No. 197a-Fetal Health Surveillance: Antepartum Consensus Guideline

Clinical practice guidelines for intrapartum cardiotocography interpretation: A systematic review

BACKGROUND

Clinical practice guidelines on intrapartum cardiotocography (CTG) interpretation provide structured tools to detect fetal hypoxia. Despite frequent use of different guidelines, little is known about their comparable consistency. We sought to appraise guidelines relevant to intrapartum CTG interpretation and summarise consensus and non-consensus recommendations.

AIMS

To compare existing intrapartum CTG interpretation guidelines.

MATERIALS AND METHODS

We searched PubMed, CINAHL, Cochrane, Embase, guideline databases and websites of guideline development institutions using terms 'cardiotocography', 'electronic fetal/foetal monitoring', and 'guideline' or equivalent term. The search was restricted to English-language articles published between January 1980 and January 2023 and excluded animal studies. The initial search yielded 2128 articles with 1253 unique citations. Guidelines were included if they: used English as the reporting language; included CTG interpretation criteria or guidelines as a primary objective; were published or updated since 1980; and were the most recently updated publications when multiple versions were identified.

RESULTS

Nineteen studies were considered for full review, and 13 met inclusion criteria. Two reviewers independently assessed guideline quality using the AGREE II instrument, and synthesised consensus and non-consensus recommendations using the content analysis approach. Most guidelines employed a three-tier interpretation framework. There were significant differences between the guidelines for relative importance of key CTG features such as accelerations, decelerations and variability, with respect to the outcome of fetal hypoxia.

CONCLUSIONS

There are significant differences between key intrapartum CTG interpretation guidelines currently being used. Greater consistency is needed across CTG interpretation guidelines to improve the quality of data, clinical governance, monitoring of outcomes, and to support future developments.

Decreased fetal movements-the utility of ultrasound to identify infants at risk and prevent stillbirth is poor

BACKGROUND

Despite a paucity of evidence, it is widely accepted that a perceived reduction in fetal movements is associated with an increased risk of stillbirth and poor obstetrical outcome. Consequently, many international guidelines recommend urgent ultrasound assessment of fetal well-being in women presenting with decreased fetal movements.

OBJECTIVE

This study aimed to compare rates of abnormal ultrasound findings reflective of fetal compromise between women presenting with decreased fetal movements and gestation-matched controls in the third trimester.

STUDY DESIGN

This was a retrospective cohort study performed at the Mater Mothers' Hospital in Brisbane between 2017 and 2020. We undertook propensity score matching analysis comparing abnormal ultrasound parameters in women with singleton, nonanomalous pregnancies presenting with decreased fetal movements after 28 weeks' gestation. The primary outcome was a composite of any abnormal scan parameter: umbilical artery pulsatility index >95th centile, middle cerebral artery pulsatility index <5th centile, cerebroplacental ratio <10th centile, estimated fetal weight <10th centile for gestation, middle cerebral artery peak systolic velocity >1.5 multiples of the median, or deepest vertical pocket of amniotic fluid <2 or >8 cm.

RESULTS

After propensity score matching, the study cohort comprised 1466 cases and 2207 controls. The rate of the primary composite outcome was not significantly different between the 2 cohorts (20.2% vs 21.3%; P=.42). There were 30 new cases of small-for-gestational-age detected in the decreased fetal movements cohort, giving a number needed to scan of 48 in the decreased fetal movements group to detect 1 case of small-for-gestational-age. However, the frequency of the composite outcome was higher (13.0% vs 5.4%) at the final scan before birth in women with multiple decreased fetal movement presentations. Despite this, there was no significant difference in clinical outcomes between the 2 cohorts.

CONCLUSION

Ultrasound abnormalities are not increased in women with decreased fetal movements compared with controls.

Sociodemographic and Geographic Disparities in Obstetrical Ultrasound Imaging Utilization: A Population-based Study

RATIONALE AND OBJECTIVES

Obstetrical ultrasound imaging is an important part of prenatal care, though not all patients have readily available access to ultrasound services. This study aimed to assess the association between sociodemographic and geographic factors and (1) having a second trimester complete obstetrical ultrasound and (2) overall obstetrical ultrasound utilization.

METHODS

All pregnancies and obstetrical ultrasound exams billed from 2014-2018 in Saskatchewan, Canada were identified from province-wide databases. Generalized estimating equation (GEE) models with binomial and Poisson distributions were used to identify factors associated with having a second trimester ultrasound and overall obstetrical ultrasound utilization, respectively.

RESULTS

80,536 pregnancies from 57,881 individuals were included. Of 57,186 pregnancies carried to ≥23 weeks, a second trimester ultrasound was performed in 50,180 (87.7%). Patients living in rural areas (adjusted odds ratio [aOR], 0.70; 95% confidence interval [CI], 0.63-0.77; p <0.0001), remote areas (aOR, 0.35 for greatest vs. least remoteness level; 95% CI, 0.32-0.39; p <0.0001), and status First Nations individuals (aOR, 0.50; 95% CI, 0.46-0.53; p <0.0001) were less likely to have a second trimester ultrasound. Patients living in higher income neighbourhoods (aOR, 1.86 for highest vs. lowest quintile; 95% CI, 1.62-2.13; p <0.0001) were more likely to have a second trimester ultrasound. GEE Poisson regression analysis demonstrated these same factors, except rural residence, were associated with overall obstetrical ultrasound utilization.

CONCLUSION

Substantial disparities in obstetrical ultrasound utilization exist among patients in remote geographic areas, Indigenous peoples, and patients in low income neighbourhoods. Addressing barriers which these demographic groups face in accessing ultrasound imaging is critical to ensure health equity.

The role of the fetal biophysical profile in the management of fetal growth restriction

Growth-restricted fetuses are at risk of hypoxemia, acidemia, and stillbirth because of progressive placental dysfunction. Current fetal well-being, neonatal risks following delivery, and the anticipated rate of fetal deterioration are the major management considerations in fetal growth restriction. Surveillance has to quantify the fetal risks accurately to determine the delivery threshold and identify the testing frequency most likely to capture future deterioration and prevent stillbirth. From the second trimester onward, the biophysical profile score correlates over 90% with the current fetal pH, and a normal score predicts a pH >7.25 with a 100% positive predictive value; an abnormal score on the other hand predicts current fetal acidemia with similar certainty. Between 30% and 70% of growth-restricted fetuses with a nonreactive heart rate require biophysical profile scoring to verify fetal well-being, and an abnormal score in 8% to 27% identifies the need for delivery, which is not suspected by Doppler findings. Future fetal well-being is not predicted by the biophysical profile score, which emphasizes the importance of umbilical artery Doppler and amniotic fluid volume to determine surveillance frequency. Studies with integrated surveillance strategies that combine frequent heart rate monitoring with biophysical profile scoring and Doppler report better outcomes and stillbirth rates of between 0% and 4%, compared with those between 8% and 11% with empirically determined surveillance frequency. The variations in clinical behavior and management challenges across gestational age are better addressed when biophysical profile scoring is integrated into the surveillance of fetal growth restriction. This review aims to provide guidance on biophysical profile scoring in the in- and outpatient management of fetal growth restriction.

Cost-effectiveness of noninvasive fetal RhD blood group genotyping in nonalloimmunized and alloimmunized pregnancies

BACKGROUND

We sought to determine the cost-effectiveness of noninvasive fetal RhD blood group genotyping in nonalloimmunized and alloimmunized pregnancies in Canada.

STUDY DESIGN AND METHODS

We developed two probabilistic state-transition (Markov) microsimulation models to compare fetal genotyping followed by targeted management versus usual care (i.e., universal Rh immunoglobulin [RhIG] prophylaxis in nonalloimmunized RhD-negative pregnancies, or universal intensive monitoring in alloimmunized pregnancies). The reference case considered a healthcare payer perspective and a 10-year time horizon. Sensitivity analysis examined assumptions related to test cost, paternal screening, subsequent pregnancies, other alloantibodies (e.g., K, Rh c/C/E), societal perspective, and lifetime horizon.

RESULTS

Fetal genotyping in nonalloimmunized pregnancies (at per-sample test cost of C$247/US$311) was associated with a slightly higher probability of maternal alloimmunization (22 vs. 21 per 10,000) and a reduced number of RhIG injections (1.427 vs. 1.795) than usual care. It was more expensive (C$154/US$194, 95% Credible Interval [CrI]: C$139/US$175-C$169/US$213) and had little impact on QALYs (0.0007, 95%CrI: -0.01-0.01). These results were sensitive to the test cost (threshold achieved at C$88/US$111), and inclusion of paternal screening. Fetal genotyping in alloimmunized pregnancies (at test cost of C$328/US$413) was less expensive (-C$6280/US$7903, 95% CrI: -C$6325/US$7959 to -C$6229/US$7838) and more effective (0.19 QALYs, 95% CrI 0.17-0.20) than usual care. These cost savings remained robust in sensitivity analyses.

DISCUSSION

Noninvasive fetal RhD genotyping saves resources and represents good value for the management of alloimmunized pregnancies. If the cost of genotyping is substantially decreased, the targeted intervention can become a viable option for nonalloimmunized pregnancies.

Every Mother and Every Fetus Matters: A Positive Pregnant Test = Multiple Offerings of Reproductive Risk Screening for personal, family, and specific obstetrical-fetal conditions

Structured OBJECTIVE: The requirement and need for a focused 'pregnant person -centered' antenatal care process with time for informed consent and shared decision making are important for optimal antenatal care. This commentary focuses on the evidenced -based screening test options and timing as part of the overall 'pregnant person-centered' preconception and antenatal care journey.

METHODS

A structured quality improvement (QI) review (Squire 2.0) was undertaken to examine the appropriate reproductive screening process in the periods of preconception and during pregnancy.

RESULTS

First, evaluated the broader antenatal care structure which, second, enabled the directed reproductive risk screening processes to be offered within an informed consent process. Four international pre-conception and antenatal evidenced-based consensus would routinely offer specific gestational age reproductive risk screening elements: totaling 21 screening elements (preconception 3; 1st trimester 9; 2nd trimester 3; 3rd trimester 4; intrapartum 1; postpartum 1).

CONCLUSION

The best evidenced-based opportunity for comprehensive and collaborative antenatal care with appropriate screening elements requires: single national access healthcare system; expert evidenced-based guideline creation; collaborative maternity care providers based for risk assessment, triage, and management; pregnant person (women) centered care model of maternity care; clearly identified evidenced-based gestational age directed screening elements; international pre-conception and antenatal guideline consensus.

Guideline No. 421: Point of Care Ultrasound in Obstetrics and Gynaecology

OBJECTIVE

To provide an opinion regarding the usefulness of point of care ultrasound in obstetrics and gynaecology.

TARGET POPULATION

Women with pregnancy-related complications or issues who could benefit from an urgent bedside sonographic evaluation.

OPTIONS

Point of care ultrasound is a readily accessible option, requiring few resources.

BENEFITS, HARMS, AND COSTS

This low-cost imaging option can expedite appropriate patient management, enhance provider confidence, and allay the patient's anxiety in a timely fashion. However, there is potential for error in imaging or interpretation, resulting in incorrect and potentially harmful patient management.

EVIDENCE

MEDLINE, PubMed, Embase, and the Cochrane Library weres earched from 2009 to 2019. Medical Subject Headings (MeSH) and keywords were related to pregnancy, PoCUS, point of care ultrasound, and bedside ultrasound. This document represents an abstraction of the evidence rather than a methodological review.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Providers of urgent care for pregnant women (obstetricians and gynaecologists, family physicians, emergency room physicians, midwives, nurse practitioners, nurses).

SUMMARY STATEMENT (GRADE RATINGS IN PARENTHESES)

RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Risk of stillbirth in singleton gestations following in vitro methods of conception: a systematic review and meta-analysis

BACKGROUND

In vitro methods of conception are associated with adverse perinatal outcomes. It is unclear if the risk of stillbirth is increased also.

OBJECTIVE

This systematic review and meta-analysis aimed to estimate the risk of stillbirth in singleton gestations following in vitro methods of conception compared to non-in vitro conceptions.

SEARCH STRATEGY

A comprehensive search in PubMed, Embase, CINAHL, and Cochrane Library was undertaken from database inception to February 2021, with backward citation tracking.

SELECTION CRITERIA

Eligible studies included randomized controlled trials, cohort studies, or case-control studies that assessed stillbirth following in vitro fertilisation and/or intracytoplasmic sperm injection in comparison to non-in vitro methods of conception, including spontaneous conceptions, intrauterine insemination, and ovarian stimulation.

DATA COLLECTION AND ANALYSIS

The Newcastle-Ottawa Scale was used to assess risk of bias. A summary odds ratio (OR) for stillbirth following in vitro methods of conception compared to non-in vitro methods was calculated using a random-effects model for meta-analysis.

MAIN RESULTS

Thirty-three cohort studies met inclusion criteria. There was an increased risk of stillbirth with in vitro methods: OR 1.41 (95% CI 1.20-1.65); however, the crude baseline risk of stillbirth was low (4.44/1000 total births). Subgroup analysis did not demonstrate an increased risk when in vitro methods were compared to conception without in vitro methods in the context of subfertility.

CONCLUSIONS

Compared to non-in vitro conceptions, in vitro conceptions have an increased risk of stillbirth. However, there is insufficient evidence to demonstrate whether this risk is associated with in vitro techniques or underlying subfertility.

TWEETABLE ABSTRACT

This meta-analysis found an increased risk of stillbirth in singletons from in vitro methods of conception.

Evaluation of Pregnancy Outcomes Among Women With Decreased Fetal Movements

IMPORTANCE

Stillbirth is a devastating pregnancy outcome with far-reaching economic and psychosocial consequences, but despite significant investment, a screening tool for identifying those fetuses at risk for stillbirth remains elusive. Maternal reporting of decreased fetal movements (DFM) has been found to be associated with stillbirth and other adverse perinatal outcomes.

OBJECTIVE

To examine pregnancy outcomes of women presenting with DFM in the third trimester at a tertiary Australian center with a clear clinical management algorithm.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data on all births meeting the inclusion criteria from 2009 through 2019 at Mater Mothers' Hospital in Brisbane, Australia. This is a tertiary center and Australia's largest maternity hospital. All singleton births without a known congenital anomaly after 28 weeks' gestation were included. Among 203 071 potential participants identified from the hospital database, 101 597 individuals met the eligibility criteria. Data analysis was performed from May through September 2020.

EXPOSURE

Presentation to hospital with DFM after 28 weeks gestation.

MAIN OUTCOMES AND MEASURES

The primary outcome of this study was the incidence of stillbirth. Multivariate analysis was undertaken to determine the association between DFM and stillbirth, obstetric intervention, and other adverse outcomes, including being born small for gestational age (SGA) and a composite adverse perinatal outcome (at least 1 of the following: neonatal intensive care unit admission, severe acidosis [ie, umbilical artery pH <7.0 or base excess -12.0 mmol/L or less], 5-minute Apgar score <4, or stillbirth or neonatal death). The hypothesis being tested was formulated prior to data collection.

RESULTS

Among 101 597 women with pregnancies that met the inclusion criteria, 8821 (8.7%) presented at least once with DFM and 92 776 women (91.3%) did not present with DFM (ie, the control population). Women presenting with DFM, compared with those presenting without DFM, were younger (mean [SD] age, 30.4 [5.4] years vs 31.5 [5.2] years; P < .001), more likely to be nulliparous (4845 women [54.9%] vs 42 210 women [45.5%]; P < .001) and have a previous stillbirth (189 women [2.1%] vs 1156 women [1.2%]; P < .001), and less likely to have a previous cesarean delivery (1199 women [13.6%] vs 17 444 women [18.8%]; P < .001). During the study period, the stillbirth rate was 2.0 per 1000 births after 28 weeks' gestation. Presenting with DFM was not associated with higher odds of stillbirth (9 women [0.1%] vs 185 women [0.2%]; adjusted odds ratio [aOR], 0.54; 95% CI, 0.23-1.26, P = .16). However, presenting with DFM was associated with higher odds of a fetus being born SGA (aOR, 1.14; 95% CI, 1.03-1.27; P = .01) and the composite adverse perinatal outcome (aOR, 1.14; 95% CI, 1.02-1.27; P = .02). Presenting with DFM was also associated with higher odds of planned early term birth (aOR, 1.26; 95% CI, 1.15-1.38; P < .001), induction of labor (aOR, 1.63; 95% CI, 1.53-1.74; P < .001), and emergency cesarean delivery (aOR, 1.18; 95% CI, 1.09-1.28; P < .001).

CONCLUSIONS AND RELEVANCE

The presence of DFM is a marker associated with increased risk for a fetus. This study's findings of a nonsignificantly lower rate of stillbirth among women with DFM may be reflective of increased community awareness of timely presentation to their obstetric care clinician when concerned about fetal movements and the benefits of tertiary level care guided by a clear clinical management protocol. However, DFM was associated with increased odds of an infant being born SGA, obstetric intervention, early term birth, and a composite of adverse perinatal outcomes.

The Present Utility of the Oxytocin Challenge Test-A Single-Center Study

Introduction: The oxytocin challenge test (OCT) used to be one of the most important tools in assessing fetal well-being before ultrasonography became prevalent. We show that, after modifying the classification of the results and the intervention algorithm, OCT can still be a useful tool in present-day obstetrics. Material and methods: The study included 318 OCTs performed in patients admitted to our department from 2010 to 2012. A modified classification of test results was introduced, dividing the results in four groups: I-negative, II-positive, III-non-diagnostic and type IV (fetal tachycardia or increased variability). The purpose of the study was to evaluate the clinical significance of OCT in assessing intrauterinal fetal well-being and predicting the necessity for ending the pregnancy. Results: A significant difference (p < 0.001) in the delivery method and the indications for cesarean sections (CS) was found between negative and positive OCT results. CS indicated by an abnormal fetal heart rate (FHR) pattern had to be performed in 40% of cases with positive OCT results, having constituted 84.6% of all CSs in this group. After negative OCTs, 12.8% pregnancies were ended by CS from FHR indications (62.3% of all the indications). Conclusions: A positive OCT result can be a valuable predictor of an abnormal fetal heart rate pattern after the test and during the delivery, as well as a higher probability of a CS from cardiotocography (CTG) indications, with positive predictive value (PPV) 0.50 and negative predictive value (NPV) 0.85.

Substrates and Clearance Products of Fetal Adrenal Glucocorticoid Synthesis in Full-Term Human Umbilical Circulation

In full-term elective caesarian sections, fetal flow of adrenal substrate steroids to products differs by sex, with males (M) in molar equilibrium whereas females (F) add net molarity and synthesize more cortisol. Using the same sampling design, paired, full-term, arterial, and venous umbilical cord samples and intrapartum chart records were obtained at the time of vaginal delivery (N = 167, 85 male) or emergency C-section (N = 38, 22 male). Eight steroids were quantified by liquid chromatography coupled to tandem mass spectrometry (adrenal glucocorticoids [cortisol, corticosterone], sequential cortisol precursor steroids [17-hydroxyprogesterone, 11-deoxycortisol], cortisol and corticosterone metabolites [cortisone and 11-dehydrocorticosterone], and gonadal steroids [androstenedione, testosterone]). Fetal sex was not significant in any analytic models. Going through both phase 1 and phase 2 labor increased fetal adrenal steroidogenesis and decreased male testosterone relative to emergency C-sections that do not reach stage 2 of labor (ie, head compressions) and elective C-sections with no labor. Sum adrenal steroid molarity arriving in venous serum was almost double the equivalent metric for deliveries without labor. No effects of operative vaginal delivery were noted. Maternal regional anesthetic suppressed venous concentrations, and fetal synthesis replaced that steroid. Approximate molar equivalence between substrate pool depletion and net glucocorticoid synthesis was seen. Paired venous and arterial umbilical cord serum has the potential to identify sex differences that underlie antenatal programming of hypothalamic-pituitary-adrenal axis function in later life. However, stage 2 labor before the collection of serum, and regional anesthetic for the mother, mask those sex differences.

Unrecognized maternal heart rate artefact in cases of perinatal mortality reported to the United States Food and Drug Administration from 2009 to 2019: a critical patient safety issue

BACKGROUND

Maternal heart rate artefact is a signal processing error whereby the fetal heart rate is masked by the maternal pulse, potentially leading to danger by failure to recognize an abnormal fetal heart rate or a pre-existing fetal death. Maternal heart rate artefact may be exacerbated by autocorrelation algorithms in modern fetal monitors due to smooth transitions between maternal and fetal heart rates rather than breaks in the tracing. In response, manufacturers of cardiotocography monitors recommend verifying fetal life prior to monitoring and have developed safeguards including signal ambiguity detection technologies to simultaneously and continuously monitor the maternal and fetal heart rates. However, these safeguards are not emphasized in current cardiotocography clinical practice guidelines, potentially leading to a patient safety gap.

METHODS

The United States Food and Drug Administration Manufacturer and User Facility Device Experience database was reviewed for records with event type "Death" for the time period March 31, 2009 to March 31, 2019, in combination with search terms selected to capture all cases reported involving cardiotocography devices. Records were reviewed to determine whether maternal heart rate artefact was probable and/or whether the report contained a recommendation from the device manufacturer regarding maternal heart rate artefact.

RESULTS

Forty-seven cases of perinatal mortality were identified with probable maternal heart rate artefact including 14 with antepartum fetal death prior to initiation of cardiotocography, 14 with intrapartum fetal death or neonatal death after initiation of cardiotocography, and 19 where the temporal relationship between initiation of cardiotocography and death cannot be definitively established from the report. In 29 cases, there was a recommendation from the manufacturer regarding diagnosis and/or management of maternal heart rate artefact.

CONCLUSIONS

This case series indicates a recurring problem with undetected maternal heart rate artefact leading to perinatal mortality and, in cases of pre-existing fetal death, healthcare provider confusion. In response, manufacturers frequently recommend safeguards which are found in their device's instructions for use but not in major intrapartum cardiotocography guidelines. Cardiotocography guidelines should be updated to include the latest safeguards against the risks of maternal heart rate artefact. An additional file summarizing key points for clinicians is included.

Sensors for Fetal Hypoxia and Metabolic Acidosis: A Review

This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal heart rate monitoring and fetal scalp blood sampling are shown to be either inadequate or time-consuming. Monitoring of lactate in blood is identified as a potential alternative for intrapartum fetal monitoring due to its ability to distinguish between different types of acidosis. A literature review from a medical and technical perspective is presented to identify the current advancements in the field of lactate sensors for this application. It is concluded that a less invasive and a more continuous monitoring device is required to fulfill the clinical needs of intrapartum fetal monitoring. Potential specifications for such a system are also presented in this paper.