Effect of dural puncture epidural block technique on fetal heart rate variability during labor analgesia.

PURPOSE: To explore the effect of dural puncture epidural (DPE) block technique on fetal heart rate variability (HRV) during labor analgesia. METHODS: Sixty full-term primiparas who were in our hospital from April 2021 to October 2021 were selected and randomized into epidural analgesia (CEA) and dural puncture epidural analgesia (DPEA) groups (n = 30). After a successful epidural puncture, routine epidural catheter (EC) was performed in CEA group, and spinal anesthesia needle (as an EC) was used to puncture the dura mater to subarachnoid space in DPE group. Anesthetics were injected through EC. The time when the temperature sensation plane reached T10 (W1) and visual analog pain score (VAS), baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 were recorded. Apgar scores at 1 min, 5 min, and 10 min of neonates after delivery were recorded. RESULTS: The onset time of anesthesia in CEA group was significantly longer than that in DPEA group (p < .05). However, there are no significant differences in W1, VAS, baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 between the two groups (p > .05). Moreover, the Apgar scores at 1 min, 5 min and 10 min of neonates after delivery were not notably different between the two groups (p > .05). CONCLUSION: Compared with CEA, DPE block technique in labor analgesia relieves maternal pain without adverse effects on fetal HRV and newborns.

Effect of Direct and Mediated through Maternal Organism Activation of the Catecholaminergic System on Heart Rate Parameters in Rat Fetuses.

We performed a comparative analysis of direct and mediated through the maternal organism effects of elevated catecholamine concentration on changes in the cardiac activity parameters in female rats and their fetuses on gestation days 18 and 20 under in vivo conditions. Administration of L-DOPA, a precursor of catecholaminergic transmitters, did not cause chronotropic effects in fetuses. Analysis of HR variability showed that in fetuses, irrespective of the administration route, there was an increase in nervous influences while the leading role of humoral-metabolic factors in the regulation of HR was preserved. In females receiving L-DOPA injection on day 18 of gestation, a decrease in humoral-metabolic and an increase in nerve effects were observed; in rats injected with L-DOPA on day 20 of gestation, an increase in sympathetic influences was found. Administration of L-DOPA to fetuses provoked a slight increase in the power of all components of the heart rhythm periodogram spectrum in females on day 18 of gestation and their decrease on day 20. Changes in the parameters of HR variability in females can confirm the hypothesis that in the "mother-fetus" system, the heart rhythm in the mother can be affected by both maternal and fetal influences presumably through the humoral-metabolic regulation.

Timing of cesarean delivery for fetal heart rate abnormalities in hypertensive pregnancies induced with oral misoprostol or Foley catheter: Secondary analysis of a randomized clinical trial.

OBJECTIVE: The study aims to assess how oral misoprostol for cervical ripening affects the time of cesarean delivery (CD) for fetal heart rate (FHR) abnormalities in pre-eclampsia patients. Secondary goals include determining the role of uterine hyperstimulation, comparing misoprostol with Foley catheter, and identifying risk factors for FHR abnormalities associated with CD. METHODS: A previously published randomized clinical trial was subjected to a secondary analysis (NCT01801410). We conducted a time-dependent analysis, stratifying the population based on the final mode of induction used (low-dose oral misoprostol vs Foley catheter). RESULTS: There was no CD for FHR abnormalities within 2 h of starting misoprostol. At 5 h, the cumulative incidence of CD for FHR abnormalities in the misoprostol group was 2.10%, while it was 1.00% in the Foley group (P = 0.565). After 25 h, the CD risk for FHR abnormalities remained constant in both groups at 21.00% (95% confidence interval [CI] 15.00%-28.00%). Within 5 h of misoprostol induction, the risk of uterine hyperstimulation was similar in both groups (0.33% in misoprostol vs 0.34% in Foley group, P = 0.161). The risk of CD for FHR abnormalities was unaffected by newborn weight centiles. CONCLUSION: There was no significant difference in CD risk for FHR abnormalities between misoprostol and Foley catheter induction. Nonetheless, the cumulative incidence of CD for FHR abnormalities increased faster in the misoprostol group, indicating that FHR monitoring timing should be tailored to the induction method.

Sodium dichloroacetate stimulates cardiac mitochondrial metabolism and improves cardiac conduction in the ovine fetus during labor.

Previous studies in our laboratory have suggested that the increase in stillbirth in pregnancies complicated by chronic maternal stress or hypercortisolemia is associated with cardiac dysfunction in late stages of labor and delivery. Transcriptomics analysis of the overly represented differentially expressed genes in the fetal heart of hypercortisolemic ewes indicated involvement of mitochondrial function. Sodium dichloroacetate (DCA) has been used to improve mitochondrial function in several disease states. We hypothesized that administration of DCA to laboring ewes would improve both cardiac mitochondrial activity and cardiac function in their fetuses. Four groups of ewes and their fetuses were studied: control, cortisol-infused (1 g/kg/day from 115 to term; CORT), DCA-treated (over 24 h), and DCA + CORT-treated; oxytocin was delivered starting 48 h before the DCA treatment. DCA significantly decreased cardiac lactate, alanine, and glucose/glucose-6-phosphate and increased acetylcarnitine/isobutyryl-carnitine. DCA increased mitochondrial activity, increasing oxidative phosphorylation (PCI, PCI + II) per tissue weight or per unit of citrate synthase. DCA also decreased the duration of the QRS, attenuating the prolongation of the QRS observed in CORT fetuses. The effect to reduce QRS duration with DCA treatment correlated with increased glycerophosphocholine and serine and decreased phosphorylcholine after DCA treatment. There were negative correlations of acetylcarnitine/isobutyryl-carnitine to both heart rate (HR) and mean arterial pressure (MAP). These results suggest that improvements in mitochondrial respiration with DCA produced changes in the cardiac lipid metabolism that favor improved conduction in the heart. DCA may therefore be an effective treatment of fetal cardiac metabolic disturbances in labor that can contribute to impairments of fetal cardiac conduction.

Low-dose oral misoprostol for induction of labour.

BACKGROUND: Misoprostol given orally is a commonly used labour induction method. Our Cochrane Review is restricted to studies with low-dose misoprostol (initially ≤ 50 µg), as higher doses pose unacceptably high risks of uterine hyperstimulation. OBJECTIVES: To assess the efficacy and safety of low-dose oral misoprostol for labour induction in women with a viable fetus in the third trimester of pregnancy. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov,  the WHO International Clinical Trials Registry Platform (14 February 2021) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised trials comparing low-dose oral misoprostol (initial dose ≤ 50 µg) versus placebo, vaginal dinoprostone, vaginal misoprostol, oxytocin, or mechanical methods; or comparing oral misoprostol protocols (one- to two-hourly versus four- to six-hourly; 20 µg to 25 µg versus 50 µg; or 20 µg hourly titrated versus 25 µg two-hourly static). DATA COLLECTION AND ANALYSIS: Using Covidence, two review authors independently screened reports, extracted trial data, and performed quality assessments. Our primary outcomes were vaginal birth within 24 hours, caesarean section, and hyperstimulation with foetal heart changes. MAIN RESULTS: We included 61 trials involving 20,026 women. GRADE assessments ranged from moderate- to very low-certainty evidence, with downgrading decisions based on imprecision, inconsistency, and study limitations. Oral misoprostol versus placebo/no treatment (four trials; 594 women) Oral misoprostol may make little to no difference in the rate of caesarean section (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.59 to 1.11; 4 trials; 594 women; moderate-certainty evidence), while its effect on uterine hyperstimulation with foetal heart rate changes is uncertain (RR 5.15, 95% CI 0.25 to 105.31; 3 trials; 495 women; very low-certainty evidence). Vaginal births within 24 hours was not reported. In all trials, oxytocin could be commenced after 12 to 24 hours and all women had pre-labour ruptured membranes. Oral misoprostol versus vaginal dinoprostone (13 trials; 9676 women) Oral misoprostol probably results in fewer caesarean sections (RR 0.84, 95% CI 0.78 to 0.90; 13 trials, 9676 women; moderate-certainty evidence). Subgroup analysis indicated that 10 µg to 25 µg (RR 0.80, 95% CI 0.74 to 0.87; 9 trials; 8652 women) may differ from 50 µg (RR 1.10, 95% CI 0.91 to 1.34; 4 trials; 1024 women) for caesarean section. Oral misoprostol may decrease vaginal births within 24 hours (RR 0.93, 95% CI 0.87 to 1.00; 10 trials; 8983 women; low-certainty evidence) and hyperstimulation with foetal heart rate changes (RR 0.49, 95% CI 0.40 to 0.59; 11 trials; 9084 women; low-certainty evidence). Oral misoprostol versus vaginal misoprostol (33 trials; 6110 women) Oral use may result in fewer vaginal births within 24 hours (average RR 0.81, 95% CI 0.68 to 0.95; 16 trials, 3451 women; low-certainty evidence), and less hyperstimulation with foetal heart rate changes (RR 0.69, 95% CI 0.53 to 0.92, 25 trials, 4857 women, low-certainty evidence), with subgroup analysis suggesting that 10 µg to 25 µg orally (RR 0.28, 95% CI 0.14 to 0.57; 6 trials, 957 women) may be superior to 50 µg orally (RR 0.82, 95% CI 0.61 to 1.11; 19 trials; 3900 women). Oral misoprostol probably does not increase caesarean sections overall (average RR 1.00, 95% CI 0.86 to 1.16; 32 trials; 5914 women; low-certainty evidence) but likely results in fewer caesareans for foetal distress (RR 0.74, 95% CI 0.55 to 0.99; 24 trials, 4775 women). Oral misoprostol versus intravenous oxytocin (6 trials; 737 women, 200 with ruptured membranes) Misoprostol may make little or no difference to vaginal births within 24 hours (RR 1.12, 95% CI 0.95 to 1.33; 3 trials; 466 women; low-certainty evidence), but probably results in fewer caesarean sections (RR 0.67, 95% CI 0.50 to 0.90; 6 trials; 737 women; moderate-certainty evidence). The effect on hyperstimulation with foetal heart rate changes is uncertain (RR 0.66, 95% CI 0.19 to 2.26; 3 trials, 331 women; very low-certainty evidence). Oral misoprostol versus mechanical methods (6 trials; 2993 women) Six trials compared oral misoprostol to transcervical Foley catheter. Misoprostol may increase vaginal birth within 24 hours (RR 1.32, 95% CI 0.98 to 1.79; 4 trials; 1044 women; low-certainty evidence), and probably reduces the risk of caesarean section (RR 0.84, 95% CI 0.75 to 0.95; 6 trials; 2993 women; moderate-certainty evidence). There may be little or no difference in hyperstimulation with foetal heart rate changes (RR 1.31, 95% CI 0.78 to 2.21; 4 trials; 2828 women; low-certainty evidence). Oral misoprostol one- to two-hourly versus four- to six-hourly (1 trial; 64 women) The evidence on hourly titration was very uncertain due to the low numbers reported. Oral misoprostol 20 µg hourly titrated versus 25 µg two-hourly static (2 trials; 296 women) The difference in regimen may have little or no effect on the rate of vaginal births in 24 hours (RR 0.97, 95% CI 0.80 to 1.16; low-certainty evidence). The evidence is of very low certainty for all other reported outcomes. AUTHORS' CONCLUSIONS: Low-dose oral misoprostol is probably associated with fewer caesarean sections (and therefore more vaginal births) than vaginal dinoprostone, and lower rates of hyperstimulation with foetal heart rate changes. However, time to birth may be increased, as seen by a reduced number of vaginal births within 24 hours. Compared to transcervical Foley catheter, low-dose oral misoprostol is associated with fewer caesarean sections, but equivalent rates of hyperstimulation. Low-dose misoprostol given orally rather than vaginally is probably associated with similar rates of vaginal birth, although rates may be lower within the first 24 hours. However, there is likely less hyperstimulation with foetal heart changes, and fewer caesarean sections performed due to foetal distress. The best available evidence suggests that low-dose oral misoprostol probably has many benefits over other methods for labour induction. This review supports the use of low-dose oral misoprostol for induction of labour, and demonstrates the lower risks of hyperstimulation than when misoprostol is given vaginally. More trials are needed to establish the optimum oral misoprostol regimen, but these findings suggest that a starting dose of 25 µg may offer a good balance of efficacy and safety.

Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): double blind randomised controlled trial.

OBJECTIVE: To determine whether discontinuing oxytocin stimulation in the active phase of induced labour is associated with lower caesarean section rates. DESIGN: International multicentre, double blind, randomised controlled trial. SETTING: Nine hospitals in Denmark and one in the Netherlands between 8 April 2016 and 30 June 2020. PARTICIPANTS: 1200 women stimulated with intravenous oxytocin infusion during the latent phase of induced labour. INTERVENTION: Women were randomly assigned to have their oxytocin stimulation discontinued or continued in the active phase of labour. MAIN OUTCOME MEASURE: Delivery by caesarean section. RESULTS: A total of 607 women were assigned to discontinuation and 593 to continuation of the oxytocin infusion. The rates of caesarean section were 16.6% (n=101) in the discontinued group and 14.2% (n=84) in the continued group (relative risk 1.17, 95% confidence interval 0.90 to 1.53). In 94 parous women with no previous caesarean section, the caesarean section rate was 7.5% (11/147) in the discontinued group and 0.6% (1/155)in the continued group (relative risk 11.6, 1.15 to 88.7). Discontinuation was associated with longer duration of labour (median from randomisation to delivery 282 v 201 min; P<0.001), a reduced risk of hyperstimulation (20/546 (3.7%) v 70/541 (12.9%); P<0.001), and a reduced risk of fetal heart rate abnormalities (153/548 (27.9%) v 219/537 (40.8%); P<0.001) but rates of other adverse maternal and neonatal outcomes were similar between groups. CONCLUSIONS: In a setting where monitoring of the fetal condition and the uterine contractions can be guaranteed, routine discontinuation of oxytocin stimulation may lead to a small increase in caesarean section rate but a significantly reduced risk of uterine hyperstimulation and abnormal fetal heart rate patterns. TRIAL REGISTRATION: ClinicalTrials.gov NCT02553226.

Transient effects of forebrain ischemia on fetal heart rate variability in fetal sheep.

Fetal heart rate variability (FHRV) is a key index of antenatal and intrapartum fetal well-being. FHRV is well established to be mediated by both arms of the autonomic nervous system, but it remains unknown whether higher centers in the forebrain contribute to FHRV. We tested the hypothesis that selective forebrain ischemia would impair the generation of FHRV. Sixteen chronically instrumented near-term fetal sheep were subjected to either forebrain ischemia induced by bilateral carotid occlusion or sham-ischemia for 30 min. Time, frequency, and nonlinear measures of FHRV were assessed during and for seven days after ischemia. Ischemia was associated with profound suppression of electroencephalographic (EEG) power, which remained suppressed throughout the recovery period (P < 0.001). During the first 5 min of ischemia, multiple time and frequency domain measures were increased (all P < 0.05) before returning back to sham levels. A delayed increase in sample entropy was observed during ischemia (P < 0.05). For the first 3 h after ischemia, there was moderate suppression of two measures of FHRV (very-low frequency power and the standard deviation of RR-intervals, both P < 0.05) and increased sample entropy (P < 0.05). Thereafter, all measures of FHRV returned to control levels. In conclusion, profound forebrain ischemia sufficient to lead to severe neural injury had only transient effect on multiple measures of FHRV. These findings suggest that the forebrain makes a limited contribution to FHRV. FHRV therefore primarily originates in the hindbrain and is unlikely to provide meaningful information on forebrain neurodevelopment or metabolism.

Opioid effect on the autonomic nervous system in a fetal sheep model.

PURPOSE: Opioid use during labour can interfere with cardiotocography patterns. Heart rate variability indirectly reflects a fluctuation in the autonomic nervous system and can be monitored through time and spectral analyses. This experimental study aimed to evaluate the impact of nalbuphine administration on the gasometric, cardiovascular, and autonomic nervous system responses in fetal sheep. METHODS: This was an experimental study on chronically instrumented sheep fetuses (surgery at 128 ± 2 days of gestational age, term = 145 days). The model was based on a maternal intravenous bolus injection of nalbuphine, a semisynthetic opioid used as an analgesic during delivery. Fetal gasometric parameters (pH, pO2, pCO2, and lactates), hemodynamic parameters (fetal heart rate and mean arterial pressure), and autonomic nervous system tone (short-term and long-term variation, low-frequency domain, high-frequency domain, and fetal stress index) were recorded. Data obtained at 30-60 min after nalbuphine injection were compared to those recorded at baseline. RESULTS: Eleven experiments were performed. Fetal heart rate, mean arterial pressure, and activities at low and high frequencies were stable after injection. Short-term variation decreased at T30 min (P = 0.02), and long-term variation decreased at T60 min (P = 0.02). Fetal stress index gradually increased and reached significance at T60 min (P = 0.02). Fetal gasometric parameters and lactate levels remained stable. CONCLUSION: Maternal nalbuphine use during labour may lead to fetal heart changes that are caused by the effect of opioid on the autonomic nervous system; these fluctuations do not reflect acidosis.

Reducing neonatal morbidity by discontinuing oxytocin during the active phase of first stage of labor: a multicenter randomized controlled trial STOPOXY.

BACKGROUND: Oxytocin is effective in reducing labor duration, but can be associated with fetal and maternal complications such as neonatal acidosis and post-partum hemorrhage. When comparing discontinuing oxytocin in the active phase with continuing oxytocin infusion, previous studies were underpowered to show a reduction in neonatal morbidity. Thus, we aim at evaluating the impact of discontinuing oxytocin during the active phase of the first stage of labor on the neonatal morbidity rate. METHODS: STOPOXY is a multicenter, randomized, open-label, controlled trial conducted in 20 maternity units in France. The first participant was recruited January 17th 2020. The trial includes women with a live term (≥37 weeks) singleton, in cephalic presentation, receiving oxytocin before 4 cm, after an induced or spontaneous labor. Women aged < 18 years, with a lack of social security coverage, a scarred uterus, a multiple pregnancy, a fetal congenital malformation, a growth retardation <3rd percentile or an abnormal fetal heart rate at randomization are excluded. Women are randomized before 6 cm when oxytocin is either continued or discontinued. Randomization is stratified by center and parity. The primary outcome, neonatal morbidity is assessed using a composite variable defined by an umbilical arterial pH at birth < 7.10 and/or a base excess > 10 mmol/L and/or umbilical arterial lactates> 7 mmol/L and/or a 5 min Apgar score < 7 and/or admission in neonatal intensive care unit. The primary outcome will be compared between the two groups using a chi-square test with a p-value of 0.05. Secondary outcomes include neonatal complications, duration of active phase, mode of delivery, fetal and maternal complications during labor and delivery, including cesarean delivery rate and postpartum hemorrhage, and birth experience. We aim at including 2475 women based on a reduction in neonatal morbidity from 8% in the control group to 5% in the experimental group, with a power of 80% and an alpha risk of 5%. DISCUSSION: Discontinuing oxytocin during the active phase of labor could improve both child health, by reducing moderate to severe neonatal morbidity, and maternal health by reducing cesarean delivery and postpartum hemorrhage rates. TRIAL REGISTRATION: Clinical trials NCT03991091 , registered June 19th, 2019.

Effects of ß-adrenergic stimulation on fetal heart rate, heart rate variability, and T-wave elevation during brief umbilical cord occlusions in fetal sheep.

Circulating catecholamines are critical for fetal adaptation to hypoxia by regulating fetal heart rate (FHR) and promoting myocardial contractility and peripheral vasoconstriction. They have been hypothesized to contribute to changes in FHR variability (FHRV) and T-wave morphology, clinical indexes of fetal well-being during labor. ß-Adrenergic blockade with propranolol does not affect FHRV during labor-like hypoxemia and only attenuated the increase in T-wave height between the episodes of hypoxemia. To further investigate the potential role of catecholamines, we investigated whether pharmacological ß-adrenergic stimulation could increase FHRV and T-wave elevation during intermittent labor-like hypoxemia. Nineteen chronically instrumented fetal sheep at 0.85 of gestation received isoprenaline hydrochloride (n = 7) or saline (control, n = 12), followed by three 1-min complete umbilical cord occlusions (UCOs) separated by 4-min reperfusion periods. Before the UCOs, infusion of isoprenaline increased FHR (P < 0.001), absolute-T/QRS ratio (P < 0.001), and one measure of FHRV [root-mean-square of successive RR interval differences (RMSSD), P < 0.05]. UCOs triggered deep FHR decelerations. During UCOs, isoprenaline was associated with increased FHR (P < 0.001) and absolute-T/QRS ratio (P < 0.05), but no effect on T/QRS ratio was observed when normalized to baseline before UCOs (normalized-T/QRS ratio). Between UCOs, isoprenaline increased FHR (P < 0.001) and absolute-T/QRS ratio (P < 0.05) but did not affect normalized-T/QRS ratio or any measures of FHRV. Arterial pressure was not affected by isoprenaline at any point. Our findings indicate that circulating catecholamines regulate FHR but not FHRV during labor-like hypoxemia and promote T-wave elevation between but not during intermittent fetal hypoxemia.

Clinical Experiences of Intravenous Hydralazine and Labetalol for Acute Treatment of Severe Hypertension in Pregnant Thai Women.

Response to acute treatment of severe hypertension during pregnancy in Asian women was not known. Labor and delivery checklists of Thai women treated with intravenous hydralazine or labetalol for systolic blood pressure (SBP) ≥ 160 or diastolic blood pressure (DBP) ≥ 110 mm Hg from January 2011 to December 2013 were reviewed as parts of an audit. Primary outcome was prompt achievement of SBP 140-150 and DBP 90-100 mm Hg after the first bolus. Secondary outcomes were medication-related undesired effects. The mean ± standard deviation age and prevalence of chronic hypertension in hydralazine (n = 62) versus labetalol (n = 64) groups were 32.5 ± 6 versus 29.9 ± 6.8 years and 50% versus 21.9%, respectively (P < .05). Magnesium sulfate was promptly administered on admission to every woman to prevent seizure. Targeted blood pressure was timely achieved in 41.9% and 67.2% of the hydralazine and labetalol groups, respectively (P < .05). Nonreassuring fetal heart rate occurred in 51.6% and 32.8% of the hydralazine and labetalol groups, respectively (P = .05). The prevalence of cesarean section and Apgar score < 7 were not significantly different (P > .05). Real-life clinical experiences suggested significant advantages of intravenous labetalol over hydralazine in pregnant women with severe hypertension.

Do we need a 200 µg misoprostol vaginal insert? A retrospective cohort study comparing the misoprostol vaginal insert to oral misoprostol.

AIM: The misoprostol vaginal insert (MVI) was reported to be more effective than dinoprostone but discussed critically because of high rates of fetal heart rate changes due to uterine tachysystole. The aim of this study was to investigate the outcome of induced labor using the MVI compared to off-label orally-administered misoprostol (OM). METHODS: Retrospective study including a total of 401 patients with singleton pregnancies in whom labor was induced at ≥36 0/7 gestational weeks with MVI (203) or OM (198). Primary outcomes were the time from induction to delivery, vaginal delivery in 24 h and the mode of delivery and the neonatal outcome. RESULTS: Median time until any delivery was 833 min (645-1278) for MVI and 1076.5 min (698-1686.3) for OM group; 83.7% of the patients in the MVI group gave birth within 24 h versus 63.6% in the OM group. The MVI group needed significantly less pre-delivery oxytocin (29%). Tachysystole (6.4%) and pathological CTG (30.5%) occurred at a significantly higher frequency in the MVI group. The cesarean section rate was significantly higher in the MVI group amounting to 21.7% versus 14.6% in the OM group (P < 0.05). Neonatal outcome did not differ between the groups. CONCLUSION: The MVI might be an option if you are in need for an approved and faster method to induce labor. Although we observed a significantly higher rate of fetal heart rate changes and cesarean sections in the MVI group this did not affect the neonatal outcome.

Tachysystole and risk of cesarean section after labor induction using misoprostol: A cohort study.

OBJECTIVES: To investigate if tachysystole was associated with an increased risk of cesarean section or unfavorable maternal or neonatal outcomes following induction of labor by misoprostol vaginal inserts. STUDY DESIGN: We conducted a retrospective cohort study of 446 women over 37 weeks of gestation admitted for labor induction by misoprostol vaginal inserts between May 2016 and May 2017. Fetal heart rate and uterine activity tracings were assessed for tachysystole, defined as ≥ 6 contractions per 10 min, averaged over a 30-minute window. Univariate analysis was performed by using t-test and Chi-square, comparing demographics, pregnancy characteristics, intrapartum monitoring, mode of delivery, neonatal outcomes (Apgar score < 7 at 5 min, umbilical cord artery pH < 7.10, neonatal intensive care unit admission) and maternal outcomes, with regard to the presence of tachysystole. The association between tachysystole and cesarean section was evaluated after adjusting for potential confounders by a modified Poisson regression model, expressed as an adjusted risk ratio and 95 % confidence intervals. RESULTS: A total of 140 women (31.4 %) presented with tachysystole. The median duration of tachysystole was 2 h 12 min. The rate of cesarean section was 25.0 % (N = 35) among patients with tachysystole and 19.6 % (N = 60) for those without tachysystole. Presence of tachysystole during induction of labor with misoprostol vaginal inserts was not associated with cesarean section (adjusted risk ratio,1.0; 95 % confidence interval, 0.7-1.4). Neonatal and maternal outcomes were similar between mothers who did and did not experience tachysystole. CONCLUSIONS: This study illustrates that tachysystole is not associated with an increased risk of cesarean section after induction of labor by misoprostol vaginal inserts. The impact of excessive uterine activity on the fetal wellbeing defined by the frequency of uterine contraction alone is probably insufficient. Further research on the development of accurate measures of uterine contractility is necessary to better understand its effect on fetal well-being.

Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience.

OBJECTIVES: To describe a single institutional experience managing fetuses with supraventricular tachycardia (SVT) and to identify associations between patient characteristics and fetal and postnatal outcomes. BACKGROUND: Sustained fetal SVT is associated with significant morbidity and mortality if untreated, yet the optimal management strategy remains unclear. METHODS: Retrospective cohort study including fetuses diagnosed with sustained SVT (>50% of the diagnostic echocardiogram) between 1985 and 2018. Fetuses with congenital heart disease were excluded. RESULTS: Sustained SVT was diagnosed in 65 fetuses at a median gestational age of 30 weeks (range, 14-37). Atrioventricular re-entrant tachycardia and atrial flutter were the most common diagnoses, seen in 41 and 16 cases, respectively. Moderate/severe ventricular dysfunction was present in 20 fetuses, and hydrops fetalis was present in 13. Of the 57 fetuses initiated on transplacental drug therapy, 47 received digoxin first-line, yet 39 of 57 (68%) required advanced therapy with sotalol, flecainide, or amiodarone. Rate or rhythm control was achieved in 47 of 57 treated fetuses. There were no cases of intrauterine fetal demise. Later gestational age at fetal diagnosis (odds ratio [OR], 1.1, 95% confidence interval [CI], 1.01-1.2, P = .02) and moderate/severe fetal ventricular dysfunction (OR, 6.1, 95% CI, 1.7-21.6, P = .005) were associated with postnatal SVT. Two postnatal deaths occurred. CONCLUSIONS: Fetuses with structurally normal hearts and sustained SVT can be effectively managed with transplacental drug therapy with minimal risk of intrauterine fetal demise. Treatment requires multiple antiarrhythmic agents in over half of cases. Later gestational age at fetal diagnosis and the presence of depressed fetal ventricular function, but not hydrops, predict postnatal arrhythmia burden.

Alterations of the Short-Term Variation of the Fetal Heart Rate after Antenatal Maternal Betamethasone Administration: Validation with Two Different Computational Algorithms.

INTRODUCTION: Antenatal betamethasone administration in the context of foetal lung maturity enhancement has a transient impact on the short-term variation (STV) of the foetal heart rate. There are currently various algorithms for computing the STV, each one resulting in different STV values. We studied the results of betamethasone administration on the STV using 2 different algorithms in order to investigate whether the effects of steroids on the STV depend on the algorithm used or not. MATERIALS AND METHODS: In the context of a larger, single-centre, prospective, observational study, we gathered CTG traces under and without the influence of steroids in order to study their effect on the STV using 2 different computational algorithms (STV240 and STV16). RESULTS: A total of 285 CTGs were registered and subsequently analysed with both algorithms. When compared to the STV240 and STV16 without or at least 72 h after the first intramuscular corticosteroid administration, a transient increase of both the STV240 and STV16 was documented in the first 24 h, followed by a transient decrease of both the STV240 and STV16 between 24 h and 72 h after the first intramuscular corticosteroid injection. CONCLUSION: Our results confirmed that betamethasone administration has a transient but significant effect on the STV independently of the algorithm used. These observations stress once again the fact that a decreased STV within the first 72 h after maternal bethametasone administration should not be an indication for early delivery.

Adverse side effects and route of administration of opioids in combined spinal-epidural analgesia for labour: a meta-analysis of randomised trials.

BACKGROUND: Studies report an increased risk of maternal and fetal adverse side effects when combined spinal-epidural, rather than standard epidural, analgesia is provided for labour and delivery. Intrathecal opioids used with local anaesthetic in combined spinal-epidural analgesia may be a cause. It is not known whether this is due to the addition of opioid to local anaesthetic in the intrathecal space only or due to concomitant administration into the intrathecal and epidural spaces. METHODS: We searched for randomised trials comparing maternal, obstetrical and neonatal outcomes in parturients having combined spinal-epidural or standard epidural analgesia, and compared subgroups of patients according to the route of administration of opioids in combined spinal-epidural techniques. Studies were evaluated for eligibility and quality. Fixed and random-effects models were used for pooled data analysis and outcomes were compared using relative risk (RR) or mean difference with 95% confidence intervals (CI). RESULTS: We identified 1658 reports and 41 fully published randomised controlled trials. In patients who received combined spinal-epidural techniques, an increased risk of nausea/vomiting (RR 1.31, CI 1.0 to 1.72), pruritus (RR 4.26, CI 2.59 to 7.0) and fetal bradycardia (RR 2.38, CI 1.57 to 3.62) was observed regardless of the route of administration. In contrast, hypotension occurred more frequently after combined intrathecal and epidural opioid (RR 1.54, 1.22 to 1.93; P-value 0.02 for subgroup difference). CONCLUSION: For combined spinal-epidural techniques, the administration of opioids in combination with local anaesthetic, particularly when used in both the intrathecal and epidural space, should be carefully considered.

Effect of maternal betamethasone administration on feto-placental vascular resistance in the mouse†.

Antenatal corticosteroids are often administered to women at risk of preterm birth to accelerate fetal lung development; however, there is evidence that this treatment may adversely affect placental function in some fetuses. Our group has recently demonstrated that wave reflections in the umbilical artery (UA), measured using high-frequency ultrasound, are sensitive to placental vascular abnormalities. In the present study, we used this approach to investigate the effect of maternal administration of betamethasone, a clinically relevant corticosteroid, on the feto-placental vasculature of the mouse. Fetuses were assessed at embryonic day (E)15.5 and E17.5 in C57BL6/J mice. At both gestational ages, the UA diameter, UA blood flow, and the wave reflection coefficient were significantly elevated in the betamethasone-treated mice compared to vehicle-treated controls. These observations support the interpretation that placental vascular resistance dropped with betamethasone treatment to an extent that could not be explained by vasodilation of the UA alone. Consistent with clinical studies, the effect of betamethasone on UA end-diastolic velocity was heterogeneous. Our results suggest that UA wave reflections are more sensitive to acute changes in placental vascular resistance compared with the UA pulsatility index, and this technique may have clinical application to identify a favorable placental vascular response to fetal therapies such as antenatal corticosteroids, where the fetal heart rate is likely to vary.

To study the changes in fetal hemodynamics with intravenous labetalol or nifedipine in acute severe hypertension.

OBJECTIVE: To compare the efficacy of intravenous labetalol or oral nifedipine in treatment of acute maternal hypertension and study the fetal hemodynamic changes using color Doppler ultrasound that follows treatment. STUDY DESIGN: Thirty women with severe preeclampsia having acute hypertension (more than or equal to 160/105 mmHg) were randomized in 2 groups to receive intravenous labetalol or oral nifedipine until blood pressure was lowered to less than or equal to 140/90 mmHg. Doppler vascular indices namely pulsatility index, resistance index, S/D ratio of umbilical (UA) and middle cerebral artery (MCA) were measured baseline at the time of acute severe hypertension and repeated after control of blood pressure, to assess the changes in fetal hemodynamics if any with labetalol or nifedipine. RESULTS: Both nifedipine and labetalol were found to be effective when used for rapid control of blood pressure. Mean age of women in both groups and mean gestational age was statistically comparable. No change in fetal heart rate before and after treatment was observed in both groups. Doppler vascular indices of UA and MCA showed no significant changes as compared to baseline values in both groups. CONCLUSION: The use of labetalol and nifedipine were not related to any significant changes in fetal Doppler, which is reassuring about the safety of these drugs when treating acute severe hypertension in pregnancy. Choice between these two drugs should be based on cost, availability respective contraindications, and clinician's experience.

The fetal electrocardiogram to detect the effects of betamethasone on fetal heart rate variability.

BACKGROUND: Betamethasone is widely used to enhance fetal lung maturation in case of threatened preterm birth. Antenatal corticosteroids are known to reduce fetal heart rate variability (fHRV) in the days following administration. Since decreased fHRV is a marker for fetal distress, this transient decrease of fHRV can cause unnecessary medical intervention. AIM: To describe the effect of betamethasone on fHRV, by applying spectral analysis on non-invasive fetal electrocardiogram (fECG) recordings. STUDY DESIGN: Secondary analysis of a prospective cohort study. SUBJECTS: Women with a singleton pregnancy, at risk for preterm delivery and receiving betamethasone, admitted to the obstetric high care unit in the period from March 2013 until July 2016. OUTCOME MEASURES: The primary outcome measure was fHRV in both time- and frequency-domain. Secondary outcome measures included basal fetal heart rate (fHR) and fHR variance. FHRV parameters were then calculated separately for the quiet and active state. RESULTS: Following 68 inclusions, 22 patients remained with complete series of measurements and sufficient data quality. FHRV parameters and fHR showed a decrease on day 2 compared to day 1, significant for short-term variability and high-frequency power. Similar results were found when analyzing for separate behavioral states. The number of segments in quiet state increased during days 1 and 2. Normalized values showed no difference for all behavioral states. CONCLUSION: FHRV decreases on day 2 after betamethasone administration, while periods of fetal quiescence increase. No changes were found in the normalized values, indicating that the influence of autonomic modulation is minor. Clinical trial registration number NL43294.015.13.