Epidural analgesia and neonatal short-term outcomes during routine childbirth: a 10-year retrospective analysis from the national birth registry of Austria

BACKGROUND

Epidural analgesia (EA) is well-accepted for pain relief during labor. Still, the impact on neonatal short-term outcome is under continuous debate. This study assessed the outcome of neonates in deliveries with and without EA in a nationwide cohort.

METHODS

We analyzed the National Birth Registry of Austria between 2008 and 2017 of primiparous women with vaginal birth of singleton pregnancies. Neonatal short-term morbidity was assessed by arterial cord pH and base excess (BE). Secondary outcomes were admission to a neonatological intensive care unit, APGAR scores, and perinatal mortality. Propensity score-adjusted regression models were used to investigate the association of EA with short-term neonatal outcome.

RESULTS

Of 247,536 included deliveries, 52 153 received EA (21%). Differences in pH (7.24 vs. 7.25; 97.5% CI -0.0066 to -0.0047) and BE (-5.89±3.2 vs. -6.15±3.2 mmol/L; 97.5% CI 0.32 to 0.40) with EA could be shown. APGAR score at five minutes <7 was more frequent with EA (OR 1.45; 95% CI: 1.29 to 1.63). Admission to a neonatological intensive care unit occurred more often with EA (4.7% vs. 3.4%) with an OR for EA of 1.2 (95% CI: 1.14 to 1.26). EA was not associated with perinatal mortality (OR 1.33; 95% CI: 0.79 to 2.25).

CONCLUSIONS

EA showed no clinically relevant association with neonatal short-term outcome. Higher rates of NICU admission and APGAR score after five minutes <7 were observed with EA. The overall use of EA in Austria is low, and an investigation of causes may be indicated.

Epidural analgesia and emergency delivery: exploring causal misconceptions

Linked article: This Correspondence comments on Tabernée Heijtmeijer et al. Click here to view the article.

The Effects of Labor Epidural Analgesia on Maternal and Fetal Hemodynamics: A Prospective Observation Study

PURPOSE

This study aimed to investigate the effect of epidural analgesia (EA) on maternal and fetal hemodynamics.

METHODS

A prospective single-center observational study was conducted from March 2022 to May 2022 on low-risk singleton pregnancies who received prenatal care at 37-40 weeks and delivered at our hospital. Pre- and post-EA, maternal and fetal hemodynamics, including maternal parameters of mean arterial pressure (MAP), heart rate (HR) and saturation of pulse oxygen (SPO2 ), fetal heart rate (FHR), Doppler flow parameters of umbilical artery (UA), middle cerebral artery (MCA), and uterine artery (UtA) during labor were measured before epidural insertion (T0), and 15 (T1), 30 (T2), and 60 (T3) minutes after. Computational analysis was performed using a one-way ANOVA test.

RESULTS

In total, 100 singleton pregnant women were enrolled. After EA, maternal MAP, HR, and SPO2 were significantly lower than baseline values at all times except for HR in T3 and remained lower for the study's duration (P < .05). As for FHR, there was no significant difference between pre- and post-epidural. The mean UtA-PI (pulsatility index), UA-PI, UA-RI (resistance index), and UA-S/D (systolic/diastolic ratio) were not significantly modified after EA. Nevertheless, MCA-PI and RI significantly decreased in 15 minutes after initiating EA compared with T0 values (P < .05), and MCA-PSV (resistance index and peak systolic velocities) was significantly increased compared with T0 at all times (P < .05). The above changes were all within the normal range.

CONCLUSION

Although maternal MAP, HR, and SPO2 significantly decreased after EA, fetal hemodynamics remained relatively stable.

Epidural analgesia in labor: A narrative review

Lumbar epidural is the most effective form of pain relief in labor with around 30% of laboring women in the UK and 60% in the USA receiving epidural analgesia. Associations of epidural on maternal, obstetric, and neonatal outcomes have been the subject of intense study, though a number of uncertainties persist. The present narrative review explores important areas of research surrounding epidural analgesia in obstetric patients including methods of initiation and administration, choice of local anesthetic solution, and the addition of adjuvants. Key meta-analyses exploring associations of epidural analgesia on maternal and neonatal outcomes are identified and summarized.

The influence of labor epidural analgesia on maternal, uteroplacental and fetoplacental hemodynamics in normotensive parturients: a prospective observational study

BACKGROUND

Epidural analgesia provides sufficient analgesia during labor but can cause hypotension despite various prophylactic measures. We studied its effects on pre-placental, fetoplacental, and fetal hemodynamics using Doppler ultrasound. The primary endpoint was the pulsatility index of the umbilical artery at 30 min after establishing epidural analgesia. Secondary endpoints included maternal blood pressures and neonatal outcome data.

METHODS

We included healthy parturients at a cervical dilation ≥2 cm, with or without a request for epidural analgesia (n=32 per group). Ultrasound studies of the uterine arteries, umbilical artery and fetal middle cerebral artery were performed before insertion of the epidural catheter, and 30, 60 and 90 min after; the same time-points were assessed in the non-epidural control group. Maternal blood pressure was measured by a continuous non-invasive arterial pressure monitor.

RESULTS

Ultrasound studies detected no significant differences in pulsatility indices over time in any blood vessel. In contrast to the control group, maternal blood pressures were significantly lower for all measures after the onset of analgesia compared with baseline values (mean systolic pressure decreased from 132.7 ± 15.9 mmHg to 123.1 ± 14.4 mmHg at 30 min, P=0.003). The mean pH value of the umbilical arterial blood was 7.29 (±0.06) in the epidural group versus 7.31 (±0.08) in the control group (P=0.33). The median Apgar score at 5 min was 10 in both groups.

CONCLUSIONS

Pre-placental, fetoplacental and fetal hemodynamics remained stable despite a statistically significant decrease in maternal blood pressure in laboring parturients receiving epidural analgesia.

Efficacy and Safety of Different Norepinephrine Regimens for Prevention of Spinal Hypotension in Cesarean Section: A Randomized Trial

The aim of this paper is to evaluate the efficacy and safety of three different norepinephrine dosing regimens for preventing spinal hypotension in cesarean section. In this randomized double-blinded controlled study, 120 parturients scheduled for elective section delivery under spinal anesthesia were assigned to 1 of 4 groups. In the control group, patients received saline infusion. In three norepinephrine groups, the infusion dosage regimens were 5, 10, and 15 μg/kg/h, respectively. Hypotension was treated with a rescue bolus of 10 μg norepinephrine. The study protocol was continued until the end of surgery. The primary outcome was the proportion of participants that underwent hypotension. The proportion of hypotension participants was significantly reduced in the norepinephrine groups (37.9%, 20%, and 25%, respectively) compared to that in the control group (86.7%). However, the highest dose of norepinephrine (15 μg/kg/h) resulted in more hypertension episodes. In addition, blood pressure was better maintained in the norepinephrine 5 μg/kg/h and 10 μg/kg/h groups than in the control group and 15 μg/kg/h group. No significant differences in other hemodynamic variables, adverse effects, maternal and neonatal blood gases, or Apgar scores were observed among the groups. In summary, for patients who undergo cesarean delivery under spinal anesthesia, infusion of 5–10 μg/kg/h norepinephrine was effective to reduce hypotension incidence without significant adverse effects on maternal and neonatal outcomes. Clinical Trial Registration Number is ChiCTR-INR-16009452.

The optimal concentration of bupivacaine and levobupivacaine for labor pain management using patient-controlled epidural analgesia: a double-blind, randomized controlled trial

BACKGROUND

The study aim was to evaluate the efficacy and safety of different low concentrations of two local anesthetics for labor analgesia using patient-controlled epidural analgesia.

METHODS

A double-blind, randomized controlled trial recruiting healthy nulliparous women was conducted from 2014 to 2017. Epidural analgesia was provided using local anesthetic and fentanyl. Patients were allocated to six groups, according to the concentration of bupivacaine or levobupivacaine (0.0625%, 0.1%, 0.125%). Analgesic efficacy, vital parameters, and side effects were evaluated at different time points. Satisfaction was evaluated using verbal and written scores. The primary outcome was the total dose of local anesthetic used.

RESULTS

Two-hundred-and-thirty-seven cases were analyzed. The total dose of local anesthetic was significantly lower in the two lower concentration groups (P <0.0001). The rate of cesarean section was lower in 0.1% bupivacaine versus 0.1% levobupivacaine (P=0.005), 0.125% levobupivacaine (P=0.049) and 0.125% bupivacaine (P=0.002) groups. Pain breakthrough, patient-controlled and rescue boluses were significantly different between groups (P=0.03, P=0.003 and P <0.0001 respectively). The rate of motor block increased with higher concentrations (P=0.033), but the incidence of other maternal and fetal side effects was not significantly different. Satisfaction with labor analgesia did not differ across groups. Satisfaction score 72 hours after delivery was significantly lower than that two hours after delivery (P <0.0001).

CONCLUSIONS

Higher local anesthetic concentration resulted in higher total doses infused and greater motor block. Labor analgesia was less effective when the lowest concentrations were used, but patient satisfaction was unaffected.

Maternal microcirculation and sidestream dark field imaging: a prospective assessment of the association between labour pain and analgesia on the microcirculation of pregnant women

BACKGROUND

Pregnancy places significant demands on the cardiovascular system leading to measurable changes in the macrocirculation and potentially the microcirculation. During labour, both uterine contractions and labour pain can further impact cardiovascular status. The objective of this observational study was to compare sublingual microcirculation in labouring parturients before and after epidural analgesia.

METHODS

Healthy pregnant, labouring women requesting epidural analgesia were approached to participate. Participants with cardiovascular disease, diabetes, obesity, smoking or caffeine intake were excluded. The sidestream dark field device was applied to the sublingual mucosa obtaining images of at least 20 seconds in 5 visual fields before and after epidural analgesia. Video clips were analyzed randomly and blindly. The primary outcome was mean microvascular flow index (MFI).

RESULTS

Twelve participants completed this study. The results demonstrate no statistically significant difference in the MFI during labour pain (2.9±0.1) compared to after epidural analgesia (3.0±0.04, p = 0.31). Furthermore, there were no statistically significant differences in any secondary outcomes.

CONCLUSION

Our findings indicate that epidural analgesia may not impact sublingual microcirculation in labouring women. This agrees with literature supporting epidural analgesia as a safe, appropriate method of pain relief during labour with limited impact on peripheral macro or microcirculation.

Maternal and foetal outcome after epidural labour analgesia in high-risk pregnancies

BACKGROUND AND AIMS

Low concentration local anaesthetic improves uteroplacental blood flow in antenatal period and during labour in preeclampsia. We compared neonatal outcome after epidural ropivacaine plus fentanyl with intramuscular tramadol analgesia during labour in high-risk parturients with intrauterine growth restriction of mixed aetiology.

METHODS

Forty-eight parturients with sonographic evidence of foetal weight <1.5 kg were enrolled in this non-randomized, double-blinded prospective study. The epidural (E) group received 0.15% ropivacaine 10 ml with 30 μg fentanyl incremental bolus followed by 7-15 ml 0.1% ropivacaine with 2 μg/ml fentanyl in continuous infusion titrated until visual analogue scale was three. Tramadol (T) group received intramuscular tramadol 1 mg/kg as bolus as well as maintenance 4-6 hourly. Neonatal outcomes were measured with cord blood base deficit, pH, ionised calcium, sugar and Apgar score after delivery. Maternal satisfaction was also assessed by four point subjective score.

RESULTS

Baseline maternal demographics and neonatal birth weight were comparable. Neonatal cord blood pH, base deficit, sugar, and ionised calcium levels were significantly improved in the epidural group in comparison to the tramadol group. Maternal satisfaction (P = 0.0001) regarding labour analgesia in epidural group was expressed as excellent by 48%, good by 52% whereas it was fair in 75% and poor in 25% in the tramadol group. Better haemodynamic and pain scores were reported in the epidural group.

CONCLUSION

Epidural labour analgesia with low concentration local anaesthetic is associated with less neonatal cord blood acidaemia, better sugar and ionised calcium levels. The analgesic efficacy and maternal satisfaction are also better with epidural labour analgesia.

The effects of spinal anaesthesia for elective caesarean section on uterine and umbilical arterial pulsatility indexes in normotensive and chronic hypertensive pregnant women: a prospective, longitudinal study

BACKGROUND

Despite the known effects of neuraxial blockade on major vessel function and the rapid decrease in uterine vascular impedance, it is unclear how the blockade affects the utero-placental circulation in the near-term. We hypothesize that among women with chronic hypertension, a loss of sympathetic tonus consequent to spinal block may cause significant changes in the utero-placental haemodynamics than the changes typical in normal pregnant women. Therefore, the main study objective was to analyse the effect of spinal anaesthesia for caesarean section on uterine and umbilical arterial impedance in pregnant women at term diagnosed with stage-1 chronic hypertension.

METHODS

A prospective, longitudinal study was performed in singleton pregnant women (203 low-risk and 33 with hypertension) scheduled to undergo elective caesarean section. The mean arterial blood pressure and pulsatility indexes for the uterine and umbilical arteries were recorded before and after spinal anaesthesia was performed using 8-9 mg hyperbaric bupivacaine (5 mg/mL) and 2-2.5 μg sufentanil (5 μg/mL). Multiple linear regression models with errors capable of correlation or with unequal variances were fitted using the generalized least squares.

RESULTS

In normotensive women, the mean arterial blood pressure decreased after administering spinal anaesthesia (p < 0.05). The pulsatility index of the uterine and umbilical arteries did not change after spinal anaesthesia. In the hypertensive women, the mean arterial blood pressure (p < 0.05) and uterine artery pulsatility index (p < 0.05) decreased. In both groups, the umbilical artery pulsatility index did not change after spinal anaesthesia.

CONCLUSIONS

In stage-1 chronic hypertensive pregnant women at term, spinal anaesthesia for caesarean section reduces uterine artery impedance but not umbilical artery impedance.

Optimising sample collection for placental research

Biobanks provide an important repository of samples for research purposes. However, for those samples to reflect the in vivo state, and for experimental reliability and reproducibility, careful attention to collection, processing and storage is essential. This is particularly true for the placenta, which is potentially subjected to stressful conditions during delivery, and sample collection may be delayed owing to routine postpartum inspection by clinical staff. In addition, standardisation of the collection procedure enables samples to be shared among research groups, allowing larger datasets to be established. Here, we provide an evidence-based and experts' review of the factors surrounding collection that may influence data obtained from the human placenta. We outline particular requirements for specific techniques, and propose a protocol for optimal sample collection. We recognise that the relevance of these factors, and of the sample types collected to a particular study will depend on the research questions being addressed. We therefore anticipate that researchers will select from the protocol to meet their needs and resources available. Wherever possible, we encourage researchers to extend their collection to include additional samples that can be shared on an international collaborative basis, with appropriate informed consent, to raise the quality, as well as quantity, of placental research.

Triplex Doppler evaluation of uterine arteries in cyclic and pregnant domestic cats

The aims were to determine resistance index (RI) and pulsatility index (PI) in the uterine arteries of cyclic and pregnant domestic cats comparing the left and right uterine horns, as well as the majority or minority uterine horns, based on fetus number per horn; to determine the presence or absence of an early diastolic notch (EDN) in the uterine artery of pregnant queens. Ten domestic cats were followed during one cycle and one pregnancy until 63rd days after mating. The estrous cycle length was 16 ± 9.57 days. The uterine horn with the highest number of fetuses (majority uterine horn - MUH) presented 2.0 ± 1.0 fetus and the lower (minority uterine horn - miUH) presentes 0.78 ± 0.67 fetus. There were no differences in indexes between uterine arteries during the cycles and pregnancies. The RI and PI of MUH were lower than miUH (P<0.05). Uterine artery of the MUH presented lower indexes than miUH during the acceptance period (P<0.05). On D14 of pregnancy, uterine artery presented reductions in both indexes for the miUH. On D56, the PI was reduced in the miUH. The indexes depended on the week of pregnancy. EDN was present on the uterine arteries of all cats until D35, but disappeared by D49. The blood flow varied according to the category of horn.