monitoring, and acute intrapartum events than controls (p<0.001). MVM and FVM were more frequent among non-asphyxiated than asphyxiated newborns (p<0.001). There was no significant difference in inflammatory lesions or abnormal umbilical insertion site. Histologic meconium-associated changes (MAC) were observed in asphyxiated newborns only (p= 0.039).

Discussion

Our results confirm the role of antepartum and intrapartum risk factors in neonatal asphyxia and HIE. No association between neonatal asphyxia and placental lesions was found, except for in the case of MAC. The association between clinical and placental data is crucial to understanding and possibly preventing perinatal asphyxia in subsequent pregnancies.

Association of fetal heart rate short term variability pattern during term labor with neonatal morbidity and small for gestational age status

OBJECTIVE

To assess the association of fetal heart rate short-term variability (STV) pattern during term labor with both neonatal composite morbidity (cord blood pH ≤ 7.10 and/or neonatal intensive care unit admission and/or Apgar score at 5 min <7) and small for gestational age (SGA) status.

STUDY DESIGN

Retrospective cohort in a single academic institution between January 2016 and December 2018. A total of 1896 women that delivered a singleton during labor in cephalic presentation after 37 weeks of gestation were included (948 women with SGA neonates and 948 women with appropriate weight for gestational age (AGA) neonates that were matched to women with SGA neonates based on maternal age, parity, induction of labor, gestational diabetes, gestational age at delivery and a history of one cesarean section using propensity score matching). STV was compared at labor onset (cervical dilation ≤ 4 cm), in the first stage of labor (cervical dilation = 6 cm) and in the second stage of labor (cervical dilation = 10 cm). A generalized linear mixed model was used to assess the association between SGA status, neonatal composite morbidity and STV.

RESULTS

After adjustment for maternal origin, term, gestational diabetes, labor length, SGA status was not associated with any change in STV during labor (mean adjusted STV: -0.20 ms, 95 %CI[-0.58-0.17], p = 0.284 at labor onset, 0.29 ms, 95 %CI[-0.1- 0.68], p = 0.155, in the first stage of labor and 0.36 ms, 95 %CI[-0.02-0.74], p = 0.065 in the second stage of labor). In case of neonatal composite morbidity mean adjusted STV was lower in the first stage of labor (mean adjusted STV: -1.29 ms, 95 %CI[-2.1 - -0.43], p = 0.003) and in the second stage of labor (mean adjusted STV: -1.15 ms, 95 %CI[-1.96 - -0.34], p = 0.005). The results were similar with the addition of delivery mode and meconium-stained amniotic fluid in the model or non-reassuring fetal heart rate and meconium-stained amniotic fluid.

CONCLUSIONS

This work suggests that STV decrease during term labor is associated with fetal well-being, independently of fetal weight. This suggests that further prospective studies should consider the evaluation of this parameter in the prediction of neonatal compromise.

Changing Perspectives of Electronic Fetal Monitoring

The delivery of healthy babies is the primary goal of obstetric care. Many technologies have been developed to reduce both maternal and fetal risks for poor outcomes. For 50 years, electronic fetal monitoring (EFM) has been used extensively in labor attempting to prevent a large proportion of neonatal encephalopathy and cerebral palsy. However, even key opinion leaders admit that EFM has mostly failed to achieve this goal. We believe this situation emanates from a fundamental misunderstanding of differences between screening and diagnostic tests, considerable subjectivity and inter-observer variability in EFM interpretation, failure to address the pathophysiology of fetal compromise, and a tunnel vision focus. To address these suboptimal results, several iterations of increasingly sophisticated analyses have intended to improve the situation. We believe that part of the continuing problem is that the focus of EFM has been too narrow ignoring important contextual issues such as maternal, fetal, and obstetrical risk factors, and increased uterine contraction frequency. All of these can significantly impact the application of EFM to intrapartum care. We have recently developed a new clinical approach, the Fetal Reserve Index (FRI), contextualizing EFM interpretation. Our data suggest the FRI is capable of providing higher accuracy and earlier detection of emerging fetal compromise. Over time, artificial intelligence/machine learning approaches will likely improve measurements and interpretation of FHR characteristics and other relevant variables. Such future developments will allow us to develop more comprehensive models that increase the interpretability and utility of interfaces for clinical decision making during the intrapartum period.

The Goal of Continuous Fetal Heart Rate Monitoring During Labor: Have We Been Successful?

Despite its ubiquitous use, fetal heart rate (FHR) monitoring has not resulted in a significant reduction in hypoxic-ischemic encephalopathy following delivery. This manuscript reviews the reasons for this failure including limitations of FHR to accurately predict hypoxia, low prevalence of hypoxic-ischemic encephalopathy, and lack of standardization of interpretation and intervention. We propose an alternative goal for FHR monitoring during labor to provide optimal care by early identification of truly concerning features, initiation of appropriate interventions, clear documentation of concerns and plans, and clear communication between team members on labor and delivery, including initiation of the chain of command as needed.

Fetal Heart Rate Decelerations in Women with Sleep-Disordered Breathing

Emerging literature has shown that women with sleep-disordered breathing (SDB) have increased risk for gestational hypertension/preeclampsia and gestational diabetes. Case reports suggest an association between maternal apnea and fetal heart rate deceleration but data are lacking on how maternal sleep impacts fetal health. Since decelerations may be associated with adverse outcomes, we sought to determine whether fetal heart rate decelerations were associated with SDB. A cohort study of third trimester pregnant women with a singleton fetus was conducted. Participants underwent a home sleep test with continuous portable electronic fetal monitoring. SDB was defined as a respiratory disturbance index (RDI)≥10 events/hour. The temporality between a respiratory event and fetal heart rate decelerations was determined to be present if a deceleration occurred < 30 s after a respiratory event. Forty women were included with mean (±SD) age, BMI, and gestational age of 32.0±5.5 years, 37.1±8.0 kg/m², and 34.6±2.4 weeks respectively. Overall, n=23 (57.5%) women had SDB. Thirty-seven late decelerations were observed in 18 women; of these, 84% were temporally associated with a respiratory event. Nine of the 18 women (50%) had SDB. Ten prolonged decelerations were observed in 6 women of which nine (90%) were temporally associated with a respiratory event. Five of the six women (83%) had an RDI≥10. These initial data suggest that, in this population, the majority of both late and prolonged fetal heart rate decelerations occur with a maternal respiratory event. Since respiratory events are characteristic of maternal SDB, this raises the possibility that SDB may influence fetal well-being.

Use of an antiemetic to shorten the length of labor in nulliparous women, exploring a potential role of an old drug: A randomized controlled trial

OBJECTIVE

To assess whether metoclopramide is effective in shortening the duration of the first stage of labor in primiparous women.

METHODS

The present randomized, double-blind, placebo-controlled trial was conducted at King Faisal Hospital, Saudi Arabia (between July 30, 2013, and September 1, 2016), and sequentially recruited young nulliparous women admitted in spontaneous active labor with or without ruptured membranes. Eligible participants were randomly assigned to receive a slow intravenous injection of either metoclopramide or placebo and consistently managed according to the local institutional intrapartum protocol and received identical monitoring and supportive care. The primary outcome was the cervical dilatation rate.

RESULTS

Fifty-nine women were included in the metoclopramide group and 52 in the placebo group. The first stage of labor was significantly shorter in the metoclopramide group (203 minutes vs 230 minutes in the placebo group, P=0.019), with a faster cervical dilatation rate (2.4 ± 0.4 cm/h vs 1.9 ± 0.5 cm/h in the placebo group, P<0.001) and shorter interval from treatment administration until full cervical dilatation. There was a significantly higher probability of faster delivery among women who were treated with metoclopramide (log-rank test, χ² =5.997, P=0.014).

CONCLUSION

Metoclopramide safely reduced the duration of the first stage of labor and was not associated with major maternal or neonatal adverse outcomes. CLINICALTRIALS.GOV: NCT01937234.

The effect of electronic fetal monitoring (EFM) education program on EFM interpretation skills

Purpose: The aim of this study is to train midwifery students on electronic fetal monitoring (EFM) within the scope of the course and then to evaluate their pre- and post-course EFM knowledge and EFM interpreting skills.Methods: This interventional study was carried out at the Department of Midwifery, Faculty of Health Sciences. The study population comprised of the senior (last-year, 4th-year) students who attended the Midwifery Department of the Faculty of Health Sciences during the academic years 2015-2016 and 2016-2017. Of the 4th year students in the midwifery department, 42 who attended the school during the academic year 2015-16 and 61 who attended the school during the academic year 2016-2017 and accepted to participate in the study comprised the study sample.Results: The difference between the pre- and post-EFM course scores was statistically significant (p<.05). While the mean score obtained by the students before the EFM course was 55.29 ± 11.17, it was 76.15 ± 6.72 after the EFM course. Analysis of the success rates of the midwifery students in the EFM/NST course demonstrated that 80.6% of the students were successful.Conclusions: The findings of the study demonstrated that the participants' postcourse EFM knowledge and trace interpretation skills were better than their precourse EFM knowledge and trace interpretation skills.

In Search of Accurate Fetal Heart Rate Monitoring Mobile Applications

Background: Regulation of medical applications (apps) has not been rigorous. Concern for inaccurate medical apps with potential health consequences has increased. Objective: To identify mobile apps for fetal heart rate monitoring (FHM) and to evaluate their accuracy through a case report. Methods: A list of FHM apps was found in the Apple iTunes stores using a comprehensive list of search terms. After excluding apps irrelevant to this study, all unique apps were then downloaded and evaluated for necessary purchase of an accessory item, presence of disclaimer regarding medical advice, and accuracy of medical content. Those apps that did not require additional purchases were tested for ability to detect heart rates. Results: A total of 30 unique FHM apps were generated. Of these apps, 1 app required an in-app purchase to use and 7 apps required purchase of an accessory device and thus were not further evaluated. Of the 22 remaining apps, all (100%) of the applications were unable to detect the fetal heart rate. Further data collection revealed additional issues, including duplicates, lack of medical disclaimers regarding medical use of the app, and false information in the app content. Conclusion: Identification of FHM apps that do not require additional purchases revealed that all apps were inaccurate. In addition, some apps did not provide a disclaimer and/or contained false information. Healthcare providers should understand the problems with these FHM apps and educate their patients on the inaccuracies and potential dangers of the use of these applications.

[Double-balloon catheter compared to vaginal dinoprostone for cervical ripening in obese women at term]

OBJECTIVE

To compare the efficacy of a double-balloon catheter versus vaginal prostaglandin E2 (dinoprostone) for cervical ripening in obese patients with unfavorable cervix at term.

METHODS

The study had an open-label, prospective combined with retrospective, observational design. From January 2013 until May 2016, a prospective cohort study of 46 women with pre-pregnancy BMI>30kg/m², live singleton term fetuses (>37 weeks) in vertex presentation and unfavorable cervix (Bishop score<6), who underwent labor induction for conventional indications using a double-balloon catheter. In the same period, 46 obese women who had undergone cervical ripening using vaginal dinoprostone (3mg) were retrospectively included. Women in groups were paired according to Bishop score before the insertion, pre-pregnancy BMI and parity. The primary outcome was a favorable cervix (Bishop score ≥6) 24h after cervical ripening.

RESULTS

After 24h, there was a significantly higher rate of women with favorable cervix (Bishop score ≥6) in the double-balloon group than in dinoprostone group (80.4% vs 47.8%; P=0.001). After adjustment, a double-balloon catheter was significantly associated with an efficient cervical ripening compared to vaginal dinoprostone (aOR 7.81, 95% CI 2.58-23.60). No difference was observed in cesarean section rate (39.1% in each group; P=0.96) and in mean induction time to vaginal delivery (34.5h in the balloon group vs 36.5h in the dinoprostone group; P=0.53). Maternal and neonatal outcomes were similar.

CONCLUSION

For obese patients at term, cervical ripening using a double-balloon catheter is more efficient on Bishop score after 24h compared to vaginal dinoprostone.

Computerised analysis of antepartum foetal heart parameters: New reference ranges

We selected 4012 cCTG records (one trace for each patient) performed in healthy pregnancies from 30th to 42nd gestational week using foetal heart rate (FHR), short-term variability (STV), long-term irregularity (LTI), Delta, approximate entropy (ApEn), spectral components as low frequency (LF), median frequency (MF), high frequency (HF) and LF/(HF + MF) ratio were analysed. Reference nomograms were created and sensitivity and specificity for the prediction of foetal compromise were calculated which were 90% and 89%, respectively. Changes of cCTG parameters according to gestational week were evaluated: FHR (r = -.65) and LF (r = -.87) showed a statistically significant reduction (p < .05) with gestational age. STV (r = .59), LTI (r = .69), Delta (r = .67), and MF (r = .88) showed a statistically significant increase (p < .05) with gestational age. In contrast, for ApEn (r = -.098), HF (r = .14) and LF/(HF + MF) ratio (r = -.47) a non-statistically significant change was found (p > .05). The identification of reference ranges for cCTG indexes in according to gestational age could provide a more objective examination of cCTG trace.

Effect of Consultation and Educating in Preparation Classes for Delivery on Pregnancy Consequences: A Randomized Controlled Clinical Trial

Background

Care during pregnancy and performing consultation for delivery preparation play an important role in improving pregnant women’s knowledge.

Objective

The purpose of this study was to investigate the effect of consultation and instruction in the preparation classes for delivery on pregnancy consequences, including choosing the type of delivery, the performed type of delivery, and infant’s weight.

Methods

This study was conducted in 2015 on 170 pregnant women who had been referred to the prenatal clinic in Hamedan. The participants were randomly divided into intervention and control groups. Eight sessions of consultation for delivery preparation were held for the women in 20 to 36 weeks of pregnancy. The control group received only the routine care. After 37 weeks of pregnancy, the participants answered a questionnaire. The infant’s weight was measured after birth. Data were analyzed Using SPSS-21 and McNemar–Bowker Test, independent t-test, chi-square test, and Fisher exact test.

Results

Results showed a significant statistical difference between the two groups concerning their selective and performed delivery (p<0.001). The weight of infants in the intervention group was significantly higher than that of those in the control group (p<0.001).

Conclusion

The findings of this study showed that the consultation for delivery preparation had a positive effect on some pregnancy consequences such as selecting the type of delivery performed and infant’s weight.

Trial registration

The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCTID: IRCT2015012513405N9.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Evaluation of the fetal QT interval using non-invasive fetal ECG technology

Non-invasive fetal electrocardiography (NI-FECG) is a promising alternative continuous fetal monitoring method that has the potential to allow morphological analysis of the FECG. However, there are a number of challenges associated with the evaluation of morphological parameters from the NI-FECG, including low signal to noise ratio of the NI-FECG and methodological challenges for getting reference annotations and evaluating the accuracy of segmentation algorithms. This work aims to validate the measurement of the fetal QT interval in term laboring women using a NI-FECG electrocardiogram monitor. Fetal electrocardiogram data were recorded from 22 laboring women at term using the NI-FECG and an invasive fetal scalp electrode simultaneously. A total of 105 one-minute epochs were selected for analysis. Three pediatric electrophysiologists independently annotated individual waveforms and averaged waveforms from each epoch. The intervals measured on the averaged cycles taken from the NI-FECG and the fetal scalp electrode showed a close agreement; the root mean square error between all corresponding averaged NI-FECG and fetal scalp electrode beats was 13.6 ms, which is lower than the lowest adult root mean square error of 16.1 ms observed in related adult QT studies. These results provide evidence that NI-FECG technology enables accurate extraction of the fetal QT interval.

The conundrum of vanishing early decelerations in British obstetrics, a step backwards? Detailed appraisal of British and American classifications of fetal heart rate decelerations - fallacies of emphasis on waveform and putative aetiology

A recent opinion survey of British Obstetricians revealed 'early' fetal heart rate (FHR) decelerations as the commonest type in their practice. This contrasts with the guidelines by the National Institute for Health and Clinical Excellence, UK (NICE 2007) that 'true uniform early decelerations are rare and most decelerations are variable'. This analytical review suggests that the emphasis on putative aetiology and 'waveform' of decelerations by NICE and other national guidelines leads to fundamental inconsistencies. 'Uniform shape' is misinterpretation of the description by Hon and Quilligan (1968). Truly 'uniform' (identical)) decelerations do not occur and no examples can be found. Gradual ('bell') or rapid shape has no correlation to putative causation or fetal condition. Obstetricians and midwives should seek clarification of these fallacies. The previous British practice of classifying decelerations based solely on time relationship to contractions seems most scientifically robust leading to more consistent interpretation and better discrimination of fetal status.

Maternal carbon dioxide level during labor and its possible effect on fetal cerebral oxygenation: mini review

During pregnancy, and especially during labor, the maternal carbon dioxide level declines considerably. Maternal carbon dioxide levels show a close relation with fetal carbon dioxide levels. The latter affects fetal cerebral oxygenation by regulating cerebral blood flow and shifting the oxyhemoglobin dissociation curve. In addition, maternal hypocapnia appears to impair placental oxygen transfer. Thus, maternal hyperventilation may interfere with optimal fetal cerebral oxygenation. Here, we provide a brief overview of the literature relevant to this issue.

Electronic fetal heart rate monitoring: applying principles of patient safety

In 1999, a highly publicized report from the Institute of Medicine identified major deficiencies in the United States health care system, which fueled the rapid growth of the modern patient safety movement. One of the greatest risks to patient safety in obstetrics is poor communication of electronic fetal heart rate monitoring findings. Standardization and elimination of unnecessary complexity are 2 of the cornerstones of improved patient safety. This article describes a standardized, simplified approach to the definition, interpretation, and management of electronic fetal heart rate monitoring that is evidence-based and reflects consensus in the literature.

American medicine as religious practice: care of the sick as a sacred obligation and the unholy descent into secularization

Modern medicine serves a religious function for modern Americans as a conduit through which science can be applied directly to the human body. The first half of this paper will focus on the theoretical foundations for viewing medicine as a religious practice arguing that just as a hierarchical structured authoritarian church historically mediated access to God, contemporary Western medicine provides a conduit by which the universalizable truths of science can be applied to the human being thereby functioning as a new established religion. I will then illustrate the many parallels between medicine and religion through an analysis of rituals and symbols surrounding and embedded within the modern practice of medicine. This analysis will pay special attention to the primacy placed on secret interior knowledge of the human body. I will end by responding to the hope for a "secularization of American medicine," exploring some of the negative consequences of secularization, and arguing that, rather than seeking to secularize, American medicine should strive to use its religious features to offer hope and healing to the sick, in keeping with its historically religious legacy.

Closing the Theory–Practice Gap: Intrapartum Midwifery Management of Planned Homebirths

In the United States, access to qualified homebirth providers varies by state, city, and community, and consistent, evidence-based guidelines for intrapartum management at home are not available. This article examines the similarities and differences in midwifery management of the intrapartum, postpartum, and neonatal course between planned homebirths and planned hospital births. Characteristics of qualified attendants, essential medical supplies and equipment, methods for maternal and fetal surveillance, and common intrapartum indications for transfer are discussed. Unique features of management of the healthy woman and baby in the home are described, as well as the process of consultation and/or referral for collaborative or medical management. Current evidence for the management of fetal intolerance of labor, meconium stained amniotic fluid, prolonged labor, postpartum hemorrhage, and the unstable newborn is discussed in the context of homebirth practice. Aspects of homebirth care that require cultural competency and affect the informed consent process are included. Homebirth practice may provide opportunities to increase the congruence between espoused midwifery philosophy and actual practice.

The Evidence for Physiologic Management of the Active Phase of the First Stage of Labor

The active phase of first stage labor is generally defined as the period between 3 cm to 4 cm to complete cervical dilatation, in the presence of regular uterine contractions. Most women will experience this portion of labor within hospital obstetric units, where care commonly features restriction to bed, electronic fetal monitoring, early treatment of "slow" labors, and few pain management options beyond epidurals and narcotics. However, the available evidence on appropriate care for healthy childbearing women favors activity in labor, intermittent auscultation, patience from caregivers, and nonpharmacologic methods of pain relief. This article reviews the evidence for care practices that support physiologic labor. Modifying intrapartum care to reflect current evidence will improve women's health, and will require a multilevel approach and consistent midwifery demonstration of the model.

Does the International Classification of Disease (ICD-9) code accurately identify neonates who clinically have hypoxic-ischemic encephalopathy?

BACKGROUND/AIMS

Hypoxic-ischemic encephalopathy (HIE) refers to neonatal neurological signs and symptoms of hypoxia and/or ischemia. Our aim was to determine the accuracy of ICD-9 codes to identify newborns with HIE confirmed by umbilical cord blood analysis.

METHODS

ICD-9 codes in the newborn chart for birth trauma, birth asphyxia, intrauterine hypoxia, and fetal distress were used to identify newborns with suspected HIE by neonatal personnel. Maternal charts were reviewed for umbilical cord gases meeting the HIE clinical criteria.

RESULTS

There were 21,008 deliveries at center I and 17,540 at center II. ICD-9 codes identified 172 neonates, 49 infants (2.3‰ births) at center I and 123 neonates (7‰) at center II. Only 3 neonates (6%) were ≥34 weeks and none met ACOG criteria [umbilical artery pH <7.00 or base excess (BE) ≥12 mmol/l at center I]. At center II, 80 infants were ≥34 weeks but only 5/123 (4%) met the ACOG clinical criteria for HIE (pH <7.00, BE ≥12 mmol/l, and Apgar ≤3 at 5 min).

CONCLUSIONS

ICD-9 codes are unreliable in identifying birth asphyxia and cannot identify newborns meeting the clinical criteria for intrapartum HIE.

In utero beta 2 adrenergic agonist exposure and adverse neurophysiologic and behavioral outcomes

Beta 2 adrenergic receptor overstimulation during critical periods of prenatal development can induce a permanent shift in the balance of sympathetic-to-parasympathetic tone. This is a biologically plausible mechanism whereby beta 2 adrenergic agonists can induce functional and behavioral teratogenesis, which explains their association with increases in autism spectrum disorders, psychiatric disorders, poor cognitive, motor function and school performance, and changes in blood pressure in the offspring. The use of beta 2 adrenergic agonists should be limited to proven indications when alternate drugs are ineffective or unavailable; the risks of untreated disease to the mother and fetus are greater than the risk of the beta 2 adrenergic agonist.

Neostigmine decreases bupivacaine use by patient-controlled epidural analgesia during labor: a randomized controlled study

BACKGROUND

Intrathecal neostigmine not only produces analgesia but also severe nausea. In contrast, epidural neostigmine enhances opioid and local anesthetic analgesia without causing nausea. Previous studies examined only single epidural neostigmine bolus administration and did not assess the efficacy of continuous epidural infusion or several aspects of maternal and fetal safety. We therefore tested the hypothesis that epidural neostigmine in combination with bupivacaine by continuous infusion during labor would reduce the amount of bupivacaine required.

METHODS

Twelve healthy women scheduled for elective cesarean delivery were assigned to receive epidural neostigmine, 40 microg (first six subjects) or 80 microg (second six subjects) as a single bolus, with fetal heart rate (FHR) and uterine contractions monitored for 20 min. In a subsequent experiment, 40 healthy laboring women were randomized to receive bupivacaine 1.25 mg/mL alone or with neostigmine 4 microg/mL by patient-controlled epidural analgesia. The primary outcome measure was hourly bupivacaine use.

RESULTS

Epidural neostigmine bolus did not alter baseline FHR, induce contractions, or produce nausea. Epidural neostigmine infusion reduced bupivacaine requirement by 19% in all patients and 25% in those with >4 h of treatment (P < 0.05 for both) but might have contributed to the incidence of mild sedation. Mode of delivery, incidence of maternal nausea, and FHR abnormality were similar between groups.

CONCLUSIONS

These data show that adding epidural neostigmine 4 microg/mL reduces the hourly bupivacaine requirement by 19%-25% with patient-controlled epidural analgesia during labor. Administered as a bolus and by continuous infusion at the studied doses, epidural neostigmine does not cause nausea and does not induce uterine contractions or FHR abnormalities, but mild sedation can occur.

Sepsis and acute renal failure in pregnancy

The unique physiology of pregnancy poses several problems for clinicians charged with caring for critically ill pregnant patients. This focused review summarizes two problems encountered in critically ill pregnant patients: pregnancy-related sepsis and acute renal failure. Common causes, and the effects of pregnancy on diagnosis and treatment are discussed.

Intrapartum stress and lipid status of term infants: relation to fetal adrenal production of dehydroepiandrosterone sulphate

OBJECTIVE

Evaluate the effect of acute intrapartum stress on umbilical cord plasma levels of cholesterol, triglyceride and dehydroepiandrosterone sulphate (DS) in term infants.

METHODS

Umbilical cord plasma levels of cholesterol, triglyceride and DS were measured in 176 infants that delivered >or=37 weeks' gestation. Eighty-eight infants experienced acute intrapartum stress while the remaining infants were non-stressed controls who were case-matched by gestational age and delivery method.

RESULTS

The umbilical cord plasma levels of cholesterol in the stressed infants (71.7 +/- 16.1 mg/dL, mean +/- SD) were similar to those of the control infants (70.9 +/- 16.0 mg/dL). Triglyceride levels in stressed infants were significantly higher (p = 0.003) than those of control infants. Both stressed and control infants with increased triglyceride levels had normal DS levels; however, those with increased cholesterol levels had reduced umbilical cord plasma levels of DS. Stressed infants with increased cholesterol levels had significantly lower DS levels than control infants (p = 0.008).

CONCLUSIONS

Intrapartum stress leads to increased fetal plasma levels of triglycerides; yet, cholesterol levels are usually unaffected. Infants with increased cholesterol levels also have reduced DS levels, suggesting that the rise in cholesterol was due to a reduction in fetal adrenal utilisation of plasma cholesterol as substrate for steroid formation.

The quality of intrapartum uterine activity monitoring

AIMS

To determine the quality of intrapartum uterine activity (UA) monitoring in daily practice during the first and second stage of labor. The total duration of inadequate UA monitoring is quantified in relation to the technique applied: external or internal.

METHODS

One hundred and ninety-two UA recordings, collected from 1 April 2006 untill 1 October 2006 from consecutive deliveries at the Vrije Universiteit Medical Center in Amsterdam, were analyzed. Included recordings were from singleton, spontaneous, vaginal deliveries. The last two hours of the first stage and the complete second stage had to be monitored. Internal and external UA recordings were judged by their quality: adequate, a recognizable and reliable UA pattern during the complete registration, or inadequate. Recordings labeled as inadequate were divided into two groups: absence of UA recording (non recognizable) or inadequate calibration (unreliable). Statistical analyses were performed with the Mann-Whitney U-test and the Wilcoxon signed ranks test.

RESULTS

The percentages of adequate UA recordings in the first stage of labor were much higher for the internal than the external mode. Only 2% of the external recordings were of good quality vs. 40% of the internal recordings. In the second stage, percentages of adequate UA recordings were nearly equal, approximately 30%. Inadequate external registrations were characterized by almost 30% of the time absent UA monitoring, whereas with inadequate internal registrations the primary problem was correct calibration.

CONCLUSION

Intrapartum UA monitoring in daily practice via the direct mode provides a more recognizable UA trace.

Integrated testing and management in fetal growth restriction

Growth-restricted fetuses are at higher risk for poor perinatal and long-term outcome than those who are appropriately grown. Multiple antenatal testing modalities can help document the sequence of fetal deterioration. The full extent of this compromise is best identified by a combination of fetal biometry, biophysical profile scoring, and arterial and venous Doppler. In the preterm growth-restricted fetus, timing of delivery is critically determined by the balance of fetal versus neonatal risks. In the near-term fetus, accurate diagnosis continues to be a challenge as unrecognized growth restriction contributes to a significant proportion of unexplained stillbirths. In this review, we present an integrated diagnostic and surveillance approach that accounts for these factors.

Uterine activity: implications for the condition of the fetus

AIM

The aim of this review is to provide more insight in the fetal mechanisms as a response to uterine contractions and to emphasize the importance of correct assessment of uterine activity (UA) patterns during labor.

STUDY RESULTS

UA causes a decreased flow through the uterine artery. In the healthy uncompromised fetus, this will not cause fetal acidemia. The fetus has developed certain protection mechanisms to survive labor; (1) During a contraction, fetal preload increases and enables the fetus to maintain a constant blood flow through the umbilical artery and (2) UA increases the blood flow in the fetal middle cerebral artery, i.e., a brain sparing effect. The shortcoming of those protection mechanisms in the compromised fetus and in case of excessive UA increases the risk of adverse fetal outcome. The brain sparing effect will become more pronounced to compensate for the decreased umbilical artery blood flow and fetal oxygen saturation. Maintenance of normal UA, especially a sufficiently long relaxation time, is essential so that the supply of well oxygenated maternal blood to the intervillous space will be restored and the fetal cerebral oxygen saturation can remain stable.

CONCLUSION

Adequate UA monitoring is a prerequisite for proper reading and interpretation of cardiotocograms. It alarms in cases of excessive UA and can help to prevent fetal acidemia. Uterine contraction monitoring deserves full attention in daily obstetric practice.

Uterine activity monitoring during labor

AIM

To summarize the currently available knowledge on (1) the methods to monitor uterine activity (UA); (2) the units to quantify UA; and (3) to assess the importance of abnormal contraction patterns on the condition of the fetus. The need for correct assessment and interpretation of the uterine contraction curve to improve fetal outcome will be emphasized.

STUDY RESULTS

Correct assessment of the uterine contraction curve is an essential part of the cardiotocogram and should be obtained by the best method available; i.e., internal tocography (IT). IT provides objective information on quantization of UA and has the ability to obtain a good quality trace in an obese, restless patient. Accurate information on UA is essential because elevated UA during the first and second stage of labor can increase the risk of adverse fetal outcome. The relaxation time appears to be an important contraction parameter to maintain fetal well-being during labor. Almost all abnormal contraction patterns are characterized by shortening of the relaxation time and can lead to severe asphyxia. Duration, amplitude and frequency of contractions are of importance as well. The mean active pressure unit is the means to quantify UA since it incorporates these three contraction parameters.

CONCLUSION

Proper application of UA monitoring by means of the internal method and adequate reading and interpretation of the uterine contraction curve is a prerequisite for high quality electronic fetal heart rate monitoring.

A comparison of subjective and mathematical estimations of fetal heart rate variability

OBJECTIVES

To develop a computerized algorithm to quantify fetal heart rate (FHR) variability and compare it to perinatologists' interpretation of FHR variability.

METHODS

FHR variability was calculated using data from 30 women who had a fetal scalp electrode placed for a clinical indication, and compared to the assessment of FHR variability from four perinatologists who interpreted paper tracings of the same data. Inter-rater reliability was calculated and receiver-operator curve analysis was done.

RESULTS

Correlation between the computer algorithm's assessment of variability and the perinatologists' assessment (0.27-0.68) was similar to the inter-rater reliability between perinatologists (0.33-0.72).

CONCLUSIONS

A computer-based algorithm can assess FHR variability as well as expert clinicians.

Randomized comparison of intravenous terbutaline vs nitroglycerin for acute intrapartum fetal resuscitation

OBJECTIVE

The purpose of this study was to compare terbutaline and nitroglycerin for acute intrapartum fetal resuscitation.

STUDY DESIGN

Women between 32-, 42 weeks' gestation were assigned randomly to 250 microg of terbutaline or 400 microg nitroglycerin intravenously for nonreassuring fetal heart rate tracings in labor. The rate of successful acute intrapartum fetal resuscitation and the maternal hemodynamic changes were compared. Assuming a 50% failure rate in the terbutaline arm, we calculated that a total of 110 patients would be required to detect a 50% reduction in failure in the nitroglycerin group (50% to 25%), with an alpha value of .05, a beta value of .20, and a power of 80%.

RESULTS

One hundred ten women had nonreassuring fetal heart rate tracings in labor; 57 women received terbutaline, and 53 women received nitroglycerin. Successful acute resuscitation rates were similar (terbutaline 71.9% and nitroglycerin 64.2%; P = .38). Terbutaline resulted in lower median contraction frequency per 10 minutes (2.9 [25-75 percentile, 1.7- 3.3] vs 4 [25-75 percentile, 2.5- 5]; P < .002) and reduced tachysystole (1.8% vs 18.9%; P = .003). Maternal mean arterial pressures decreased with nitroglycerin (81-76 mm Hg; P = .02), but not terbutaline (82-81 mm Hg; P = .73).

CONCLUSION

Although terbutaline provided more effective tocolysis with less impact on maternal blood pressure, no difference was noted between nitroglycerin and terbutaline in successful acute intrapartum fetal resuscitation.

Fetal heart rate pattern reflecting the severity of placental abruption

OBJECTIVE

To identify fetal heart rate (FHR) patterns reflecting the severity of placental abruption, and to determine the incidence of normal FHR pattern in cases of placental abruption.

MATERIALS AND METHODS

We analyzed FHR tracings from 40 pregnant Japanese women with placental abruption. We analyzed which FHR patterns appeared more frequently in cases of low 5-min Apgar score, low cord arterial pH, and large separation.

RESULTS

Eight out of 40 cases showed a normal FHR pattern, while 32 cases did not show a normal FHR pattern. Undetectable variability and bradycardia appeared more frequently in cases with 5-min Apgar < 7, with cord blood pH < 7.1, and with larger placental separation than in cases without these features. The normal FHR pattern was associated with 5-min Apgar > or = 7, cord blood pH > or = 7.1, and separation of <25%.

CONCLUSION

Fetal heart rate pattern reflected the severity of placental abruption. Undetectable variability and bradycardia occurred significantly more frequently in cases of severe placental abruption, and thus may reflect the severity of placental abruption.

Error reduction and quality assurance in obstetrics

This article outlines an approach to improve patient safety in obstetrics and gynecology, with the goal to reduce errors in labor and delivery. Every institution should create guidelines and provide education and training to address potential safety issues such as fetal heart rate pattern interpretation, induction and stimulation of labor, vaginal birth after cesarean, magnesium sulfate, shoulder dystocia, hemorrhage, forceps/vacuum, and thromboembolic disease. This article discusses the patient safety objectives published by the American College of Obstetricians and Gynecologists Committee on Quality Improvement and Patient Safety; the National Patient Safety Goals, which are regularly established by the Joint Committee on Accreditation of Healthcare Organizations; and patient safety indicators developed by the Agency for Healthcare Research and Quality.

Medical legal issues in fetal monitoring

Despite almost universal fetal monitoring during labor, debates over its role and benefits persist in the medical community and in obstetric negligence lawsuits. Irrespective, there is widespread agreement that improvement in perinatal outcome is possible and that the events of labor contribute significantly to perinatal hazards. Timely application and proper interpretation of the fetal heart rate pattern in concert with evaluations of the maternal condition and the feasibility of safe vaginal delivery permit an evaluation of the quality of care and the preventability of fetal injury whether in peer review or in malpractice cases.