Examination of the Pharmacology of Oxytocin and Clinical Guidelines for Use in Labor

Is Oxytocin Administration During Childbirth Associated With Increased Risk for Postpartum Posttraumatic Stress Symptoms?: A Preliminary Investigation

INTRODUCTION

Synthetic oxytocin is one of the most regularly administered medications to facilitate labor induction and augmentation. The present study examined the associations between oxytocin administration during childbirth and postpartum posttraumatic stress symptoms (PTSS).

MATERIALS AND METHODS

In a multicenter longitudinal study, women completed questionnaires during pregnancy and at 2 months postpartum ( N = 386). PTSS were assessed with the Impact of Event Scale. Logistic regression was used to examine the difference in PTSS at Time 2 between women who received oxytocin and women who did not.

RESULTS

In comparison with women who did not receive oxytocin, women who received oxytocin induction were 3.20 times as likely to report substantial PTSS ( P = .036, 95% confidence interval: 1.08-9.52), and women who received oxytocin augmentation were 3.29 times as likely to report substantial PTSS ( P = .036, 95% confidence interval: 1.08-10.03), after controlling for being primiparous, preeclampsia, prior mental health diagnosis, mode of birth, postpartum hemorrhage, and satisfaction with staff.

DISCUSSION

Oxytocin administration was associated with a 3-fold increased risk of PTSS. The findings may reflect biological and psychological mechanisms related to postpartum mental health and call for future research to establish the causation of this relationship.

Mechanical Birth Injuries: A Comprehensive Five-Year Analysis From a Tertiary Care Hospital

BACKGROUND

Birth injury or birth trauma refers to physical damage or trauma that occurs to a newborn during the birthing process. To ensure continuous care and improve neonatal outcomes, it is crucial to know the incidence, types, relation to the mode of delivery, and their management.

METHODOLOGY

This is a retrospective cohort study conducted at Aga Khan University Hospital, Pakistan from January 2018 to December 2022. Neonates aged from birth to 28 days of life identified to sustain any form of mechanical birth injuries were included. Data analysis was done using SPSS version 19 (IBM Corp., Armonk, NY).

RESULTS

In the last five years, 51 mechanical birth injuries were found among 27,854 deliveries, which accounts for one in 546 births with an overall prevalence of 0.001%. Out of the total mechanical birth injuries, 12 (23.5%) were noticed in spontaneous vaginal delivery, six (11.8%) had instrumental delivery, and 33 (64.7%) patients had cesarean sections. More birth injuries were noticed in emergency cesarean section as compared to vaginal deliveries. There were 40 babies (78%) with soft tissue injuries, seven (14%) had musculoskeletal injuries/fractures, two (4%) babies had intracranial bleeding, and two (4%) had fractures along with intracranial bleeding. There was no mortality reported among these neonates.

CONCLUSION

The overall rate of birth injuries was significantly lower as compared to other low and middle-income countries. Most of the birth injuries were soft tissue injuries in patients with cesarean sections. The rate of birth injury did not show any association with the time of delivery. More frequent obstetric emergency drills would improve complications associated with shoulder dystocia.

Understanding the effects of oxytocin receptor variants on OXT-OXT receptor binding: A mathematical model

Approximately half of U.S. women giving birth annually receive Pitocin, the synthetic form of oxytocin (OXT), yet its effective dose can vary significantly. This variability presents safety concerns due to unpredictable responses, which may lead to adverse outcomes for both mother and baby. To address the need for improved dosing, we developed a data-driven mathematical model to predict OXT receptor (OXTR) binding. Our study focuses on five prevalent OXTR variants (V45L, P108A, L206V, V281M, and E339K) and their impact on OXT-OXTR binding dynamics in two distinct cell types: human embryonic kidney cells (HEK293T), commonly used in experimental systems, and human myometrial smooth muscle cells, containing endogenous OXTR. We parameterized the model with cell-specific OXTR surface localization measurements. To strengthen the robustness of our study, we conducted a comprehensive meta-analysis of OXT- OXTR binding, enabling parameterization of our model with cell-specific OXT-OXTR binding kinetics (myometrial OXT-OXTR K d = 1.6 nM, kon = 6.8 × 10 5 M -1 min -1 , and koff = 0.0011 min -1 ). Our meta-analysis revealed significant homogeneity in OXT-OXTR affinity across experiments and species with a K d = 0.52 - 9.32 nM and mean K d = 1.48 ± 0.36 nM. Our model achieves several valuable insights into designing dosage strategies. First, we predicted that the OXTR complex reaches maximum occupancy at 10 nM OXT in myometrial cells and at 1 µM in HEK293T cells. This information is pivotal for guiding experimental design and data interpretation when working with these distinct cell types, emphasizing the need to consider effects for specific cell types when choosing OXTR-transfected cell lines. Second, our model recapitulated the significant effects of genetic variants for both experimental and physiologically relevant systems, with V281M and E339K substantially compromising OXT-OXTR binding capacity. These findings suggest the need for personalized oxytocin dosing based on individual genetic profiles to enhance therapeutic efficacy and reduce risks, especially in the context of labor and delivery. Third, we demonstrated the potential for rescuing the attenuated cell response observed in V281M and E339K variants by increasing the OXT dosage at specific, early time points. Cellular responses to OXT, including Ca 2+ release, manifest within minutes. Our model indicates that providing V281M- and E339K-expressing cells with doubled OXT dose during the initial minute of binding can elevate OXT-OXTR complex formation to levels comparable to wild-type OXTR. In summary, our study provides a computational framework for precision oxytocin dosing strategies, paving the way for personalized medicine.

Oxytocin augmentation and neurotransmitters in prolonged delivery: An experimental appraisal

The uterus is a highly innervated organ, and during labor, this innervation is at its highest level. Oxytocinergic fibers play an important role in labor and delivery and, in particular, the Lower Uterine Segment, cervix, and fundus are all controlled by motor neurofibers. Oxytocin is a neurohormone that acts on receptors located on the membrane of the smooth cells of the myometrium. During the stages of labor and delivery, its binding causes myofibers to contract, which enables the fundus of the uterus to act as a mediator. The aim of this study was to investigate the presence of oxytocinergic fibers in prolonged and non-prolonged dystocic delivery in a cohort of 90 patients, evaluated during the first and second stages of labor. Myometrial tissue samples were collected and evaluated by electron microscopy, in order to quantify differences in neurofibers concentrations between the investigated and control cohorts of patients. The authors of this experiment showed that the concentration of oxytocinergic fibers differs between non-prolonged and prolonged dystocic delivery. In particular, in prolonged dystocic delivery, compared to non-prolonged dystocic delivery, there is a lower amount of oxytocin fiber. The increase in oxytocin appeared to be ineffective in patients who experienced prolonged dystocic delivery, since the dystocic labor ended as a result of the altered presence of oxytocinergic fibers detected in this group of patients.

Methods for the induction of labor: efficacy and safety

This review assessed the efficacy and safety of pharmacologic agents (prostaglandins, oxytocin, mifepristone, hyaluronidase, and nitric oxide donors) and mechanical methods (single- and double-balloon catheters, laminaria, membrane stripping, and amniotomy) and those generally considered under the rubric of complementary medicine (castor oil, nipple stimulation, sexual intercourse, herbal medicine, and acupuncture). A substantial body of published reports, including 2 large network meta-analyses, support the safety and efficacy of misoprostol (PGE1) when used for cervical ripening and labor induction. Misoprostol administered vaginally at doses of 50 μg has the highest probability of achieving vaginal delivery within 24 hours. Regardless of dosing, route, and schedule of administration, when used for cervical ripening and labor induction, prostaglandin E2 seems to have similar efficacy in decreasing cesarean delivery rates. Globally, although oxytocin represents the most widely used pharmacologic agent for labor induction, its effectiveness is highly dependent on parity and cervical status. Oxytocin is more effective than expectant management in inducing labor, and the efficacy of oxytocin is enhanced when combined with amniotomy. However, prostaglandins administered vaginally or intracervically are more effective in inducing labor than oxytocin. A single 200-mg oral tablet of mifepristone seems to represent the lowest effective dose for cervical ripening. The bulk of the literature assessing relaxin suggests this agent has limited benefit when used for this indication. Although intracervical injection of hyaluronidase may cause cervical ripening, the need for intracervical administration has limited the use of this agent. Concerning the vaginal administration of nitric oxide donors, including isosorbide mononitrate, isosorbide, nitroglycerin, and sodium nitroprusside, the higher incidence of side effects with these agents has limited their use. A synthetic hygroscopic cervical dilator has been found to be effective for preinduction cervical ripening. Although a pharmacologic agent may be administered after the use of the synthetic hygroscopic dilator, in an attempt to reduce the interval to vaginal delivery, concomitant use of mechanical and pharmacologic methods is being explored. Combining the use of a single-balloon catheter with dinoprostone, misoprostol, or oxytocin enhances the efficacy of these pharmacologic agents in cervical ripening and labor induction. The efficacy of single- and double-balloon catheters in cervical ripening and labor induction seems similar. To date, the combination of misoprostol with an intracervical catheter seems to be the best approach when balancing delivery times with safety. Although complementary methods are occasionally used by patients, given the lack of data documenting their efficacy and safety, these methods are rarely used in hospital settings.

"Blind men and an elephant": The need for animals in research, drug safety studies, and understanding civilizational diseases

Animal-based research and drug safety studies are essential to understanding the mysteries of nature and the long-term survival of humans. Due to the rapid increase in the global human population, conflict- and economically driven human migration, tourism-related activities, densely populated metropolitan areas, and local policies, humans will be affected by a multitude of novel disease-causing microorganisms and civilizational diseases. Despite disparities among countries, recent and planned changes in regulations concerning animal research and drug safety studies could have detrimental effects on both the animal research community and nations lacking sufficient social support systems. Based on existing scientific literature, I argue that we need animal research encompassing aspects such as animal development, behavior, drug safety studies, and for the understanding of future civilizational diseases. Depending on the nature of the research questions and local challenges, a suitable animal model organism should be made mandatory.

A prolonged latent phase: An early career in oxytocin during birth

•The author, a nurse-midwife scientist, shares her path to the study of the causes and consequences of clinical oxytocin use.•This paper highlights mentors and key research that informed new thinking about the role of oxytocin during parturition.•Future directions for improving maternal care during childbirth are presented, including genetic and epigenetic perspectives.

Targeting Protein-Protein Interfaces with Peptides: The Contribution of Chemical Combinatorial Peptide Library Approaches

Protein-protein interfaces play fundamental roles in the molecular mechanisms underlying pathophysiological pathways and are important targets for the design of compounds of therapeutic interest. However, the identification of binding sites on protein surfaces and the development of modulators of protein-protein interactions still represent a major challenge due to their highly dynamic and extensive interfacial areas. Over the years, multiple strategies including structural, computational, and combinatorial approaches have been developed to characterize PPI and to date, several successful examples of small molecules, antibodies, peptides, and aptamers able to modulate these interfaces have been determined. Notably, peptides are a particularly useful tool for inhibiting PPIs due to their exquisite potency, specificity, and selectivity. Here, after an overview of PPIs and of the commonly used approaches to identify and characterize them, we describe and evaluate the impact of chemical peptide libraries in medicinal chemistry with a special focus on the results achieved through recent applications of this methodology. Finally, we also discuss the role that this methodology can have in the framework of the opportunities, and challenges that the application of new predictive approaches based on artificial intelligence is generating in structural biology.

Quantitative analysis for grading uterine electromyography activities during labor

BACKGROUND

The strength of uterine contraction is one of the decisive factors for labor progression and parturition. Clinicians usually encounter difficulties in early identification of inadequate contractions and in oxytocin treatment. Electromyography-an emerging technology for uterine contraction monitoring-can quantify the intensity of myoelectric activity of uterine contraction. Therefore, grading patients with different uterine contraction intensities by electromyography is of great significance to the clinical intensive management of uterine contraction and labor process.

OBJECTIVE

This study aimed to quantify and grade electromyography activity during the latent phase of the first stage of labor and explore its relationship with oxytocin treatment and length of labor.

STUDY DESIGN

We performed a retrospective cohort study to identify electromyography parameters as a predictor for oxytocin treatment and length of labor among a cohort of term singleton primipara (n=508) during the latent phase who delivered in Guangzhou between August 2018 and December 2021. The electromyography parameters were graded according to the quartile method, and the significance of grading and delivery outcome was explored. Univariate and multivariate logistic regression were used to determine the predictors of oxytocin treatment.

RESULTS

Maternal gestational age (adjusted risk ratio, 1.2; 95% confidence interval, 1.0-1.5), root mean square (adjusted risk ratio, 0.01; 95% confidence interval, 0.004-0.03), and power (adjusted risk ratio, 0.02; 95% confidence interval, 0.01-0.05) were significant predictors of oxytocin argumentation. The low electromyography activity group had a longer first stage labor and total labor time and were more likely to use oxytocin.

CONCLUSION

Electromyography parameters root mean square and power had high predictive values for later oxytocin treatment among patients with spontaneous labor. Patients with low-grade electromyography were more likely need oxytocin treatment. Electromyography grading is very important for its clinical promotion and use, and it could lead to more reliable analyses of oxytocin treatments and eventually to more effective interventions to prevent prolonged labor.

Establishment of a model for predicting the outcome of induced labor in full-term pregnancy based on machine learning algorithm

To evaluate and establish a prediction model of the outcome of induced labor based on machine learning algorithm. This was a cross-sectional design. The subjects were divided into primipara and multipara, and the risk factors for the outcomes of induced labor were assessed by multifactor logistic regression analysis. The outcome model of labor induced with oxytocin (OT) was constructed based on the four machine learning algorithms, including AdaBoost, logistic regression, naive Bayes classifier, and support vector machine. Factors, such as accuracy, recall, precision, F1 value, and receiver operating characteristic curve, were used to evaluate the prediction performance of the model, and the clinical application of the model was verified. A total of 907 participants were included in this study. Logistic regression algorithm obtained better results in both primipara and multipara groups compared to the other three models. The accuracy of the model for the prediction of "successful induction of labor" was 94.24% and 96.55%, and that of "failed induction of labor" was 65.00% and 66.67% in the primipara and the multipara groups, respectively. This study established a prediction model of OT-induced labor based on the Logistic regression algorithm, with rapid response, high accuracy, and strong extrapolation, which was critical for obstetric clinical nursing.

Effects of different doses of synthetic oxytocin on neonatal instinctive behaviors and breastfeeding

Synthetic oxytocin is the current domestic first-line agent of induced labor and labor augmentation, and its potential effects on neonatal neurobehavioral development is currently attracting increased attention. To explore the effect of different doses of synthetic oxytocin on neonatal instinctive breastfeeding behavior and breastfeeding by observing neonatal behaviors during skin-to-skin contact with mothers after delivery. Observations and comparisons of neonatal instinctive behaviors were conducted by using Widström's 9 Stages method. According to the total dosage of oxytocin administered during labor, participants were divided into a low dose group (≤ 2.5 U) of 39 pairs, a medium dose group (> 2.5 U) of 38 pairs, a high dose group (> 7.5 U) of 38 pairs and a control group (no synthetic oxytocin use) of 39 pairs. The occurrence time of newborns' instinctive movements and the duration of each behavior stage for the four groups were also analyzed. The number of exclusive breastfeeding sessions within 3 days after birth and the rate of exclusive breastfeeding at 3 months were collected and compared. There were significant differences among the four groups in the occurrence time of raising head or turning head (p = 0.004), eating hands (p = 0.011), moving body (p = 0.001), locating areola (p < 0.001), licking nipples (p = 0.002), containing nipple (p = 0.001), sucking (p < 0.001). There were significant differences among the four groups in the duration of activity (p = 0.004), clawing (p = 0.001), familiarization (p = 0.001), and sucking (p < 0.001). There was also a significant difference in the number of exclusive breastfeeding sessions of 24 h (p = 0.011), 48 h (p < 0.001), 72 h (p = 0.001) after birth among the four groups, but there was no statistical difference in the rate of exclusive breastfeeding at 3 months after birth. The intrapartum administration of synthetic oxytocin was associated with the expression of neonatal instinctive breastfeeding. With increases in drug dose, the effect of breast seeking activity and breast attachment was more significant, and the association of synthetic oxytocin on sucking and breastfeeding was dose-dependent.

Effect of Oxytocin Combined with Different Volume of Water Sac in High-Risk Term Pregnancies

Objective

The study estimated the impacts of water sac of different capacities combined with oxytocin (OXT) on pregnant women with high-risk term pregnancies.

Methods

Women with high-risk term pregnancies who received OXT were enrolled to perform labor induction using 30  mL (group A), 80 mL (group B), and 150  mL (group C), followed by the comparisons regarding to the success rate of labor induction, cesarean section rate, duration of induced labor to labor, duration of the first stage of labor, postpartum blood loss, the incidence of adverse reactions, and the assessment of cervical ripening using Bishop Score. Besides, neonatal weight, Apgar score, as well as psychological status, and satisfaction of patients were compared among these groups.

Results

As compared with group A, the success rate of induced labor was higher in groups B and C with lower cesarean section rate and shorter duration of induced labor to labor, but the duration of the first stage of labor in group B was the shortest among the three groups. The amount of postpartum hemorrhage decreased stepwise from groups A to B to C. In addition, groups A and B showed a reduced incidence of adverse reactions than group C, but the highest level of cervical ripening and highest patient satisfaction was revealed in group C and group B, respectively. Furthermore, the highest patient satisfaction was found in group B.

Conclusion

The usage of an 80  mL water sac combined with OXT  in high-risk term pregnancy has ideal induction effects, which can guarantee maternal cervical maturity and shorten the time of the first stage of labor.

The Effect of Oxytocin plus Carboprost Methylate in Preventing Postpartum Hemorrhage in High-Risk Pregnancy and Its Effect on Blood Pressure

Objective. This study aimed to explore and analyze the effectiveness of oxytocin plus carboprost methylate in preventing postpartum hemorrhage in high-risk pregnancies and its effect on blood pressure. A total of 60 women with high-risk pregnancies who gave birth in our hospital from January 2020 to May 2021 were recruited and assigned via random number table method (1 : 1) to receive either oxytocin (control group) or oxytocin plus carboprost methylate (observation group). Outcome measures included hemorrhage and blood pressure. The bleeding volume of the women in the observation group (210.55 ± 45.98, 45.21 ± 9.27, and 73.74 ± 12.18) was significantly less than that in the control group during delivery and 2h and 24h after the delivery (276.91 ± 49.21, 72.98 ± 19.68, and 92.61 ± 15.67) (all P < 0.05). The observation group showed a significantly lower bleeding rate (6.67%) than the control group (16.67%) (P < 0.05). The two groups showed similar diastolic and systolic blood pressures (P > 0.05). Oxytocin plus carboprost methylate suppository effectively prevents postpartum hemorrhage in high-risk pregnancies, significantly reduces the amount of postpartum hemorrhage in high-risk pregnancies, and has little effect on the blood pressure of patients. Given its favorable treatment efficiency and high safety profile, this treatment protocol shows great potential for clinical application.

Potentials of Neuropeptides as Therapeutic Agents for Neurological Diseases

Despite recent leaps in modern medicine, progress in the treatment of neurological diseases remains slow. The near impermeable blood-brain barrier (BBB) that prevents the entry of therapeutics into the brain, and the complexity of neurological processes, limits the specificity of potential therapeutics. Moreover, a lack of etiological understanding and the irreversible nature of neurological conditions have resulted in low tolerability and high failure rates towards existing small molecule-based treatments. Neuropeptides, which are small proteinaceous molecules produced by the body, either in the nervous system or the peripheral organs, modulate neurological function. Although peptide-based therapeutics originated from the treatment of metabolic diseases in the 1920s, the adoption and development of peptide drugs for neurological conditions are relatively recent. In this review, we examine the natural roles of neuropeptides in the modulation of neurological function and the development of neurological disorders. Furthermore, we highlight the potential of these proteinaceous molecules in filling gaps in current therapeutics.

American College of Nurse-Midwives Clinical Bulletin Number 18: Induction of Labor

Induction of labor is an increasingly common component of intrapartum care in the United States. This rise is fueled by a nationwide escalation in both medically indicated and elective inductions at or beyond term, supported by recent research showing some benefits of induction over expectant management. However, induction of labor medicalizes the birth experience and may lead to a complex cascade of interventions. The purpose of this Clinical Bulletin is twofold: (1) to guide clinicians on the use of person-centered decision-making when discussing induction of labor and (2) to review evidence-based practice recommendations for intrapartum midwifery care during labor induction.

Oxytocin: A citation network analysis of 10 000 papers

Our understanding of the oxytocin system has been built over the last 70 years by the work of hundreds of scientists, reported in thousands of papers. Here, we construct a map to that literature, using citation network analysis in conjunction with bibliometrics. The map identifies ten major 'clusters' of papers on oxytocin that differ in their particular research focus and that densely cite papers from the same cluster. We identify highly cited papers within each cluster and in each decade, not because citations are a good indicator of quality, but as a guide to recognising what questions were of wide interest at particular times. The clusters differ in their temporal profiles and bibliometric features; here, we attempt to understand the origins of these differences.

Association of Self-Reported Physical Fitness during Late Pregnancy with Birth Outcomes and Oxytocin Administration during Labour-The GESTAFIT Project

We explored (a) the associations between self-reported maternal physical fitness and birth outcomes; (b) whether self-reported maternal physical fitness (PF) is related to the administration of oxytocin to induce or stimulate labour. Pregnant women from the GESTAFIT project randomized controlled trial (n = 117) participated in this prospective longitudinal study. Maternal physical fitness was assessed through the International Fitness Scale at the 34th gestational week. Maternal and neonatal birth outcomes and oxytocin administration were collected from the obstetric medical records. Umbilical arterial and venous cord blood gas were analysed immediately after birth. Self-reported overall fitness, cardiorespiratory fitness, muscular strength and flexibility were not related to any maternal and neonatal birth outcomes (all p > 0.05). Greater speed-agility was associated with a more alkaline arterial (p = 0.04) and venous (p = 0.02) pH in the umbilical cord blood. Women who were administered oxytocin to induce or stimulate labour reported lower cardiorespiratory fitness (p = 0.013, Cohen's d = 0.55; 95% confidence interval (CI): 0.14, 0.93) and flexibility (p = 0.040, Cohen´s d = 0.51; 95% CI: 0.09, 0.89) compared to women who were not administered oxytocin. Greater maternal physical fitness during pregnancy could be associated with better neonatal birth outcomes and lower risk of needing oxytocin administration.

Oxytocin Receptor Activation Rescues Opioid-Induced Respiratory Depression by Systemic Fentanyl in the Rat

Opioid overdose intervention by naloxone, a high affinity receptor antagonist, reverses opioid-induced respiratory depression (OIRD) and analgesia by displacing opioids. Systemic naloxone stimulates release of the hypothalamic neuropeptide oxytocin, which has analgesic properties and participates in cardiorespiratory homeostasis. To test the hypothesis that oxytocin can reverse OIRD, we assessed the rescue potential of graded doses (0, 0.1, 2, 5, 10, 50 nmol/kg, i.v.) of oxytocin to counter fentanyl (60 nmol/kg, i.v.)-induced depression of neural inspiration indexed by recording phrenic nerve activity (PNA) in anesthetized (urethane/α-chloralose), vagotomized, and artificially ventilated rats. Oxytocin dose-dependently rescued fentanyl OIRD by almost immediately reversing PNA burst arrest (P = 0.0057) and restoring baseline burst frequency (P = 0.0016) and amplitude (P = 0.0025) at low but not high doses, resulting in inverted bell-shaped dose-response curves. Oxytocin receptor antagonism (40 nmol/kg, i.v.) prevented oxytocin reversal of OIRD (arrest: P = 0.0066, frequency: P = 0.0207, amplitude: P = 0.0022). Vasopressin 1A receptor (V1aR) antagonism restored high-dose oxytocin efficacy to rescue OIRD (P = 0.0170 to P < 0.0001), resulting in classic sigmoidal dose-response curves, and prevented (P = 0.0135) transient hypertension from V1aR cross-activation (P = 0.0275). Alone, vasopressin (5 nmol/kg, i.v.) failed to reverse fentanyl respiratory arrest (P = 0.6184). The nonpeptide oxytocin receptor agonist WAY-267464 (75 nmol/kg, i.v.), which has V1aR antagonist properties, quickly reversed fentanyl OIRD (P < 0.0001), with rapid recovery of PNA frequency (P = 0.0011) and amplitude (P = 0.0044) without adverse hemodynamic consequences (P = 0.9991). Findings indicate that peptide and nonpeptide agonist activation of oxytocin receptors without V1aR cross-activation rescues fentanyl OIRD. Oxytocin receptor agonists could be lifesaving resuscitation agents that enhance rather than interrupt opioid analgesia. SIGNIFICANCE STATEMENT: Oxytocin receptor activation produces analgesia. Here, we demonstrate that activation by the US Food and Drug Administration-approved agonist oxytocin and the nonpeptide partial agonist WAY-267464 can each reverse fentanyl cardiorespiratory depression. Selective targeting of oxytocin receptors for resuscitation from opioid overdose, alone or in combination with an opioid antagonist, could eliminate or attenuate negative side effects associated with traditional opioid receptor antagonism.

Oxytocin and Misoprostol With Diclofenac in the Preparation for Magnetic Resonance-Guided High-Intensity Ultrasound Treatment of Symptomatic Uterine Fibroids: A Prospective Cohort Study

Uterine fibroids (UFs) are very common benign tumors of the female reproductive tract. According to recent reports, magnetic resonance-guided high-intensity ultrasound (MR-HIFU) appears to be a well-tolerated and efficient treatment option for UFs. However, MR-HIFU still presents several limitations. The treatment is rarely associated with achieving complete non-perfused volume (NPV). Not all patients are qualified for a final procedure, and selected women obtain very good results in such treatment. The primary objective of this experimental study was to assess the effect of transvaginal misoprostol and intravenous oxytocin preparation on UF volume change, sonication time and NPV after MR-HIFU procedure in women of reproductive age with symptomatic UFs. Secondary outcomes included the effect on the peri-procedural effectiveness of misoprostol and oxytocin. This study enrolled 247 women with symptomatic UFs; based on gynecologic examinations and magnetic resonance imaging (MRI) scans, 128 women qualified for MR-HIFU without pharmacologic treatment, 57 women qualified for the misoprostol/diclofenac group and 62 women qualified for the oxytocin group. Pharmacologic pre-treatment improved NPV compared with non-pharmacologic treatment (average NPV: controls 61.9% ± 25.8%; oxytocin 76.8% ± 20.7%; misoprostol/diclofenac 85.2% ± 15.1%; average sonication time: controls 120 min ± 56.4%; oxytocin 111 min ± 45.4%; misoprostol/diclofenac 80 min ± 47.7%). Statistical analysis did not reveal significant intergroup differences in UF volume changes after 6 mo (controls: n = 40, 37.4% ± 27.5%; oxytocin n = 25, 45.8% ± 31%; misoprostol/diclofenac n = 19, 33.4% ± 23.2%). The misoprostol/diclofenac group, which achieved the highest NPV immediately after the MR-HIFU procedure, was characterized by the lowest UF volume change percentages 6 mo later. The administration of vasoconstrictor drugs (oxytocin and misoprostol/diclofenac) to support MR-HIFU in UF treatment is a new issue that may improve the total effectiveness of this method. Randomized controlled trials are necessary to estimate the real effect of vasoconstrictors on MR-HIFU.

Oxytocin Administration in Low-Risk Women, a Retrospective Analysis of Birth and Neonatal Outcomes

BACKGROUND

In recent years, higher than the recommended rate of oxytocin use has been observed among low-risk women. This study examines the relationship between oxytocin administration and birth outcomes in women and neonates.

METHODS

A retrospective analysis of birth and neonatal outcomes for women who received oxytocin versus those who did not. The sample included 322 women with a low-risk pregnancy.

RESULTS

Oxytocin administration was associated with cesarean section (aOR 4.81, 95% CI: 1.80-12.81), instrumental birth (aOR 3.34, 95% CI: 1.45-7.67), episiotomy (aOR 3.79, 95% CI: 2.20-6.52) and length of the second stage (aOR 00:18, 95% CI: 00:04-00:31). In neonatal outcomes, oxytocin in labor was associated with umbilical artery pH ≤ 7.20 (OR 3.29, 95% CI: 1.33-8.14). Admission to neonatal intensive care unit (OR 0.56, 95% CI: 0.22-1.42), neonatal resuscitation (OR 1.04, 95% CI: 0.22-1.42), and Apgar score <7 (OR 0.48, 95% CI: 0.17-1.33) were not associated with oxytocin administration during labor.

CONCLUSIONS

Oxytocin administration during labor for low-risk women may lead to worse birth outcomes with an increased risk of instrumental birth and cesarean, episiotomy and the use of epidural analgesia for pain relief. Neonatal results may be also worse with an increased proportion of neonates displaying an umbilical arterial pH ≤ 7.20.

Current Resources for Evidence-Based Practice, May 2021

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of the prenatal prediction of fetal macrosomia and commentaries on reviews focused on the effects of date palm and dill seed on labor outcomes and the current research available on SARS-CoV-2 and pregnancy outcomes.

Maternal body mass index and oxytocin in augmentation of labour in nulliparous women: a prospective observational study

OBJECTIVE

To evaluate oxytocin use for augmentation of labour in relation to body mass index (BMI) on admission to the labour ward, focusing on cumulative oxytocin dose and maximum rate of oxytocin infusion during the first stage of labour.

DESIGN

Prospective observational study.

SETTING

Seven hospitals in Sweden.

PARTICIPANTS

1097 nulliparous women with singleton cephalic presentation pregnancy, ≥37 weeks of gestation, spontaneous onset of labour and treatment with oxytocin infusion for labour augmentation. The study population was classified into three BMI subgroups on admission to the labour ward: normal weight (18.5-24.9), overweight (25.0-29.9) and obese (≥30.0). The cumulative oxytocin dose was measured from the start of oxytocin infusion until the neonate was born.

PRIMARY OUTCOME

Cumulative oxytocin dose.

SECONDARY OUTCOME

Maximum rate of oxytocin infusion during the active phase of first stage of labour.

RESULTS

The mean cumulative oxytocin dose increased in the BMI groups (normal weight 2278 mU, overweight 3108 mU and obese 4082 mU (p<0.0001)). However, when adjusted for the confounders (cervical dilatation when oxytocin infusion was started, fetal birth weight, epidural analgesia), the significant difference was no longer seen. The maximum oxytocin infusion rate during the first stage of labour differed significantly in the BMI groups when adjusted for the confounding factors individually but not when adjusted for all three factors simultaneously. In addition, the maximum oxytocin infusion rate was significantly higher in women with emergency caesarean section compared with women with vaginal delivery.

CONCLUSIONS

Women with increasing BMI with augmentation of labour received a higher cumulative oxytocin dose and had a higher maximum oxytocin infusion rate during first stage of labour, however, when adjusted for relevant confounders, the difference was no longer seen. In the future, the guidelines for augmentation of labour with oxytocin infusion might be reconsidered and include modifications related to BMI.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

Effect of oxytocin on lipid accumulation under inflammatory conditions in human macrophages

INTRODUCTION AND AIMS

Oxytocin (OT) is a neuropeptide hormone secreted by the posterior pituitary gland. Deficits in OT action have been observed in patients with behavioral and mood disorders, some of which correlate with an increased risk of cardiovascular disease (CVD). Recent research has revealed a wider systemic role that OT plays in inflammatory modulation and development of atherosclerotic plaques. This study investigated the role that OT plays in cholesterol transport and foam cell formation in LPS-stimulated THP-1 human macrophages.

METHODS

THP-1 differentiated macrophages were treated with media, LPS (100 ng/ml), LPS + OT (10 pM), or LPS + OT (100 pM). Changes in gene expression and protein levels of cholesterol transporters were analyzed by real time quantitative PCR (RT-qPCR) and Western blot, while oxLDL uptake and cholesterol efflux capacity were evaluated with fluorometric assays.

RESULTS

RT-qPCR analysis revealed a significant increase in ABCG1 gene expression upon OT + LPS treatment, compared to LPS alone (p = 0.0081), with Western blotting supporting the increase in expression of the ABCG1 protein. Analysis of oxLDL uptake showed a significantly lower fluorescent value in LPS + OT (100pM) -treated cells when compared to LPS alone (p < 0.0001). While not statistically significant (p = 0.06), cholesterol efflux capacity increased with LPS + OT treatment.

CONCLUSION

We demonstrate here that OT can attenuate LPS-mediated lipid accumulation in THP-1 macrophages. These findings support the hypothesis that OT could be used to reduce pro-inflammatory and potentially atherogenic changes observed in patients with heightened CVD risk. This study suggests further exploration of OT effects on monocyte and macrophage cholesterol handling in vivo.

The Role of Oxytocin and the Effect of Stress During Childbirth: Neurobiological Basics and Implications for Mother and Child

The neuropeptide oxytocin acts as a hormone and a neuromodulator, influencing a multitude of human social behaviors, including reproduction. During childbirth and the postpartum period, it plays a key role in regulating and controlling processes that ensure a safe birth and the health of mother and child. Especially the onset of labor, the progress of labor and initial breastfeeding are mediated by oxytocin. In the maternal brain it controls the initiation of the mother-infant bond and the mother's emotional responses towards her child. In this review we summarize the current state of knowledge about the role of oxytocin during the different aspects and mechanisms of human childbirth, combining research from human and animal studies. Physiological and psychological stress during childbirth and lactation can have negative effects on the progress of labor, breastfeeding and bonding. We discuss how maternity caregivers can support the positive effects of oxytocin and minimize the effects of stress. Furthermore, we highlight aspects of the basic neurobiological principles and connections where further research is needed to improve our understanding of the regulation and the effects of oxytocin to support maternal and infant health.

The Role of Skin-to-Skin Contact and Breastfeeding on Atonic Postpartum Hemorrhage

Objectives: were to (a) determine incidence of postpartum hemorrhage (PPH) in all women delivering between 2009 and 2015, and (b) determine the amount of Estimated Blood Loss (EBL) and duration of the third stage of labor in each subgroup for women with or without PPH, and (c) compare EBL and duration of 3rd stage of labor between subgroups in groups of women with or without PPH. Design: A retrospective chart review conducted using codes for atonic PPH. Setting: Records from a University based tertiary setting, 264 charts were reviewed and data from 154 charts were analyzed. One-way ANOVAs followed with post-hocs and a 2-way ANOVA were conducted. Results: PPH rate increased by 47.50% from 2009–2015. For women with PPH, EBL was lower in skin to skin contact (SSC) + Breastfeeding (BF) subgroup. For women without PPH, EBL was lower in SSC only subgroup. Third stage of labor duration was longer in women with PPH. Conclusions: Study confirmed the increasing trends of PPH due to uterine atony and proposed role of SSC and BF in decreasing EBL and shorten the duration of the 3rd stage of labor for PPH women, usefulness of SSC and BF as physiologic practices merit further study.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

Perspectives of Pitocin administration on behavioral outcomes in the pediatric population: recent insights and future implications

Oxytocin plays an important role in the regulation of parturition as this peptide hormone promotes uterine smooth muscle contractility in gravid women undergoing labor. Here, we review the impact of Pitocin administration on behavioral outcomes in the pediatric population. Pitocin is a synthetic preparation of oxytocin widely used in the obstetric practice for the management of labor and postpartum hemorrhage. We begin by tracing the neuroanatomy of oxytocin-containing cells from an evolutionary perspective and then summarize key findings on behavioral and neural activity reported from offspring dosed with Pitocin during vaginal delivery. Finally, we discuss future directions that are experimentally tractable for understanding the developmental consequences of Pitocin administration on a small but growing subset of children worldwide. Given that fetal past experiences can shape the future behavior of the adult, further work on oxytocin signaling pathways will provide valuable references and insights for early-brain development and state-dependent regulation of behavioral outcome.

Hypothalamic Neuropeptide Brain Protection: Focus on Oxytocin

Oxytocin (OXT) is hypothalamic neuropeptide synthetized in the brain by magnocellular and parvo cellular neurons of the paraventricular (PVN), supraoptic (SON) and accessory nuclei (AN) of the hypothalamus. OXT acts in the central and peripheral nervous systems via G-protein-coupled receptors. The classical physiological functions of OXT are uterine contractions, the milk ejection reflex during lactation, penile erection and sexual arousal, but recent studies have demonstrated that OXT may have anti-inflammatory and anti-oxidant properties and regulate immune and anti-inflammatory responses. In the pathogenesis of various neurodegenerative diseases, microglia are present in an active form and release high levels of pro-inflammatory cytokines and chemokines that are implicated in the process of neural injury. A promising treatment for neurodegenerative diseases involves new therapeutic approaches targeting activated microglia. Recent studies have reported that OXT exerts neuroprotective effects through the inhibition of production of pro-inflammatory mediators, and in the development of correct neural circuitry. The focus of this review is to attribute a new important role of OXT in neuroprotection through the microglia–OXT interaction of immature and adult brains. In addition, we analyzed the strategies that could enhance the delivery of OXT in the brain and amplify its positive effects.

Relation between Length of Exposure to Epidural Analgesia during Labour and Birth Mode

Objective: To appraise the relationship between the length of exposure to epidural analgesia and the risk of non-spontaneous birth, and to identify additional risk factors. This study is framed within the MidconBirth project. Study design: A multicentre prospective study was conducted between July 2016 and November 2017 in three maternity hospitals in different Spanish regions. The independent variable of the study was the length of exposure to epidural analgesia, and the dependent variable was the type of birth in women with uncomplicated pregnancies. The data was analyzed separately by parity. A multivariate logistic regression was performed. The odds ratios (OR), using 95% confidence intervals (CI) were constructed. Main outcome measures: During the study period, 807 eligible women gave birth. Non-spontaneous births occurred in 29.37% of the sample, and 75.59% received oxytocin for augmentation of labour. The mean exposure length to epidural analgesia when non-spontaneous birth happened was 8.05 for primiparous and 6.32 for multiparous women (5.98 and 3.37 in spontaneous birth, respectively). A logistic regression showed the length of exposure to epidural during labour was the major predictor for non-spontaneous births in primiparous and multiparous women followed by use of oxytocin (multiparous group). Conclusions: The length of exposure to epidural analgesia during labour is associated with non-spontaneous births in our study. It highlights the need for practice change through the development of clinical guidelines, training programs for professionals and the continuity of midwifery care in order to support women to cope with labour pain using less invasive forms of analgesia. Women also need to be provided with evidence-based information.

Design of Oxytocin Analogs

The neurohypophyseal hormone oxytocin (OT) and related modulators of the oxytocin receptor (OTR) have been the subject of intensive research for nearly seven decades. Despite having rather poor drug-like properties, OT is used as a treatment for labor induction, postpartum hemorrhage, and lactation support. The potential use of OT in the treatment of central nervous system (CNS)-related diseases has recently renewed interest in the pharmacology of OT. Oxytocin is one of the most extensively studied cyclic peptides and since the elucidation of its structure in 1953 thousands of peptidic OT analogs with antagonistic and agonistic properties have been synthesized and biologically evaluated. Among them are atosiban, a mixed oxytocin receptor (OTR)/vasopressin 1a receptor (V_1aR) antagonist used as a tocolytic agent approved (in certain countries), and carbetocin, a longer acting OTR agonist on the market for the treatment of postpartum hemorrhage. Many other OT analogs with improved pharmacological properties (e.g., barusiban, Antag III) have been identified. These peptides have been tested in clinical trials and/or used as pharmacological tools. In this chapter, the modifications of the OT molecule that led to the discovery of these compounds are reviewed.

Administration of oxytocin during spontaneous labour: A national vignette-based study among midwives

OBJECTIVE

(1) to assess variations in oxytocin use by midwives during spontaneous labour (indication, dose, moment), and (2) to identify factors potentially associated with oxytocin administration.

DESIGN

descriptive cross-sectional study using a case-vignette and questionnaire among French midwives from November 2015 to May 2016.

METHODS

Midwives were asked to complete an online survey including a case-vignette with hourly partograms of a slowly progressing labour, and a short self-administered questionnaire. Two choices were proposed with each hourly partogram: administration of oxytocin or expectant management. Midwives who selected oxytocin were then asked about the dose, dose-increment and dose-increase delay. The questionnaire asked the midwives about work experience, day or night work, and organisational factors.

FINDINGS

The study included 204 midwives. At some point during the case-vignette, 159 (77.9%) midwives responded that they would use oxytocin. Answers demonstrated variations in oxytocin administration for initial doses, dose-increments and dose-increase delays. Specifically, a substantial majority of respondents chose high doses of oxytocin (64.1% at doses exceeding 2 mIU/min) and short dose-increase delays (62.9% under 30 min). Excessive administration of oxytocin by midwives was significantly associated with the number of births per year in their maternity unit, midwives' workload (p < 0.001), overload of delivery rooms (p < 0.001) and lack of protocol (22% versus 55.6%, p < 0.001). Midwives considered that their use of oxytocin was related mainly to an overburdened department (48.5%).

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

We observed overuse of oxytocin, influenced by organisational factors. Every maternity unit should implement a protocol and/or checklist for oxytocin administration to reduce variation in practice and improve safety of care by using evidence-based clinical indications, initial doses, dose-increments and dose-increase delays. Modifying the organisation of care appears necessary to reduce hospital patient volume or increase staffing to ensure that the number of midwives on duty matches the activity in the delivery room without causing excess work or stress to midwives.

Modulating the Oxytocin System During the Perinatal Period: A New Strategy for Neuroprotection of the Immature Brain?

Oxytocin is a neurohypophysal hormone known for its activity during labor and its role in lactation. However, the function of oxytocin (OTX) goes far beyond the peripheral regulation of reproduction, and the central effects of OTX have been extensively investigated, since it has been recognized to influence the learning and memory processes. OTX has also prominent effects on social behavior, anxiety, and autism. Interaction between glucocorticoids, OTX, and maternal behavior may have long-term effects on the developmental program of the developing brain subjected to adverse events during pre and perinatal periods. OTX treatment in humans improves many aspects of social cognition and behavior. Its effects on the hypothalamic–pituitary–adrenal axis and inflammation appear to be of interest in neonates because these properties may confer benefits when the perinatal brain has been subjected to injury. Indeed, early life inflammation and abnormal adrenal response to stress have been associated with an abnormal white matter development. Recent investigations demonstrated that OTX is involved in the modulation of microglial reactivity in the developing brain. This review recapitulates state-of-the art data supporting the hypothesis that the OTX system could be considered as an innovative candidate for neuroprotection, especially in the immature brain.

Oxytocin Use in Labor: Legal Implications

Oxytocin is one of the most commonly used medications in obstetrics and has been associated with claims of negligence in cases of adverse outcomes. Errors involving intravenous oxytocin administration for induction or augmentation of labor are most commonly dose related and include failure to avoid or treat tachysystole or failure to asses or treat a fetal heart rate pattern indicative of disruption in oxygenation. Clinicians should be knowledgeable regarding pharmacokinetics of oxytocin and the effect of uterine contractions on fetal oxygenation as well as safe titration of oxytocin to achieve the desired effect while minimizing harm.