Food and fluid intake during labor in maternity wards: A scoping review protocol.

During the 1940s, aspiration of stomach contents was recognized as a serious problem during labor, which is why fluid and food restriction was adopted for women who would undergo general anesthesia. Currently, the practice of generalized food restriction is a routine that is being discontinued. This review aims to map the evidence on the effects of the intake of foods, supplements and drinks in women on labor outcomes. To that end, documents investigating this topic in pregnant women admitted for uncomplicated deliveries in maternity wards, published from 2013 onwards, will be assessed. This interval was defined based on the publication by Singata et al., who carried out a systematic review on the benefits and harms of oral fluid intake or food restriction during labor. The scoping review methods of the JBI and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review (PRISMA) were followed. Firstly, a preliminary search was carried out to identify the existence of similar scoping reviews or protocols, as well as the keywords and MeSH descriptors in the titles and abstracts, with a view to developing a complete search strategy. Subsequently, a search will be carried out in the Cochrane Library, Medline/PubMed, Embase, SCOPUS and Web of Science databases. The search strategy will be adapted for each of these databases. Finally, a reverse search will be carried out using the references of the included studies. The obtained documents will be imported into Rayyan for duplicate detection and removal. Two independent reviewers will read the titles and abstracts, observing the inclusion and exclusion criteria. The data extraction from each included study will be carried out independently by two reviewers, using the extraction form created for this purpose. In order to report results, we will follow the PRISMA checklist and report descriptive statistics and a narrative summary.

The White Blood Cell Count in Laboring Women at Term Is Associated with Neonatal Macrosomia.

BACKGROUND: Fetal weight estimation at term is a challenging clinical task. OBJECTIVES: To evaluate the association between peripheral white blood cell (WBC) count of the laboring women and neonatal birth weight (BW) for term uncomplicated pregnancies. METHODS: We conducted a single-center, retrospective cohort study (2006-2021) of women admitted in the first stage of labor or planned cesarean delivery. Complete blood counts were collected at admission. BW groups were categorized by weight (grams): < 2500 (group A), 2500-3499 (group B), 3500-4000 (group C), and > 4000 (group D). Two study periods were used to evaluate the association between WBC count and neonatal BW. RESULTS: There were a total of 98,632 deliveries. The dataset analyses showed a lower WBC count that was significantly and linearly associated with a higher BW; P for trend < 0.001 for women in labor. The most significant association was noted for the > 4000-gram newborns; adjusted odds ratio 0.97, 95% confidence interval 0.96-0.98; P < 0.001; adjusted for hemoglobin level, gestational age, and fetal sex. The 2018-2021 dataset analyses revealed WBC as an independent predictor of macrosomia with a significant incremental predictive value (P < 0.0001). The negative predictive value of the WBC count for macrosomia was significantly high, 93.85% for a threshold of WBC < 10.25 × 103/µl. CONCLUSIONS: WBC count should be considered to support the in-labor fetal weight estimation, especially valuable for the macrosomic fetus.

Epidural Analgesia During Labor and Neonatal Hypoxic-Ischemic Encephalopathy.

Importance: Epidural analgesia is used by approximately 70% of birthing persons in the US to alleviate labor pain and is a common cause of elevated temperature in the birthing parent during labor, which, in turn, is associated with adverse neonatal outcomes such as hypoxic-ischemic encephalopathy (HIE). Objective: To determine whether epidural analgesia is associated with increased risk of HIE after adjusting for the birthing person's maximal temperature before epidural placement and for the propensity to get an epidural. Design, Setting, and Participants: This retrospective, population-based cohort study was conducted at 15 Kaiser Permanente Northern California hospitals. Participants included singleton neonates born at 35 weeks' or later gestational age between 2012 and 2019. Elective cesarean deliveries and deliveries within 2 hours of hospital admission were excluded. Data analysis was performed from November 2022 to June 2024. Exposure: The primary exposure was epidural analgesia during labor. Main Outcomes and Measures: The primary outcome was HIE, defined as the presence of both neonatal acidosis (ie, pH <7 or base deficit ≥10) and encephalopathy. The presence and timing of epidural analgesia and demographic, pregnancy, and labor characteristics were extracted from electronic medical records. A propensity score for receiving epidural analgesia was created including demographic variables and comorbidities predating epidural placement. Logistic regression was used to evaluate the association between epidural analgesia and HIE, adjusting for maximal birthing parent's temperature before epidural placement and the propensity for receiving an epidural. Results: Among 233 056 infants born at 35 weeks' or later gestational age by vaginal or unplanned cesarean delivery after at least 2 hours of in-hospital labor, 177 603 (76%) were exposed to epidural analgesia and 439 (0.19%) had HIE. On unadjusted analysis, epidural analgesia was associated with an increased risk of maximal temperature greater than 38 °C during labor (risk ratio [RR], 8.58; 95% CI, 8.06-9.14). Each degree increase in maximal temperature during labor was associated with nearly triple the odds of HIE (odds ratio [OR], 2.82; 95% CI, 2.51-3.17). However, there was no significant association between epidural analgesia and the risk of HIE either on crude (RR, 1.21; 95% CI, 0.96-1.53) or adjusted (adjusted OR, 0.93; 95% CI, 0.73-1.17) analyses. Conclusions and Relevance: In this cohort study including more than 230 000 parent-infant dyads, epidural analgesia was associated with increased maximal temperature during labor, a known risk factor for HIE. However, epidural analgesia was not associated with increased odds of HIE.

The effect of Rebozo technique on perceived labour pain and childbirth experience: A randomized controlled trial.

BACKGROUND: Pain, stress, and anxiety experienced during childbirth can have detrimental effects on labor and delivery. The rebozo technique is an ancestral method used to minimize pain and enhance relief during gestation. This study aimed to investigate the effects of the rebozo technique on the birth process and its probable benefits on the birth experience. METHODS: This survey was conducted from January to May 2021 in a randomized and controlled manner. A total of 113 pregnant women with their first children were surveyed. Women between 37 and 41 weeks of gestation without complications who were admitted to the delivery room with a cervical dilation of 4 cm or more were chosen as participants. In the Rebozo group, subjects were randomly selected by trained personnel to apply the standardized method, while the control group received a relaxing massage. Cervical dilation, fetal position, contraction patterns, and measures related to the birth experience were key indicators. RESULTS: Women in the rebozo group had lower pain levels during birth and greater birth satisfaction. Mean cervical dilation in the latent phase was 5.61 cm in the rebozo group and 5.71 cm in the control group. In the active phase, cervical dilatation was 6.03 cm in the rebozo group and 6.68 cm in the control group, and this difference was statistically significant (P < .001). In the transition phase, the birth time was 46.29 minutes in the rebozo group and 68.71 minutes in the control group (P = <.007**). In the total birth experience score, the rebozo group received an average of 68.52 points, while the control group received 51.58 points (P < .001). CONCLUSION: This research has established that the use of the rebozo technique throughout labor helps enhance her feelings about being pregnant, as well as heightening fulfillment with delivery.

Optimizing labor duration with pilates: evidence from a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Pilates has captured interest due to its possible advantages during pregnancy and childbirth. Although research indicates that Pilates may reduce labor duration, alleviate pain, and improve satisfaction with the childbirth experience, consensus on these outcomes remains elusive, underscoring the necessity for additional studies. AIM: This systematic review and meta-analysis aimed to assess the impact of Pilates exercises on labor duration among pregnant women. METHODS: The online database was searched to yield the literature using the terms of 'Pilates', 'childbirth', and 'labor duration', and similar terms including PubMed, Clinical Key, Scopus, Web of Science, Embase, and Cochrane Database of Systematic Reviews up to June 25, 2023. Studies were considered eligible if they were randomized or clinical controlled trials (RCTs/CCTs) published in English, focusing on healthy pregnant women without exercise contraindications. The studies needed to include interventions involving Pilates or exercise movement techniques, a comparison group with no exercise, and outcomes related to labor duration, the period of the active phase, and the second stage of delivery. RESULTS: Eleven studies, totalling 1239 participants, were included in the analysis. These studies provided high-quality evidence from exercise only RCTs/CCTs. The findings indicated a significant reduction in the active phase of labor (8 RCTs, n = 1195; Mean Difference [MD] = -56.35, 95% Confidence Interval [CI] [-89.46 to -23.25]) and overall labor duration (8 RCTs, n = 898; MD = -93.93, 95% CI [-138.34 to -49.51]) in pregnant women who engaged in Pilates exercises compared to those who did not but doesn't affect on the duration of the second stage of labor (7 RCTs, n = 1135; MD = -0.11, 95% CI [-7.21 to 6.99]). CONCLUSIONS: While this review primarily addresses the effects of Pilates on healthy and low-risk pregnant women, the findings suggest a potential role for Pilates in shortening labor duration. Therefore, engaging in Pilates or similar physical activities is recommended for pregnant women to potentially facilitate a more efficient labor process.

A new effect of intravenous iron treatment in pregnancy: contraction in nonstress test and timing of labor.

OBJECTIVE: The aim of this study was to elucidate the cause and results of contractions occurring in term pregnant women receiving intravenous iron therapy. METHODS: During 2019-2020, 136 pregnant women beyond 35 weeks of gestation, who received intravenous iron treatment due to iron deficiency anemia, were included through retrospective screening. Iron deficiency anemia was defined as having hemoglobin levels <10 g/dL and ferritin levels <15 ng/mL, and the pregnant women underwent nonstress test before and after treatment. RESULTS: The average treatment week for the pregnant women was 36.82±0.74, and the presence of regular contractions in post-treatment follow-up nonstress tests was 72.1% (n=98). The average week of birth was 38.48±1.60. Pregnant women with contractions who had previous cesarean were found to have a mean delivery week of 36.82±0.67, which was statistically significant earlier than for nulliparous and multiparous women (p<0.001). CONCLUSION: In pregnant women with iron deficiency anemia who were beyond 35 weeks, temporary regular contractions may be observed in the nonstress test following intravenous iron replacement. We think that this effect may lead to early term birth in pregnant women with a history of cesarean section. It needs to be confirmed by further prospective studies and animal studies.

Labor patterns of spontaneous first-stage labor in Chinese women with normal neonatal outcomes.

BACKGROUND: Friedman's standards, developed almost 50 years ago, may no longer align with the needs of today's obstetric population and current pregnancy management practices. This study aims to analyze contemporary labor patterns and estimate labor duration in China, focusing on first-stage labor data from Chinese parturients with a spontaneous onset of labor. METHODS: This retrospective observational study utilized data from electronic medical records of a tertiary hospital in Changsha, Hunan. Out of a total of 2,689 parturients, exclusions were made for multiple gestations, preterm, post-term, or stillbirth, cesarean delivery, non-vertex presentation, and neonatal intensive care unit admission. Average labor curves were constructed by parity using repeated-measure analysis, and labor duration was estimated through interval-censored regression, stratified by cervical dilation at admission. We performed an analysis to assess the impact of oxytocin augmentation and amniotomy on labor progression and conducted a sensitivity analysis using women with complicated outcomes. RESULTS: Nulliparous women take over 180 minutes for cervical dilation from 3 to 4 cm, and the duration from 5 to 6 cm exceeds 145 minutes. Multiparous women experience shorter labor durations than nulliparous. Labor acceleration is observed after 5 cm in nulliparous, but no distinct inflection point is evident in the average labor curve. In the second stage of labor, the 95th percentile for nulliparous, with and without epidural analgesia, is 142 minutes and 127 minutes, respectively. CONCLUSIONS: These findings provide valuable insights for the reassessment of labor and delivery processes in contemporary obstetric populations, including current Chinese obstetric practice.

Maternal excessive weight gain as a potential risk factor for prolonged labor in Japanese pregnant women: The Japan Environment and Children's Study.

AIM: This study aimed to determine whether excessive maternal weight gain during pregnancy was associated with a higher risk of prolonged labor. METHODS: We analyzed the data regarding maternal weight gain during pregnancy for the participants of Japan Environment and Children's Study (JECS), which is an ongoing nationwide prospective birth cohort study in Japan. After excluding participants with multiple pregnancies, with deliveries before 37 or beyond 42 weeks of gestation, or who had undergone cesarean section, 71,154 (nulliparous, n = 28,442) Japanese women were included. Prolonged labor was defined by a cutoff ranking at the 95th percentile and consequently defined as labor duration exceeding 12.7 h in multiparous women and exceeding 23.2 h in nulliparous women. These classifications were made according to labor curves established by the Japanese Society of Obstetrics and Gynecology Perinatal Committee developed in June 2021. Considering that no studies have conducted an investigation based on this new guideline, we analyzed the association between excessive maternal weight gain during pregnancy and prolonged labor by parity. RESULTS: The overall incidence of prolonged labor was 10.2% (2,907/28,442) in nulliparous women and 6.1% (2,597/42,712) in multiparous women. Multivariable analysis indicated that excessive maternal weight gain was significantly associated with prolonged labor in nulliparous (adjusted odds ratio, 1.21; 95% confidence interval, 1.10-1.32) and multiparous women (adjusted odds ratio, 1.15; 95% confidence interval, 1.05-1.27). Kaplan-Meier survival analysis showed that as labor progressed, the percentage of women who had not yet delivered was higher among those with excessive maternal weight gain than among those with normal maternal weight gain in both the nulliparous (median labor duration 12.9 h vs 12.2 h, p<0.001) and multiparous (median labor duration 6.2 h vs 5.8 h, p<0.001) groups. CONCLUSION: Excessive maternal weight gain was significantly associated with prolonged labor in Japanese women.

Association between interpregnancy interval and the labor curve.

BACKGROUND: Both short and long interpregnancy intervals are associated with adverse pregnancy outcomes; however, the impact of interpregnancy intervals on labor progression is unknown. OBJECTIVE: We examined the impact of interpregnancy intervals on the labor curve, hypothesizing that those with a longer interpregnancy intervals would have slower labor progression. STUDY DESIGN: This is a retrospective cohort study of patients with a history of one prior vaginal delivery admitted for induction of labor or spontaneous labor with a singleton gestation ≥37 weeks at an academic medical center between 2004 and 2015. Repeated measures regression was used to construct labor curves, which were compared between patients with short interpregnancy intervals, defined as <3 years since the last delivery, and long interpregnancy intervals, defined as >3 years since the last delivery. We chose this interval as it approximates the median birth interval in the United States. Interval-censored regression was used to estimate the median duration of labor after 4 centimeters of dilation, stratified by type of labor (spontaneous vs induced). Multivariate analysis was used to adjust for potential confounders. RESULTS: Of the 1331 patients who were included in the analysis, 544 (41%) had a long interpregnancy interval. Among the entire cohort, there were no significant differences in first or second-stage progression between short and long interpregnancy interval groups. In the stratified analysis, first-stage progression varied between groups on the basis of labor type: long interpregnancy interval was associated with a slower active phase among those being induced and a quicker active phase among those in spontaneous labor. The second-stage duration was similar between cohorts regardless of labor type. CONCLUSION: Multiparas with an interpregnancy interval >3 years may have a slower active phase than those with a shorter interpregnancy interval when undergoing induction of labor. Interpregnancy interval does not demonstrate an effect on the length of the second stage.

Programmed Intermittent Epidural Bolus Reduces Workloads in Labor Analgesia: A Single Center's Experience.

Background and Objectives: Labor epidural analgesia can be maintained through programmed intermittent epidural bolus (PIEB), continuous epidural infusion (CEI), or patient-controlled epidural analgesia (PCEA). Our department changed from CEI+PCEA to PIEB+PCEA as the maintenance method. The higher hourly dose setting in the current regimen brought to our concern that side effects would increase with proportional staff workloads. This study aimed to investigate the validity of our proposal that PIEB+PCEA may function as a feasible tool in reducing the amount of work in the obstetrics anesthesia units. Materials and methods: This 2-year retrospective review included parturients with vaginal deliveries under epidural analgesia. We compared the staff burden before and after the switch from CEI (6 mL/h, PCEA 6 mL lockout 15 min, group A) to PIEB (8 mL/h, PCEA 8 mL lockout 10 min, group B). The primary outcome was the difference of proportion of parturients requiring unscheduled visits between groups. Side effects and labor and neonatal outcomes were compared. Results: Of the 694 parturients analyzed, the proportion of those requiring unscheduled visits were significantly reduced in group B (20.8% vs. 27.7%, chi-square test, p = 0.033). The multivariate logistic regression showed that PIEB was associated with fewer unscheduled visits than CEI (OR = 0.53, 95% CI [0.36-0.80], p < 0.01). Group B exhibited a significantly lower incidence of asymmetric blockade, as well as motor blockade. In nulliparous subjects, obstetric anal sphincter injury occurred less frequently when PIEB+PCEA was used. Significantly more multiparous women experienced vacuum extraction delivery in group B than in group A, and they had a longer second stage of labor. Conclusions: The PIEB+PCEA protocol in our study reduced workloads in labor epidural analgesia as compared to CEI+PCEA, despite that a higher dose of analgesics was administered. Future studies are warranted to investigate the effect of manipulating the PIEB settings on the labor outcomes.

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

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

Influence of non-pharmacological methods on duration of labor: a systematic review.

The article aims to verify the influence of MNFs on the duration of the birth process. A systematic review was carried out in the MEDLINE, Web of Science and LILACS databases, through a combination of terms that cover the topic addressed, from 1996 to 2021/April. The Excel spreadsheet was used to collect data to extract information regarding each selected article, in turn, data analysis included the evaluation and classification of quality, reliability and risk of bias, thus, the following tools were used: Cochrane RoB 2, Checklist and Newcastle-Ottawa Scale. Warm bath, walking, exercises with a birthing ball, breathing techniques, supine position, acupuncture, acupressure and water birth reduced labor time. While spontaneous pushing, massage and immersion baths prolonged labor. Non-pharmacological methods capable of reducing the duration of labor were hot/warm shower, walking, birth ball exercises, breathing techniques, maternal mobility, dorsal position, acupuncture, acupressure and water birth, as well. associated applied techniques such as hot/warm bath, ball exercises and lumbosacral massage, as well as immersion bath, ball exercises, aromatherapy, vertical postures and maternal mobility with alternating vertical postures, shortened the birth time.

The Rate of Cesarean Section and Newborn Apgar score In Two Types Of Physiological Delivery and Facilitated Delivery in Mothers with First Pregnancy.

INTRODUCTION: Labor pain is often severe and its lack of relief can have a bad effect on the mother's physiological condition. Accurate measurement and appropriate treatment of pain is an important problem. There are several choices for the control of labor pain, however, each method has its own risks and benefits regarding its efficiency and availability; therefore, the aim of this study was to compare the rate of cesarean section and newborn Apgar in two types of physiological delivery and facilitated delivery among mothers with first delivery. MATERIALS AND METHODS: This case-control study was conducted on mothers aged 18-35 who went to the hospital to give birth. In the present study, 8 sessions (90 minutes each session) were held to prepare mothers from 20 to 37 weeks of pregnancy. Candidate mothers for physiological labor were hospitalized without intervention and in the active phase of labor, and their labor stages were planned physiologically. The pain intensity of mothers was asked using a scale (VAS) during labor every half hour (according to the pain scale from 0 to 10). The average score of pain during the first and second stages, type of delivery, amount of postpartum bleeding, length of the stage of delivery, infection, and fever after delivery, Apgar score of the baby, perineal status, mother's satisfaction and the rate of hospitalization of the baby in NICU were recorded. Furthermore, the level of satisfaction with childbirth was evaluated with the help of Mackey's standard satisfaction questionnaire. RESULTS: The average age of the physiological delivery and facilitated delivery groups was 26.37 ± 5.23 years and 26.58 ± 5.79 years, respectively. Physiological delivery significantly required less conversion to cesarean section. The most common etiology was caesarean section in the physiologic labor group, and a drop in NST was reported in the facilitated group. The analysis of the results demonstrated no significant difference between the etiology of cesarean section and the study groups. The Apgar score in the physiological group was significantly better than the facilitated group. There is no significant relationship between the study group and the amount of bleeding during delivery. Furthermore, there was no significant relationship between the study group and the incidence of postpartum infection. The rate of NICU admission in the facilitated group was found to be significantly higher than physiological delivery. CONCLUSION: The results of this study revealed that the rate of caesarean section, the rate of need for NICU, newborns' Apgar score, and the rate of mothers' satisfaction in physiological delivery group were significantly different from the other groups, but the rate of wound infection and the amount of postpartum bleeding in the two groups showed a significant difference.

Multichannel mapping of in vivo rat uterine myometrium exhibits both high and low frequency electrical activity in non-pregnancy.

The uterus exhibits intermittent electrophysiological activity in vivo. Although most active during labor, the non-pregnant uterus can exhibit activity of comparable magnitude to the early stages of labor. In this study, two types of flexible electrodes were utilized to measure the electrical activity of uterine smooth muscle in vivo in anesthetized, non-pregnant rats. Flexible printed circuit electrodes were placed on the serosal surface of the uterine horn of six anesthetized rats. Electrical activity was recorded for a duration of 20-30 min. Activity contained two components: high frequency activity (bursts) and an underlying low frequency 'slow wave' which occurred concurrently. These components had dominant frequencies of 6.82 ± 0.63 Hz for the burst frequency and 0.032 ± 0.0055 Hz for the slow wave frequency. There was a mean burst occurrence rate of 0.76 ± 0.23 bursts per minute and mean burst duration of 20.1 ± 6.5 s. The use of multiple high-resolution electrodes enabled 2D mapping of the initiation and propagation of activity along the uterine horn. This in vivo approach has the potential to provide the organ level detail to help interpret non-invasive body surface recordings.

Relationship between labour analgesia modalities and types of anaesthetic techniques in categories 2 and 3 intrapartum caesarean deliveries.

General anesthesia (GA) is typically recommended for category 1 emergency cesarean delivery (CD). For categories 2-4 emergencies, either regional or GA can be used. The factors influencing the choice of anesthetic technique in these categories remain poorly understood. We analyzed the association between the type of labor analgesia and subsequent anesthetic techniques employed for intrapartum categories 2 and 3 CD. In a prospective longitudinal cohort study, 300 women were consequently enrolled and categorized according to Lucas's classification of CD urgency. The techniques of anesthesia (GA, spinal, and epidural anesthesia [EA]) employed for CD were analyzed with respect to labor analgesia methods (remifentanil patient-controlled analgesia [remifentanil-PCA], EA, and nitrous oxide [N2O]). EA was the most frequent analgesic option (43.8%), followed by remifentanil-PCA (20.7%) and N2O (5.1%), while 30.4% of parturient women received no analgesia. All anesthetic methods showed a significant relationship with analgesic modalities (P < 0.001). Remifentanil-PCA was associated with a higher incidence of GA. Contraindication to EA was the primary factor related to the transition from remifentanil-PCA to GA. Most parturients who received EA were successfully converted to EA. Spinal anesthesia was the most common technique in women using N2O and those without labor analgesia. GA was associated with lower 5-min Apgar scores. The method of labor analgesia was associated with the anesthesia technique employed for categories 2 and 3 CD. This finding may guide patient counseling and intrapartum anesthetic planning. However, the analysis should be cautiously interpreted as the selection of anesthesia is a complex decision influenced by several clinical considerations.

Changes in rate-pressure product associated with pregnancy.

BACKGROUND: In nonpregnant individuals, the rate-pressure product, the product of heart rate and systolic blood pressure, is used as a noninvasive surrogate of myocardial O2 consumption during cardiac stress testing. Pregnancy is considered a physiological cardiovascular stress test. Evidence describing the impact of pregnancy on myocardial O2 demand, as assessed by the rate-pressure product, is limited. OBJECTIVE: This study aimed to describe changes in the rate-pressure product for each pregnancy trimester, during labor and delivery, and the postpartum period among low-risk pregnancies. STUDY DESIGN: This was a retrospective cohort study that assessed uncomplicated pregnancies delivered vaginally at term. We collected rate-pressure product (heart rate × systolic blood pressure) values preconception, during pregnancy for each trimester (at ≤13 weeks + 6/7 days, at 14 weeks + 0/7 days through 27 weeks + 6/7 days, and at ≥28 weeks + 0/7 days), during the labor and delivery encounter (hospital admission until complete cervical dilation, complete cervical dilation until placental delivery, and after placental delivery until hospital discharge), and during the outpatient postpartum visit at 2 to 6 weeks after delivery. We calculated the percentage change at each time point from the preconception rate-pressure product (delta rate-pressure product). We used a mixed-linear model to analyze differences in the mean delta rate-pressure product over time and the influence of prepregnancy age, prepregnancy body mass index, and neuraxial anesthesia status during labor and delivery on these estimates. RESULTS: Our cohort comprised 316 patients. The mean rate-pressure product increased significantly from preconception starting at the third trimester of pregnancy and during labor and delivery (P≤.05). The mean delta rate-pressure product peaked at 12% and 38% in the third trimester and during labor and delivery, respectively. Prepregnancy body mass index was inversely correlated with the mean delta rate-pressure product changes (estimate, -0.308; 95% confidence interval, -0.536 to -0.80; P=.008). In contrast, neither the prepregnancy age, nor neuraxial anesthesia status during labor had a significant influence on this parameter. CONCLUSION: This study validates the transient but significant increase in the rate-pressure product, a clinical estimate of myocardial O2 demand, during uncomplicated pregnancies delivered vaginally at term. Pregnant individuals with lower prepregnancy body mass index experienced a sharper increase in this parameter. Patients who receive neuraxial anesthesia during labor and delivery experience similar changes in the rate-pressure product as those who did not.

The physiology and pharmacology of oxytocin in labor and in the peripartum period.

Oxytocin is a reproductive hormone implicated in the process of parturition and widely used during labor. Oxytocin is produced within the supraoptic nucleus and paraventricular nucleus of the hypothalamus and released from the posterior pituitary lobe into the circulation. Oxytocin is released in pulses with increasing frequency and amplitude in the first and second stages of labor, with a few pulses released in the third stage of labor. During labor, the fetus exerts pressure on the cervix of the uterus, which activates a feedforward reflex-the Ferguson reflex-which releases oxytocin. When myometrial contractions activate sympathetic nerves, it decreases oxytocin release. When oxytocin binds to specific myometrial oxytocin receptors, it induces myometrial contractions. High levels of circulating estrogen at term make the receptors more sensitive. In addition, oxytocin stimulates prostaglandin synthesis and release in the decidua and chorioamniotic membranes by activating a specific type of oxytocin receptor. Prostaglandins contribute to cervical ripening and uterine contractility in labor. The oxytocin system in the brain has been implicated in decreasing maternal levels of fear, pain, and stress, and oxytocin release and function during labor are stimulated by a social support. Moreover, studies suggest, but have not yet proven, that labor may be associated with long-term, behavioral and physiological adaptations in the mother and infant, possibly involving epigenetic modulation of oxytocin production and release and the oxytocin receptor. In addition, infusions of synthetic oxytocin are used to induce and augment labor. Oxytocin may be administered according to different dose regimens at increasing rates from 1 to 3 mIU/min to a maximal rate of 36 mIU/min at 15- to 40-minute intervals. The total amount of synthetic oxytocin given during labor can be 5 to 10 IU, but lower and higher amounts of oxytocin may also be given. High-dose infusions of oxytocin may shorten the duration of labor by up to 2 hours compared with no infusion of oxytocin; however, it does not lower the frequency of cesarean delivery. When synthetic oxytocin is administered, the plasma concentration of oxytocin increases in a dose-dependent way: at infusion rates of 20 to 30 mIU/min, plasma oxytocin concentration increases approximately 2- to 3-fold above the basal level. Synthetic oxytocin administered at recommended dose levels is not likely to cross the placenta or maternal blood-brain barrier. Synthetic oxytocin should be administered with caution as high levels may induce tachystole and uterine overstimulation, with potentially negative consequences for the fetus and possibly the mother. Of note, 5 to 10 IU of synthetic oxytocin is often routinely given as an intravenous or intramuscular bolus administration after delivery to induce uterine contractility, which, in turn, induces uterine separation of the placenta and prevents postpartum hemorrhage. Furthermore, it promotes the expulsion of the placenta.

Labor curves based on cervical dilatation over time and their accuracy and effectiveness: A systematic scoping review.

OBJECTIVES: This systematic scoping review was conducted to 1) identify and describe labor curves that illustrate cervical dilatation over time; 2) map any evidence for, as well as outcomes used to evaluate the accuracy and effectiveness of the curves; and 3) identify areas in research that require further investigation. METHODS: A three-step systematic literature search was conducted for publications up to May 2023. We searched the Medline, Maternity & Infant Care, Embase, Cochrane Library, Epistemonikos, CINAHL, Scopus, and African Index Medicus databases for studies describing labor curves, assessing their effectiveness in improving birth outcomes, or assessing their accuracy as screening or diagnostic tools. Original research articles and systematic reviews were included. We excluded studies investigating adverse birth outcomes retrospectively, and those investigating the effect of analgesia-related interventions on labor progression. Study eligibility was assessed, and data were extracted from included studies using a piloted charting form. The findings are presented according to descriptive summaries created for the included studies. RESULTS AND IMPLICATIONS FOR RESEARCH: Of 26,073 potentially eligible studies, 108 studies were included. Seventy-three studies described labor curves, of which ten of the thirteen largest were based mainly on the United States Consortium on Safe Labor cohort. Labor curve endpoints were 10 cm cervical dilatation in 69 studies and vaginal birth in 4 studies. Labor curve accuracy was assessed in 26 studies, of which all 15 published after 1986 were from low- and middle-income countries. Recent studies of labor curve accuracy in high-income countries are lacking. The effectiveness of labor curves was assessed in 13 studies, which failed to prove the superiority of any curve. Patient-reported health and well-being is an underrepresented outcome in evaluations of labor curves. The usefulness of labor curves is still a matter of debate, as studies have failed to prove their accuracy or effectiveness.

Implementation of sonopartogram: multicenter feasibility study.

OBJECTIVES: Well-established clinical practice for assessing progress in labor involves routine abdominal palpation and vaginal examination (VE). However, VE is subjective, poorly reproducible and painful for most women. In this study, our aim was to evaluate the feasibility of systematically integrating transabdominal and transperineal ultrasound assessment of fetal position, parasagittal angle of progression (psAOP), head-perineum distance (HPD) and sonographic cervical dilatation (SCD) to monitor the progress of labor in women undergoing induction of labor (IOL). We also aimed to determine if ultrasound can reduce women's pain during such examinations. METHODS: Women were recruited as they presented for IOL in three maternity units. Ultrasound assessments were performed in 100 women between 37 + 0 and 41 + 6 weeks' gestation. A baseline combined transabdominal and transperineal scan was performed, including assessment of fetal biometry, umbilical artery and fetal middle cerebral artery Doppler, amniotic fluid index, fetal spine and occiput positions, psAOP, HPD, SCD and cervical length. Intrapartum scans were performed instead of VE, unless there was a clinical indication to perform a VE, according to protocol. Participants were asked to indicate their level of pain by verbally giving a pain score between 0 and 10 (with 0 representing no pain) during assessment. Repeated measures data were analyzed using mixed-effect models to identify significant factors that affected the relationship between psAOP, HPD, SCD and mode of delivery. RESULTS: A total of 100 women were included in the study. Of these, 20% delivered by Cesarean section, 65% vaginally and 15% by instrumental delivery. There were no adverse fetal or maternal outcomes. A total of 223 intrapartum ultrasound scans were performed in 87 participants (13 women delivered before intrapartum ultrasound was performed), with a median of two scans per participant (interquartile range (IQR), 1-3). Of these, 76 women underwent a total of 151 VEs with a median of one VE per participant (IQR, 0-2), with no significant difference between vaginal- or Cesarean-delivery groups. After excluding those with epidural anesthesia during examination, the median pain score for intrapartum scans was 0 (IQR, 0-1) and for VE it was 3 (IQR, 0-6). Cesarean delivery was significantly associated with a slower rate of change in psAOP, HPD and SCD. CONCLUSIONS: Comprehensive transabdominal and transperineal ultrasound assessment can be used to assess progress in labor and can reduce the level of pain experienced during examination. Ultrasound assessment may be able to replace some transabdominal and vaginal examinations during labor. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Artificial intelligence based cardiotocogram assessment during labor.

OBJECTIVE: To assess whether artificial intelligence, inspired by clinical decision-making procedures in delivery rooms, can correctly interpret cardiotocographic tracings and distinguish between normal and pathological events. STUDY DESIGN: A method based on artificial intelligence was developed to determine whether a cardiotocogram shows a normal response of the fetal heart rate to uterine activity (UA). For a given fetus and given the UA and previous FHR, the method predicts a fetal heart rate response, under the assumption that the fetus is still in good condition and based on how that specific fetus has responded so far. We hypothesize that this method, when having only learned from fetuses born in good condition, is incapable of predicting the response of a compromised fetus or an episode of transient fetal distress. The (in)capability of the method to predict the fetal heart rate response would then yield a method that can help to assess fetal condition when the obstetrician is in doubt. Cardiotocographic data of 678 deliveries during labor were selected based on a healthy outcome just after birth. The method was trained on the cardiotocographic data of 548 fetuses of this group to learn their heart rate response. Subsequently it was evaluated on 87 fetuses, by assessing whether the method was able to predict their heart rate responses. The remaining 43 cardiotocograms were segment-by-segment annotated by three experienced gynecologists, indicating normal, suspicious, and pathological segments, while having access to the full recording and neonatal outcome. This future knowledge makes the expert annotations of a quality that is unachievable during live interpretation. RESULTS: The comparison between abnormalities detected by the method (only using past and present input) and the annotated CTG segments by gynecologists (also looking at future input) yields an area under the curve of 0.96 for the distinction between normal and pathological events in majority-voted annotations. CONCLUSION: The developed method can distinguish between normal and pathological events in near real-time, with a performance close to the agreement between three gynecologists with access to the entire CTG tracing and fetal outcome. The method has a strong potential to support clinicians in assessing fetal condition in clinical practice.