Oxytocin Infusion Research Articles

Transvaginal ultrasonography-measured cervical length versus the modified Bishop score for preinduction cervical assessment at term: A randomised controlled trial

Introduction: The inducibility of the cervix for labour induction is usually determined by cervical status evaluation. The Bishop score is historically used to forecast the success of induction of labour, although it is subjective, and not reproducible. However, transvaginal ultrasound measurements of cervical length are rarely used for preinduction cervical assessment. The study compared cervical length measured via transvaginal ultrasound and the modified Bishop score for preinduction cervical assessment at term. Methods: The study involved 72 pregnant, nulliparous women for induction of labour at term. They were randomised into the transvaginal ultrasound group and the modified Bishop score group. The cervix was said to be ‘ripe’ when the transvaginal ultrasound cervical length (CL) was < 28 mm or the modified Bishop score was ⩾ 6. The cervix was considered ‘unripe’ when the Bishop score was < 6 or the transvaginal ultrasound was ⩾ 28 mm. Participants with ripe cervices had induction of labour with an oxytocin infusion, while those with unripe cervices had preinduction cervical ripening with misoprostol. The primary outcome measures were the mode of delivery and the total amount of prostaglandins administered for preinduction cervical ripening. Results: There was no significant difference between the two groups with regard to the mode of delivery ( p = 0.795), the total amount of prostaglandins administered for preinduction cervical ripening (105.0 ± 51.04 µg vs 111.90 ± 52.2 µg; p = 0.0671), the proportion of women who were administered prostaglandins due to an unfavourable cervix (41.7% vs 55.6%; p = 0.812), induction-to-the-active phase of the labour interval (11.00 ± 4.2 hours vs 11.82 ± 4.12 hours; p = 0.407) or the induction-delivery interval (20.15 ± 5.7 hours vs 22.66 ± 4.33 hours; p = 0.06) in both groups, respectively. Compared with those in the Bishop score group (Bishop score ⩾ 6), the induction-to-active phase of labour intervals (6.47 ± 0.77 hours vs 7.33 ± 1.21 hours, p = 0.024) and the induction-to-delivery intervals (14.97 ± 1.0 hours vs 18.39 ± 0.85 hours; p = 0.0001) in the transvaginal ultrasound group (cervical length < 28 mm) were significantly shorter, respectively. Conclusion: Preinduction cervical assessment using transvaginal ultrasound (cervical length < 28 mm) or the modified Bishop score is a successful predictor of the outcome of labour induction A larger multicentre studies are needed to identify optimal cervical length cutoffs and to determine if this could decrease unnecessary prostaglandin use or decrease caesarean section rate.

Severe hyponatremia in obstetrics: Presentations and outcome. Retrospective cohort over 10 years.

Hyponatremia in labor and the postpartum period is generally underreported. In this study we aimed to identify attributable causes of severe hyponatremia in an obstetric population and define maternal outcomes. This was a retrospective cohort study, in a single center over a period of 10 years. The study setting was an NHS maternity trust serving a multi-ethnic population in southwest London. The hospital cared for 53 649 pregnant women in the study period. All patients with severe hyponatremia in labor and immediate postpartum period from January 2011 until December 2020 were identified from the laboratory database. Individual case notes were analyzed for fluid use, use and duration of oxytocin, medical conditions, and delivery details. Severe peripartum hyponatremia was identified in 77 patients. A total of 28% of those analyzed required ITU admission for electrolyte correction, of whom 6% presented with severe neurologic symptoms, making symptoms a poor marker of severity (P = 0.051). The main association was to oxytocin and intravenous fluid infusions (80% and 86%, respectively), only one-third of patients had pre-eclampsia. Other associated medical conditions did not appear to have a significant influence on disease course nor prognosis (P = 0.359). Hyponatremia during labor can have detrimental effect on maternal outcomes. Lower threshold for testing and diligent maintenance of fluid balance charts during labor can help with primary prevention.

Cervical ripening with a double balloon device for 6 h in patients with a long cervix: Secondary analysis of a randomized controlled trial.

To examine whether cervical ripening with a double balloon device for 6 h is as effective as 12 h in patients with a cervical length ≥ 30 mm measured on transvaginal ultrasound before induction of labor, and to determine whether patients with a long cervix need to have the balloon placed for a longer time. This is a secondary analysis of data from a randomized controlled trial that compared maternal and neonatal outcomes between women undergoing cervical ripening with a double balloon device for 6 h (study group) versus 12 h (control group). In this secondary analysis, we included only patients who had cervical length ≥ 30 mm measured on transvaginal ultrasound on admission. Our primary outcome was a Bishop score change after removal of the device. Secondary outcomes included insertion to delivery interval, mode of delivery, and oxytocin infusion duration. Sixty-seven women met the inclusion criteria and were included in the analysis: 33 in the 6-h group and 34 in the 12-h group. Maternal characteristics were similar between both groups. Bishop score difference between the preinsertion and the postremoval scores were similar in the two groups (2.67 ± 1.8 vs. 2.53 ± 1.69, P = 0.76), while insertion to delivery time was 10 h shorter in the 6-h group (20.95 vs. 31.21, P = 0.02; mean difference, -10.26 [95% CI, -19.0 to -1.51]). The other secondary outcomes remained similar in both groups. In women undergoing induction of labor who have a cervical length ≥ 30 mm measured on admission transvaginal ultrasound, removing a double balloon device after 6 h achieved similar Bishop score changes as removal after 12 h, but significantly reduced the time to delivery. REGISTRATION AT CLINICAL TRIALS: https://classic. gov/ct2/show/NCT03045939.

Sympathetic Innervation of Interscapular Brown Adipose Tissue Is Not a Predominant Mediator of Oxytocin-Induced Brown Adipose Tissue Thermogenesis in Female High Fat Diet-Fed Rats.

Recent studies have indicated that hindbrain [fourth ventricle (4V)] administration of the neurohypophyseal hormone, oxytocin (OT), reduces body weight, energy intake and stimulates interscapular brown adipose tissue temperature (TIBAT) in male diet-induced obese (DIO) rats. What remains unclear is whether chronic hindbrain (4V) OT can impact body weight in female high fat diet-fed (HFD) rodents and whether this involves activation of brown adipose tissue (BAT). We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of interscapular brown adipose tissue (IBAT) contributes to its ability to activate BAT and reduce body weight in female high HFD-fed rats. To test this hypothesis, we determined the effect of disrupting SNS activation of IBAT on OT-elicited stimulation of TIBAT and reduction of body weight in DIO rats. We first measured the impact of bilateral surgical SNS denervation to IBAT on the ability of acute 4V OT (0.5, 1, and 5 µg ≈ 0.5, 0.99, and 4.96 nmol) to stimulate TIBAT in female HFD-fed rats. We found that the high dose of 4V OT (5 µg ≈ 4.96 nmol) stimulated TIBAT similarly between sham rats and denervated rats (p = NS). We subsequently measured the effect of bilateral surgical denervation of IBAT on the effect of chronic 4V OT (16 nmol/day ≈ 16.1 μg/day) or vehicle infusion to reduce body weight, adiposity and energy intake in female HFD-fed rats (N = 7-8/group). Chronic 4V OT reduced body weight gain (sham: -18.0 ± 4.9 g; denervation: -15.9 ± 3.7 g) and adiposity (sham: -13.9 ± 3.7 g; denervation: -13.6 ± 2.4 g) relative to vehicle treatment (p < 0.05) and these effects were similar between groups (p = NS). These effects were attributed, in part, to reduced energy intake evident during weeks 2 (p < 0.05) and 3 (p < 0.05). To test whether these results translate to other female rodent species, we also examined the effect of chronic 4V infusion of OT on body weight and adiposity in two strains of female HFD-fed mice. Similar to what we found in the HFD-fed rat model, we also found that chronic 4V OT (16 nmol/day) infusion resulted in reduced body weight gain, adiposity and energy intake in female DIO C57BL/6J and DBA/2J mice (p < 0.05 vs. vehicle). Together, these findings suggest that (1) sympathetic innervation of IBAT is not necessary for OT-elicited increases in BAT thermogenesis and weight loss in female HFD-fed rats and (2) the effects of OT to reduce weight gain and adiposity translate to other female mouse models of diet-induced obesity (DIO).

Routine vaginal examination to assess labour progress at 8 compared to 4 h after early amniotomy following Foley balloon ripening in the labor induction of nulliparas: A randomized trial.

Our objective was to compare the performance of the first vaginal examination at 8 versus 4 h after amniotomy following Foley ripening in nulliparous labor induction. A randomized controlled trial was conducted from June 2021 to January 2022. 210 nulliparas at term for labor induction were randomized: 105 each to first vaginal examination at 8 or 4 h after Foley balloon ripening and amniotomy. Titrated oxytocin infusion was routinely commenced after amniotomy to expedite labor. Primary outcomes were the amniotomy-to-delivery interval (non-inferiority hypothesis) and maternal satisfaction with their allocated labor care (superiority hypothesis) within 24 h after delivery. Analyses performed using t-test, Mann-Whitney U test, and Chi-squared test as appropriate. The amniotomy-to-delivery interval was mean ± standard deviation 8.7 ± 3.4 versus 8.4 ± 3.7, mean difference 0.4 (97.5% CI: -0.7 to 1.5) hours, p = 0.442 within the pre-specified 2-hour non-inferiority margin, and maternal satisfaction score with allocated labor care was median [interquartile range] 8[7.5-10] versus 8[7.0-10], p = 0.248 for 8 versus 4 h arms, respectively. The amniotomy to first vaginal examination intervals was 5.9 ± 2.3 versus 3.6 ± 1.0 h, p < 0.001, and the number of vaginal examinations was 2[1-2.5] versus 3 [2, 3], p < 0.001 for 8 versus 4 h, respectively. The first vaginal examination was less likely to have been performed as scheduled, more likely to be indicated by the urge to bear down, and non-reassuring cardiotocography for the 8 h arm (p < 0.001). Spontaneous vaginal delivery was significantly more likely and instrumental vaginal delivery less likely, but cesarean rate was not significantly different for the 8 h arm (p = 0.017). A routine first vaginal examination at 8 h compared to 4 h is non-inferior for the time to birth but does not increase maternal satisfaction although the number of vaginal examinations is fewer. The increase in spontaneous vaginal delivery and reduction in instrumental vaginal delivery rates warrant further powered primary evaluation.

Effects of systemic oxytocin and beta-3 receptor agonist (CL 316243) treatment on body weight and adiposity in male diet-induced obese rats.

Previous studies have implicated hindbrain oxytocin (OT) receptors in the control of food intake and brown adipose tissue (BAT) thermogenesis. We recently demonstrated that hindbrain [fourth ventricle (4V)] administration of oxytocin (OT) could be used as an adjunct to drugs that directly target beta-3 adrenergic receptors (β3-AR) to elicit weight loss in diet-induced obese (DIO) rodents. What remains unclear is whether systemic OT can be used as an adjunct with the β3-AR agonist, CL 316243, to increase BAT thermogenesis and elicit weight loss in DIO rats. We hypothesized that systemic OT and β3-AR agonist (CL 316243) treatment would produce an additive effect to reduce body weight and adiposity in DIO rats by decreasing food intake and stimulating BAT thermogenesis. To test this hypothesis, we determined the effects of systemic (subcutaneous) infusions of OT (50 nmol/day) or vehicle (VEH) when combined with daily systemic (intraperitoneal) injections of CL 316243 (0.5 mg/kg) or VEH on body weight, adiposity, food intake and brown adipose tissue temperature (T IBAT ). OT and CL 316243 monotherapy decreased body weight by 8.0±0.9% ( P <0.05) and 8.6±0.6% ( P <0.05), respectively, but OT in combination with CL 316243 produced more substantial weight loss (14.9±1.0%; P <0.05) compared to either treatment alone. These effects were associated with decreased adiposity, energy intake and elevated T IBAT during the treatment period. The findings from the current study suggest that the effects of systemic OT and CL 316243 to elicit weight loss are additive and appear to be driven primarily by OT-elicited changes in food intake and CL 316243-elicited increases in BAT thermogenesis.

Sympathetic innervation of interscapular brown adipose tissue is not a predominant mediator of OT-elicited reductions of body weight gain and adiposity in male diet-induced obese rats.

Recent studies indicate that central administration of oxytocin (OT) reduces body weight (BW) in high fat diet-induced obese (DIO) rodents by reducing energy intake and increasing energy expenditure (EE). Previous studies in our lab have shown that administration of OT into the fourth ventricle (4V; hindbrain) elicits weight loss and stimulates interscapular brown adipose tissue temperature (TIBAT) in DIO rats. We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of IBAT contributes to its ability to activate BAT and reduce BW in DIO rats. To test this, we determined the effect of disrupting SNS activation of IBAT on OT-elicited stimulation of TIBAT and reduction of BW in DIO rats. We first confirmed that bilateral surgical SNS denervation to IBAT was successful based on having achieved ≥ 60% reduction in IBAT norepinephrine (NE) content from DIO rats. NE content was selectively reduced in IBAT by 94.7 ± 2.7, 96.8 ± 1.8 and 85.9 ± 6.1% (P<0.05) at 1, 6 and 7-weeks post-denervation, respectively, and was unchanged in liver or inguinal white adipose tissue. We then measured the impact of bilateral surgical SNS denervation to IBAT on the ability of acute 4V OT (1, 5 μg) to stimulate TIBAT in DIO rats. We found that the high dose of 4V OT (5 μg) stimulated TIBAT similarly between sham and denervated rats (P=NS) and that the effects of 4V OT to stimulate TIBAT did not require beta-3 adrenergic receptor signaling. We subsequently measured the effect of bilateral surgical denervation of IBAT on the effect of chronic 4V OT (16 nmol/day) or vehicle infusion to reduce BW, adiposity and energy intake in DIO rats. Chronic 4V OT reduced BW gain by -7.2 ± 9.6 g and -14.1 ± 8.8 g in sham and denervated rats (P<0.05 vs vehicle treatment), respectively, and this effect was similar between groups (P=NS). These effects were associated with reductions in adiposity and energy intake (P<0.05). Collectively, these findings support the hypothesis that sympathetic innervation of IBAT is not required for central OT to increase BAT thermogenesis and reduce BW gain and adiposity in male DIO rats.

Oxytocin with calcium vs oxytocin for induction of labor in women with term premature rupture of membranes: a randomized controlled trial

BackgroundIntravenous calcium administration has shown promise in enhancing uterine contractions and reducing blood loss during cesarean section, but this regimen has not been compared in vaginal labor induction. ObjectiveTo determine the efficacy of oxytocin combined with calcium versus oxytocin alone for inducing labor among women with term premature rupture of membranes (PROM). Study designThis single-blind, randomized control trial was conducted between October 2022 and May 2023 in a tertiary university hospital. Patients diagnosed with PROM were randomly allocated into two groups. The intervention group received a bolus of 10 mL of calcium gluconate followed by a continuous infusion of oxytocin via a pump (n = 210), whereas the control group received only oxytocin infusion (n = 218). The primary outcome was successful vaginal deliveries within 24 hours of labor induction. Secondary outcomes included the interval from labor induction to delivery, vaginal delivery blood loss, and maternal and neonatal complications. ResultsBaseline characteristics, including maternal age, BMI, Bishop score before labor induction, were comparable between groups. The rate of vaginal delivery within 24 hours of labor induction was statistically higher in the intervention group (79.52% vs. 70.64%; P = 0.04). Participants in intervention group experienced a shortened interval between induction and delivery (10.48 h vs. 11.25h; P = 0.037), and demonstrated a higher success rate in induction of labor assessed by the onset of active phase (93.80% vs. 87.61%; P = 0.04) without increasing the cesarean rate. Reduced hemorrhage was presented in the intervention group (242.5ml vs. 255.0ml; P = 0.0015) while the maternal and neonatal outcomes were comparable between groups. ConclusionThe co-administration of calcium and oxytocin in labor induction among pregnancies with PROM was more efficient and safer than oxytocin alone. Our research suggests that the combination therapy of calcium and oxytocin may offer significant advantages during the process of labor induction and result in better outcomes.

Stimulation Therapy to Induce Mothers: Protocol for a Multicenter Randomized Controlled Trial.

More than 1 million women have their labor induced in the United States each year, and synthetic oxytocin infusion is the most common method used. However, compared to spontaneous labor, medical induction is resource intensive, has increased obstetric risks, and is associated with less successful breastfeeding. In contrast to the endogenous oxytocin hormone, which is released in a pulsatile fashion in the brain, synthetic oxytocin is continuously infused intravenously, resulting in important limitations related to efficacy, safety, and cost. Akin to spontaneous labor contractions, infant suckling of the breast nipple is known to stimulate the pulsatile release of endogenous oxytocin from the posterior pituitary gland. Nipple stimulation therapy via an electric breast pump similarly stimulates endogenous oxytocin release and may be a favorable inpatient method for patients undergoing labor induction. This study aims to examine whether inpatient nipple stimulation therapy is an efficacious labor induction method that increases the likelihood of spontaneous vaginal delivery and sustained breastfeeding and determine whether it is a cost-effective approach. This is a multicenter, pragmatic, open-label, parallel-group randomized controlled trial of nulliparous patients with singleton gestations ≥36 weeks undergoing labor induction. This trial compares inpatient nipple stimulation therapy via an electric breast pump versus immediate synthetic oxytocin infusion without nipple stimulation. This trial including 988 nulliparas will provide adequate statistical power to detect clinically meaningful differences in delivery mode and breast milk as the sole source of nutrition for newborns at hospital discharge or 72 hours after birth. The project received pilot funding in 2021 and full funding in 2023. Enrollment for this study began in November 2021 at a single site, and as of May 2024, recruitment is underway at 3 study sites. It is anticipated that enrollment will be completed by late 2026. Successful completion of this trial will provide rigorous data to determine whether inpatient nipple stimulation therapy with an electric breast pump can improve the way we induce labor and positively impact breastfeeding success and early infant nutrition through lactation. ClinicalTrials.gov NCT05079841; https://clinicaltrials.gov/study/NCT05079841. DERR1-10.2196/63463.

Sympathetic innervation of interscapular brown adipose tissue is not a predominant mediator of oxytocin-elicited reductions of body weight and adiposity in male diet-induced obese mice.

Previous studies indicate that CNS administration of oxytocin (OT) reduces body weight in high fat diet-induced obese (DIO) rodents by reducing food intake and increasing energy expenditure (EE). We recently demonstrated that hindbrain (fourth ventricular [4V]) administration of OT elicits weight loss and elevates interscapular brown adipose tissue temperature (TIBAT, a surrogate measure of increased EE) in DIO mice. What remains unclear is whether OT-elicited weight loss requires increased sympathetic nervous system (SNS) outflow to IBAT. We hypothesized that OT-induced stimulation of SNS outflow to IBAT contributes to its ability to activate BAT and elicit weight loss in DIO mice. To test this hypothesis, we determined the effect of disrupting SNS activation of IBAT on the ability of 4V OT administration to increase TIBAT and elicit weight loss in DIO mice. We first determined whether bilateral surgical SNS denervation to IBAT was successful as noted by ≥ 60% reduction in IBAT norepinephrine (NE) content in DIO mice. NE content was selectively reduced in IBAT at 1-, 6- and 7-weeks post-denervation by 95.9 ± 2.0, 77.4 ± 12.7 and 93.6 ± 4.6% (P<0.05), respectively and was unchanged in inguinal white adipose tissue, pancreas or liver. We subsequently measured the effects of acute 4V OT (1, 5 µg ≈ 0.99, 4.96 nmol) on TIBAT in DIO mice following sham or bilateral surgical SNS denervation to IBAT. We found that the high dose of 4V OT (5 µg ≈ 4.96 nmol) elevated TIBAT similarly in sham mice as in denervated mice. We subsequently measured the effects of chronic 4V OT (16 nmol/day over 29 days) or vehicle infusions on body weight, adiposity and food intake in DIO mice following sham or bilateral surgical denervation of IBAT. Chronic 4V OT reduced body weight by 5.7 ± 2.23% and 6.6 ± 1.4% in sham and denervated mice (P<0.05), respectively, and this effect was similar between groups (P=NS). OT produced corresponding reductions in whole body fat mass (P<0.05). Together, these findings support the hypothesis that sympathetic innervation of IBAT is not necessary for OT-elicited increases in BAT thermogenesis and reductions of body weight and adiposity in male DIO mice.

Effectiveness of Misoprostol Versus Manual Vacuum Aspiration for the Treatment of the First Trimester Pregnancy Termination

Objective: To compare the effectiveness of misoprostol versus manual vacuum aspiration (MVA) in the treatment of pregnancy termination at first 12 weeks of pregnancy, evaluating the outcomes among women undergoing these procedures. Methodology: A comparative analysis was carried out at the Obstetrics and Gynaecology department of Bakhtawar Amin Hospital, Multan from January 2023 to December 2023, included pregnant women presented with age of gestation age up to 12 weeks, open cervical os and indication for elective termination of pregnancy. Participants were randomized into two groups. Misoprostol group received 400 mcg of misoprostol intravaginally every 4 hours for up to three doses for softening cervix, its dilatation, and uterine contractions, with starting oxytocin infusion after 6 hours. While manual vacuum aspiration group underwent the procedure under general anesthesia without receiving any uterotonics. Patients were followed up on the 7th day post-procedure, undergoing ultrasonography to measure endometrial thickness for efficacy assessment based on complete abortion. Results: A total of 126 patients were comparatively studied; 63 in each group with mean age in the Misoprostol group was 33.45±3.11 years, and was slightly lower the MVA group as30.22±4.76 years. The average gestational age at the time of treatment was almost similar between the groups, 8.33 ±1.29 weeks for Misoprostol group and 7.99±2.56 weeks for the MVA group. The Misoprostol group exhibited an efficacy rate of 95.20% among patients, compared to 90.50% in the MVA group (P=0.148). Furthermore, the efficacy between Misoprostol and MVA across different age groups, gestational ages, and parity, was statistically insignificant (p-&gt;0.05). Conclusion: Basis on the study findings, the efficacy of misoprostol for first trimester termination of pregnancy was observed to be 95.20%, slightly higher than the 90.50% with manual vacuum aspiration (MVA).

Oxytocin Attenuates Sympathetic Innervation with Inhibition of Cardiac Mast Cell Degranulation in Rats after Myocardial Infarction.

Sympathetic hyperinnervation is the leading cause of fatal ventricular arrhythmia (VA) after myocardial infarction (MI). Cardiac mast cells cause arrhythmias directly through degranulation. However, the role and mechanism of mast cell degranulation in sympathetic remodeling remain unknown. We investigated the role of oxytocin (OT) in stabilizing cardiac mast cells and improving sympathetic innervation in rats. MI was induced by coronary artery ligation. Western blotting, immunofluorescence, and toluidine staining of mast cells were performed to determine the expression and location of target protein. Mast cells accumulated significantly in peri-infarcted tissues and were present in a degranulated state. They expressed OT receptor (OTR), and OT infusion reduced the number of degranulated cardiac mast cells post-MI. Sympathetic hyperinnervation was attenuated as assessed by immunofluorescence for tyrosine hydroxylase (TH). Seven days post-MI, the arrhythmia score of programmed electrical stimulation was higher in vehicle-treated rats with MI than in rats treated with OT. An in vitro study showed that OT stabilized mast cells via the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Further in vivo studies on OTR-deficient mice showed worsening mast cell degranulation and worsening sympathetic innervation. OT pretreatment inhibited cardiac mast cell degranulation post-MI and prevented sympathetic hyperinnervation, along with mast cell stabilization via the PI3K/Akt pathway. SIGNIFICANCE STATEMENT: This is the first study to elucidate the role and mechanism of oxytocin (OT) in inflammatory-sympathetic communication mediated sympathetic hyperinnervation after myocardial infarction (MI), providing new approaches to prevent fatal arrhythmias.

Determinants of Higher Oxytocin Dose Need During Labor Induction

Background: Several guidelines have been published regarding intrapartum oxytocin infusion for labor induction or augmentation; however, many of them lack specificity. Objectives: Therefore, this study aimed to assess the oxytocin dose administered during labor and evaluate its association with maternal characteristics and short-term perinatal outcomes. Methods: This retrospective cross-sectional study was conducted on 162 term pregnant women who were admitted to the labor ward for vaginal delivery in two academic hospitals during 2021 - 2022. Maternal demographic features, obstetric and medical history data, labor process details (initial Bishop score, membrane status on admission and at the time of labor induction or augmentation, latent and active phase duration, oxytocin dose, delivery mode, and neonatal outcomes) were obtained and recorded. Participants were divided into two main groups based on the intrapartum oxytocin dose, and the desired outcomes were reported and compared between the groups. Results: The median maternal age was 28 years (range: 16 - 46). The median oxytocin dose administered during labor induction was 10 mU/min (range: 2.5 - 25 mU/min). Oxytocin dose was significantly correlated with gestational age (P &lt; 0.001), cervical dilation and effacement (P &lt; 0.001), fetal head station (P &lt; 0.001), cervical consistency (P &lt; 0.001), and cervical Bishop score before labor induction (P &lt; 0.001). The cervical dilation at the time of membrane rupture was also positively correlated with the intrapartum oxytocin dose (P = 0.013). Higher gestational age was correlated with a higher required oxytocin dose (P &lt; 0.001). The cesarean rate was 22.8% in the study population, and it was positively correlated with intrapartum oxytocin dose (P &lt; 0.001). Conclusions: The cervical Bishop score and its components, except for cervical position, were correlated with the intrapartum oxytocin dose. In other words, the less favorable the cervix, the higher the likelihood of requiring higher doses of oxytocin and consequently experiencing a longer duration of labor. Additionally, the cesarean rate was higher in those who needed oxytocin doses of more than 10 mU/min; however, short - term neonatal outcomes were not different.

A Comparative Study between Oxytocin Intravenous Bolus versus Oxytocin Intravenous Bolus and Infusion for Control of Blood Loss at Elective Cesarean Section

A Comparative Study between Oxytocin Intravenous Bolus versus Oxytocin Intravenous Bolus and Infusion for Control of Blood Loss at Elective Cesarean Section

Comparison of Carbetocin and Oxytocin Efficacy in Preventing Postpartum Hemorrhage after C-Section

Introduction: Postpartum hemorrhage (PPH) is defined as a blood loss of more than 0.5 liters within 24 hours of birth, and a blood loss of more than 1 liter is considered a significant PPH. In low- and middle-income countries, PPH is a major factor causing maternal morbidity and mortality, whereas in high-income countries, the mortality is comparatively lower, but still PPH poses a major risk for postpregnancy complications. Uterine atony is the most frequent cause of the PPH, and it accounts for up to 80% of PPH cases. Aim: The aim of this study is to examine the prophylactic effects of oxytocin and carbetocin in preventing atonic PPH in individuals receiving recurrent elective CS under spinal anesthesia. Materials and Methods: A computerized, randomized, cross-sectional prospective comparative study was conducted on 100 pregnant women at Konaseema Institute of Medical Sciences and Research Foundation for the time period of an year, from October 2020 to October 2021. Inclusion Criteria: This study includes patients with singleton pregnancy, gestational age &gt;38 weeks, spinal anesthesia and repeated C.S with cephalic, breech, or any malpresentations. Exclusion Criteria: Patients with placenta previa and placental abruption, uterine myomata, congenital uterine anomalies, gestational age before 38 weeks, women having emergency cesarean section for fetal or maternal distress, and patients with hepatic or pre-existing bleeding disorder were excluded from the study. The patients included based on the above criteria were split into two equal groups. Group I received carbetocin as a single dose of 100 microgram slow intravenous, and Group II received oxytocin as 5 IU intravenous drip followed by 20 IU of oxytocin infusion on 500 ml saline or lactated ringer with a rate of 150 ml per hour. Results: When compared to the oxytocin group, the blood loss was considerably reduced in the carbetocin group. The levels of Hb and hematocrit [HCT] were evaluated pre- and postoperative in both the groups. The levels of preoperative Hb and HCT showed nonsignificant difference between the two groups, while the levels of postoperative Hb and HCT were significantly higher in carbetocin group than oxytocin group concluding that carbetocin showed the better results in controlling the blood loss and maintaining the levels of Hb and HCT volume and the carbetocin group showed less need for administration of uterotonic agents (20%) in comparison with (32%) in oxytocin group but with no statistically significant difference. Only 8 (16%) patients showed PPH in carbetocin treatment, whereas 14 (28%) showed PPH in patients on oxytocin treatment.

Primary Posterior Uterine Rupture in Labor: Case Report and Literature Review

Purpose: To report a rare case of primary posterior uterine rupture in a healthy term multigravida. Methods: Case report. Results: We present the case of an otherwise healthy 35-year-old gravida 4 para 3 with no reported medical or surgical history and three prior uncomplicated term vaginal deliveries who presented in labor at 39 weeks gestation. After four hours of oxytocin augmentation, the fetus was noted to have recurrent late decelerations and then became bradycardic with a baseline of 60 bpm. The patient’s cervix was found to be 7 cm dilated, 90% effaced, and -1 station. Standard resuscitative measures were undertaken at which point the patient’s cervix was rechecked and found to be 9 cm dilated, 90% effaced, and -1 station. Attempts at manually reducing the cervix while the patient pushed were unsuccessful. With the fetus still bradycardic with a baseline of 60 bpm, the patient was taken for an emergency Cesarean delivery. Within seven minutes of calling the emergency Cesarean delivery, surgery had started. However, there was difficulty with delivering the fetus, who had flipped to transverse back down. The fetus was rotated to breech before being delivered through a “T” incision made on the uterus to facilitate delivery of the head. Three tight nuchal cords were reduced at time of delivery. Examination of the uterus after delivery of the fetus revealed a full thickness, cruciate-shaped laceration in the posterior lower uterine segment extending ~9 cm in the vertical plane, involving the vagina, and ~5 cm in the transverse plane. The rupture was repaired, and the remainder of the surgery proceeded without further complication. Blood loss was estimated at 2500 mL, and she required transfusion of 4 units of packed red cells, 2 units cryoprecipitate, 1 unit fresh frozen plasma, and 1 unit of platelets. The infant was atonic upon delivery with a weight of 3785g and APGARs of 1/5/7. Umbilical artery blood gas analysis was normal with a pH of 7.19 and a base deficit of 7.9 mmol/L. The infant initially required intubation, but quickly improved and was extubated to room air at 1 hour of life. Imaging and neurological exams indicated possible moderate encephalopathy, and the infant underwent therapeutic hypothermia for four days at which point cooling was discontinued after improvement was noted. The remainder of his NICU stay was unremarkable and he was discharged on day nine of life. The mother required 2 additional units of packed red cells during the remainder of her postpartum course, but otherwise did well and she was discharged on post-op day five. Conclusion(s): Uterine rupture is the complete separation of all three layers of the uterus. It is a life-threatening event for both the fetus and the mother. Most uterine ruptures occur in a previously scarred uterus. Uterine rupture in a previously unscarred uterus (primary uterine rupture) is rare and estimated to occur in ~1:20,000 pregnancies. Over 90% of primary uterine ruptures occur in the anterior lower uterine segment. Although this patient did not have any reported medical or surgical history, her status as a multipara and being of advanced maternal age did pose a higher risk of primary rupture. This patient also underwent 3 ½ hours of oxytocin infusion at the time the Cesarean was called. Although she was not on oxytocin for long, its use is associated with primary uterine rupture more so than secondary rupture. Normal indicators of uterine rupture include non-reassuring fetal heart rate tracing, sudden unexplained abdominal pain, unexplained vaginal bleeding, and loss of fetal station. In this patient, fetal bradycardia was the only sign that her uterus was compromised. Although the uterine arteries were not involved in this patient’s rupture, blood loss was still profound due to the extensive uterine defect. This case highlights that, while rare, uterine rupture can occur in any patient, regardless of uterine surgical history and physicians must be prepared to intervene quickly.

Sympathetic innervation of interscapular brown adipose tissue is not a predominant mediator of oxytocin-elicited reductions of body weight and adiposity in male diet-induced obese mice.

Previous studies indicate that CNS administration of oxytocin (OT) reduces body weight in high fat diet-induced obese (DIO) rodents by reducing food intake and increasing energy expenditure (EE). We recently demonstrated that hindbrain (fourth ventricular [4V]) administration of OT elicits weight loss and elevates interscapular brown adipose tissue temperature (T IBAT , a surrogate measure of increased EE) in DIO mice. What remains unclear is whether OT-elicited weight loss requires increased sympathetic nervous system (SNS) outflow to IBAT. We hypothesized that OT-induced stimulation of SNS outflow to IBAT contributes to its ability to activate BAT and elicit weight loss in DIO mice. To test this hypothesis, we determined the effect of disrupting SNS activation of IBAT on the ability of 4V OT administration to increase T IBAT and elicit weight loss in DIO mice. We first determined whether bilateral surgical SNS denervation to IBAT was successful as noted by ≥ 60% reduction in IBAT norepinephrine (NE) content in DIO mice. NE content was selectively reduced in IBAT at 1-, 6- and 7-weeks post-denervation by 95.9±2.0, 77.4±12.7 and 93.6±4.6% ( P <0.05), respectively and was unchanged in inguinal white adipose tissue, pancreas or liver. We subsequently measured the effects of acute 4V OT (1, 5 µg ≈ 0.99, 4.96 nmol) on T IBAT in DIO mice following sham or bilateral surgical SNS denervation to IBAT. We found that the high dose of 4V OT (5 µg ≈ 4.96 nmol) elevated T IBAT similarly in sham mice as in denervated mice. We subsequently measured the effects of chronic 4V OT (16 nmol/day over 29 days) or vehicle infusions on body weight, adiposity and food intake in DIO mice following sham or bilateral surgical denervation of IBAT. Chronic 4V OT reduced body weight by 5.7±2.23% and 6.6±1.4% in sham and denervated mice ( P <0.05), respectively, and this effect was similar between groups ( P =NS). OT produced corresponding reductions in whole body fat mass ( P <0.05). Together, these findings support the hypothesis that sympathetic innervation of IBAT is not necessary for OT-elicited increases in BAT thermogenesis and reductions of body weight and adiposity in male DIO mice.

Oxytocin attenuates cocaine-associated place preference via the dorsal hippocampus in male and female rats

Cocaine addiction is the third largest cause of overdose-related deaths in the United States. Research investigating therapeutic targets for cocaine reward processes is key to combating this issue. The neuropeptide oxytocin (OXT) has been shown to reduce cocaine reward processes, though specific mechanisms are not understood. This study examines the effect of intra-dorsal hippocampal (DH) OXT on the expression of cocaine context associations using a conditioned place preference (CPP) paradigm. In this paradigm, one of two visually distinct chambers is paired with a drug. With repeated pairings, control animals display preference for the drug-associated context by spending more time in that context at test. In the present study, four conditioning days took place where male and female rats were injected with either cocaine or saline and placed into the corresponding chamber. On test day, rats received infusions of OXT or saline (VEH) into the DH and were allowed access to both chambers. The results show that while VEH-infused rats displayed cocaine CPP, OXT-infused rats did not prefer the cocaine-paired chamber. These findings implicate the DH as necessary in the mechanism by which OXT acts to block the expression of cocaine-context associations, providing insight into how OXT may exert its therapeutic effect in cocaine reward processes.

Effect of administration routes of oxytocin on hemoglobin in neonates with delayed umbilical cord clamping: a multi-centre randomized controlled clinical trial

PurposeTo evaluate the effect of intravenous infusion versus intramyometrial injection of oxytocin on hemoglobin levels in neonates with delayed umbilical cord clamping during cesarean section.MethodsThe multi-centre randomized controlled trial was performed at three hospitals from February to June 2023. Women with term singleton gestations scheduled for cesarean delivery were allocated to receive an intravenous infusion of 10 units of oxytocin or a myometrial injection of 10 units of oxytocin during the surgery. The primary outcome was neonatal hemoglobin at 48 to 96 h after birth. Secondary outcomes were side-effects of oxytocin, postpartum haemorrhage, phototherapy for jaundice, feeding at 1 month, maternal and neonatal morbidity and re-admissions.ResultsA total of 360 women were randomized (180 women in each group). The mean neonatal hemoglobin did not show a significant difference between the intravenous infusion group (194.3 ± 21.7 g/L) and the intramyometrial groups (195.2 ± 24.3 g/L) (p = 0.715). Secondary neonatal outcomes, involving phototherapy for jaundice, feeding at 1 month and neonatal intensive care unit admission were similar between the two groups. The maternal outcomes did not differ significantly between the two groups, except for a 200 mL higher intraoperative infusion volume observed in the intravenous group compared to the intramyometrial group.ConclusionAmong women undergoing elective cesarean delivery of term singleton pregnancies, there was no significant difference in neonatal hemoglobin at 48 to 96 h after birth between infants with delayed cord clamping, whether the oxytocin was administrated by intravenous infusion or intramyometrial injection.Trial registrationChinese Clinical trial registry: ChiCTR2300067953 (1 February 2023).

Inhibitory Effect and Mechanism upon Glucose-Insulin-Potassium Administration on Postpartum Mice with Uterine Cramping Pain

This study aimed to explore the effect of glucose-insulin-potassium (GIK) on postpartum uterine cramping pain(UCP) in mice and the possible underlying mechanisms. Thirty full-term pregnancy C57BL/6 mice, within 6 h after spontaneous labor, the mice were randomly assigned into the following three groups: the control group (group C), the oxytocin group (group O), and the GIK plus oxytocin group (group G). Group G and group O were administered GIK and normal saline, respectively, and 10 min later, oxytocin was injected intraperitoneally; group C received normal saline twice. The pain scores of the mice were assessed after establishment of the postpartum UCP model. The differential expressions of energy metabolism and oxidized lipid metabolites in the uterus were analyzed. The behavioral scores in group G were significantly lower than those in group O (P < 0.05).When compared to group O, group G showed a significant increase in ATP levels (P = 0.046), and group G exhibited elevated levels of amino acids, including L-glutamine, L-aspartic acid, and ornithine. Additionally, phosphate compounds (2-phosphoglyceric acid and 3-phosphoglyceric acid) showed elevated levels. When compared to group O, group G exhibited a decrease in 19R-hydroxy PGF2α, an increase in 9,10-EpOME and 12,13-EpOME, and a decrease in trans-EKODE-E-Ib. Additionally, group G showed an elevation in 16,17-EpDPE and 8-HDoHE. This study confirms the analgesic effect of GIK during postpartum oxytocin infusion. Metabolomics and glycolysis product analysis suggest that GIK’s alleviation of UCP is associated with its enhancement of glycolysis and the influence of phenylalanine synthesis, aspartate metabolism, and arginine synthesis pathways. Additionally, the effects of GIK appears to be linked to its influence on the linoleic acid metabolic pathway.