Acupuncture and Acupressure in Labor

Acupuncture and acupressure, 2 modalities of Traditional Chinese Medicine, are based on reducing pain and symptoms of disease through balancing yin and yang. Acupuncture and acupressure have been used in China for reduction of labor pain, labor augmentation, and other intrapartum indications for more than 2 millennia. This article presents a review of the current literature that has addressed the effects of acupuncture and acupressure on intrapartum events. Studies of acupuncture have demonstrated that acupuncture may reduce labor pain, the use of pharmacologic agents, the use of forceps and vacuum-assisted births, and the length of labor. Studies that examined the effect of acupuncture on labor that is induced or augmented for premature rupture of membranes have found that acupuncture may increase the degree of cervical ripening but does not reduce the amount of oxytocin or epidural analgesia administration, nor does it shorten length of induced labor. Acupressure may reduce labor pain and labor duration, but acupressure has not been found to increase cervical ripening or induce labor. There are insufficient studies about acupuncture and acupressure and their effects on labor at this time, and there is need for further research. Areas of uncertainty include efficacy, optimal point selection, best techniques, and length of time for point stimulation.

Medical augmentation of labor and the risk of ADHD in offspring: a population-based study

BACKGROUND AND OBJECTIVE

Oxytocin for labor augmentation is widely used in obstetric care in Western countries. Two recent, smaller studies found opposing results regarding the association between prenatal exposure to oxytocin for labor augmentation and attention-deficit/hyperactivity disorder (ADHD). In Denmark, oxytocin is the medication used for nearly all medical augmentations of labor, and we examined the association between medical augmentation of labor and ADHD in a large cohort study based on national register data.

METHODS

All singletons born after spontaneous onset of labor in Denmark between 2000 and 2008 (N = 546 146) were included in the study. Data from the Danish Medical Birth Registry on medical augmentation of labor (yes/no) were used to identify exposed children. ADHD was defined based on the diagnostic codes of International Classification of Diseases, 10th Revision, for hyperkinetic disorder and information on dispensed ADHD medication. A multivariate proportional hazards regression model was used to test the association.

RESULTS

Among 546 146 deliveries, 26% included medical augmentation of labor, and 0.9% of the children were identified as having ADHD (n = 4617). We found no association between augmentation of labor and ADHD in the offspring (hazard ratio: 1.05 [95% confidence interval: 0.98-1.13]).

CONCLUSIONS

Our study does not support an association between medical augmentation of labor and ADHD in the child.

Novel oxytocin receptor variants in laboring women requiring high doses of oxytocin

BACKGROUND

Although oxytocin commonly is used to augment or induce labor, it is difficult to predict its effectiveness because oxytocin dose requirements vary significantly among women. One possibility is that women requiring high or low doses of oxytocin have variations in the oxytocin receptor gene.

OBJECTIVES

To identify oxytocin receptor gene variants in laboring women with low and high oxytocin dosage requirements.

STUDY DESIGN

Term, nulliparous women requiring oxytocin doses of ≤4 mU/min (low-dose-requiring, n = 83) or ≥20 mU/min (high-dose-requiring, n = 104) for labor augmentation or induction provided consent to a postpartum blood draw as a source of genomic DNA. Targeted-amplicon sequencing (coverage >30×) with MiSeq (Illumina) was performed to discover variants in the coding exons of the oxytocin receptor gene. Baseline relevant clinical history, outcomes, demographics, and oxytocin receptor gene sequence variants and their allele frequencies were compared between low-dose-requiring and high-dose-requiring women. The Scale-Invariant Feature Transform algorithm was used to predict the effect of variants on oxytocin receptor function. The Fisher exact or χ² tests were used for categorical variables, and Student t tests or Wilcoxon rank sum tests were used for continuous variables. A P value < .05 was considered statistically significant.

RESULTS

The high-dose-requiring women had greater rates of obesity and diabetes and were more likely to have undergone labor induction and required prostaglandins. High-dose-requiring women were more likely to undergo cesarean delivery for first-stage arrest and less likely to undergo cesarean delivery for nonreassuring fetal status. Targeted sequencing of the oxytocin receptor gene in the total cohort (n = 187) revealed 30 distinct coding variants: 17 nonsynonymous, 11 synonymous, and 2 small structural variants. One novel variant (A243T) was found in both the low- and high-dose-requiring groups. Three novel variants (Y106H, A240_A249del, and P197delfs*206) resulting in an amino acid substitution, loss of 9 amino acids, and a frameshift stop mutation, respectively, were identified only in low-dose-requiring women. Nine nonsynonymous variants were unique to the high-dose-requiring group. These included 3 known variants (R151C, G221S, and W228C) and 6 novel variants (M133V, R150L, H173R, A248V, G253R, and I266V). Of these, R150L, R151C, and H173R were predicted by Scale-Invariant Feature Transform algorithm to damage oxytocin receptor function. There was no statistically significant association between the numbers of synonymous and nonsynonymous substitutions in the patient groups.

CONCLUSION

Obesity, diabetes, and labor induction were associated with the requirement for high doses of oxytocin. We did not identify significant differences in the prevalence of oxytocin receptor variants between low-dose-requiring and high-dose-requiring women, but novel oxytocin receptor variants were enriched in the high-dose-requiring women. We also found 3 oxytocin receptor variants (2 novel, 1 known) that were predicted to damage oxytocin receptor function and would likely increase an individual's risk for requiring a high oxytocin dose. Further investigation of oxytocin receptor variants and their effects on protein function will inform precision medicine in pregnant women.

Spontaneous Labor Onset and Outcomes in Obese Women at Term

OBJECTIVE

The objective of this study was to compare the rates of spontaneous labor onset and its progression in obese and nonobese women after 37 weeks.

STUDY DESIGN

We performed a secondary analysis of a retrospective cohort of all women who were admitted for delivery at ≥ 37 weeks of gestation at a university-based tertiary care center between 2004 and 2010. The cohort was stratified by weeks of gestation at which the patient presented for delivery. The rates of spontaneous labor, vaginal delivery, and augmentation with oxytocin were compared between obese (body mass index [BMI] ≥ 30) and nonobese (BMI < 30) women.

RESULTS

Obese women had lower rates of spontaneous labor than nonobese women at every gestational week (37 weeks, 6.1 vs. 9.3%, p < 0.001; 38 weeks, 12.8 vs. 19.2%, p < 0.001; 39 weeks 26.0 vs. 37.0%, p < 0.001; 40 weeks, 39.6 vs. 50.2%, p < 0.001; 41 weeks, 30.8 vs. 38.0%, p < 0.012). Among women who presented in spontaneous labor, obesity was associated with higher rates of augmentation with oxytocin and lower rates of vaginal delivery.

CONCLUSION

Obese women at or beyond 37 weeks are less likely to experience spontaneous labor compared with nonobese women. In addition, obese women presenting in spontaneous labor are less likely that nonobese women to have a vaginal delivery at 37 to 40 weeks, even after oxytocin augmentation.

High dose vs. low dose oxytocin for labor augmentation: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare the safety and efficacy between high dose and low dose oxytocin administration for labor augmentation.

METHODS

We searched for the available studies during March 2020 in PubMed, Cochrane Library, Scopus, and ISI Web of science. All randomized clinical trials (RCTs) that assessed safety and efficacy of high dose vs. low dose oxytocin for labor augmentation were considered. The extracted data were entered into RevMan software. Dichotomous and continuous data were pooled as odds ratio (OR) and mean difference (MD) respectively, with the corresponding 95% confidence intervals (CI). Our main outcomes were cesarean delivery rate, spontaneous vaginal delivery rate, uterine hyperstimulation and tachysystole, and labor duration from oxytocin infusion.

RESULTS

Eight RCTs with 3,154 patients were included. High dose oxytocin did not reduce cesarean delivery rate compared to low dose oxytocin (OR=0.76, 95% CI [0.52, 1.10], p=0.15). After solving the reported heterogeneity, high dose oxytocin did not increase the rate of spontaneous vaginal deliveries vs. low dose oxytocin (OR=1.06, 95% CI [0.84, 1.32], p=0.64). Low dose oxytocin was linked to a significant decline in uterine hyperstimulation and tachysystole (p>0.001). A reduction in labor duration was found in high dose oxytocin group over low oxytocin regimen (MD=-1.02 h, 95% CI [-1.77, -0.27], p=0.008).

CONCLUSIONS

We found no advantages for high dose oxytocin over low dose oxytocin in labor augmentation except in reducing labor duration. Low dose oxytocin is safer as it decreases the incidence of uterine hyperstimulation and tachysystole. More trials are needed to confirm our findings.

European Guidelines on Perinatal Care - Oxytocin for induction and augmentation of labor

OF RECOMMENDATIONS1. Oxytocin for induction or augmentation of labor should not be started when there is a previous scar on the body of the uterus (such as previous classical cesarean section, uterine perforation or myomectomy when uterine cavity is reached) or in any other condition where labor or vaginal delivery are contraindicated. (Moderate quality evidence +++-; Strong recommendation).2. Oxytocin should not be started before at least 1 h has elapsed since amniotomy, 6 h since the use of dinoprostone (30 min if vaginal insert) and 4 h since the use of misoprostol (Low quality evidence ++- -; Moderate recommendation).3. Cardiotocography (CTG) should be performed and a normal pattern without tachysystole should be documented for at least 30 min before oxytocin is used. Continuous CTG, with adequate monitoring of both fetal heart rate and uterine contractions, should be maintained for as long as oxytocin is used, and thereafter until delivery (Low ++- - to moderate +++- quality evidence; Strong recommendation).4. For labor induction, at least 1-h should be allowed after amniotomy before oxytocin infusion is started, to evaluate whether adequate uterine contractility has meanwhile ensued. For augmentation of labor, if the membranes are intact and there are conditions for a safe amniotomy, the latter should be considered before oxytocin is started (Very low quality evidence +- --; Weak recommendation).5. Oxytocin should be administered intravenously using the following regimen: 5 IU oxytocin diluted in 500 mL of 0.9% normal saline (NaCl) (each mL contains 10 mIU of oxytocin), in an infusion pump at increasing rates, as shown in Table 1, until a frequency of 3-4 contractions per 10 min is reached, a non-reassuring CTG pattern ensues, or maximum rates are reached (Low quality evidence ++ - -; Strong recommendation). If the frequency of contractions exceeds 5 in 10 min, the infusion rate should be reduced, even if a normal CTG pattern is present. With a non-reassuring CTG pattern, urgent clinical assessment by an obstetrician is indicated, and strong consideration should be given to reducing or stopping the oxytocin infusion. The minimal effective dose of oxytocin should always be used. (Low ++- - to Moderate +++- - quality evidence; Strong recommendation).[Table: see text]6. Use of oxytocin for induction and augmentation of labor should be regularly audited (Low quality evidence ++--; Strong recommendation).

Research summaries for normal birth

In this column, the author summarizes four research studies relevant to normal birth. The studies summarized include a systematic review of trials evaluating the benefits versus harms of routine artificial rupture of the membranes; a study of the effect of continuous female labor support by a minimally trained family member or friend on attachment and early parenting; a systematic review examining the relationship between cesarean surgery and postpartum urinary incontinence; and a randomized controlled trial of warm perineal compresses during the second stage of labor.

The effect of propranolol on cesarean section rate in prolonged labor: a systematic review and meta-analysis

Background

Propranolol is widely recognized as a nonselective β-adrenergic receptor blocker known to enhance uterine activity in both pregnant and non-pregnant women. Prolonged labor and serious concerns about maternal and neonatal health prompted us to investigate medical issues. The aim of this systematic review and meta-analysis was to assess the effect of propranolol on cesarean deliveries during prolonged labor.

Methods

A systematic search was conducted in databases including PubMed, Cochrane CENTRAL, Science Direct, Google Scholar, Embase, and Web of Science from inception to 1 November 2023. We included randomized clinical trials that evaluated maternal and neonatal outcomes in patients receiving intrapartum propranolol during prolonged labor. Unadjusted risk ratios with 95% confidence intervals were calculated using a fixed-effects model. The I2 statistic was used to measure and assess heterogeneity. The primary outcome was cesarean delivery rate, and secondary outcomes included Apgar score, cord arterial pH, neonatal birth weight, neonatal intensive care unit admission, postpartum hemorrhage, and composite maternal and neonatal morbidity.

Results

Of the 704 identified articles, six were included in the meta-analyses. There was a significant difference in cesarean deliveries between propranolol and placebo (RR 0.80, 95% confidence interval 0.59-1.09, P = 0.02). In addition, there was no significant difference between study groups in secondary outcomes.

Conclusion

In this meta-analysis, a notable reduction in cesarean rates was observed when propranolol was given to women in prolonged labor. The results of this meta-analysis show that the use of propranolol safely reduces the need for cesarean deliveries due to labor arrest disorders.

High- vs low-dose oxytocin regimens for labor augmentation: a systematic review and meta-analysis

OBJECTIVE

This study aimed to assess whether high- vs low-dose oxytocin regimens for labor augmentation are associated with differential risk of low Apgar score, neonatal acidosis, and other adverse labor outcomes.

DATA SOURCES

We searched electronic databases (MEDLINE, Embase, the Cochrane Library, CINAHL, Scopus, ClinicalTrials.gov) from inception up to March 2024 using combinations of the following key words: "oxytocin," "oxytocin regimen," "oxytocin protocol," "oxytocin dosage," "active management," "high dose protocol," "low dose protocol," and "augmentation of labor."

STUDY ELIGIBILITY CRITERIA

We included quasi-randomized and randomized controlled trials comparing continuous oxytocin infusion with high-dose regimens (intervention group) vs low-dose regimens (control group) in nulliparous or multiparous patients undergoing labor augmentation. High-dose regimens were defined as a starting oxytocin dose of ≥4 mU/min, increasing in increments of 3 to 7 mU/min every 15 to 40 minutes. Low-dose regimens were defined as a starting oxytocin dose of <4 mU/min, increasing in increments of 1 to 2 mU/min every 15 to 40 minutes (PROSPERO CRD42024500197).

METHODS

The coprimary outcomes were incidence of Apgar score <7 at 5 minutes and umbilical arterial pH <7.00. The secondary outcomes included cesarean delivery and chorioamnionitis. We performed random-effects head-to-head meta-analyses to compare high-dose with low-dose strategies, and reported summary risk ratios with 95% confidence intervals.

RESULTS

Ten randomized and quasi-randomized controlled trials of 5508 pregnancies met the inclusion criteria and were included in this meta-analysis. There was no difference in risk for the coprimary outcomes of Apgar score <7 at 5 minutes (relative risk, 0.94; 95% confidence interval, 0.60-1.46) and umbilical arterial pH <7.00 (relative risk, 0.77; 95% confidence interval, 0.50-1.20). There was also no difference in risk for cesarean delivery (relative risk, 0.83; 95% confidence interval, 0.67-1.02). High-dose oxytocin regimens were associated with significantly lower risk of chorioamnionitis (relative risk, 0.70; 95% confidence interval, 0.57-0.84; number needed to treat=25) and higher risk of tachysystole (relative risk, 1.32; 95% confidence interval, 1.21-1.43; P<.001).

CONCLUSION

When used for labor augmentation, high-dose oxytocin regimens decreased the risk of chorioamnionitis compared with low-dose regimens without affecting the risk of low Apgar scores, neonatal acidosis, or cesarean delivery. El resumen está disponible en Español al final del artículo.

A Case of Postpartum Pulmonary Edema Induced by Oxytocin

Postpartum dyspnea can be due to many causes, such as pulmonary embolism, amniotic fluid embolism, peripartum cardiomyopathy, but less frequently due to acute pulmonary edema. The incidence of acute pulmonary edema during pregnancy and in the postpartum period has been estimated to be around 0.08%. About half of the cases are attributed to tocolytic therapy. Herein, we present a case of a young woman presenting with acute hypoxia after induction of labor with oxytocin and found to have acute pulmonary edema. This case aims to illustrate and add to a growing body of literature regarding oxytocin-induced acute pulmonary edema and highlights the importance of recognizing the rare complication of oxytocin and necessary interventions to avoid complications. Oxytocin-induced pulmonary edema is a relatively uncommon condition, but physicians should have a high index of suspicion to initiate timely intervention and to avoid fetal complications.

High-Dose versus Low-Dose Oxytocin for Labor Augmentation: A Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Although oxytocin administration is recommended for delayed labor progress, there is no consensus over the preferred optimal dose of oxytocin. We aimed to perform a meta-analysis of pregnancy outcomes comparing high-dose versus low-dose oxytocin regimens for augmentation of delayed labor. Methods: PubMed, Embase, and Cochrane databases were systematically searched for studies comparing high-dose with low-dose oxytocin for labor augmentation from inception up to May 2023. The outcomes assessed were cesarean rate, instrumental delivery rate, postpartum hemorrhage, neonatal death, and uterine tachysystole. Subgroup analysis was performed with randomized controlled trials (RCTs) and propensity-matched studies. Statistical analysis was performed using Rstudio. Heterogeneity was assessed with I2 statistics, and a random-risk effect was used if I2 > 50%. Results: Twenty-one studies met inclusion criteria, and eighteen were RCTs. A total of 14.834 patients were included, of whom 7.921 (53.3%) received high-dose and 6.913 (46.6%) received low-dose oxytocin during labor augmentation. No statistical differences were found in cesarean delivery, neonatal mortality, postpartum hemorrhage and vaginal instrumentation rate. However, uterine tachysystole incidence was significantly higher with high-dose oxytocin (95% Cl, 1.30-1.94, p = 0.3; 0.6; I2 = 9%). Conclusions: Labor augmentation with a low-dose oxytocin regimen is effective as with a high-dose regimen, but with significantly less uterine tachysystole events, which can lead to intrauterine and neonatal complications. Our findings suggest that a low-dose regimen may be safe and effective for labor augmentation in medical practice.

Propranolol and Oxytocin-Induced Contractility in Gravid Human Myometrium: An Ex Vivo Laboratory Study

OBJECTIVE

To determine the effect of propranolol on myometrial contractions induced by low dose and high dose oxytocin.

DESIGN

Prospective ex vivo laboratory study.

SETTING

Mount Sinai Hospital, Toronto.

POPULATION

Full-term parturients who underwent elective caesarean deliveries (CD).

METHODS

Two models were developed in the organ bath chamber using myometrial samples obtained during CDs: (i) Labor induction-augmentation model with low-dose oxytocin consisting of 3 groups with the administration of propranolol before and during simulated labor, and a control group. (ii) Postpartum haemorrhage (PPH) model with high-dose oxytocin consisting of 4 groups with the administration of propranolol during and/or after augmented labor (desensitised with oxytocin), and a control group.

MAIN OUTCOME MEASURES

Myometrial contractility was recorded using force transducers.

RESULTS

In the labor induction-augmentation model, propranolol pre-treatment produced a higher area under the curve (AUC) of myometrial contractility induced by low-dose oxytocin (relative percentage difference [diff]: 20.4%; 95% CI [1.4%, 43.2%], p = 0.035) compared to control; however, no difference was observed when propranolol was given after the initiation of labor. In the oxytocin-desensitised PPH model, the AUC of myometrial contractility induced by high-dose oxytocin was improved with propranolol pre-treatment (diff 25.4% [0.2%, 56.8%], p = 0.048), co-treatment (diff 26.7% [3.7%, 54.7%], p = 0.02), and both pre- and co-treatment (diff 28.4% [7.0%, 54.1%], p = 0.007) when compared to the control group.

CONCLUSIONS

Our ex vivo study suggests that propranolol can augment uterine activity by approximately 20%-25% when administered early during labor induction and augmentation. Clinical studies are warranted to determine the relevance of these findings in vivo.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03434444; https://clinicaltrials.gov/.

Exogenous oxytocin administration during labor and autism spectrum disorder

BACKGROUND

Oxytocin is a neuropeptide hormone that plays a key role in social behavior, stress regulation, and mental health. Synthetic oxytocin administration is a common obstetrical practice, and importantly, previous research has suggested that intrapartum exposure may increase the risk of neurodevelopmental disorders, such as autism spectrum disorder.

OBJECTIVE

This study aimed to examine the association between synthetic oxytocin exposure during labor and autism spectrum disorder diagnosis in the child.

STUDY DESIGN

This population-based retrospective cohort study compared 2 cohorts of children: (1) all children born in British Columbia, Canada between April 1, 2000 and December 31, 2014 (n=414,336 births), and (2) all children delivered at Soroka University Medical Center in Be'er-Sheva, Israel between January 1, 2011 and December 31, 2019 (n=82,892 births). Nine different exposure groups were examined. Cox proportional hazards models were used to estimate crude and adjusted hazard ratios of autism spectrum disorder in both cohorts on the basis of induction and/or augmentation exposure status. To further control for confounding by indication, we conducted sensitivity analyses among a cohort of healthy, uncomplicated deliveries and among a group that was induced only for postdates. In addition, we stratified our analyses by infant sex to assess for potential sex differences.

RESULTS

In the British Columbia cohort, 170,013 of 414,336 deliveries (41.0%) were not induced or augmented, 107,543 (26.0%) were exposed to oxytocin, and 136,780 (33.0%) were induced or augmented but not exposed to oxytocin. In the Israel cohort, 51,790 of 82,892 deliveries (62.5%) were not induced or augmented, 28,852 (34.8%) were exposed to oxytocin, and 2250 (2.7%) were induced or augmented but not exposed to oxytocin. On adjusting for covariates in the main analysis, significant associations were observed in the Israel cohort, including adjusted hazard ratios of 1.51 (95% confidence interval, 1.20-1.90) for oxytocin-augmented births and 2.18 (95% confidence interval, 1.32-3.57) for those induced by means other than oxytocin and not augmented. However, oxytocin induction was not significantly associated with autism spectrum disorder in the Israel cohort. In the Canadian cohort, there were no statistically significant adjusted hazard ratios. Further, no significant sex differences were observed in the fully adjusted models.

CONCLUSION

This study supports that induction of labor through oxytocin administration does not increase the risk of autism spectrum disorder in the child. Our international comparison of 2 countries with differences in clinical practice regarding oxytocin administration for induction and/or augmentation suggests that previous studies reporting a significant association were likely confounded by the underlying indication for the induction.

Safety and Efficacy of Oral Mifepristone for Cervical Ripening and Induction of Labor

Background Labor induction, a common practice to prevent maternal and fetal complications from prolonged labor, involves stimulating contractions before they begin naturally. This can be achieved through medications, mechanical methods, or surgical interventions. Cervical ripening is crucial for successful delivery. When the cervix is not sufficiently ripe, drugs are often used to augment this process chemically. Objective To evaluate the safety and efficacy of mifepristone for cervical ripening and induction of labor. Method A sample size of 200 was used in this single-blind randomized control trial. Primarily, pregnant women with term pregnancies, Bishop scores <6, and cephalic fetal presentation were included in the study. The study population was randomly divided into test and control groups. The test group (n=100) was administered 200 mg of mifepristone orally, while the control group (n=100) received a placebo. The Bishop score was reassessed 24 hours after mifepristone administration. Patients were taken for labor induction if their Bishop score was >6. For individuals with a Bishop score of <6, 1 mg of dinoprostone gel was administered intracervically once every six hours. Safety and efficacy were assessed by analyzing several parameters associated with labor progression, maternal outcomes, and fetal outcomes. Results The mean age of patients in the test group was 26±4.5 years, while in the control group, it was 26±5 years. The induction-to-delivery interval was notably shorter in the test group (18.8±2.3 hours) than in the control group (19.24±1.8 hours, p<0.0001). After the administration of 200 mg mifepristone, the mean Bishop score in the test group was 5.74±0.8, compared to 5.13±0.76 in the control group. The increase in the Bishop score after mifepristone treatment was significantly higher in the test group than in the control group (p-value=0.013). In the study, 73 (73%) patients in the test group had a normal vaginal delivery (NVD), whereas NVD accounted for 64 (64%) patients in the control group. Instrumental deliveries were less frequent in the test group, accounting for 14 (14%) patients, compared to 16 (16%) patients in the control group. The frequency of lower segment cesarean section (LSCS) was also lower in the mifepristone-treated group at 13 (13%) compared to the control group at 20 (20%). Fetal distress in five (38%) patients and non-progression of labor in 11 (55%) patients were the most frequent indications for LSCS in the test and control groups, respectively. There was no significant difference in neonatal outcomes between the test and control groups. Meconium-stained liquor was the most frequent complication in both the test group (10, 10%) and the control group (5, or 5%). Conclusion Administration of mifepristone effectively increased the Bishop scores and reduced the induction-to-delivery interval compared to controls, highlighting its potential as a cervical ripening agent.