Intrapartum Fetal Heart Rate Patterns Research Articles

Category II Intrapartum Fetal Heart Rate Patterns Unassociated With Recognized Sentinel Events: Castles in the Air.

Cedars-Sinai Medical Center, Los Angeles, California Financial Disclosure The author did not report any potential conflicts of interest.

Category II Intrapartum Fetal Heart Rate Patterns Unassociated With Recognized Sentinel Events: Castles in the Air.

The evolution of continuous electronic fetal heart rate (FHR) monitoring has presented the obstetrician with a critical clinical conundrum: basic science observations suggest that such monitoring might be associated with improved long-term neurologic outcomes, yet, after a half century of use and millions of cesarean deliveries based on FHR monitoring, evidence for such improvement remains absent. This dichotomy appears to be related to widespread misconceptions regarding the physiology underlying various FHR patterns and the developmental origins of cerebral palsy. These misconceptions are strengthened by a reliance on anecdotal experience and tradition in lieu of evidence-based medicine, the confusing "category II" FHR designation, medical-legal considerations, and our tendency to view fetal monitoring, as originally conceptualized, as a single, indivisible entity whose concepts must be accepted or rejected en bloc. Ill-defined and largely imaginary conditions such as "depletion of fetal reserve" are particularly harmful and their use in clinical medicine uniquely not evidence based. A solution to this self-inflicted injury to our specialty will require a concerted effort involving teachers, authors, and researchers.

Intrapartum fetal heart rate patterns and perinatal outcome in chorioamnionitis at or beyond 34 weeks of gestation.

To investigate intrapartum fetal heart rate (FHR) patterns in women with chorioamnionitis at or beyond 34 weeks of gestation in relation to neonatal outcome and to compare clinical and subclinical chorioamnionitis. A retrospective questionnaire survey on deliveries during 2015 was conducted by the Perinatology Committee of the Japan Society of Obstetrics and Gynecology from 2016 to 2018. A total of 498 singleton births complicated by chorioamnionitis delivered at ≥34 weeks of gestation without major congenital malformations were included. The subjects were divided into clinical and subclinical chorioamnionitis groups based on Lencki's criteria. Poor perinatal outcome was defined as death or brain damage. We analyzed clinical features, FHR patterns in the last 2 h before delivery, gestational age, birthweight, Apgar score, umbilical arterial blood gas analysis, and infant's outcome. Incidence of chorioamnionitis at ≥34 weeks of gestation was 0.59% (522/87827). Clinical and subclinical chorioamnionitis comprised 240 and 258 cases, respectively. Abnormal FHR patterns (late deceleration or decreased baseline variability) were significantly associated with poor perinatal outcome. Combined late deceleration and decreased variability showed low positive predictive value (12.8%) and high negative predictive value (99.5%), and was significantly associated with long-term poor outcome in clinical chorioamnionitis only (odds ratio: 29.4, p < 0.01). Poor perinatal outcome showed no significant difference between the clinical and subclinical chorioamnionitis groups. Combined late deceleration and decreased variability could predict poor perinatal outcome in clinical chorioamnionitis. Poor perinatal outcome occurred in infants born to mothers with clinical and subclinical chorioamnionitis.

Dietary Inflammatory Index during Pregnancy and the Risk of Intrapartum Fetal Asphyxia: The Japan Environment and Children's Study.

We aimed to examine the impact of a daily pro-inflammatory diet during pregnancy on intrapartum fetal acidemia using a large birth cohort study in Japan. We used data on singleton pregnancies in the Japan Environment and Children’s Study (JECS) involving births from 2011 to 2014 through vaginal delivery to calculate the maternal dietary inflammatory index (DII). Participants were categorized according to DII quintiles. A multiple logistic regression model was used to estimate the risk of a pro-inflammatory diet on fetal umbilical artery pH. In total, 56,490 participants were eligible for this study. Multiple regression analysis showed that nulliparous women who had undergone vaginal delivery and were consuming a pro-inflammatory diet had an increased risk of pH < 7.10 (adjusted odds ratio [aOR]: 1.64, 95% confidence interval [CI]: 1.12–2.39). Among these women, the risk of pH < 7.10 was not affected by the duration of labor (aOR: 1.64, 95% CI: 1.11–2.42). In conclusion, following a pro-inflammatory diet during pregnancy is a risk factor for fetal acidosis among nulliparous women undergoing vaginal delivery. A high DII diet during pregnancy may modify the intrapartum fetal heart rate pattern via intrauterine inflammation.

Unusual Circumstances and Additional Procedures for Fetal Evaluation in Labor.

This chapter describes several circumstances in which the interpretation of the intrapartum fetal heart rate pattern falls outside the usual frame of reference. This includes a more extensive discussion of causes of tachycardia and bradycardia. Ways in which a fetal dysrhythmia may manifest itself in the context of heart rate monitoring are described. Finally, the chapter reviews technological innovations designed to clarify the fetal status when compromise is suspected from the fetal heart rate pattern.

Computerized Analysis of Intrapartum Fetal Heart Rate Patterns and Adverse Outcomes in the INFANT Trial

(Abstracted from BJOG 2019;126:1354–1361) During the 1960s and 1970s, intermittent auscultation was replaced by the alternative method of continuous electronic fetal monitoring (EFM) and cardiotocography (electronic monitoring of the fetal heart rate [FHR] and uterine contractions, or CTG). Meta-analyses have reported a 59% drop in intrapartum deaths attributable to hypoxia and a reduced risk of neonatal seizures, but a 2017 Cochrane review concluded that while EFM did reduce the rates of neonatal seizures, it did not provide “clear differences in cerebral palsy, infant mortality, or other standard measures of neonatal well-being.” Human error in interpreting the FHR pattern is a possible explanation for the ineffectiveness of EFM.

Authors' reply re: Computerised analysis of intrapartum fetal heart rate patterns and adverse outcomes in the INFANT trial

Authors' reply re: Computerised analysis of intrapartum fetal heart rate patterns and adverse outcomes in the INFANT trial

Marked variability in intrapartum electronic fetal heart rate patterns: association with neonatal morbidity and abnormal arterial cord gas.

Objective:Investigate marked variability in fetal heart rate (FHR) patterns before delivery and its association with neonatal morbidity and abnormal arterial cord gases.Study Design:Prospective cohort of laboring patients at term. Composite neonatal morbidity (respiratory distress, mechanical ventilation, suspected sepsis, meconium aspiration syndrome, therapeutic hypothermia, hypoxic-ischemic encephalopathy, seizure and death) and abnormal arterial cord gases (pH<7.10, lactate ≥4 mmol/L, base deficit < −12 mEq/L) were assessed with multivariable logistic regression.Result:390 (4.5%) neonates had marked variability in FHR patterns before delivery. There was no difference in composite neonatal morbidity (aRR 1.22; 95%CI 0.91-1.63), though neonates with marked variability in FHR patterns were more likely to have respiratory distress (aRR 1.85; 95%CI 1.25-2.70). There was an increased risk of composite abnormal arterial cord gases (aRR 1.66; 95%CI 1.47-1.88).Conclusion:Marked variability in FHR patterns was not associated with composite neonatal morbidity but was associated with abnormal arterial cord gases.

Computerised analysis of intrapartum fetal heart rate patterns and adverse outcomes in the INFANT trial.

To assess if a computerised decision support system reliably identified abnormal fetal heart rate (FHR) patterns in fetuses with adverse neonatal outcomes in the INFANT trial, and whether its use reduced substandard care. Prospective cohort study within a randomised controlled trial. Twenty-four maternity units in the UK and Ireland. A total of 46614 labours between January 6 2010 and August 31 2013 in the INFANT trial. Panelreview of intrapartum and neonatal care in infants with adverse outcome, and an assessment of the effectiveness of computerised interpretation of fetal heart rate in reducing substandard care. Descriptive analysis of other factors associated with adverse outcome. Incidence and detection rate of abnormal fetal heart rate patterns, other characteristics associated with perinatal adverse outcome, and frequency of substandard care. Computer interpretation of FHR patterns was deemed to be completely valid in only 24 of 71 (33.8%) cases of adverse outcome. On a scale of 0-10 (completely invalid to completely valid), 28 cases (39.4%) had a score of 6 or less, mainly due to lack of recognition of decelerations (15 cases), or reduced variability (seven cases), or failure to recognise tachysystole (five cases). There were multiple associated factors that modified the clinical assessment of FHR patterns. There was substandard care in 45/71 cases (63%). A significant proportion of abnormal fetal heart rate patterns were not detected accurately by computer analysis, and its use did not reduce the incidence of substandard care. UK National Institute for Health Research Health Technology Assessment Programme (project number 06.38.01). Improved recognition of abnormal fetal heart rate patterns is insufficient to reduce the incidence of substandard care.

293: Term appropriate for gestational age infants with Neonatal Encephalopathy: Is there a characteristic intrapartum fetal heart rate pattern?

Neonatal encephalopathy (NE) of the term AGA newborn is source of severe neurological morbidity. Strict criteria for therapeutic Hypothermia (Hth) eligibility enables consistency in diagnosis of NE. We aimed to evaluate intrapartum fetal heart rate patterns in NE eligible for Hth. A retrospective cohort of clinical data and FHR of term AGA infants treated by Hth; computerized records in a tertiary center, 2009 - 2017. Entry criteria for Hth: GA ≥ 36+0w and two obligatory conditions: Bundle (1) 10’ Apgar ≤ 5, CPR > 10’, pH<7.0, BE>16 mEq/ml in cord blood. Bundle (2): altered consciousness and one of the following: hypotonia, decreased reflexes, clinical seizures. FHR 1h prior to delivery was assessed by trained obstetrician. We characterized the pattern of the FHR: Category system (1-3), FHR-NICHD criteria, mean total deceleration area (area = Half of depth x Duration of deceleration, added over given time), mean deceleration duration 50 infants filled the criteria, 30 had recorded antenatal FHR for at least an hour prior to delivery. Overall, group characteristics were: mean maternal age 28.4y±6.04, GA 39w±1.77, parity 2.94±2.44, BW 3136gr±480.34, cord pH 6.9±0.227. Groups with vs without recorded FHR were similar, including the rate of sentinel events such as uterine rupture, placental abruption, heavy meconium (Table). Notably, two third of cases (58%) in both groups were preceded by such a sentinel event. FHR characteristics were: reduced variability 43.3%, terminal bradycardia 50%, tachycardia 40%. Mean area of deceleration 29.06±24.30 and mean duration of deceleration 1.736±1.105. 21 (70%) infants with FHR Category 2 and 9 (30%) Category 3. We compared FHR characteristics of Category 2 vs 3 (not inherent to definitions), respectively: baseline and total number of variable decelerations were significantly different between the groups mean baseline 147bpm±12.18 and 157.77bpm±12.01, p=0.038, total number of variable decelerations 17.23±11.67 and 6.22±4.29, p=0.012. FHR patterns between these two categories were similar for bradycardia, number of severe variable or late decelerations, mean area and mean duration of deceleration Term AGA infants affected by NE have no preceding pathognomonic intrapartum FHR tracing. The majority of NE are determined by unforeseen sentinel events

Decision-to-delivery interval in pregnant women with intrapartum non-reassuring fetal heart rate patterns.

It has been proposed that delivery should be accomplished within 30 minutes after diagnosis of fetal distress. The objective of this study was to determine the decision-to-delivery interval (DDI) in emergency caesarean delivery for non-reassuring fetal heart rate (FHR). A total of 272 term, singleton pregnant women who underwent an emergency caesarean section for non-reassuring FHR were included. Patient characteristics and clinical data were reviewed. The timing of the decision-to-delivery process was reviewed. The mean age was 28.7 years; the mean gestational age at delivery was 38.4 weeks; and 93.7% were in FHR category 2. The decision for emergency caesarean delivery was made during normal office hours in 31.6%. Median time for decision-to-operating room, decision-to-incision and decision-to-delivery was 42.3, 48.5 and 56 minutes, respectively. Only 6.6% of women had a DDI of <30 minutes, whereas 30.5% had a DDI of >75 minutes. Significantly shorter intervals were observed for every endpoint among patients in FHR category 3, and they were significantly more likely to deliver within 30 minutes than were those in FHR category 2 (41.2% vs. 4.3%, P < 0.001). Similar results were observed for cases that occurred during normal and after hours. Neonatal outcomes were comparable among different DDI categories. Only 6.6% of women with non-reassuring FHR achieved the 30-minute goal for caesarean delivery (median 56 minutes). Better performance was observed among patients in FHR category 3 regardless of diagnosis time, with 41.2% of these patients having a DDI of <30 minutes.

The myths and physiology surrounding intrapartum decelerations: the critical role of the peripheral chemoreflex.

A distinctive pattern of recurrent rapid falls in fetal heart rate, called decelerations, are commonly associated with uterine contractions during labour. These brief decelerations are mediated by vagal activation. The reflex triggering this vagal response has been variably attributed to a mechanoreceptor response to fetal head compression, to baroreflex activation following increased blood pressure during umbilical cord compression, and/or a Bezold-Jarisch reflex response to reduced venous return from the placenta. Although these complex explanations are still widespread today, there is no consistent evidence that they are common during labour. Instead, the only mechanism that has been systematically investigated, proven to be reliably active during labour and, crucially, capable of producing rapid decelerations is the peripheral chemoreflex. The peripheral chemoreflex is triggered by transient periods of asphyxia that are a normal phenomenon associated with all uterine contractions. This should not cause concern as the healthy fetus has a remarkable ability to adapt to these repeated but short periods of asphyxia. This means that the healthy fetus is typically not at risk of hypotension and injury during uncomplicated labour even during repeated brief decelerations. The physiologically incorrect theories surrounding decelerations that ignore the natural occurrence of repeated asphyxia probably gained widespread support to help explain why many babies are born healthy despite repeated decelerations during labour. We propose that a unified and physiological understanding of intrapartum decelerations that accepts the true nature of labour is critical to improve interpretation of intrapartum fetal heart rate patterns.

Intrapartum fetal heart rate patterns preceding terminal bradycardia in infants (>34 weeks) with poor neurological outcome: A regional population-based study in Japan.

Intrapartum fetal bradycardia necessitates immediate operative delivery. Our aim was to investigate the hypothesis that some non-reassuring fetal heart rate (FHR) patterns were present before the onset of terminal bradycardia in infants who developed subsequent brain damage. From a population-based study of 65,197 deliveries, 190 stillbirths, 115 neonatal deaths, and 136 neurologically high-risk infants were registered by the Miyazaki Perinatal Conference. There were 15 cases of neurologically high-risk infants born at >34 weeks of gestation exhibiting intrapartum terminal bradycardia. Focusing on the brain-damaged infants, we retrospectively analyzed FHR patterns for at least 1 h prior to the bradycardia. Brain damage (cerebral palsy [n = 11] and mental retardation [n = 2]) was diagnosed at 2 years old in 13 out of 15 neurologically high-risk infants. Two infants had bradycardia on admission. In the remaining 11 infants, FHR patterns were reassuring in six (55%) and non-reassuring in five (45%), including late decelerations (n = 4) and variable decelerations (n = 2). Clinically relevant factors in the non-reassuring group included intrauterine infection (n = 3), malpresentation with umbilical cord coiling (n = 1), and unknown causes (n = 1). Clinically relevant features in the reassuring group included cord prolapse (n = 1), vaginal breech delivery (n = 1), shoulder dystocia (n = 1), rupture of membranes (n = 1), and unknown causes (n = 2). More than half of the brain-damaged infants born at >34 weeks of gestation who exhibited intrapartum terminal bradycardia had unremarkable FHR patterns before abrupt-onset bradycardia. For those with non-reassuring patterns preceding bradycardia, intrauterine infection was the major sentinel event.

Tribute to a great obstetrician: in memory of Ingemar Ingemarsson.

Ingemar Ingemarsson, grew up in a rural area in Smaland in the southern part of Sweden. He studied and graduated at the Medical Faculty at Lund University and started his career in obstetrics and gynecology in 1972 at the University Hospital in Lund. He defended his PhD thesis in 1975, was appointed consultant and later became Head of the Department and Professor in Obstetrics at Lund University. In 1997 the Royal College of Obstetricians and Gynaecologists acknowledged Ingemar Ingemarsson's contributions to our speciality and honored him by the "Fellow ad eundum" award; one of seven Swedish obstetricians and gynecologists to be given that honor. This article is protected by copyright. All rights reserved.

W316 EFFECT OF INTRAPARTUM PETHIDINE ON THE NEONATAL OUTCOME: IS IT DURATION RELATED?

Objectives: To study the effect of pethidine on the intrapartum fetal heart rate (FHR) pattern and to assess the neonatal outcome with regards to the interval between pethidine administration to delivery of the fetus. Materials: 73 healthy women intrapartum from labour suite hospital Tengku Ampuan Afzan, Kuantan, Malaysia Methods: This is a prospective observational study done on 73 healthy consented women with singleton pregnancy at term . All fetus were normal, vertex presentation with reactive FHR tracing before pethidine administration. FHR recording were performed for 40 minutes prior to and one hour post pethidine. Cervical dilatation of all patients ≤ 4 cm at time of pethidine administration. Intramuscular pethidine 1mg/kg was given as an intrapartum analgesia. The study sample was divided into two groups, first group delivered within 4 hours and second group delivered more than 4 hours after the pethidine administration. The data were analysed by SSPS 17.0. Results: the mean age of the recruited patients is 28.15 ± 6.15 years and mean gestational age of 39.14 ± 1.094 weeks. The mean duration from pethidine administration to delivery is 296.48 ± 173.65 minutes (4 hours and 56 minutes). Four (5.5%) cases had suspicious CTG 1 hour post pethidine, 1 with absence of acceleration for 45 minutes and 3 cases with early deceleration lasted for 60 to 90 minutes. Out of 73 patients, 38 babies delivered within 4 hours and 35 delivered after 4 hours of pethidine. All neonates delivered with good Apgar Score (AS), 8 at 1 minute and 9 at 5 minute except 1 with AS of 5 at 1 min and 7 at 5 min which delivered more than 4 hours after pethidine. Sixteen (21.9%) cases were admitted to the Neonatal Intensive Care Unit (NICU). Eleven (68.75%) cases were admitted due to neonatal sedation from the delivery group less than 4 hours after pethidine. Five (31.25%) cases from the delivery group more than 4 hours, 4 cases with a diagnosis of transient tachypnea of newborn and 1 secondary to meconium aspiration syndrome (MAS). All discharge to mother after 24 hours, non required ventilation apart from the one with MAS which required ventilation for one day and longer admission. Despite of the higher number of those require admission in the less than 4 hours group, it was not statistically significant with P value of 7.44. Conclusions: Pethidine can be used as an intrapartum analgesia which is safe, easily available without major effect on fetal heart rate pattern and neonatal outcome even if given in advance stage of labour.

Assessment and Management of Intrapartum Fetal Monitoring

Abstract This training session involves a didactic session and hands-on training sessions in the evaluation and management of intrapartum fetal heart rate patterns on a high-fidelity mannequin. The...

Association between intrapartum fetal heart rate patterns and neonatal abstinence syndrome in methadone exposed neonates

Objective. Determine whether infants exposed to chronic maternal methadone with abnormal intrapartum fetal heart rate (FHR) patterns are more likely to require treatment for neonatal abstinence syndrome (NAS).Study design. Intrapartum FHR tracings analyzed in 104 pregnancies at ≥34 weeks gestation for FHR variability, accelerations, and decelerations. FHR patterns compared between neonates based on treatment with methadone for NAS. Secondary analysis included relation between maternal methadone dose and intrapartum FHR patterns, initiation of methadone, age at methadone initiation, and total neonatal methadone dose. Study powered to detect 30% increase in NAS incidence in neonates with abnormal FHR tracings.Results. Seventy-six (73%) of 104 neonates required methadone treatment for NAS. Neonates who required methadone had higher average baseline FHR (131 vs. 126 bpm; p < 0.04) in active labor and less likely to have FHR tracings without accelerations (1.7% vs. 20.3%; p = 0.007) in latent labor. No significant associations between neonate's need for methadone and intrapartum FHR variability or FHR decelerations. No association between maternal methadone dose (range 30–280 mg) and treatment for NAS.Conclusion. The need for an infant to require methadone treatment for NAS was not reliably predicted by the intrapartum FHR patterns or the maternal methadone dose.

Obstetrical and fetal outcomes of a new management strategy in patients with intra-hepatic cholestasis of pregnancy

To determine the incidence, obstetrical, and fetal complication rates of intrahepatic cholestasis of pregnancy (ICP) in patients managed expectantly to 40-weeks gestation. In a prospective cohort study conducted between February 2008 and January 2010, a total of 21,960 pregnant women in Qassim Region of Saudi Arabia were screened for ICP using specific criteria for diagnosis. The course of pregnancy was monitored to 40-weeks gestation or spontaneous onset of labor, whichever comes first. The measured outcomes were compared with a cross-matched group of healthy pregnant women. Continuous variables were analyzed with t test, while χ(2) test was used for comparing percentages. The incidence of ICP was 0.35% (76/21,960). There was no significant difference between groups in gestational age at delivery, preterm labor, intrauterine fetal death, cesarean section, or respiratory distress syndrome. There was significantly higher intrapartum non-reassuring fetal heart rate patterns and meconium-stained amniotic fluid in ICP group (P < 0.01 and <0.0001, respectively). The incidence of ICP in this region is low compared to worldwide range. Expectant management to 40-weeks gestation is associated with obstetrical and fetal outcomes comparable to normal pregnancy; however, intrapartum fetal asphyxia is more likely.

663: Association between intrapartum fetal heart rate patterns and neonatal abstinence syndrome in methadone exposed neonates

Determine if infants exposed to chronic maternal methadone treatment who have abnormal intrapartum fetal heart rate (FHR) patterns are more likely to require treatment for neonatal abstinence syndrome (NAS).

Intrapartum fetal heart rate monitoring in cases of congenital heart disease

We evaluated the intrapartum fetal heart rate (FHR) patterns in fetuses with congenital heart disease (CHD). One hundred sixteen cases of fetal CHD were identified at our institute between 2000-2007; 464 fetuses without CHD were used as controls. The incidences of abnormal FHR patterns and umbilical blood gases were compared. More fetuses with CHD showed variant FHR than did control fetuses (46.6% vs 17.7%; P < .01). Cesarean section deliveries that were based on fetal indications were performed more frequently in fetuses with CHD than in control fetuses (12.9% vs 3.2%; P < .01). Isomerism and tetralogy of Fallot were observed frequently with variant FHR. When chromosomal abnormalities and intrauterine growth restriction were excluded, the fetuses with CHD showed more variant FHR than did the control fetuses. Fetuses with CHD are more likely to show abnormal FHR patterns than are control fetuses. We suggest that cardiac abnormalities are associated with abnormalities in FHR patterns.