Intrapartum Cesarean Birth Research Articles

Association of inpatient postpartum recovery with patient-reported outcome measures following hospital discharge: a prospective cohort study

BackgroundThe relationship between the quality of inpatient versus outpatient obstetric postpartum recovery is under-explored. We examined the association between inpatient reported quality of recovery with outpatient global recovery, pain severity, pain interference, anxiety, and depression screening scores postpartum.MethodsWe conducted a multicenter observational cohort study of women in labor who underwent vaginal, operative vaginal, or intrapartum cesarean birth. Subjects completed baseline assessments of pain, social support, anxiety, and depression in early labor. We assessed the Obstetric Quality of Recovery-10 (ObsQoR-10) on the day of discharge and the ObsQoR-10, Global Health Scale (GHVAS; 0–100), Brief Pain Inventory (BPI), and the Edinburgh Postnatal Depression Scale (EPDS) on postpartum day seven. We hypothesized that the ObsQoR-10 scores at discharge would be useful in predicting postpartum day seven measures of recovery and postpartum depression screening scores.ResultsWe consented 558 subjects, 551/558(98%) completed baseline assessments, 400/551(72%) completed the ObsQoR-10 tool, and 344/551(62%) completed an EPDS assessment. Median (1st, 3rd quartile) ObsQoR-10 scores were 78 (63, 90) at discharge and 85 (68,93) on postpartum day seven, (difference of 7 [99% CI 2 to 13], P < 0.001). GHVAS on postpartum day seven identified 204/344 (59%) of subjects with good recovery. An ObsQoR-10 score of > 86 at discharge had a RR of 1.5 [95% CI 1.2 to 1.8], P < 0.001 for good recovery at postpartum day seven, the EPDS identified 20/344 (5.8%) respondents with a score ≥ 13 on postpartum day seven. The area under the curve between the ObsQoR-10 at discharge with an EPDS ≥ 13 was 0.74 (99% CI 0.61 to 0.86, P < 0.001). The RR for an EPDS ≥ 13 on postpartum day seven with an ObsQoR-10 < 77 on the day of discharge was 7.8 (95% CI 1.8 to 33.8; P = 0.001).ConclusionsObsQoR-10 scores at discharge and postpartum day seven demonstrated increased obstetric recovery in the post-discharge period. The observed association between the ObsQoR-10 and the EPDS, suggests that the ObsQoR-10 might facilitate identification of women at increased risk of postpartum anxiety or depression. Identification of high-risk women at discharge may allow early interventions to reduce morbidity secondary to postpartum depression.

Maternal and neonatal outcomes associated with breech presentation in planned community (home and birth center) births in the United States: A prospective observational cohort study.

Investigate maternal and neonatal outcomes associated with breech presentation in planned community births in the United States, including outcomes associated with types of breech presentation (i.e., frank, complete, footling/kneeling). Secondary analysis of prospective cohort data from a national perinatal data registry (MANA Stats). Planned community birth (homes and birth centers), United States. Individuals with a term, singleton gestation (N = 71,943) planning community birth at labor onset. Descriptive statistics to calculate associations between types of breech presentation and maternal and neonatal outcomes. Maternal: intrapartum/postpartum transfer, hospitalization, cesarean, hemorrhage, severe perineal laceration, duration of labor stages and membrane rupture Neonatal: transfer, hospitalization, NICU admission, congenital anomalies, umbilical cord prolapse, birth injury, intrapartum/neonatal death. One percent (n = 695) of individuals experienced breech birth (n = 401, 57.6% vaginally). Most fetuses presented frank breech (57%), with 19% complete, 18% footling/kneeling, and 5% unknown type of breech presentation. Among all breech labors, there were high rates of intrapartum transfer and cesarean birth compared to cephalic presentation (OR 9.0, 95% CI 7.7-10.4 and OR 18.6, 95% CI 15.9-21.7, respectively), with no substantive difference based on parity, planned site of birth, or level of care integration into the health system. For all types of breech presentations, there was increased risk for nearly all assessed neonatal outcomes including hospital transfer, NICU admission, birth injury, and umbilical cord prolapse. Breech presentation was also associated with increased risk of intrapartum/neonatal death (OR 8.5, 95% CI 4.4-16.3), even after congenital anomalies were excluded. All types of breech presentations in community birth settings are associated with increased risk of adverse neonatal outcomes. These research findings contribute to informed decision-making and reinforce the need for breech training and research and an increase in accessible, high-quality care for planned vaginal breech birth in US hospitals.

Optimal Timing of Delivery for Pregnant Individuals With Mild Chronic Hypertension.

To investigate the optimal gestational age to deliver pregnant people with chronic hypertension to improve perinatal outcomes. We conducted a planned secondary analysis of a randomized controlled trial of chronic hypertension treatment to different blood pressure goals. Participants with term, singleton gestations were included. Those with fetal anomalies and those with a diagnosis of preeclampsia before 37 weeks of gestation were excluded. The primary maternal composite outcome included death, serious morbidity (heart failure, stroke, encephalopathy, myocardial infarction, pulmonary edema, intensive care unit admission, intubation, renal failure), preeclampsia with severe features, hemorrhage requiring blood transfusion, or abruption. The primary neonatal outcome included fetal or neonatal death, respiratory support beyond oxygen mask, Apgar score less than 3 at 5 minutes, neonatal seizures, or suspected sepsis. Secondary outcomes included intrapartum cesarean birth, length of stay, neonatal intensive care unit admission, respiratory distress syndrome (RDS), transient tachypnea of the newborn, and hypoglycemia. Those with a planned delivery were compared with those expectantly managed at each gestational week. Adjusted odds ratios (aORs) with 95% CIs are reported. We included 1,417 participants with mild chronic hypertension; 305 (21.5%) with a new diagnosis in pregnancy and 1,112 (78.5%) with known preexisting hypertension. Groups differed by body mass index (BMI) and preexisting diabetes. In adjusted models, there was no association between planned delivery and the primary maternal or neonatal composite outcome in any gestational age week compared with expectant management. Planned delivery at 37 weeks of gestation was associated with RDS (7.9% vs 3.0%, aOR 2.70, 95% CI, 1.40-5.22), and planned delivery at 37 and 38 weeks was associated with neonatal hypoglycemia (19.4% vs 10.7%, aOR 1.97, 95% CI, 1.27-3.08 in week 37; 14.4% vs 7.7%, aOR 1.82, 95% CI, 1.06-3.10 in week 38). Planned delivery in the early-term period compared with expectant management was not associated with a reduction in adverse maternal outcomes. However, it was associated with increased odds of some neonatal complications. Delivery timing for individuals with mild chronic hypertension should weigh maternal and neonatal outcomes in each gestational week but may be optimized by delivery at 39 weeks.

A Qualitative Study Exploring Women's Experiences of Unplanned Cesarean Surgery and Their Suggestions for Improving Care

The rate of unplanned cesarean birth is increasing and there is a growing body of evidence regarding the associated psychosocial harms. A phenomenological study exploring eight women's lived experiences of intrapartum cesarean birth in Nova Scotia was undertaken. Two groups of women were recruited, three receiving care from a midwife with transfer from a planned home birth and five women under the care of a physician. Semi-structured interviews were tape-recorded and transcribed. These data, combined with participantdiariesande-mails,wereanalyzedusingColazzi'smethod. Threemajorthemesemerged:1) Immediate and lingering emotional reactions, which were wide ranging, the majority negative, particularly fear, disappointment and self-doubt, 2) Mediating factors, most significantly, continuous contact with the baby and provider support, especially from midwives, and 3) Participant suggestions for improving care which included prenatal operating room (OR) tours, family-friendly OR policies, postnatal medical review with extended follow-up and peer support. This study adds to the already substantial evidence of associated psychosocial harms which can be mediated by concurrently reducing unnecessary cesarean surgery and implementing measures to improve the quality of cesarean care.

Mediating processes underlying the associations between maternal obesity and the likelihood of cesarean birth.

Pregnant women with obesity are more likely to experience cesarean birth compared to women without obesity. Yet, little is known about the underlying mechanisms. The objective of this study was therefore to evaluate how mediators contribute to the association between obesity and prelabor/intrapartum cesarean birth. We retrospectively analyzed Swiss cohort data from 394,812 singleton, cephalic deliveries between 2005 and 2020. Obesity (BMI ≥ 30 kg/m2 ) was defined as the exposure and prelabor or intrapartum cesarean birth as the outcomes. Hypothesized mediators included gestational comorbidities, large-for-gestational-age infant, pregnancy duration >410/7 weeks, slower labor progress, labor induction, and history of cesarean birth. We performed path analyses using generalized structural equation modeling and assessed mediation by a counterfactual approach. Women with obesity had a cesarean birth rate of 39.36% vs. 24.12% in women without obesity. The path models mainly showed positive direct and indirect associations between obesity and cesarean birth. In the total sample, the mediation models explained up to 39.47% (95% CI 36.92-42.02) of the association between obesity and cesarean birth, and up to 57.13% (95% CI 54.10-60.16) when including history of cesarean birth as mediator in multiparous women. Slower labor progress and history of cesarean birth were found to be the most clinically significant mediators. This study provides empirical insights into how obesity may increase cesarean birth rates through mediating processes. Particularly allowing for a slower labor progress in women with obesity might reduce cesarean birth rates and prevent subsequent repeat cesarean births in multiparous women.

Mode of delivery of Finnish dichorionic and monochorionic-diamniotic twins: A retrospective observational study including a risk score for intrapartum cesarean birth.

Trial of labor is considered safe also among twins, yet nearly 50% are born via cesarean section in Finland. While planned cesarean births have declined among twins, intrapartum cesarean deliveries have risen, postulating evaluation of criteria for trial of labor. The objective of this study was to create an outline of the mode of delivery of dichorionic and monochorionic-diamniotic Finnish twins. By evaluating risk factors for intrapartum cesarean delivery (CD), we aimed at creating a risk score for intrapartum cesarean birth for twins. A retrospective observational study based on a cohort of dichorionic and monochorionic-diamniotic twin pregnancies considered as candidates for trial of labor in 2006, 2010, 2014, and 2018 (n = 720) was performed. Differences between parturients with vaginal delivery and intrapartum CD to identify potential risk factors for intrapartum CD were assessed. Logistic regression analysis (n = 707) was used to further define risk score points for recognized risk factors. A total of 23.8% (171/720, 95% confidence interval [CI] = 20.7-26.9) of parturients experienced intrapartum CD. Induction of labor, primiparity, fear of childbirth, artificial reproductive technology, higher maternal age, and other than cephalic/cephalic presentation independently associated with intrapartum CD. The achieved total risk score ranged from 0 to 13 points with significantly higher points among the CD group (6.61 vs. 4.42, p < 0.001). Using ≥8 points as a cut-off, 51.4% (56/109) were delivered by intrapartum CD (sensitivity = 33.73%, specificity = 90.20%, positive predictive value = 51.38%, negative predictive value = 81.61%). The total risk score had a fair predictive capability for intrapartum CD (area under the curve = 0.729, 95% CI = 0.685-0.773). Fair-level risk stratification could be achieved with higher maternal age, primiparity, induction of labor, artificial reproductive technology, fear of childbirth, and other than cephalic/cephalic presentation increasing the risk. Parturients with low-risk score (0-7 points) appear to be the best candidates for trial of labor with acceptable CD rates in this group (18.4%).

Prophylactic Methylergonovine and Oxytocin Compared With Oxytocin Alone in Patients Undergoing Intrapartum Cesarean Birth: A Randomized Controlled Trial.

To evaluate whether the administration of prophylactic methylergonovine in addition to oxytocin in patients undergoing intrapartum cesarean birth reduces the need for additional uterotonic agents. This was a single-center, placebo-controlled, randomized trial of patients undergoing intrapartum cesarean birth. Patients were randomly allocated to receive intravenous oxytocin 300 mL/minute plus intramuscular methylergonovine 0.2 mg (1 mL) or intravenous oxytocin 300 mL/minute plus intramuscular normal saline (1 mL). The primary outcome was the receipt of additional uterotonic agents. Secondary outcomes included surgeon assessment of uterine tone, incidence of postpartum hemorrhage, quantitative blood loss, and blood transfusion. To detect a twofold decrease in the need for additional uterotonic agents (assuming a 42% baseline) with a two-sided type 1 error of 5% and power of 80%, a sample size of 76 patients per group was required. From June 2019 through February 2021, 80 patients were randomized to receive methylergonovine plus oxytocin and 80 were randomized to receive to oxytocin alone. Significantly fewer patients who were allocated to the methylergonovine group received additional uterotonic agents (20% vs 55%, relative risk [RR] 0.4, 95% CI 0.2-0.6). Participants receiving methylergonovine were more likely to have satisfactory uterine tone (80% vs 41%, RR 1.9, 95% CI 1.5-2.6), lower incidence of postpartum hemorrhage (35% vs 59%, RR 0.6, 95% CI 0.4-0.9), lower mean quantitative blood loss (967 mL vs 1,315 mL; mean difference 348, 95% CI 124-572), and a lower frequency of blood transfusion (5% vs 23%, RR 0.2, 95% CI 0.1-0.6). The administration of prophylactic methylergonovine in addition to oxytocin in patients undergoing intrapartum cesarean birth reduces the need for additional uterotonic agents. ClinicalTrials.gov, NCT03904446.

Advancing understanding of maternal age: correlating epigenetic clocks in blood and myometrium

BackgroundAdvanced maternal age is currently a term defined by chronological age. However, a group of biomarkers known as epigenetic clocks, which can predict morbidity and mortality, has been used to estimate measures of biological aging. Uterine myometrial function during the process of parturition may be influenced by aging, as labor dystocia, unplanned intrapartum cesarean birth, and postpartum hemorrhage are more common in older individuals. The purpose of this study was to evaluate the use of epigenetic clocks in maternal myometrium and blood for predicting age and to evaluate the correlation of epigenetic age between the tissues.ResultsWe compared epigenetic age in blood and myometrial samples provided by women undergoing planned cesarean birth at term gestation. Chronological age ranged from 20 to 50 with a median (IQR) age of 35.5(8) years. The MethylationEPIC BeadChip was used to obtain DNA methylation data, and then epigenetic age was calculated using the Horvath, Hannum, GrimAge, and PhenoAge clocks. Spearman correlations of epigenetic age with chronological age were calculated. We tested the relationship of epigenetic age in maternal blood to epigenetic age in myometrium. Age acceleration, for each clock, was also correlated between tissues. Twenty-seven participants provided samples, and 21 matched specimens were included in the final analysis after quality control. Spearman correlation between maternal chronological age and epigenetic age were significant in three of the four clocks (pan-tissue Horvath, Hannum, and GrimAge), for both myometrium and blood samples. Correlations between blood epigenetic age and maternal age ranged from 0.72 to 0.87 (all p < 0.001). Correlations between myometrial epigenetic age and maternal age were also significant (0.62–0.70, p = 0.002), though lower than correlations seen in blood. Maternal blood epigenetic age also correlated with epigenetic age in myometrium with each of these three clocks 0.60 (p = 0.004, Horvath), 0.63 (p = 0.003, Hannum), and 0.80 (p < 0.001, GrimAge). GrimAge age acceleration had the highest correlation between tissues among the clocks (0.49, p = 0.02).ConclusionsGiven the limited sample, this study provides insight into the potential use of epigenetic age derived from blood as a proxy for myometrial epigenetic age, which may be a useful biomarker in estimating myometrial biological age in relationship to myometrial dysfunction. GrimAge outperformed the other tested clocks in terms of concordance of epigenetic age and age acceleration between tissues; however, the Horvath and Hannum clocks may be useful depending on the outcome of interest in pregnancy.

The association of timing of repeat cesarean with outcomes among a cohort of Guatemalan women with a history of prior cesarean birth

BackgroundThe objective of this analysis was to observe whether maternal and perinatal/neonatal outcomes of birth vary by timing of repeat cesarean among women with a history of one prior cesarean birth in a Guatemalan cohort.MethodsThis secondary analysis was conducted using data from a prospective study conducted in communities in Chimaltenango, Guatemala through the Global Network for Women’s and Children’s Health Research.ResultsBetween January 2017 and April 2020, 26,465 women delivered; 3,143 (11.9%) of those women had a singleton gestation and a history of prior cesarean delivery. 2,210 (79.9%) women with a history of prior cesarean birth had data available on mode of delivery and gave birth by repeat cesarean; 1312 (59.4%) were pre-labor cesareans while 896 (40.5%) were intrapartum cesarean births. Risk factors associated with an increased risk of intrapartum cesarean birth included hospital delivery as compared to “other” location (ARR 1.6 [1.2,2.1]) and dysfunctional labor (ARR 1.6 [1.4,1.9]). Variables associated with a reduced risk of intrapartum cesarean birth were hypertensive disease (ARR 0.7 [0.6,0.9]), schooling (ARR 0.9 [0.8,0.9]), and increasing age, which was associated with a very slight reduction in the outcome (ARR 0.99 [0.98,0.99]). Maternal and neonatal outcomes did not vary by type of cesarean birth.ConclusionOutcomes of cesarean birth do not seem to vary by timing of repeat cesarean birth, with hypertensive disease increasing the likelihood of pre-labor cesarean. This information might be useful in counseling women that outcomes after failed trial of labor do not appear worse than those after pre-labor cesarean birth.

Cesarean birth, obstetric emergencies, and adverse neonatal outcomes in Iceland during a period of increasing labor induction.

The rate of labor induction has risen steeply throughout the world. This project aimed to estimate changes in the rates of adverse maternal and neonatal outcomes in Iceland between 1997 and 2018, and to assess whether the changes can be explained by an increased rate of labor induction. Singleton live births, occurring between 1997 and 2018, that did not start by prelabor cesarean, were identified from the Icelandic Medical Birth Register (n=85971). Rates of intrapartum cesarean birth (CB), obstetric emergencies, and neonatal outcomes were calculated, and adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) were estimated with log-binomial regression (reference: 1997-2001). Adjustments were made for: (a) maternal characteristics, and (b) labor induction and gestational age. The rate of labor induction increased from 13.6% in the period 1997-2001 to 28.1% in the period 2014-2018. The rate of intrapartum CB decreased between the periods of 1997-2001 and 2014-2018 for both primiparous (aRR 0.76, 95% CI: 0.69 to 0.84) and multiparous women (aRR 0.55, 95% CI: 0.49 to 0.63). The rate of obstetric emergencies and adverse neonatal outcomes also decreased between these time periods. Adjusting for labor induction did not attenuate these associations. The rates of adverse maternal outcomes and adverse neonatal outcomes decreased over the study period. However, there was no evidence that this decrease could be explained by the increased rate of labor induction.

Contemporary duration of spontaneous labor and association with maternal characteristics: A French national population-based study.

The objective of this study was to describe labor duration of women managed with current obstetric practices in a French national population-based cohort and to assess the association of age and BMI on this duration. All women in the French perinatal survey of 2016 with a singleton cephalic fetus, delivering at term after a spontaneous labor were included. Duration of labor was defined as time between admission to the labor ward and birth. Duration of total labor and first and second stage of labor were described. Then, duration of labor was estimated according to maternal age and BMI, using Kaplan-Meier's method and compared with the log-rank test after stratification on parity. Intrapartum cesarean birth was considered as a censoring event. Multivariable modeling was performed using Cox's proportional hazard's method. Data of 3120 nulliparous and 4385 multiparous women were analyzed. Median labor duration was 6.1hours ([5th; 95th percentile]) [1.4; 12.6] and 3.1hours [0.3; 8.5] in nulliparous and multiparous women. Multivariable Cox analysis showed no independent association of maternal age and duration of labor. Nulliparous obese women had significantly lower odds of having a shorter labor than women with a BMI<25kg/m2 , HR: 0.75; 95% CI [0.64-0.88], but BMI was not associated with labor duration in multiparous women. Our study provides important information for both women and care practitioners on what to expect when entering the labor ward. There appears to be little association between maternal characteristics and labor duration, with the exception of BMI in nulliparous women.

Risk factors associated with adverse maternal outcomes following intrapartum cesarean birth: a secondary analysis of the WHO global survey on maternal and perinatal health, 2004\u20132008

BackgroundTo identify risk factors associated with a composite adverse maternal outcomes in women undergoing intrapartum cesarean birth.MethodsWe used the facility-based, multi-country, cross-sectional WHO Global Survey of Maternal and Perinatal Health (2004–2008) to examine associations between woman-, labor/obstetric-, and facility-level characteristics and a composite adverse maternal outcome of postpartum morbidity and mortality. This analysis was performed among women who underwent intrapartum cesarean birth during the course of labor.ResultsWe analyzed outcomes of 29,516 women from low- and middle-income countries who underwent intrapartum cesarean birth between the gestational ages of 24 and 43 weeks, 3.5% (1040) of whom experienced the composite adverse maternal outcome. In adjusted analyses, factors associated with a decreased risk of the adverse maternal outcome associated with intrapartum cesarean birth included having four or more antenatal visits (AOR 0.60; 95% CI: 0.43–0.84; p = 0.003), delivering in a medium- or high-human development index country (vs. low-human development index country: AOR 0.07; 95% CI: 0.01–0.85 and AOR 0.02; 95% CI: 0.001–0.39, respectively; p = 0.03), and malpresentation (vs. cephalic: breech AOR 0.52; CI: 0.31–0.87; p = 0.04). Women who were medically high risk (vs. not medically high risk: AOR 1.81; CI: 1.30–2.51, p < 0.0004), had less education (0–6 years) (vs. 13+ years; AOR 1.64; CI: 1.03–2.63; p = 0.01), were obstetrically high risk (vs. not high risk; AOR 3.67; CI: 2.58–5.23; p < 0.0001), or had a maternal or obstetric indication (vs. elective: AOR 4.74; CI: 2.36–9.50; p < 0.0001) had increased odds of the adverse outcome.ConclusionWe found reduced adverse maternal outcomes of intrapartum cesarean birth in women with ≥ 4 antenatal visits, those who delivered in a medium or high human development index country, and those with malpresenting fetuses. Maternal adverse outcomes associated with intrapartum cesarean birth were medically and obstetrically high risk women, those with less education, and those with a maternal or obstetric indication for intrapartum cesarean birth.

Variation of intrapartum care and cesarean rates among practitioners attending births of low-risk, nulliparous women.

Variation in hospital cesarean birth rates across the United States is likely because of differences in practitioner practice patterns. Yet, few studies conducted in the last twenty years have examined the relationships between practitioner characteristics and the use of intrapartum interventions and cesarean birth. The objective of this study was to examine associations among practitioner characteristics and the use of amniotomy, epidural, oxytocin augmentation, and cesarean birth in low-risk women with spontaneous onset of labor. A secondary analysis was performed using data collected by the Consortium on Safe Labor. The sample included nulliparous term singleton vertex (NTSV) births with spontaneous onset of labor (n=13196) from 2002 to 2007 across eight hospitals. Generalized linear mixed models were conducted to examine outcomes. The cesarean birth rate ranged from 7.2% to 18.9% across hospitals and from 0% to 53.3% across physicians. Practice type (P<.05) and specialty type (P<.0001) were associated with physician cesarean birth rates. Compared with obstetrician/gynecologists, midwives were nearly twice as likely to use no intrapartum interventions (relative risk 1.80 [CI 95 1.45-2.24]) and 26% less likely to use amniotomy-epidural-oxytocin (0.74 [0.62-0.89]). Family practice physicians had a 21% lower likelihood of using amniotomy-epidural-oxytocin (0.79 [0.67-0.94]) and a 53% lower likelihood of performing cesarean births (0.47 [0.35-0.63]). Wide variation in hospital and physician cesarean birth rates was observed in this sample of low-risk, nulliparous women. Practitioner practice type and specialty were significantly associated with the use of intrapartum interventions. Interprofessional practitioner education could beone strategy to reduce variation of intrapartum care and cesarean birth.

Associations Among Intrapartum Interventions and Cesarean Birth in Low-Risk Nulliparous Women with Spontaneous Onset of Labor.

Cesarean birth rates vary widely across hospitals in the United States, even among women who are considered low-risk for the procedure. This variation has been attributed to differences in health care provider practice, but few studies have explored patterns of labor management in relation to cesarean birth. This was a retrospective observational study of 26,259 nulliparous, term, singleton gestation, vertex presentation births following spontaneous onset of labor. Births occurred from 2002 to 2007 in 11 hospitals in the Consortium on Safe Labor. Generalized linear mixed modeling was used to examine the relationship between intrapartum interventions (amniotomy, epidural analgesia, oxytocin augmentation) used individually and in combination and the outcome of cesarean birth. More than 90% of the women in this low-risk sample received at least one intervention regardless of mode of birth. Epidural analgesia was the most frequently applied intervention, both when used as a single intervention (18.7%) and in combination with other interventions (79.9%). The strongest associations between these interventions and cesarean birth were observed when 2 or 3 interventions were applied during labor. Compared with women who received no interventions, the strongest association was observed among women who received amniotomy-oxytocin augmentation (adjusted odds ratio [aOR], 1.89; 95% CI, 1.36-2.62). The use of all 3 interventions (amniotomy-epidural analgesia-oxytocin augmentation) showed a similar positive association with cesarean birth (aOR 1.83; 95% CI, 1.50-2.21). Findings show that the combined use of amniotomy, epidural analgesia, and oxytocin augmentation is positively associated with cesarean birth. Additional research is needed to examine the timing and sequence of interventions as well as whether a causal relationship exists between combinations of interventions and cesarean birth in low-risk nulliparous women.

The Effect of Maternal Age on Obstetric Interventions in a Low-Risk Population.

Obstetric interventions appear to increase with advancing maternal age, but limited supporting evidence exists, particularly for young women and specifically for prelabor and intrapartum cesarean birth. The aim of this study was to explore the association between obstetric interventions and maternal age in a low-risk population. The study was restricted to all low-risk, nulliparous women with singleton, vertex, term births who gave birth in Iceland from 1997 to 2015, identified in the Icelandic Medical Birth Registry. Logistic regression models were used to calculate adjusted odds ratios (aORs) and 95% CIs for the risks of labor induction, instrumental birth, and cesarean birth (prelabor and intrapartum), according to maternal age group. All models were adjusted for gestational age, year of birth, and demographic factors, and the models for intrapartum cesarean birth were also adjusted for dystocia and fetal distress. For women aged more than 40 years, the aOR for induction of labor was 4.69 (95% CI, 3.2-6.8) compared with women aged between 25 and 29 years. In women aged more than 40 years, the increased risks for prelabor cesarean birth and intrapartum cesarean birth were 7.4 (95% CI, 3.0-18.0) and 3.6 (95% CI, 2.1-6.0), respectively. The risk of instrumental birth was slightly increased for women aged between 35 and 39 years (aOR, 1.6; 95% CI, 1.3-2.0), compared with women aged between 25 and 29 years, but not for women aged at least 40 years (aOR, 1.1; 95% CI, 0.7-1.9). For women aged less than 20 years, the risk of induction of labor (aOR, 0.8; 95% CI, 0.7-0.9) and instrumental births (aOR, 0.6; 95% CI, 0.5-0.7) was reduced compared with women aged between 25 and 29 years. The risk of interventions generally increased with increasing maternal age, but the risk of instrumental births was not increased for women aged over 40 years. Also, young women were at a decreased risk of induction of labor and instrumental births.

Factors affecting outcome in post-term birth

Studies published in the past year confirm that, under current conditions of good ascertainment of gestational age and careful clinical management of post-term pregnancies, post-term births are not at increased risk of perinatal mortality. They are, however, still at increased risk of intrapartum fetal distress and cesarean birth. The main risk factor for poor fetal and neonatal outcomes is small fetal size. Risk markers for those at risk of intrapartum difficulties include amniotic fluid volume and fetal biophysical profile. While there is no longer increased mortality associated with post-term birth per se, this is very much the result of clinical selection factors and modern perinatal management. Post-term pregnancies remain an obstetrical risk group.