Intrapartum Cesarean Delivery Research Articles

Intravenous Calcium to Decrease Blood Loss During Intrapartum Cesarean Delivery

Intravenous Calcium to Decrease Blood Loss During Intrapartum Cesarean Delivery

The Association of Second-Trimester Cervical Length With Mode of Delivery [ID 2683533

INTRODUCTION: Second-trimester transvaginal cervical length (TVCL) under 2.5 cm is a well-established risk factor for preterm birth and mid-trimester loss. However, few studies have investigated birth outcomes associated with increasing lengths of “normal” TVCL (2.5 cm or greater). We aimed to evaluate the association of normal TVCL tertiles with mode of delivery. METHODS: This is a retrospective cohort study of patients eligible for vaginal birth with singleton term gestations and normal TVCL (at 16–24 weeks of gestation) delivering at a tertiary care center from June 2022 to June 2023. Mode of delivery was compared by TVCL tertiles: T1, 2.5–3.49 cm; T2, 3.5–4.49 cm; and T3, 4.5 cm or greater. Multivariable logistic regression controlled for potential confounders. Institutional review board approval was obtained. RESULTS: Of 1,033 eligible deliveries, 175 (16.9%), 621 (60.1%), and 237 (22.9%) had TVCL in T1, T2, and T3, respectively. Compared to patients with TVCL in T1, those in T2 and T3 were significantly more likely to have an intrapartum cesarean delivery (CD) (T1 3.4% versus T2 8.5%, P=.02; T3 11.8%, P=.002), with odds ratios (ORs) of 2.63 (CI, 1.1–7.6) and 3.77 (CI, 1.5–11.4), respectively. After adjusting for confounders, those with TVCL in T3 remained statistically more likely to undergo CD than those in T1, adjusted OR 6.7 (CI, 2.3–19.2). Of note, no patients with TVCL in T1 had CD for Stage 1 arrest. CONCLUSION: Patients with longer TVCL at 16–24 weeks are significantly more likely to undergo an intrapartum CD. This association can be considered during patient counseling on delivery outcome expectations.

Artificial Intelligence, Intrapartum Ultrasound and Dystocic Delivery: AIDA (Artificial Intelligence Dystocia Algorithm), a Promising Helping Decision Support System.

The position of the fetal head during engagement and progression in the birth canal is the primary cause of dystocic labor and arrest of progression, often due to malposition and malrotation. The authors performed an investigation on pregnant women in labor, who all underwent vaginal digital examination by obstetricians and midwives as well as intrapartum ultrasonography to collect four "geometric parameters", measured in all the women. All parameters were measured using artificial intelligence and machine learning algorithms, called AIDA (artificial intelligence dystocia algorithm), which incorporates a human-in-the-loop approach, that is, to use AI (artificial intelligence) algorithms that prioritize the physician's decision and explainable artificial intelligence (XAI). The AIDA was structured into five classes. After a number of "geometric parameters" were collected, the data obtained from the AIDA analysis were entered into a red, yellow, or green zone, linked to the analysis of the progress of labor. Using the AIDA analysis, we were able to identify five reference classes for patients in labor, each of which had a certain sort of birth outcome. A 100% cesarean birth prediction was made in two of these five classes. The use of artificial intelligence, through the evaluation of certain obstetric parameters in specific decision-making algorithms, allows physicians to systematically understand how the results of the algorithms can be explained. This approach can be useful in evaluating the progress of labor and predicting the labor outcome, including spontaneous, whether operative VD (vaginal delivery) should be attempted, or if ICD (intrapartum cesarean delivery) is preferable or necessary.

Risk of intrapartum cesarean delivery in twin pregnancies: A retrospective cohort study.

To compare the risk of intrapartum cesarean delivery (CD) between patients with twin and singleton pregnancies undergoing a trial of labor and identify risk factors for intrapartum CD in twin pregnancies. The present study was a retrospective cohort study of patients with a twin or singleton pregnancy who underwent a trial of labor at ≥340/7 weeks in a single center (2015-2022). The primary outcome was the rate of intrapartum CD. In twin pregnancies, this outcome was limited to CD of both twins. The association of plurality with intrapartum CD was estimated using multivariable Poisson regression. A total of 20 754 patients met the study criteria, 669 of whom had a twin pregnancy. Patients with twins had a greater risk of intrapartum CD (of both twins) than those with singleton pregnancies (22.1% vs 15.9%, respectively; aRR 1.38 [95% CI: 1.15-1.66]), primarily due to a greater risk of failure to progress. In addition, 4.1% of the twin pregnancies had a CD for the second twin, resulting in an overall CD rate in twin pregnancies of 26.2%. Variables associated with intrapartum CD in twin pregnancies included nulliparity (aOR 3.50, 95% CI: 2.34-5.25), birthweight discordance >20% (aOR 2.47, 95% CI: 1.27-4.78), and labor induction (aOR 1.64, 95% CI: 1.07-2.53). The rate of intrapartum CD was highest when all three risk factors were present (67% [95% CI: 41%-87%]). Twin pregnancies are associated with a greater risk of intrapartum CD than singleton pregnancies. Information on the individualized risk of intrapartum CD may be valuable when counseling patients with twins regarding mode of delivery.

Maternal Morbidity According to Mode of Delivery Among Pregnant Patients With Pulmonary Hypertension.

Patients with pulmonary hypertension have a high risk of maternal morbidity and mortality. It is unknown if a trial of labor carries a lower risk of morbidity in these patients compared to a planned cesarean delivery. The objective of this study was to examine the association of delivery mode with severe maternal morbidity events during delivery hospitalization among patients with pulmonary hypertension. This retrospective cohort study used the Premier inpatient administrative database. Patients delivering ≥25 weeks gestation from January 1, 2016, to September 30, 2020, and with pulmonary hypertension were included. The primary analysis compared intended vaginal delivery (ie, trial of labor) to intended cesarean delivery (intention to treat analysis). A sensitivity analysis was conducted comparing vaginal delivery to cesarean delivery (as treated analysis). The primary outcome was nontransfusion severe maternal morbidity during the delivery hospitalization. Secondary outcomes included blood transfusion (4 or more units) and readmission to the delivery hospital within 90 days from discharge from delivery hospitalization. The cohort consisted of 727 deliveries. In the primary analysis, there was no difference in nontransfusion morbidity between intended vaginal delivery and intended cesarean delivery groups (adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], 0.49-1.15). In secondary analyses, intended cesarean delivery was not associated with blood transfusion (aOR, 0.71; 95% CI, 0.34-1.50) or readmission within 90 days (aOR, 0.60; 95% CI, 0.32-1.14). In the sensitivity analysis, cesarean delivery was associated with a 3-fold higher risk of nontransfusion morbidity compared to vaginal delivery (aOR, 2.64; 95% CI, 1.54-3.93), a 3-fold higher risk of blood transfusion (aOR, 3.06; 95% CI, 1.17-7.99), and a 2-fold higher risk of readmission within 90 days (aOR, 2.20; 95% CI, 1.09-4.46) compared to vaginal delivery. Among pregnant patients with pulmonary hypertension, a trial of labor was not associated with a higher risk of morbidity compared to an intended cesarean delivery. One-third of patients who required an intrapartum cesarean delivery had a morbidity event, demonstrating the increased risk of adverse events in this group.

To know or not to know: Effect of third-trimester sonographic fetal weight estimation on outcomes of large-for-gestational age neonates.

The aim of the present study was to evaluate the impact of late third-trimester sonographic estimation of large for gestational age fetuses on pregnancy management and selected fetal and maternal adverse outcomes. A retrospective cohort study was conducted in a tertiary, university-affiliated medical center between 2015 and 2019. All singleton large-for-gestational-age neonates born during this period were included. The cohort was divided into two groups: neonates for whom fetal weight was estimated on late third trimester (<14 days before delivery) sonography and neonates with no recent fetal weight estimation. The groups were compared for pregnancy management strategies, rates of labor induction, cesarean deliveries, and maternal and neonatal outcomes. A total of 1712 neonates were included in the study, among whom 791 (46.2%) had a late third-trimester fetal weight estimation (study group) and 921 (53.8%) did not (control group). Compared to the control group, the study group was characterized by higher rates of maternal primiparity (24.20% vs 19.20%, P = 0.013), higher maternal body mass index (26.0 ± 6.2 kg/m2 vs 24.7 ± 4.5 kg/m2, P = 0.002), more inductions of labor (29.84% vs 16.40%, P < 0.001) and cesarean deliveries (31.0% vs 19.97%, P < 0.001). There were no clinical differences in neonatal birth weight (4041 ± 256 g vs 3984 264 g, P < 0.001) and no significant differences between other neonatal outcomes, as rates of admission to the neonatal intensive care unit, jaundice, hypoglycemia, and shoulder dystocia. Late third-trimester sonographic fetal weight estimation is associated with a higher rate of labor induction and planned and intrapartum cesarean deliveries. In this retrospective cohort study, those interventions did not lead to reduction in maternal or neonatal adverse outcomes.

Timing of induction of labor in suspected macrosomia: retrospective cohort study, systematic review and meta-analysis.

Large-for-gestational-age (LGA) is associated with several adverse maternal and neonatal outcomes. Although many studies have found that early induction of labor (eIOL) in LGA reduces the incidence of shoulder dystocia (SD), no current guidelines recommend this particular strategy, due to concerns about increased rates of cesarean delivery (CD) and neonatal complications. The purpose of this study was to assess whether the timing of IOL in LGA fetuses affects maternal and neonatal outcomes in a single center; and to combine these results with the evidence reported in the literature. This study comprised two parts. The first was a retrospective cohort study that included: consecutive patients with singleton pregnancy, an estimated fetal weight (EFW) ≥90th percentile on ultrasound (US) between 35+0 and 39+0 weeks of gestation (WG), who were eligible for normal vaginal delivery. The second part was a systematic review of literature and meta-analysis that included the results of the first part as well as all previously reported studies that have compared IOL to expectant management in patients with LGA. The perinatal outcomes were CD, operative vaginal delivery (OVD), SD, brachial plexus palsy, anal sphincter injury, postpartum hemorrhage (PPH), APGAR score, umbilical arterial pH, neonatal intensive care unit (NICU) admission, use of continuous positive airway pressure (CPAP), intracranial hemorrhage (ICH), phototherapy, and bone fracture. Retrospective cohort: of the 547 patients, 329 (60.1%) were induced and 218 (39.9%) entered spontaneous labor. Following covariate balancing, CD was significantly higher in the IOL group in comparison to the spontaneous labor group. This difference only became apparent beyond 40WG (hazard ratio: 1.9, p=0.030). The difference between both groups for shoulder dystocia was not statistically significant. Systematic review and metanalysis: 17 studies were included in addition to our own results giving a total sample size of 111,300 participants. When IOL was performed <40+0WG, the risk for SD was significantly lower in the IOL group (OR: 0.64, 95%CI: 0.42-0.98, I2 =19%). There was no significant difference in CD rate between IOL and expectant management after pooling the results of these 17 studies. However, when removing the studies in which IOL was done exclusively before 40+0WG, the risk for CD in the remaining studies (IOL not exclusively <40+0WG) was significantly higher in the IOL group (odds ratio [OR]: 1.46, 95% confidence interval [95%CI]: 1.02-2.09, I2 =56%). There were no statistically significant differences between IOL and expectant management for the remaining perinatal outcomes. Nulliparity, history of CD, and low Bishop score but not methods of induction were independent risk factors for intrapartum CD in patients who were induced for LGA. Timing of IOL in patients with suspected macrosomia significantly impacts perinatal adverse outcomes. IOL has no impact on rates of SD but does increase CD when considered irrespective of gestational age, but it may decrease the risk of SD without increasing the risk of other adverse maternal outcomes, in particular cesarean section when performed before 40+0 WG. (GRADE: Low/Very low). This article is protected by copyright. All rights reserved.

Trial of labor after 2 previous cesareans: a multicenter study

Trial of labor after cesarean after 2 cesarean deliveries is linked to a lower success rate of vaginal delivery and higher rates of adverse obstetrical outcomes than trial of labor after cesarean after 1 previous cesarean delivery. This study aimed to investigate the factors associated with failed trial of labor after cesarean among women with 2 previous cesarean deliveries. This was a multicenter retrospective cohort study, which included all women with singleton pregnancies attempting trial of labor after cesarean after 2 previous cesarean deliveries between 2003 and 2021. This study compared labor, maternal, and neonatal characteristics between women with failed trial of labor after cesarean and those with successful trial of labor after cesarean. Univariate analysis was initially performed, followed by multivariable analysis (adjusted odds ratios with 95% confidence intervals). The study included a total of 1181 women attempting trial of labor after cesarean after 2 previous cesarean deliveries. Among these cases, vaginal birth after cesarean was achieved in 973 women (82.4%). Women with failed trial of labor after cesarean had higher rates of maternal and neonatal morbidities. Several factors were found to be associated with failed trial of labor after cesarean, including longer interpregnancy and interdelivery intervals, lower gravidity and parity, lower rates of previous successful vaginal delivery, smoking, earlier gestational age at delivery (38.3±2.1 vs 39.5±1.3 weeks), late preterm delivery (34-37 weeks of gestation), lower cervical dilation on admission, no use of epidural, and smaller neonatal birthweight. Our multivariable model revealed that late preterm delivery (adjusted odds ratio, 3.79; 95% confidence interval, 1.37-10.47) and cervical dilation on admission for labor <3 cm (adjusted odds ratio, 2.58; 95% confidence interval, 1.47-4.54) were associated with higher odds of failed trial of labor after cesarean. In the investigated population of women with 2 previous cesarean deliveries undergoing trial of labor after cesarean, admission at the late preterm period with a cervical dilation of <3 cm, which reflects the latent phase, may elevate the risk of failed trial of labor after cesarean and a repeated intrapartum cesarean delivery.

New labor curves of dilation and station to improve the accuracy of predicting labor progress

BackgroundThe diagnosis of failure to progress, the most common indication for intrapartum cesarean delivery, is based on the assessment of cervical dilation and station over time. Labor curves serve as references of expected changes in dilation and fetal descent. The labor curves of Friedman, Zhang et al and others are based on time alone and derived from mothers with spontaneous labor onset. However, labor induction is now common, and clinicians also consider other factors when assessing labor progress. Labor curves that consider the use of induction and other factors that influence labor progress have the potential to be more accurate and closer to clinical decision-making. ObjectiveTo compare the prediction errors of labor curves based on a single factor (time) or multiple clinically relevant factors using 2 modeling methods: mixed-effects regression, a standard statistical method, and Gaussian processes, a machine learning method. Study designThis was a longitudinal cohort study of changes in dilation and station based on data from 8022 births in nulliparous women with a live, singleton, vertex presenting fetus at ≥35 weeks of gestation with a vaginal delivery. New labor curves of dilation and station were generated with 10-fold cross-validation. External validation was performed using a geographically independent group. Model variables included time from the first exam in the 20 hours before delivery; dilation, effacement and station recorded at the previous examination; cumulative contraction counts; and use of epidural anesthesia and labor induction. To assess model accuracy, we calculated the differences between each model’s predicted value and its corresponding observed value. These prediction errors were summarized using mean absolute error and root mean squared error statistics. Results(1) Dilation curves based on multiple parameters were more accurate than those derived from time alone. (2) The mean absolute error with the multifactor methods were better (lower) than those from the single-factor methods [0.826 cm (95% CI, 0.820–0.832) for the multifactor machine learning and 0.893 cm (95% CI, 0.885–0.901) for the multifactor mixed-effects method and 2.122 cm (95% CI, 2.108–2.136) for the single-factor methods; P<0.0001 for both comparisons]. (3) The root mean squared errors with the multifactor methods were also better (lower) than those from the single-factor methods [1.126 cm (95% CI, 1.118–1.133) P<0.0001 for the machine learning and 1.172cm (95% CI, 1.164–1.181) for the mixed-effects method and 2.504 cm (95% CI, 2.487–2.521) for the single-factor; P<0.0001 for both comparisons]. (4) The multifactor machine learning dilation models showed small but statistically significant improvements in accuracy compared to the mixed-effects regression models (P<0.0001). (5) The multifactor machine learning method produced a curve of descent with a mean absolute error of 0.512 cm (95% CI, 0.509–0.515) and a root mean squared error of 0.660 cm (95% CI, 0.655–0.666). (6) External validation using independent data produced similar findings. Conclusions(1) Cervical dilation models based on multiple clinically relevant parameters showed improved (lower) prediction errors compared to models based on time alone; (2) the mean prediction errors were reduced by more than 50%; and (3) a more accurate assessment of departure from expected dilation and station may help clinicians optimize intrapartum management.

Association of free maternal and fetal ropivacaine after epidural analgesia for intrapartum caesarean delivery: a prospective observational trial

BackgroundRopivacaine is present in plasma in both protein-bound and free forms. The free form is responsible for the occurrence of toxic side effects. During obstetric epidural analgesia, free ropivacaine enters the fetal circulation depending on various factors. The aim of this study was to analyse a potential association between ropivacaine concentrations in maternal and fetal plasma and hence the extent of fetal exposure to ropivacaine. MethodsIn this prospective monocentre study, parturients who met the following criteria were included in the study: 1. epidural administration as part of obstetric anaesthesia, and 2. subsequent intrapartum caesarean delivery, which 3. was performed after an epidural bolus administration of ropivacaine within the existing epidural analgesia. Total and free ropivacaine concentrations were analysed in maternal blood at baseline, prior to epidural bolus administration for caesarean delivery, and in maternal and fetal (umbilical venous, oxygenated) blood at delivery. The results are presented as mean ± SD or median (25/75th percentile). ResultsWe screened 128 parturients who went into labour at term and requested epidural analgesia, of whom 39 were ultimately included in the study. An intrapartum caesarean delivery was performed after the epidural application of 207 (166/276) mg ropivacaine during an epidural treatment period of 577 (360/1010) min. Total and free ropivacaine concentrations were 1402 ± 357 ng/ml and 53 ± 46 ng/ml, respectively, in maternal venous blood and 457 ± 243 ng/ml and 43 ± 27 ng/ml, respectively, in fetal blood. The maternal total and free ropivacaine concentrations were significantly correlated (r = 0.873; P < 0.0001). ConclusionThe results of the present study suggest that determining the concentration of free ropivacaine in maternal blood may be a feasible option for estimating neonatal exposure to ropivacaine.

Effects of early- and late- neuraxial analgesia on multiparous women: a retrospective monocentric study.

The mechanism underlying maternal fever and prolonged labor progression associated with neuraxial analgesia (NA) remains elusive, raising concerns among certain pregnant women regarding the application of NA during vaginal delivery. This study aimed to investigate the impact of early and late NA on maternal and neonatal outcomes in multiparous women. This retrospective study collected data from 1119 multiparous women with singleton pregnancies, full term and live births at our labor and delivery center between August 1st, 2021 and July 31st, 2022. Based on the timing of NA initiation, participants were categorized into three groups: no-NA, early-NA and late-NA. The no-NA group comprised of 172 women who did not receive NA during vaginal delivery; the early-NA group included 603 women in which NA was initiated when cervical dilation was between 0.5 and 2.0cm; and the late-NA group comprising 344 cases in which NA was initiated at the cervical dilation of ≥ 2cm. Maternal and neonatal outcomes were observed, including durations of the first, second, third and total stage of labor, the rate of intrapartum cesarean delivery (CD), intrapartum fever, postpartum hemorrhage (PPH), transfer to intensive care unit (ICU), admission to the neonatal intensive care unit (NICU), meconium-stained amniotic fluid, and neonatal Apgar scores at 1 and 5min. No differences were noted in the maternal age, body mass index (BMI) on admission, gestations, parity, gestational weeks at delivery and neonatal birth weight, or the rate of gestational diabetes mellitus (GDM) and hypertension disorder did not significantly differ among the three groups (p > 0.05). The no-NA group had shorter durations of first stage, second stage of labor compared to the early-NA or late-NA group (median, 215.0min and 10.0min vs. 300.0min and 12.0min vs. 280.0min and 13.0min) (p < 0.05), but no differences were observed between the early-NA and late-NA group (p > 0.05). There were no differences in the rate of intrapartum CD, intrapartum fever, PPH, maternal transferred to ICU, neonatal transfer to NICU, meconium-stained amniotic fluid, and postpartum stay ≥ 7d, as well as the neonatal the Apgar scores at 1 and 5min among the three groups (p > 0.05). NA is associated with extended durations of the first, second and total stages of labor. However, the early initiation of NA in multiparous women (cervical dilation within 0.5-2.0cm) does not increase the risk of intrapartum CD or intrapartum fever. These findings endorse the secure utilization of early NA for pain relief during labor in multiparous women.

605 Fetal extraction time during intrapartum cesarean deliveries and the risk of neonatal acidemia

605 Fetal extraction time during intrapartum cesarean deliveries and the risk of neonatal acidemia

111 Establishing a risk score for prediction of intrapartum cesarean delivery among elderly gravidae

111 Establishing a risk score for prediction of intrapartum cesarean delivery among elderly gravidae

Comparing adverse maternal and perinatal outcomes in primary caesarean delivery during first versus second-stage of labour in Kenya: An institution-based cohort study.

As caesarean delivery rates continue to increase globally, so are the number of second-stage caesarean deliveries. Second-stage caesareans may carry additional risk of complications for both the mother and fetus owing to fetal head impaction into the maternal pelvis and manipulations required for delivery. So far, data on this procedure's outcomes from low resource countries are limited. To compare adverse maternal and perinatal outcomes between second-stage and first-stage of labour intrapartum primary caesarean deliveries over 12 months at a tertiary referral obstetric hospital in Kenya. In a hospital-based cohort study, 222 women with singleton, cephalic presenting fetuses at term gestation who had intrapartum primary caesarean delivery during active labour were recruited post-partum. Second-stage caesarean deliveries (73) were compared to 149 first-stage caesarean deliveries. The proportion of caesarean deliveries in the second-stage of labour was estimated and the adverse maternal and perinatal outcomes were compared. The study was conducted from August 2021 to July 2022 at the Moi Teaching and Referral Hospital, Eldoret. The proportion of second-stage caesarean deliveries among intrapartum primary caesarean deliveries was 4.3% [95% CI: 2.9% - 4.7%]. Compared to first-stage caesarean deliveries, second-stage caesarean deliveries had a significantly higher risk of adverse maternal outcomes (RR 3.272, 95% CI 2.28-4.71, P < 0.001), including intraoperative trauma, atony, blood transfusion, and a postoperative hospital stay of more than three days. Additionally, there was a higher risk of adverse perinatal outcomes (RR 2.748, 95% CI 2.45-4.50, P < 0.001), including increased risk of a 5-min APGAR ≤3, admission to NBU, and neonatal death. An increased risk of adverse maternal and perinatal outcomes is associated with primary second-stage caesarean deliveries compared to primary first-stage caesarean deliveries.

Intravenous Calcium to Decrease Blood Loss During Intrapartum Cesarean Delivery: A Randomized Controlled Trial.

To evaluate whether prophylactic administration of 1 g of intravenous calcium chloride after cord clamping reduces blood loss from uterine atony during intrapartum cesarean delivery. This single-center, block-randomized, placebo-controlled, double-blind superiority trial compared the effects of 1 g intravenous calcium chloride with those of saline placebo control on blood loss at cesarean delivery. Parturients at 34 or more weeks of gestation requiring intrapartum cesarean delivery after oxytocin exposure in labor were enrolled. Calcium or saline placebo was infused over 10 minutes beginning 1minute after umbilical cord clamping in addition to standard care with oxytocin. The primary outcome was quantitative blood loss, analyzed by inverse Gaussian regression. Planned subgroup analysis excluded nonatonic bleeding, such as hysterotomy extension, arterial bleeding, and occult placenta accreta. We planned to enroll 120 patients to show a 200-mL reduction in quantitative blood loss in planned subgroup analysis, assuming up to 40% incidence of nonatonic bleeding (80% power, α<0.05). From April 2022 through March 2023, 828 laboring parturients provided consent and 120 participants were enrolled. Median blood loss was 840 mL in patients allocated to calcium chloride (n=60) and 1,051 mL in patients allocated to placebo (n=60), which was not statistically different (mean reduction 211 mL, 95% CI -33 to 410). In the planned subgroup analysis (n=39 calcium and n=40 placebo), excluding cases of surgeon-documented nonatonic bleeding, calcium reduced quantitative blood loss by 356 mL (95% CI 159-515). Rates of reported side effects were similar between the two groups (38% calcium vs 42% placebo). Prophylactic intravenous calcium chloride administered during intrapartum cesarean delivery after umbilical cord clamping did not significantly reduce blood loss in the primary analysis. However, in the planned subgroup analysis, calcium infusion significantly reduced blood loss by approximately 350 mL. These data suggest that this inexpensive and shelf-stable medication warrants future study as a novel treatment strategy to decrease postpartum hemorrhage, the leading global cause of maternal morbidity and mortality. ClinicalTrials.gov, NCT05027048.

A prediction tool for mode of delivery in twin pregnancies—a secondary analysis of the Twin Birth Study

One of the controversies regarding the management of twin gestations relates to the mode of delivery. Currently, counseling regarding the mode of delivery and the chance of successful vaginal twin delivery is based on the average risk for intrapartum cesarean delivery in the general population of twin pregnancies. Decision support tools that provide an individualized risk for intrapartum cesarean delivery based on the unique characteristics of each patient can improve counseling and decision-making regarding the choice of mode of delivery in twin pregnancies. This study aimed to develop and validate a prediction model to determine the risk for intrapartum cesarean delivery in twin pregnancies. In this secondary analysis of the Twin Birth Study, a multicenter randomized controlled trial, we considered the subgroup of individuals who underwent a trial of vaginal delivery. Candidate predictors included maternal age, parity, previous cesarean delivery, conception method, chorionicity, diabetes and hypertension in pregnancy, gestational age at birth, the onset of labor, presentation of the second twin, sonographic fetal weight estimation, and fetal sex. The co-primary outcomes were overall intrapartum cesarean delivery and cesarean delivery of the second twin. Multivariable logistic regression models were used to estimate the probability of the study outcomes. Model performance was evaluated using measures of discrimination (the area under the receiver operating characteristic curve), calibration, and predictive accuracy. Internal validation was performed using the bootstrap resampling technique. A total of 1221 individuals met the study criteria. The rate of overall intrapartum cesarean delivery and cesarean delivery for the second twin was 25.4% and 5.7%, respectively. The most contributory predictor variables were nulliparity, term birth (≥37 weeks), a noncephalic presentation of the second twin, previous cesarean delivery, and labor induction. The models for overall intrapartum cesarean delivery and cesarean delivery of the second twin had good overall discriminatory accuracy (area under the receiver operating characteristic curve, 0.720; 95% confidence interval, 0.688-0.752 and 0.736; 95% confidence interval, 0.669-0.803, respectively) and calibration (as illustrated by the calibration plot and Brier scores of 0.168; 95% confidence interval, 0.156-0.180 and 0.051; 95% confidence interval, 0.040-0.061, respectively). The models achieved good specificity (66.7% and 81.6%, respectively), high negative predictive value (86.0% and 96.9%, respectively), and moderate sensitivity (68.1% and 57.1%, respectively). The prediction models developed in this study may assist care providers in counseling individuals regarding the optimal timing and mode of delivery in twin pregnancies by providing individualized estimates of the risk for intrapartum cesarean delivery.

Reducing macrosomia-related birth complications in primigravid women: ultrasound- and magnetic resonance imaging–based models

Many complications increase with macrosomia, which is defined as birthweight of ≥4000 g. The ability to estimate when the fetus would exceed 4000 g could help to guide decisions surrounding the optimal timing of delivery. To the best of our knowledge, there is no available tool to perform this estimation independent of the currently available growth charts. This study aimed to develop ultrasound- and magnetic resonance imaging-based models to estimate at which gestational age the birthweight would exceed 4000 g, evaluate their predictive performance, and assess the effect of each model in reducing adverse outcomes in a prospectively collected cohort. This study was a subgroup analysis of women who were recruited for the estimation of fetal weight by ultrasound and magnetic resonance imaging at 36 0/7 to 36 6/7 weeks of gestation. Primigravid women who were eligible for normal vaginal delivery were selected. Multiparous patients, patients with preeclampsia spectrum, patients with elective cesarean delivery, and patients with contraindications for normal vaginal delivery were excluded. Of note, 2 linear models were built for the magnetic resonance imaging- and ultrasound-based models to predict a birthweight of ≥4000 g. Moreover, 2 formulas were created to predict the gestational age at which birthweight will reach 4000 g (predicted gestational age); one was based on the magnetic resonance imaging model, and the second one was based on the ultrasound model. This study compared the adverse birth outcomes, such as intrapartum cesarean delivery, operative vaginal delivery, anal sphincter injury, postpartum hemorrhage, shoulder dystocia, brachial plexus injury, Apgar score of <7 at 5 minutes of life, neonatal intensive care unit admission, and intracranial hemorrhage in the group of patients who delivered after the predicted gestational age according to the magnetic resonance imaging-based or the ultrasound-based models with those who delivered before the predicted gestational age by each model, respectively. Of 2378 patients, 732 (30.8%) were eligible for inclusion in the current study. The median gestational age at birth was 39.86 weeks of gestation (interquartile range, 39.00-40.57), the median birthweight was 3340 g (interquartile range, 3080-3650), and 63 patients (8.6%) had a birthweight of ≥4000 g. Prepregnancy body mass index, geographic origin, gestational age at birth, and fetal body volume were retained for the optimal magnetic resonance imaging-based model, whereas maternal age, gestational diabetes mellitus, diabetes mellitus type 1 or 2, geographic origin, fetal gender, gestational age at birth, and estimated fetal weight were retained for the optimal ultrasound-based model. The performance of the first model was significantly better than the second model (area under the curve: 0.98 vs 0.89, respectively; P<.001). The group of patients who delivered after the predicted gestational age by the first model (n=40) had a higher risk of cesarean delivery, postpartum hemorrhage, and shoulder dystocia (adjusted odds ratio: 3.15, 4.50, and 9.67, respectively) than the group who delivered before this limit. Similarly, the group who delivered after the predicted gestational age by the second model (n=25) had a higher risk of cesarean delivery and postpartum hemorrhage (adjusted odds ratio: 5.27 and 6.74, respectively) than the group who delivered before this limit. The clinical use of magnetic resonance imaging- and ultrasound-based models, which predict a gestational age at which birthweight will exceed 4000 g, may reduce macrosomia-related adverse outcomes in a primigravid population. The magnetic resonance imaging-based model is better for the identification of the highest-risk patients.

Epidural Catheter Replacement Rates With Dural Puncture Epidural Labor Analgesia Compared With Epidural Analgesia Without Dural Puncture: A Retrospective Cohort Study

(Int J Obstet Anesth. 2022;52:103590) Lumbar epidural analgesia (LEA) is a common method of labor analgesia. Traditional LEA, dural-puncture epidural (DPE), and combined spinal-epidural analgesia (CSE) are approaches to epidural catheter placement. Epidural catheters are known to malfunction following placement (12% to 13%), requiring replacement or conversion to general anesthesia (GA) if failure occurs during emergency intrapartum cesarean delivery (CD). Factors contributing to placement failure include body mass index (BMI) or weight, procedure type (CSE vs. LEA), gestational age, anesthesiologist experience, type of epidural catheter, patient age, and mode of delivery. Few studies have compared catheter failure rates between LEA and CSE. This retrospective analysis compares epidural catheter failure rates of DPE or LEA.

Mid-trimester cervical length and prediction of vaginal birth after cesarean delivery in Chinese parturients: A retrospective study

BackgroundA successful trial of labor after cesarean (TOLAC) is linked with the best maternal/neonatal outcomes and is more cost-effective than elective repeat cesarean section (ERCS). Predictive models of vaginal birth after cesarean (VBAC) have been established worldwide to improve the success rate of TOLAC. ObjectiveTo validate a VBAC prediction model (the updated Grobman's predictive model without ethnicity) and identify whether mid-trimester cervical lengths (MCL) improve the prediction of VBAC among Chinese women undergoing a TOLAC. MethodsIn this retrospective cohort study, the inclusion criteria were a previous history of cesarean delivery (CD) as well as a singleton gestation in the vertex position with routine CL measurements between 20 and 24 weeks and the experience of a TOLAC. MCL as well as identifiable characteristics in early prenatal care that have been used in updated Grobman's predictive model (maternal age, height, pre-pregnancy weight, vaginal delivery history, VBAC history, arrest disorder in previous CD, and treated chronic hypertension) were obtained from the medical records. Associations of maternal characteristics and MCL with VBAC were evaluated using multivariate logistic regression. Two multivariable regression models with and without MCL as one of the risk factors were established and their predictive accuracy for VBAC was critically compared based on receiver-operating characteristic (ROC) curves. ResultsThis study involved 409 women, among which, 347 (84.8%) achieved a VBAC. The mean MCL was significantly shorter in women who had a successful VBAC than in those who required an intrapartum CD (4.16±0.49 cm vs. 4.35±0.46 cm, P=0.007). Multivariable logistic regression revealed that a longer MCL (cm) was significantly related to a lower success rate of TOLAC [adjusted odds ratio (aOR), 0.48; 95% confidence interval (CI), 0.26−0.88]. The areas under the ROCs of Grobman's model with and without MCL as one of the risk factors were 0.785 (95% CI, 0.725−0.844) and 0.774 (95% CI, 0.710−0.837), respectively, but not significantly different (Z = −0.968, P = 0.333). ConclusionsWe first evaluated the efficiency of the updated Grobman's model (without race and ethnicity) in the Chinese population. The area under the curve is relatively high, indicating that the model can be used efficiently in China. The shorter MCL was associated with a greater chance of VBAC and MCL was the independent factor from the factors of Grobman's model. However, the predictive capacity of the modified model by adding MCL as one of the risk factors did not improve significantly.

Oxytocin is not associated with postpartum hemorrhage in labor augmentation in a retrospective cohort study in the United States

Previous studies reported conflicting results on the relationship between oxytocin use for labor augmentation and the risk of postpartum hemorrhage, probably because it is rather challenging to disentangle oxytocin use from labor dystocia. This study aimed to investigate the independent association between oxytocin use for augmentation and the risk of postpartum hemorrhage by using advanced statistical modeling to control for labor patterns and other covariates. We used data from 20,899 term, cephalic, singleton pregnancies of patients with spontaneous onset of labor and no previous cesarean delivery from Intermountain Healthcare in Utah in the Consortium on Safe Labor. Presence of postpartum hemorrhage was identified on the basis of a clinical diagnosis. Propensity scores were calculated using a generalized linear mixed model for oxytocin use for augmentation, and covariate balancing generalized propensity score was applied to obtain propensity scores for the duration and total dosage of oxytocin augmentation. A weighted generalized additive mixed model was used to depict dose-response curves between the duration and total dosage of oxytocin augmentation and the outcomes. The average treatment effects of oxytocin use for augmentation on postpartum hemorrhage and estimated blood loss (mL) were assessed by inverse probability weighting of propensity scores. The odds of both postpartum hemorrhage and estimated blood loss increased modestly when the duration and/or total dosage of oxytocin used for augmentation increased. However, in comparison with women for whom oxytocin was not used, oxytocin augmentation was not clinically or statistically significantly associated with estimated blood loss (6.5 mL; 95% confidence interval, 2.5-10.3) or postpartum hemorrhage (adjusted odds ratio, 1.02; 95% confidence interval, 0.82-1.24) when rigorously controlling for labor pattern and potential confounders. The results remained consistent regardless of inclusion of women with an intrapartum cesarean delivery. The odds of postpartum hemorrhage and estimated blood loss increased modestly with increasing duration and total dosage of oxytocin augmentation. However, in comparison with women for whom oxytocin was not used and after controlling for potential confounders, there was no clinically significant association between oxytocin use for augmentation and estimated blood loss or the risk of postpartum hemorrhage.