Delivery In Nulliparous Women Research Articles

Is There an Age Limit for a Trial of Vaginal Delivery in Nulliparous Women?

The number of nulliparous women over the age of 35 is consistently increasing, and the optimal delivery strategy is a subject of ongoing discussion. This study compares perinatal outcomes in nulliparous women aged ≥35 years undergoing a trial of labor (TOL) versus a planned cesarean delivery (CD). A retrospective cohort study including all nulliparous women ≥ 35 years who delivered a single term fetus at a single center between 2007-2019. We compared obstetric and perinatal outcomes according to mode of delivery-TOL versus a planned CD, in three different age groups: (1) 35-37 years, (2) 38-40 years, and (3) >40 years. Out of 103,920 deliveries during the study period, 3034 women met the inclusion criteria. Of them, 1626 (53.59%) were 35-37 years old (group 1), 848 (27.95%) were 38-40 (group 2), and 560 (18.46%) were >40 years (group 3). TOL rates decreased as age increased: 87.7% in group 1, 79.3% in group 2, and 50.1% in group 3, p < 0.001. Rates of successful vaginal delivery were 83.4% in group 1, 79.0% in group 2, and 69.4% in group 3, p < 0.001). Neonatal outcomes were comparable between a TOL and a planned CD. Using multivariate logistic regression, maternal age was found to be independently associated with slightly increased odds for a failed TOL (aOR = 1.13, CI 95% 1.067-1.202). A TOL at advanced maternal age appears to be safe, with considerable success rates. As maternal age advances, there is a small additive risk of intrapartum CD.

The REDUCED trial: a cluster randomized trial for REDucing the Utilization of CEsarean delivery for Dystocia

To reduce cesarean delivery rates in nulliparous women, guidelines for diagnosing nonprogressive labor have been developed by the National Institute of Child Health and Human Development, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine. These are mainly based on data from the Consortium for Safe Labor study. The guidelines have not been tested in a clinical trial, so the efficacy and safety of this new approach is uncertain. This study aimed to assess whether adoption of new guidelines for diagnosing nonprogressing labor would reduce cesarean delivery rates. We conducted a cluster randomized controlled trial of a knowledge translation program of the guidelines in 26 Canadian hospitals (13 control sites and 13 intervention sites). The sites included all intrapartum care sites in Alberta that perform cesarean delivery and deliver at least 70 nulliparous women annually. The baseline period started on January 1, 2015. The intervention was initiated at the first intervention site in January 2017. The follow-up period began at the first intervention site in February 2017 and lasted till February 2020. The primary outcome was the rate of cesarean delivery in nulliparous women with vertex presentation in labor at term. The secondary outcomes included spontaneous vaginal birth and maternal and neonatal safety. The main data source for the primary and secondary outcomes was the Alberta Perinatal Health Program database. The cesarean delivery rates were assessed using repeated measures mixed effects logistic regression applied to individual births. The analysis was based on 45,193 deliveries at intervention sites and 43,725 deliveries at control sites. There was no evidence of a decrease in the rate of cesarean delivery in association with the intervention (baseline-adjusted odds ratio, 0.94; 95% confidence interval [0.85-1.05]; P=.259). The rate of spontaneous vaginal delivery increased slightly (baseline-adjusted odds ratio, 1.10; 95% confidence interval, [1.01-1.18]; P=.024). We did not observe any differences in adverse maternal or neonatal outcomes. Cesarean delivery rates in nulliparous women were not reduced by the application of recent guidelines for the diagnosis of nonprogressive labor. Spontaneous vaginal delivery-a secondary outcome-was increased in the intervention group. The intervention appears to be safe.

Nomogram based on the final antepartum ultrasound features before delivery for predicting failed spontaneous vaginal delivery in nulliparous women.

Accurate identification of nulliparous women with failed spontaneous vaginal delivery (SVD) is crucial to minimize the hazards associated with obstetrical intervention (OI). While abnormal labor progression can be identified with intrapartum ultrasonography, labor-related complications may be unavoidable due to the limited time window left to the obstetrician. Antepartum ultrasound enables sufficient obstetric planning. However, there is typically a longer gap between ultrasound assessment and delivery that often lowers the prediction accuracy compared to intrapartum ultrasonography. In this study, antepartum ultrasound assessment was included to each fetal ultrasound examination after 36 weeks of gestation until the onset of labor. We aim to establish a nomogram to predict the likelihood of failed SVD in nulliparous women using the last antepartum ultrasound findings before labor beginning. Of the 2,143 nulliparous women recruited, 1,373 were included in a training cohort and 770 in a validation cohort, based on their delivery date. Maternal and perinatal characteristics, as well as perinatal ultrasound parameters were collected. In the training cohort, the screened correlates of SVD failure were used to develop a nomogram for determining whether a nulliparous woman would experience SVD failure. This model was validated in both training and validation cohorts. SVD failure affected 217 nulliparous women (10.13%). In the training cohort, SVD failure was independently associated with BMI [odds ratio (OR) = 1.636], FHC (OR = 1.194), CL (OR = 1.398), and PCA (OR = 0.824) (all P < 0.05). They constituted a nomogram to estimate the individual risk of SVD failure. The model obtained clinical net benefits in both the training and validation cohorts and was validated to present strong discrimination and calibration. The developed nomogram based on the last antepartum ultrasound findings may be helpful in avoiding OI and its related complications by assessing the likelihood of a failed SVD in nulliparous women.

Effect of Date Fruit Consumption in Later Pregnancy on Length of Gestation, Labour and Delivery of Nulliparous Women

Objective: To assess the effect of date fruit consumption in late pregnancy on the onset and progress of labour, the need for induction and augmentation, and delivery outcomes.&#x0D; Study Design: Randomized controlled trial (NCT05105893).&#x0D; Place and Duration of Study: Pak Emirates Military Hospital, Rawalpindi Pakistan, from Jan to Jun 2021.&#x0D; Methodology: One hundred and forty women were randomized into equal-strength Experimental and Control Groups (70 in each Group). The Experimental-Group included those pregnant females who were advised to consume seven dates per day from 35 weeks onwards till the spontaneous onset of labour. In contrast, the Control-Group comprised primigravidae who did not consume dates in later pregnancy.&#x0D; Results: Spontaneous onset of labour was reported in 59(84.2%) pregnant women of the Experimental-Group compared to 43(61.4%) of Control-Group. 55(78.5%) pregnant women who consumed date fruit had a spontaneous vaginal delivery,4(5.7%) required instrumental delivery, and 11(15%) ended up having a caesarean section, whereas 43 out of 70(61.4%) women of the Control-Group had a spontaneous vaginal delivery, 6(8.5%) had an instrumental vaginal delivery, and 21(30%) underwent a cesarean section.&#x0D; Conclusion: The patients who had consumed date fruit in later pregnancy had an improved Bishop score at the onset of labour, a shorter duration of labour, a lesser need for induction and augmentation of labour and more spontaneous vaginal deliveries.

Association between maternal pre-pregnancy BMI category and fetal umbilical artery pH

To evaluate the association between maternal pre-pregnancy body mass index (BMI kg/m2) and fetal umbilical arterial pH at the time of delivery in nulliparous women. We performed a secondary analysis of the nuMoM2b study. Subjects in this study were nulliparous with a singleton pregnancy. Subjects with fetal anomalies or missing fetal umbilical artery pH were excluded. Subjects were categorized based on pre-pregnancy BMI (less than 18.5, 18.5-24.9, 25-29.9, 30-34.9, 35-39.9, and 40 or greater). Our primary outcome was an umbilical artery pH at the time of delivery. We also examined base deficit, the rate of fetal acidosis defined as pH < 7.0, and the need for advanced neonatal resuscitation. Analyses were stratified by the route of delivery. Multivariable linear or logistic regression models were used to calculate adjusted P-values or adjusted odds ratios (95% confidence intervals), controlling for confounders. Of 3,015 subjects, 1,870 (62%) had a vaginal delivery, and 1,145 (38%) had a cesarean delivery. There were significant differences in demographics across the BMI categories in both subjects who had a vaginal delivery and cesarean delivery (age, race, chronic hypertension, gestational diabetes, pregestational diabetes, preeclampsia, and gestational hypertension). Among subjects who had a vaginal delivery, there was no difference in fetal umbilical artery pH (p=0.31) across the BMI categories (Table 1). Base deficit of subjects with BMI < 18.5 and BMI 40 or greater was significantly lower than that of subjects with BMI 18.5-24.9 (adjusted p< 0.05). Among subjects who had a cesarean delivery, the fetal umbilical arterial pH of subjects with BMI 30-34.9 and BMI 40 or greater was significantly lower than that of subjects with BMI 18.5-24.9 (adjusted p< 0.05) (Table 2). In nulliparous subjects with a singleton pregnancy, obesity was associated with decreased fetal umbilical arterial pH at the time of cesarean delivery. However, this finding was not observed in subjects who had a vaginal delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Effect of the length of the second stage of labor on pelvic floor dysfunction

Pelvic floor dysfunction refers to any combination of incontinence, overactive bladder, pelvic organ prolapse, and sexual dysfunction. Pelvic floor dysfunction affects approximately 25% to 30% of women and is linked to parity and age. Some obstetrical risk factors have been highlighted, though the second stage of labor has not been as thoroughly investigated. Allowing a longer second stage has been suggested as a method of reducing the rates of cesarean delivery in nulliparous women, though it has also been linked to pelvic floor injuries. This study aimed to determine the effect of the length of the second stage of labor on self-reported pelvic floor dysfunction. This was a single-center prospective cohort study in a tertiary referral obstetrical unit. Nulliparous women attending routine antenatal clinics were recruited to complete the Australian Pelvic Floor Questionnaire during pregnancy and again 3 months after delivery. The primary outcome in this study was the effect of the length of the second stage of labor on total pelvic floor scores when analyzed using multiple regression. The models were adjusted for the mother's age, mother's body mass index, length of the second stage of labor, fetal birthweight, mode of delivery, and perineal trauma. The secondary outcomes included the comparison of maternal, obstetrical, and functional pelvic floor outcomes based on the mode of delivery and the length of the second stage of labor. Among the 295 women who were recruited, the length of the second stage of labor and body mass index were associated with self-reported bladder dysfunction on multiple regression, whereas maternal age was protective. Compared with those with 60 to 120 minutes or <60 minutes of second stage of labor, women with that longer than 120 minutes had higher rates of stress incontinence (85.7% [>120 minutes] vs 41.7% [60-120 minutes] or 52.5% [<60 minutes], P=.001), urinary urgency (89.3% [>120 minutes] vs 39.6% [60-120 minutes] or 53.8% [<60 minutes], P<.001), and fecal incontinence (10.7% [>120 minutes] vs 0% [60-120 minutes] or 1.2% [<60 minutes], P=.027). There were no differences in the rates of sexual activity or dyspareunia. Women delivering vaginally had higher rates of stress incontinence (57.6% vs 38.0%, P=.006) than those undergoing cesarean delivery, though there were no differences in other pelvic floor symptoms or pelvic floor scores. A prolonged second stage of labor is associated with more self-reported bladder dysfunction at 3 months postnatal in primiparous women. Women with a longer second stage of labor should be informed about the risk of short-term bladder dysfunction, though the prevalence of long-term sequelae is unknown.

Development and Validation of a Novel Pre-Pregnancy Score Predictive of Preterm Birth in Nulliparous Women Using Data from Italian Healthcare Utilization Databases.

Background: Preterm birth is a major worldwide public health concern, being the leading cause of infant mortality. Understanding of risk factors remains limited, and early identification of women at high risk of preterm birth is an open challenge. Objective: The aim of the study was to develop and validate a novel pre-pregnancy score for preterm delivery in nulliparous women using information from Italian healthcare utilization databases. Study Design: Twenty-six variables independently able to predict preterm delivery were selected, using a LASSO logistic regression, from a large number of features collected in the 4 years prior to conception, related to clinical history and socio-demographic characteristics of 126,839 nulliparous women from Lombardy region who gave birth between 2012 and 2017. A weight proportional to the coefficient estimated by the model was assigned to each of the selected variables, which contributed to the Preterm Birth Score. Discrimination and calibration of the Preterm Birth Score were assessed using an internal validation set (i.e., other 54,359 deliveries from Lombardy) and two external validation sets (i.e., 14,703 and 62,131 deliveries from Marche and Sicily, respectively). Results: The occurrence of preterm delivery increased with increasing the Preterm Birth Score value in all regions in the study. Almost ideal calibration plots were obtained for the internal validation set and Marche, while expected and observed probabilities differed slightly in Sicily for high Preterm Birth Score values. The area under the receiver operating characteristic curve was 60%, 61% and 56% for the internal validation set, Marche and Sicily, respectively. Conclusions: Despite the limited discriminatory power, the Preterm Birth Score is able to stratify women according to their risk of preterm birth, allowing the early identification of mothers who are more likely to have a preterm delivery.

Optimal Plan for Delivery in Women with Obesity: A Large Population-Based Retrospective Study Using the Better Outcomes Registry and Network (BORN) Database

To discern the optimal plan for delivery in nulliparous women with obesity at term gestation.

Outcome of Induction of Labour in Nulliparous Women

Objective: To determine the outcomes following induction of labor in nulliparous women presenting to tertiary care facility. Study Design: Case Series Place and Duration: Department of Obstetrics &amp; Gynaecology, Aga Khan University &amp; Hospital Karachi. Duration was Six months from 15thJanuary 2016 - 15th June 2016. Methadology: Admitted women was selected, women were induced with PGE2 3mg vaginal tablet, inserted in the posterior vaginal fornix. This was repeated at 4-hour intervals, if contractions are not initiated. Maximum 6 mg was given. Decision was taken for cesarean section 4 hours post second dose by the consultant having more than 2 years of post-fellowship experience. Results: 100 women enrolled in this study, mean age of the patients was 26.9±3.9 years. BMI of the patient were 30.4±4.5 kg/m2. Stratification analysis was performed and observed that statistically significant association in MOD in nulliparous women with age and dose of PGE2. MOD of delivery in nulliparous women was not associated with height weight BMI gestational age and baby NICU admission. Conclusion: Elective induction of labour at term gestation can reduce perinatal mortality and morbidity in Pakistan with increasing the risk of operative delivery. Keywords: Induction of labour, Nulliparous women, Unfavorable cervix.

Mediolateral episiotomy and risk of obstetric anal sphincter injuries and adverse neonatal outcomes during operative vaginal delivery in nulliparous women: a propensity-score analysis

BackgroundThe potential protective effect of mediolateral episiotomy for obstetrical anal sphincter injuries (OASIs) remains controversial during operative vaginal delivery because of the difficulties to take into account the risk factors and clinical conditions at delivery; in addition, little is known about the potential benefits of mediolateral episiotomy on neonatal outcomes.The objectives were to investigate the associations between mediolateral episiotomy and both OASIs and neonatal outcomes, using propensity scores.MethodsWe performed a retrospective population-based observational study from a perinatal registry that includes all births in a French region between 2010 and 2017. All nulliparous women with singleton pregnancy delivering by operative vaginal deliveries at 37 weeks gestational age or later were included. Inverse-probability-of-treatment weighting with propensity scores was used to minimize indication bias. OASIs was defined as third and fourth-degree tears according to Royal College of Obstetricians and Gynecologists. Two neonatal outcomes were studied: condition at birth (5-min Apgar score less than 7 and/or umbilical artery pH less than 7.10), and admission to neonatal intensive care unit.ResultsThe study population consisted of 7589 women; 2880 (38.0%) received mediolateral episiotomy. After applying propensity scores, episiotomy was associated with a lower rate of OASIs in forceps/spatula delivery (2.3 vs 6.8%, Risk Ratio (RR) 0.38, 95% Confidence Interval (CI) 0.28–0.52) and in vacuum delivery (1.3 vs 3.4%, RR 0.27, 95% CI 0.20–0.38) as compared with no episiotomy. Mediolateral episiotomy was associated with better condition at birth in case of forceps/spatula delivery (4.5 vs 8.8%, RR 0.56, 95% CI 0.39–0.81). In cases of fetal distress (40.7%), mediolateral episiotomy was associated with better condition of infant at birth in women who delivered by forceps/spatula (4.2 vs 13.5%, RR 0.52, 95% CI 0.31–0.89). No association was found with neonatal unit admission (RR 0.93, 95% CI 0.50–1.74).ConclusionsUse of mediolateral episiotomy was associated with a lower rate of OASIs during operative vaginal delivery, and in infants it was associated with better condition at birth following forceps/spatula delivery.

The prediction of morbidity related to vaginal delivery in nulliparous women – A secondary analysis from the genesis multicenter trial

ObjectiveIn the prospective multicenter Genesis study, we developed a prediction model for Cesarean delivery (CD) in term nulliparous women. The objective of this secondary analysis was to determine whether the Genesis model has the potential to predict maternal and neonatal morbidity associated with vaginal delivery. Study designThe national prospective Genesis trial recruited 2,336 nulliparous women with a vertex presentation between 39 + 0- and 40 + 6-weeks’ gestation from seven tertiary centers. The prediction model used five parameters to assess the risk of CD: maternal age, maternal height, body mass index, fetal head circumference and fetal abdominal circumference. Simple and multiple logistic regression analyses were used to develop the Genesis model. The risk score calculated using this model were correlated with maternal and neonatal morbidity in women who delivered vaginally: postpartum hemorrhage (PPH), obstetric anal sphincter injury (OASI), shoulder dystocia, one- and five-minute Apgar score ≤ 7, neonatal intensive care (NICU) admission, cephalohematoma, fetal laceration, nerve palsy and fractures. The morbidities associated with spontaneous vaginal delivery were compared with those associated with operative vaginal delivery (OVD). The likelihood ratios for composite morbidity and the morbidity associated with OVD based on the Genesis risk scores were also calculated. ResultsA total of 1,845 (79%) nulliparous women had a vaginal delivery. A trend of increasing intervention and morbidity was observed with increasing Genesis risk score, including OVD (p < 0.001), PPH (p < 0.008), NICU admission (p < 0.001), low Apgar score at one-minute (p < 0.001) and OASI (p = 0.009). The morbidity associated with OVD was significantly higher compared to spontaneous vaginal delivery, including NICU admission (p < 0.001), PPH (p = 0.022), birth injury (p < 0.001), shoulder dystocia (p = 0.002) and Apgar score of<7 at one-minute (p < 0.001). The positive likelihood ratios for composite outcomes (where the OVD was excluded) increases with increasing risk score from 1.005 at risk score of 5% to 2.507 for risk score of>50%. ConclusionIn women who ultimately achieved a vaginal birth, we have shown more maternal and neonatal morbidity in the setting of a Genesis nomogram-determined high-risk score for intrapartum CD. Therefore, the Genesis prediction tool also has the potential to predict a more morbid vaginal delivery.

A core outcome set development for a French national prospective study about the effect of mediolateral episiotomy on obstetric anal sphincter injury during operative vaginal delivery (INSTRUMODA)

BackgroundWe aimed at developing a core outcome and variables of interest set to investigate the effects of mediolateral episiotomy on Obstetric Anal Sphincter Injury (OASI) during and after operative delivery in nulliparous women in a large-scale one-year observational French study including 15,000 women (INSTRUMODA).MethodsA list of outcomes and variables of interest was suggested to obstetricians participating in the INSTRUMODA study using online questionnaires divided into 7 categories: the woman’s history and course of pregnancy, course of labor, modalities of operative delivery, episiotomy characteristics, immediate maternal morbidity, one-year maternal morbidity, immediate neonatal morbidity. We used a three-round DELPHI method to reach a consensus. In the first round, outcomes and variables considered as essential by 70% or more of obstetricians were included in the corpus whereas they were excluded when 70% rated them as “not important”. In the second round, non-consensual outcomes and variables were reassessed and excluded or definitively included if considered as “not important” or essential by 50% or more of the obstetricians. During the first round, obstetricians were invited to suggest new outcomes and/or variables that were then assessed in the second and third round. We used the same method to develop a core outcome and variables of interest set in a population of women in the community recruited via an association of patients. At the end of the procedure the core outcome and variables of interest sets were merged to provide the final core outcome set for the INSTRUMODA study.ResultsFifty-three obstetricians and 16 women filled out questionnaires. After the 3 rounds of Delphi procedure in each population, 74 outcomes and variables were consensually reported by obstetricians and 92 by women in the community. By mixing these two consensual corpora we reported a final consensual list of 114 variables of interest and outcomes for both obstetricians and women.ConclusionWe established a core outcome and variables of interest set among obstetricians and women in the community to investigate the association between mediolateral episiotomy and OASI during operative delivery.Trial registrationThe INSTRUMODA study was registered on https://clinicaltrials.gov on June 25, 2020 (NCT04446780).

694 Impact of neonatal birth weight on adverse perinatal outcomes in cesarean deliveries in nulliparous women

To investigate the association between neonatal birth weight (NBW) and adverse perinatal outcomes in nulliparous cesarean deliveries (CD). This is a retrospective cohort study of singleton, non-anomalous, term CD of nulliparous women 2007-2011 using linked vital statistics and ICD-9 data. Neonatal adverse outcomes examined included brachial plexus injury (BPI), clavicular fracture (CVF), neonatal intensive care unit (NICU) admission, hypoxic-ischemic encephalopathy (HIE), hypoglycemia (HG), and a composite of severe neonatal outcomes (including neonatal seizure, APGAR score ≤3, and neonatal death). Maternal adverse outcomes examined included postpartum hemorrhage (PPH) and maternal blood transfusion (MBT). Chi-square tests were used to compare rates of perinatal adverse outcomes for births in varying neonatal birth weight categories. Multivariable logistic regression was used to control for maternal BMI, diabetes, race/ethnicity, age, education, insurance, parity, and prenatal care. In a cohort of 258,490 CD, we found significantly higher rates of neonatal adverse outcomes, including BPI, CVF, NICU admission, and HG, with rising NBW (Figure 1). Risk of BPI and CVF rose from 0.01% in 3000-3400 neonates to 0.06% and 0.08%, respectively, in neonates ≥4500g (p=0.003). Risk of HG increased from 0.6% in 3000-3400g neonates to 3.7% in neonates ≥4500g (p<0.001). Regarding maternal outcomes, the risk of PPH and MBT rose from 1.8% and 1.1%, respectively, in 3000-3499g neonates, to 4.8% and 2.1%, respectively, in neonates ≥4500g (p<0.001). After controlling for potential confounders, there remains a statistically significant increase in odds of PPH and MBT across all NBW categories when compared with 3000-3499g neonates (Table 1). A statistically significant increase in odds of HG was also noted for 4000-4499g and ≥4500g when compared with 3000-3499g neonates. Higher NBW increases the risk of perinatal complications in the setting of nulliparous CD. Providers should exercise heightened awareness of the effect of NBW on these potential adverse outcomes when managing CD.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

47 A Double-Blinded Randomized Controlled Trial on Increased Intravenous Hydration in Nulliparous Women Undergoing Labor Induction

High-dose intravenous fluid (250cc/hr) has been previously demonstrated to shorten the time to delivery in nulliparous women in spontaneous labor. Whether or not this relationship ship exists in women undergoing induction of labor is unknown. Our study aimed to evaluate the effect of high-dose intravenous hydration (compared to standard dose) on time to delivery among nulliparous women undergoing induction of labor. Nulliparous women presenting for induction of labor with a Bishop score of less than or equal to 6 (with and without rupture of membranes) were randomized to receive either 125cc/hr or 250cc/hr of normal saline. The primary outcome was length of labor (defined as time from initiation of study fluids to delivery). Both time to overall delivery and vaginal delivery were evaluated. Secondary outcomes included the lengths of each stage of labor, the percentage of women delivering within 24 hours, and maternal and neonatal outcomes. 180 individuals meeting inclusion criteria were enrolled and randomized. Baseline demographic characteristics were similar between groups, however there was a higher incidence of maternal diabetes in the group receiving 125cc/hr. Average length of labor was similar between groups (27.6hr in 250cc/hr and 27.8hr in 125cc/hr) as was the length of each stage of labor. Cox regression analysis did not demonstrate an effect of fluid rate on time to delivery. Neither admission bishop score, BMI, nor other demographic characteristics impacted time to delivery or vaginal delivery. There were no differences in maternal or neonatal outcomes including overall cesarean rate, clinical iatrogenic intrapartum infection, Apgar scores, need for neonatal phototherapy, or neonatal intensive care unit stay. There are no observed differences in the length of labor or maternal or neonatal outcomes with the administration of an increased rate of intravenous fluids among nulliparous women undergoing induction of labor.

422 An RCT of sequential versus simultaneous use of foley balloon and oxytocin for labor induction

To determine whether the induction of labor with simultaneous use of oxytocin and decreases the time to delivery in nulliparous women as compared to sequential use of Foley balloon followed by oxytocin. We conducted a randomized clinical trial of nulliparous women presenting for induction of labor at Saint Paul’s Hospital. Nulliparous women with singleton pregnancies for whom ripening of the cervix followed by induction of labor with oxytocin was decided were recruited for the study. They were randomly assigned to either simultaneous or sequential groups. In the sequential group, oxytocin was started after the Foley catheter is expelled or was put in place for 12 hours whichever comes first. While in the simultaneous group oxytocin was started within one hour of the insertion of Foley catheter and the two groups were compared. The primary outcome was the induction to delivery time. Secondary outcomes included are cesarean delivery rate, rates of chorioamnionitis, and composite neonatal score. An intention-to-treat (ITT) analyses was used. A total of 140 women were recruited and 70 women were started on simultaneous trans-cervical Foley balloon insertion with oxytocin while the rest 70 were started with sequential mode. The median (interquartile range) of the oxytocin initiation to delivery time was 6.9 (4.3, 10.7) hrs and 8.1 (4.7, 11.6) hrs for the sequential and simultaneous group respectively (P-value= 0.46). There was no difference in the induction delivery time and the rate of the cesarean section between the two groups. Contrary to the previous studies the simultaneous initiation of oxytocin didn’t show a reduction in the Oxytocin to delivery time.

Changes in the Frequency of Cesarean Delivery in Nulliparous Women in Labor in a Canadian Population, 1992-2018.

To examine the relative contribution of changes in patient demographics and physician management to changes in the cesarean delivery rate in labor among nulliparous women. We conducted a retrospective cohort study of 485,451 births to nulliparous women who experienced labor at or beyond 35 weeks of gestation in Alberta, Canada, from 1992 to 2018. The data were from a province-wide perinatal database. The primary outcome was cesarean delivery. Multivariate logistic regression and calculation of population attributable risk for identified risk factors were performed. The cesarean delivery rate increased from 12.5% in 1992 to 24% in 2018. The prevalence of maternal risk factors for cesarean delivery such as obesity, maternal age 35 years or older at delivery, and comorbidities increased over the study period. However, this did not account for the increase in cesarean delivery, because the frequency of cesarean delivery increased irrespective of risk status. Additionally, the population-attributable risk for each risk factor was stable across the study period. For example, for maternal age 35 years or older at delivery, the number of cesarean deliveries attributable to this factor (the population-attributable risk) was 0.9 per 100 deliveries in 1992-1998 and 1 per 100 in 2014-2018. The proportion of cesarean deliveries in which nonreassuring fetal status was the indication increased from 30.1% in 1992 to 51.1% in 2018. The absolute rate of cesarean delivery in the second stage of labor increased from 3.1% in 1992 to 5.9% in 2018. This was due to a significant increase, among those who entered the second stage, in cesarean delivery without a trial of forceps, from 2.5% in 1992 to 7.0% in 2018. The observed doubling of the rate of cesarean delivery in labor in first-time mothers was not driven by patient risk factors. Increases in the rate of cesarean delivery for nonreassuring fetal status and decreased operative vaginal deliveries were important factors.

Effectiveness of Prenatal Perineal Massage in Reducing the Risk of Perineal Trauma during Vaginal Delivery in Nulliparous Women: A Meta-Analysis and Evidence Based Review

Background: Perineal injury occurs in 85% of all women who experience a vaginal, delivery. Perineal injury involves an episiotomy and/or a laceration. Urinary incontinence (UI) is the most frequently reported morbidity following a perineal injury.

Low-dose Aspirin for the Prevention of Preterm Delivery in Nulliparous Women With a Singleton Pregnancy (ASPIRIN): A Randomized, Double-blind, Placebo-controlled Trial

(Lancet. 2020;395:285–293) Preterm birth is a common cause of infant morbidity and mortality, especially in low- and middle-income countries with limited resources. Previous studies of aspirin used to prevent preeclampsia also suggested that low-dose aspirin may help lower the incidence of preterm births. However, no large-scale trial has specifically evaluated the use of low-dose aspirin initiated in early pregnancy with the primary purpose of preventing preterm birth. The aim of this study (the ASPIRIN trial) was to determine if low-dose aspirin administered daily starting in early pregnancy reduced the incidence of preterm delivery.

Facteurs de risque de césarienne en cours de travail pour la nullipare avec une obésité morbide

ObjectivesObesity is a well-known caesarean and obstetrical risk factor. However, the number of obese nulliparous women is increasing worldwide, creating an urgent need for research into the impact of obesity on the mode of delivery. Our objective was to identify caesarean risk factors in obese nulliparous women with a BMI (body mass index) greater than 40kg/m2. MethodsA literature review was conducted on PubMed; including articles published between 2009 and 2019 in French and English, on caesarean risk during labor among class III obese nulliparous women. ResultsOne prospective study, and 6 retrospective analyses were included. Their results suggest that the rate of caesarean delivery increases with the BMI. Maternal age, particularly after 35 years, as well as induced labor and the use of oxytocin during labor, were positively associated with cesarean delivery. Moreover, maternal BMI was linked to an increased risk of non-elective caesarean section due to non-reassuring fetal heart tracing. ConclusionExtreme BMI, age, induced labor and oxytocin use are associated with caesarean delivery in nulliparous women with BMI≥40kg/m2. Further research are needed to estimate the best candidates for elective cesarean delivery.

OC13.03: Intrapartum ultrasound at the initiation of the active second stage of labour predicts spontaneous vaginal delivery in nulliparous women

OC13.03: Intrapartum ultrasound at the initiation of the active second stage of labour predicts spontaneous vaginal delivery in nulliparous women