Effect of maternal hyperoxygenation on neonatal outcomes among women in labour with pathological cardiotocography: an open-label randomized controlled trial

BACKGROUND

Hyperoxygenation has shown promise in improving suspicious fetal heart patterns in women in labor. However, the effect of hyperoxygenation on neonatal outcomes in women in labor with pathologic fetal heart rate tracing has not been studied.

OBJECTIVE

This study aimed to evaluate the effect of fractional inspiration of oxygen of 80% compared with fractional inspiration of oxygen of 40% on neonatal outcomes in women with pathologic fetal heart rate tracing.

STUDY DESIGN

This randomized, open-label, parallel arm, outcome assessor-blinded clinical trial was conducted in a large tertiary care university hospital. Singleton parturients aged ≥18 years at term gestation in active labor (cervical dilatation of ≥6 cm) with pathologic fetal heart rate tracing were recruited in the study. Pathologic fetal heart rate tracing was defined according to the International Federation of Gynecology and Obstetrics 2015 guidelines. The International Federation of Gynecology and Obstetrics classifies fetal heart rate tracings into 3 categories (normal, suspicious, and pathologic) based on rate, variability, and deceleration. Women in the intervention arm received oxygen at 10 L/min via a nonrebreathing mask, and those in the usual care arm received oxygen at 6 L/min with a simple face mask. Oxygen supplementation was continued until cord clamping. The primary outcome measure was a 5-minute Apgar score. The secondary outcome measures were the proportion of neonatal intensive care unit admission, umbilical cord blood gas variables, level of methyl malondialdehyde in the cord blood, and mode of delivery.

RESULTS

Overall, 148 women (74 women in the high fractional inspiration of oxygen arm and 74 in the low fractional inspiration of oxygen arm) with pathologic fetal heart rate tracing were analyzed. The demographic data, obstetrical profiles, and comorbidities were comparable. The median 5-minute Apgar scores were 9 (interquartile range, 8-10) in the hyperoxygenation arm and 9 (interquartile range, 8-10) in the usual care arm (P=.12). Furthermore, the rate of neonatal intensive care unit admission (9.5% vs 12.2%; P=.6) and the requirement of positive pressure ventilation (6.8% vs 8.1%; P=.75) were comparable. Concerning cord blood gas parameters, the hyperoxygenation arm had a significantly higher base deficit in the umbilical vein and lactate level in the umbilical artery. The cesarean delivery rate was significantly lower in women who received hyperoxygenation (4.1% [3/74]) than in women who received normal oxygen supplementation (25.7% [19/74]) (P=.00). In addition, umbilical vein malondialdehyde level in the umbilical vein was lower in the hyperoxygenation group (8.28±4.65 μmol/L) than in the normal oxygen supplementation group (13.44±8.34 μmol/L) (P=.00).

CONCLUSION

Hyperoxygenation did not improve the neonatal Apgar score in women with pathologic fetal heart rate tracing. In addition, neonatal intensive care unit admission rate and blood gas parameters remained comparable. Therefore, the results of this trial suggest that a high fractional inspiration of oxygen supplementation confers no benefit on neonatal outcomes in women with pathologic fetal heart rate tracings and normal oxygen saturation.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

The effect of perceptual decision-making on the interpretation of twin fetal heart rate tracings

Objective: Decision-making is an integrative process during which multiple sources of available evidence are combined into a singular response. Importantly, subconscious processes occur in perceptual decisions that may influence interpretations of visually displayed data such as fetal heart rate tracings (FHRT), which are typically presented together for twins. To examine the potential impact of subconscious perceptual influences on fetal well-being, differences in assessments of FHRTs for twin gestations presented singly or paired were evaluated for baseline fetal heart rate, variability, accelerations, decelerations, and overall concern.Study design: Obstetrical nurses (N = 27) assessed FHRTs from 20 twin gestations (each of which had at least one live birth with a 5-min Apgar <7) presented either on the same tracing or as singletons on separate tracings. Nurses were naïve to the fact that the fetal heart rate tracings presented in the unpaired condition were the same as those presented in the paired condition. Assessments were then compared between the two conditions.Results: Each nurse participant completed ratings on five metrics for each of 20 twin gestations across two conditions (80 FHRT assessments, 400 metrics total per participant). The intraobserver impact of visual context was calculated as the frequency of changed opinions regarding an individual metric (e.g. variability) between the paired and unpaired contexts for each individual fetal heart rate. Assessments of variability (average Kappa = 0.59), decelerations (average Kappa = 0.34), and overall level of concern (average Kappa = 0.33) were moderately to heavily impacted by viewing condition (unpaired vs. paired FHRT). Analysis of interobserver agreement using intraclass correlations (two-way random effect, absolute agreement) indicates poor agreement on unpaired assessments for both accelerations (ICC = 0.01, 95% CI -0.01-0.04) and decelerations (ICC = 0.22, 95% CI 0.15-0.33). These results are mirrored in poor agreement on paired assessments for both accelerations (ICC = 0.00, 95% CI -0.01-0.03) and decelerations (ICC = 0.27, 95% CI 0.19-0.39). There was moderate agreement on overall level of concern for unpaired assessments (ICC = 0.55, 95% CI 0.44-0.67) and near moderate agreement for the paired condition (ICC = 0.45, 95% CI 0.34-0.58).Conclusions: The simultaneous presentation of fetal heart rate tracings in twin gestations introduces both intraobserver and interobserver variances in the interpretation of variability, accelerations, and decelerations, likely due to the influence of subconscious perceptual decision-making. This may theoretically affect outcomes in cases in which visual information is nuanced. More research is necessary to determine whether the standard protocol of simultaneous assessment of FHRT in twins is subliminally affected by perceptual decision-making.

Decline number of uterine fundal pressure maneuver in Japan recent 5 years

AIM

To clarify whether the incidence of uterine fundal pressure (UFP) maneuver at delivery and consequent uterine rupture were declined.

METHODS

Population-based postal questionnaire study was conducted. A questionnaire was sent to obstetric institutions across Japan. Questions were included the total number of deliveries, UFP and uterine ruptures associated with UFP in 2012 and 2017. As the primary outcome, frequencies of the UFP and uterine rupture were compared between 2012 and 2017. The secondary outcomes were included improved managements of delivery regarding UFP.

RESULTS

A number of vaginal deliveries were significantly declined from 80.4% in 2012 to 78.1% in 2017 (P < 0.001). Frequencies of UFP per vaginal deliveries were also significantly declined 11.2% (38 973/347771) in 2012 to 9.5% (35 205/404444) in 2017 (<0.001). Number of uterine ruptures were 6 cases in 2012 (1:6496) and 11 cases in 2017 (1:3473) (P = 0.210). Compared to situation in 2012, informed consent was more frequently obtained for UFP in 2017. Written informed consent for UFP became to be obtained in 12% of institutions in 2017 from only 3% in 2012. More than 80% of institutions are performing UFP within 3 times. Regarding to uterine rupture, try of labor after the cesarean section, UFP and augmentation were improved in more than 10% of institutions. Most impact vehicle changing behavior was OBGY clinical guideline.

CONCLUSION

Although significant declined incidence of uterine rupture after UFP could not be demonstrated, frequency of UFP was decreased recent 5 years. This is due to improvement of obstetric management by obstetric caregivers throughout Japan.

Early Accreta and Uterine Rupture in the Second Trimester

The differential diagnosis of third trimester bleeding can range from placenta abruptia to placenta previa to uterine rupture and the placenta accreta spectrum (PAS). However, patients with risk factors such as multiple cesarean sections (c-sections), advanced maternal age (AMA), grand multiparity, and single-layer uterine closure are at greater risk of developing these complications earlier than we would traditionally expect. This case recounts a 38-year-old gravida 6 preterm 3 term 1 abortus 1 live 4 (G6P3114) at 23 weeks and five days gestational age (GA) with a past medical history of preterm pregnancy, pre-eclampsia, chronic abruptia, three previous c-sections, and low-lying placenta who presented to the emergency department (ED) with vaginal bleeding. Initial workup revealed placenta accreta and possible percreta. The patient was placed on intramuscular (IM) corticosteroids in anticipation of preterm delivery. As soon as the patient was stable, she was discharged home. She presented to a different hospital the next day with the same complaints. Imaging was consistent with accreta and her presentation with abruption. During the hospital stay, the patient went into threatened preterm labor (PTL). At first, we suspected preterm premature rupture of membranes (PPROM) due to apparent pooling of amniotic fluid in the vaginal canal. Upon further work up, the diagnosis was consistent with chronic abruption oligohydramnios sequence (CAOS). Before this could be investigated, her hospital course was complicated by acute abruption and Category III/nonreassuring fetal heart rate (FHR) tracing. The patient underwent an emergency c-section at 26 weeks GA as well as a planned supracervical hysterectomy for desired permanent sterilization. During the operation, the patient suffered a postpartum hemorrhage (PPH) of 4500 mL. She was later discharged home on postoperative day (POD) eight.