The correlation between fetal bradycardia area in the second stage of labor and acidemia at birth

The Correlation Between the Total Decelerations and Accelerations Areas and Cord Blood pH in Women with Low-Risk Pregnancies

Fetal acidosis among low-risk pregnancies is not common; however, identifying those at risk for this complication antenatally is of great interest. We aimed to assess the correlation between the total decelerations area during the last 120 min of fetal monitoring prior to delivery and neonatal acidemia in low-risk pregnancies and whether the total acceleration area has a protective effect in the presence of decelerations. A retrospective cohort study was conducted among women with term low-risk pregnancies. A researcher blinded to fetal outcomes interpreted electronic fetal monitor patterns during the 120 min prior to delivery. The primary outcome was fetal acidemia, defined as umbilical artery pH below 7.10. The correlation between the total decelerations and accelerations areas and cord blood pH was tested using the Spearman correlation coefficient. A total of 109 women were included and of these, six (5.5%) delivered infants with cord blood pH < 7.10. A significant correlation was demonstrated between the total decelerations area and cord blood pH (p = 0.01). No correlation was found between the total accelerations area and cord blood pH. Among low-risk pregnancies, a correlation was found between the total decelerations area but not the total accelerations area during the final 120 min of labor and cord blood pH.

The association of intrapartum deceleration and acceleration areas with MRI findings in neonatal encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is an important contributor to disability worldwide. The current cardiotocography (CTG) predictive value for neonatal outcome is limited.

OBJECTIVE

To assess the association of intrapartum CTG deceleration and acceleration areas with early MRI cerebral pathology in infants with HIE.

METHODS

Term and near-term low-risk pregnancies that resulted in HIE, treated with therapeutic hypothermia with sufficient CTG records from a single, tertiary hospital between 2013 and 2021 were enrolled. Accelerations and decelerations areas, their minimum and maximum depths, and duration were calculated as well as the acceleration-to-deceleration area ratio during the 120 min prior to delivery. These data were assessed for associations with higher degrees of abnormality on early MRI scans.

RESULTS

A total of 77 infants were included in the final analysis. Significant associations between increased total acceleration area (p = 0.007) and between a higher acceleration-to-deceleration area ratio (p = 0.003) and better MRI results were detected.

CONCLUSION

In neonates treated for HIE, acceleration area and acceleration-to-deceleration ratio are associated with the risk of neonatal brain MRI abnormalities. To increase the role of these measurements as a relevant clinical tool, larger, more powered prospective trials are needed, using computerized real-time analysis.

IMPACT

The current cardiotocography predictive value for neonatal outcome is limited. This study aimed to assess the association of intrapartum deceleration and acceleration areas with the degree of cerebral injury in early cerebral MRI of neonates with encephalopathy. Lower acceleration area and acceleration-to-deceleration ratio were found to be associated with a higher degree of neonatal brain injury. Brain MRI is a marker of long-term outcome; its association with cardiotocography indices supports their association with long-term outcome in these neonates. Future computer-based CTG area analysis could assist in delivery room decision making to better time interventions and prevent hypoxic-ischemic encephalopathy.

Intrapartum deceleration and acceleration areas are associated with neonatal encephalopathy

OBJECTIVE

To investigate whether an association exists between deceleration and acceleration areas on continuous fetal cardiotocography (CTG) and neonatal encephalopathy (NE).

METHODS

A single center, retrospective case-control study was conducted to compare CTG characteristics of low-risk pregnancies (35 weeks of gestation or more), complicated by moderate to severe NE with two matched controls for every case. Controls were matched by gestational age and cord blood pH. We analyzed the intrapartum CTG recordings by calculation of the deceleration and acceleration areas and the ratio between the two.

RESULTS

During the period between 2013 and 2019, we identified 95 cases of low-risk pregnancies that were complicated by moderate to severe NE in our center. Thirty-three (34.7%) deliveries were excluded, mostly because of an insufficient duration of the CTG recordings. The remaining 62 cases were matched with 123 controls. We found that NE was significantly associated with an increased total deceleration area, a decreased total acceleration area, and a lower acceleration-to-deceleration ratio.

CONCLUSIONS

NE was significantly associated with increased total deceleration area, decreased total acceleration area, and a lower acceleration-to-deceleration ratio, independent of cord blood pH. Development of a computerized real-time analysis of fetal heart rate tracings may contribute to making these measurements a more valid clinical tool.

Intrapartum cardiotocography in pregnancies with and without fetal CHD

OBJECTIVES

Congenital heart defects (CHD) are the most common inherited abnormalities. Intrapartum cardiotocography (CTG) is still considered a "gold standard" during labor. However, there is a lack of evidence regarding the interpretation of intrapartum CTG in fetuses with CHD. Therefore, the study aimed to compare intrapartum CTG in normal fetuses and fetuses with CHD and describe the association between CTG and neonatal outcomes.

METHODS

The present study is a retrospective analysis of the CTG of 395 fetuses. There were three study groups: Group 1: 185 pregnancies with a prenatal diagnosis of CHD, Group 2: 132 high-risk pregnancies without CHD, and Group 3: 78 low-risk pregnancies without CHD.

RESULTS

Abnormal CTG was present statistically OR=3.4 (95%CI: 1.61-6.95) more often in Group 1. The rate of the emergency CS was higher in this group OR=3 (95%CI: 1.3-3.1). Fetuses with CHD and abnormal CTG were more often scored ≤7 Apgar, with no difference in acidemia. The multivariate regression model for Group 1 does not show clinical differences between Apgar scores or CTG assessment in neonatal acidemia prediction.

CONCLUSIONS

CTG in fetuses with CHD should be interpreted individually according to the type of CHD and conduction abnormalities. Observed abnormalities in CTG are associated with the fetal heart defect itself. Preterm delivery and rapid cesarean delivery lead to a higher rate of neonatal complications. Health practitioners should consider this fact during decision-making regarding delivery in cases complicated with fetal cardiac problems.

The cumulative incidence of neonatal metabolic acidemia after terminal bradycardia in the 2nd stage of labor: a survival-based model

PURPOSE

The aim of the study was to estimate by a survival analysis model the hazard function (HF) for neonatal metabolic acidemia (MA) throughout the 2nd stage of labor (2STG) at the time of occurrence of a terminal bradycardia ≥ 10 min requiring expedited delivery, and the cumulative incidence function (CIF) for MA according with the duration of bradycardia stratified in 10-12 min and > 12 min.

METHODS

Singleton pregnancies experiencing terminal fetal bradycardia requiring expedited delivery in the 2STG at 38 + 0-41 + 3 weeks and delivering in the year 2019, were identified. The presence of MA (pH < 7 and/or BE ≤ - 12 mmol/L) was determined based on the acid-base status in the umbilical artery cord blood. Survival analysis was used to assess the hazard function (HF) and the cumulative incidence function (CIF) for MA occurring after terminal fetal bradycardia, at the 2STG.

RESULTS

Out of a non-consecutive population of 12,331 pregnancies, there were 52 cases that fit the inclusion criteria. Twenty-four (46.2%) of those develop MA. Abnormal quantitative pH values and the HF for MA correlated with the duration of 2STG at the time of bradycardia onset, but not with bradycardia duration. After 60 min of duration of 2STG, the HF (or instantaneous rate of failure) increased dramatically (from 1.2 to 20 about at 120 min). At paired duration of 2STG, a higher CIF was observed for the terminal bradycardia > 12 min.

CONCLUSION

Forty-six percent of term fetuses with terminal bradycardia had MA at birth. Despite the low sensitivity and a non-significant association with quantitative pH values, the duration of terminal bradycardia in the 2STG is associated with a higher CIF for MA.

Placental growth factor level is correlated with intrapartum fetal heart rate findings

Objective

Here, we tested the correlation between maternal placental growth factor (PlGF) and fetal heart rate (FHR) monitoring findings.

Methods

We included 35 women with single pregnancies from 35 to 42 weeks of gestation who were hospitalized owing to onset of labor. Blood samples were collected at the start of labor. Intrapartum FHR monitoring parameters included total deceleration area, average deceleration area (mean deceleration area per 10 min), and five-tier classification level.

Results

Of the 35 women, 26 (74%) had vaginal delivery and 9 (26%) had cesarean section. After excluding 2 women who had cesarean section for arrest of labor, we analyzed 26 women who had vaginal delivery (VD group) and 7 who had cesarean section for fetal indications (CSF group). PlGF level was significantly higher in the VD group (157 ± 106 pg/ml) than in the CSF group (74 ± 62 pg/ml) (P = 0.03). There were no significant correlations between PlGF and total (r = -0.07) or average (r = -0.08) deceleration area.　There was a significant negative correlation (r = -0.42, P = 0.01) between PlGF and the percentage of level 3 or higher in the five-level classification.

Conclusion

PlGF was correlated with FHR monitoring findings and might be a promising biomarker of intrapartum fetal function.

Timing intrapartum management based on the evolution and duration of fetal heart rate patterns

One of the most important challenges in obstetrics is to determine the appropriate time to deliver the fetus without exposing the mother to unnecessary operative interventions. The use of continuous cardiotocography (cCTG) during labor has resulted in dramatic reductions in intrapartum fetal deaths, but fetal central nervous system (CNS) injury and cerebral palsy (CP) rates have remain relatively unchanged as related to the use of cCTG . In our view, this is due to continuing inability to recognize progressive fetal deterioration and intervene promptly prior to the development of fetal CNS injury. Although the 2008 NICHD workshop proposed a 3-tier classification system, most fetuses born with severe (pathologic) acidemia (cord artery pH < 7.00), as well as those who eventually develop CP, will never reach the stage of NICHD Category III fetal heart rate (FHR) pattern. In the present "Clinical Opinion," we promote a concept derived from observations, that the evolution of the FHR changes of the deteriorating fetus can be visually defined by three color "zones" that are clinically recognizable and, therefore, are actionable. In addition, we will review information regarding how long the fetus may be able to tolerate an abnormal FHR pattern before it suffers an adverse perinatal outcome, an area of investigation that has been rarely addressed before. Based on the available evidence, Category III FHR patterns should not be used as screening criteria because of low sensitivity for either fetal CNS injury (45%) or severe (pathologic) fetal acidemia (36-44%). In addition, the duration of the Category III pattern required for the development of severe fetal acidemia is extremely short to allow for a timely preventative operative intervention. On the contrary, the use of our proposed "red" zone, which includes the most advanced stages in the progressive deterioration of Category II patterns and Category III, will identify the overwhelming majority of fetuses who develop severe (pathologic) acidemia (96%) and/or CNS injury during labor (100%); moreover, the detection of fetal jeopardy by the use of the "red" zone occurs much earlier, as compared to using Category III, thus allowing reasonable amount of time for a timely obstetrical intervention. Further research is needed to determine the false positive rate and positive predictive value for a pre-determined period of time in the red zone.

Total intrapartum fetal reperfusion time (fetal resilience) and neonatal acidemia

OBJECTIVE

The main objective is to study the predictive capacity of intrapartum total fetal reperfusion (fetal resilience) by itself or in combination with other parameters as a predictor of neonatal acidemia.

STUDY DESIGN

A retrospective case-control study was carried out at the Miguel Servet University Hospital (Zaragoza, Spain) on a cohort of 5694 pregnant women between June 2017 and October 2018. Maternal, perinatal, and cardiotocographic records were collected. Two reviewers blindly described the monitors with the American College of Obstetricians and Gynecologists (ACOG) categorizations and parameters and the non-ACOG parameters. Neonatal acidemia was defined as pH <7.10. The parameters analyzed to predict acidemia were evaluated using the sensitivity for specificity 90% value, and the area under the receiver operating characteristic curve.

RESULTS

We recorded 192 infants with acidemia, corresponding to a global acidemia rate of 3.4%. Of these, 72 were excluded for lack of criteria, leaving 120 patients with arterial acidemia included in the study and 258 in the control group. The sensitivity (specificity 90%) of detection of acidemia was 42% for the ACOG III categorization (AUC, 0.524: 95% CI, 0.470-0.578), 24% for fetal reperfusion (AUC, 0.704: 95% CI, 0.649-0.759), 27% for total area of decelerations (AUC, 0.717: 95% CI, 0.664-0.771) and 50% for the multivariate model built from total reperfusion time (AUC, 0.826: 95% CI, 0.783-0.869). The total reperfusion time corresponding to a false negative rate of 10% is 23.75 min, with 28% of fetuses above this time. The AUC and sensitivity for a false negative rate of 10% are equivalent for deceleration area and time of reperfusion (p = .504).

CONCLUSION

The total reperfusion time (fetal resilience) and total deceleration area are non-ACOG parameters with a good predictive ability for neonatal acidemia, higher than the ACOG III classification and without statistical differences between them. The discrimination ability of total reperfusion time can be improved using a multivariate model. As a cutoff for its use we suggest 23.75 min in 30 min corresponding to an acidemic classification rate of 90%. New parameters in combination with other maternal, obstetrics, or fetal variables, are required for the interpretation of fetal well-being.

[Per-partum risk factors of neonatal acidemia in planned vaginal delivery for fetuses in breech presentation]

OBJECTIVES

Delivery mode of term breech presentation is debated because of higher rate of neonatal acidosis (pH<7.15) in planned vaginal delivery than in planned caesarean section. The objective was to evaluate per-partum risk factors of neonatal acidosis in vaginal delivery for podalic fetuses.

METHODS

It was a single-centre, case-control retrospective study that included planned vaginal delivery in singleton term breech presentation between 2012 and 2016. The "case" group defined by neonatal pH≤7.10 and the "control" group defined by neonatal pH≥7.20 were matched. The maternal, labor, and neonatal characteristics were noted.

RESULTS

One hundred and thirty-two patients were included: each of 44 patients in "case" group, has been matched according to breech type (legs position) to 2 patients in the "control" group, so 88. In multivariate analysis, significant risk factors identified were oxytocin use [ORa=5.663 (95% CI=1.844-17.397)], "high risk" fetal heart rate (FHR) abnormalities according to FIGO classification [ORa=10.997 (95% CI=1.864-64.866)] and FHR abnormalities during expulsion, Melchior 2 [ORa=8.088 (95% CI=1.192-54.875)] and Melchior 4 [ORa=12.705 (95% CI=1.157-139.541)].

CONCLUSIONS

These risk factors of neonatal acidemia have to be known to improve the labor management in case of breech planned vaginal delivery.

CTG Analyzer: A graphical user interface for cardiotocography

Cardiotocography (CTG) is the most commonly used test for establishing the good health of the fetus during pregnancy and labor. CTG consists in the recording of fetal heart rate (FHR; bpm) and maternal uterine contractions (UC; mmHg). FHR is characterized by baseline, baseline variability, tachycardia, bradycardia, acceleration and decelerations. Instead, UC signal is characterized by presence of contractions and contractions period. Such parameters are usually evaluated by visual inspection. However, visual analysis of CTG recordings has a well-demonstrated poor reproducibility, due to the complexity of physiological phenomena affecting fetal heart rhythm and being related to clinician's experience. Computerized tools in support of clinicians represents a possible solution for improving correctness in CTG interpretation. This paper proposes CTG Analyzer as a graphical tool for automatic and objective analysis of CTG tracings. CTG Analyzer was developed under MATLAB®; it is a very intuitive and user friendly graphical user interface. FHR time series and UC signal are represented one under the other, on a grid with reference lines, as usually done for CTG reports printed on paper. Colors help identification of FHR and UC features. Automatic analysis is based on some unchangeable features definitions provided by the FIGO guidelines, and other arbitrary settings whose default values can be changed by the user. Eventually, CTG Analyzer provides a report file listing all the quantitative results of the analysis. Thus, CTG Analyzer represents a potentially useful graphical tool for automatic and objective analysis of CTG tracings.

The temporal effect of Category II fetal monitoring on neonatal outcomes

OBJECTIVE

To correlate the duration of Category II cardiotocograms (CTG) with adverse neonatal outcomes associated with perinatal asphyxia and determine the duration before fetal compromise.

STUDY DESIGN

This retrospective, observational study used electronic medical record data from a cohort of 271 patients, delivered by C-section due to non-reassuring fetal heart rate, at a tertiary medical center, from 2015 through 2017. Duration of Category II CTG, variability, tachycardia and deceleration frequency were analyzed and correlated to immediate postnatal outcomes. including cord pH ≤ 7, cord base excess >12, 1- and 5-min Apgar scores ≤7, need for ventilation, need for chest compressions, NICU admission, hypoglycemia and convulsions. Intrapartum fever and meconium stained amniotic fluid were correlated to the same outcomes. Categorical and continuous variables were analyzed using chi-square and t-tests, respectively. P < 0.05 was considered significant.

RESULTS

The mean duration of Category II CTG was 146 min (range 17-553). Longer duration did not result in increased rates of adverse neonatal outcomes. In contrast, reduced fetal heart rate (FHR) variability, fetal tachycardia and intrapartum fever did show increased rates of adverse neonatal outcomes, as follows: patients exhibiting reduced vs. normal (FHR) variability had 12.9% vs. 1.4% cord pH ≤ 7, P = 0.006 and 12.5% vs. 1.3% cord BE > 12, P = 0.004: patients with fetal tachycardia vs. normal baseline FHR exhibited 48% vs. 17.9% 1-minute Apgar score ≤7, P = 0.0004; 8% vs. 0.8% 5-minute Apgar score ≤7, P = 0.04; and 48% vs. 18.7% ventilation support, P < 0.001; patients with intrapartum fever vs. normal temperature, cord BE > 12 was seen in 9.7% vs. 1.7%, P = 0.035; 1-minute Apgar score was ≤7 in 35.5% vs. 18.7%, P = 0.03; 5-minute Apgar score ≤7 in 9.7% vs. 0.4%, P = 0.005; need for ventilation in 35.5% vs. 19.6%, P = 0.042; need for chest compressions in 6.45% vs. none, P = 0.013; and NICU admission in 12.9% vs. 2.5%, P = 0.018.

CONCLUSIONS

Our results suggest that the duration of Category II CTG alone does not appear to predict perinatal asphyxia. Parameters associated with perinatal asphyxia are reduced FHR variability, fetal tachycardia and intrapartum fever. Therefore, when contemplating intervention during labor to avoid fetal asphyxia, these parameters should be strongly considered.

Correlation between umbilical arterial pH values and fetal vertebral artery Doppler waveforms at the beginning of the second stage of labor: a pilot prospective study

Objective: The aim of this study was to evaluate the association between umbilical arterial pH and fetal vertebral artery Doppler velocimetry waveforms measured at the beginning of the second stage of labor in physiological term pregnancies. Methods: This was a prospective cohort study of 250 pregnancies. The resistance index, pulsatility index, and peak systolic velocity were measured. The relationship between the fetal Doppler and the umbilical arterial pH was evaluated. A simple linear regression and a general linear model were used to explore possible correlations of Doppler parameters with fetal and neonatal outcome adjusted for confundents. Results: Umbilical arterial pH values were directly associated with vertebral artery pulsatility index. Fetuses with lower pulsatility index values were at increased risk of a subsequent diagnosis of pathological fetal heart rate tracing patterns (presence of decelerations or reduced variability according to FIGO criteria during the second stage of labor). We estimated a decrease in pulsatility index of 10% in those fetuses destined to show a pathological fetal heart rate tracing. Conclusion: Vertebral artery Doppler waveforms correlates with umbilical pH in normal pregnancies and is also a function of fetal heart rate patterns. If this proportional association would be demonstrated also for abnormal pH values, vertebral artery pulsatility index might be useful to evaluate fetal wellbeing in those cases of suspected hypoxia/academia.

eCTG: an automatic procedure to extract digital cardiotocographic signals from digital images

BACKGROUND AND OBJECTIVE

Cardiotocography (CTG), consisting in the simultaneous recording of fetal heart rate (FHR) and maternal uterine contractions (UC), is a popular clinical test to assess fetal health status. Typically, CTG machines provide paper reports that are visually interpreted by clinicians. Consequently, visual CTG interpretation depends on clinician's experience and has a poor reproducibility. The lack of databases containing digital CTG signals has limited number and importance of retrospective studies finalized to set up procedures for automatic CTG analysis that could contrast visual CTG interpretation subjectivity. In order to help overcoming this problem, this study proposes an electronic procedure, termed eCTG, to extract digital CTG signals from digital CTG images, possibly obtainable by scanning paper CTG reports.

METHODS

eCTG was specifically designed to extract digital CTG signals from digital CTG images. It includes four main steps: pre-processing, Otsu's global thresholding, signal extraction and signal calibration. Its validation was performed by means of the "CTU-UHB Intrapartum Cardiotocography Database" by Physionet, that contains digital signals of 552 CTG recordings. Using MATLAB, each signal was plotted and saved as a digital image that was then submitted to eCTG. Digital CTG signals extracted by eCTG were eventually compared to corresponding signals directly available in the database. Comparison occurred in terms of signal similarity (evaluated by the correlation coefficient ρ, and the mean signal error MSE) and clinical features (including FHR baseline and variability; number, amplitude and duration of tachycardia, bradycardia, acceleration and deceleration episodes; number of early, variable, late and prolonged decelerations; and UC number, amplitude, duration and period).

RESULTS

The value of ρ between eCTG and reference signals was 0.85 (P < 10^-560) for FHR and 0.97 (P < 10^-560) for UC. On average, MSE value was 0.00 for both FHR and UC. No CTG feature was found significantly different when measured in eCTG vs. reference signals.

CONCLUSIONS

eCTG procedure is a promising useful tool to accurately extract digital FHR and UC signals from digital CTG images.

Atypical decelerations: do they matter?

OBJECTIVE

To estimate the association between atypical variable decelerations and neonatal acidemia.

METHOD

We conducted a one-year case-control study comparing the last thirty minutes before delivery of fetal heart rate tracings of 102 acidemic neonates (umbilical arterial cord gas pH ≤ 7.10) with 100 non-acidemic controls (umbilical arterial cord gas pH > 7.10). Incidence of atypical features and total number of decelerations, number of atypical decelerations, number of slow return decelerations and number of decelerations with loss of moderate variability during deceleration were extracted. We estimated the association between atypical features, neonatal acidemia and neonatal morbidity.

RESULTS

Acidemic neonates showed a larger number of atypical decelerations (4 [0-12] vs. 3 [0-10]), "slow return" decelerations (4 [0-11] vs. 1 [0-10]) and decelerations with non-moderate variability (0[0-12] vs. 0 [0-6]) compared to non-acidemic controls. "Slow return" was significantly associated with an increased risk of acidemia at birth (OR 4.46; CI 95%: 2.18 - 9.15) "Slow return" was the most discriminating feature between groups with an AUC: 0.745.

CONCLUSION

Certain atypical features, as "slow return" and loss of moderate variability within decelerations are associated with neonatal acidemia. "Slow return" could help in the gradation of acidemia risk levels, as an indicator of gravity.

The Burden of Provider-Initiated Preterm Birth and Associated Factors: Evidence from the Brazilian Multicenter Study on Preterm Birth (EMIP)

Background

About 15 million children are born under 37 weeks of gestation worldwide. Prematurity is the leading cause of neonatal deaths and short/long term morbidities, entailing consequences not only for the individual, but also their family, health agencies, facilities and all community. The provider-initiated preterm birth is currently one of the most important obstetric conditions related to preterm births, particularly in middle and high income countries, thus decreasing the need for therapeutic preterm birth is essential to reduce global prematurity. Therefore detailed knowledge on the factors associated with provider-initiated preterm birth is essential for the efforts to reduce preterm birth rates and its consequences. In this current analysis we aimed to assess the proportion of provider-initiated (pi-PTB) among preterm births in Brazil and identify associated factors.

Methods and Findings

This is an analysis of a multicenter cross-sectional study with a nested case-control component called Brazilian Multicenter Study on Preterm Birth (EMIP). EMIP was conducted in 20 referral obstetric hospitals located in the three most populated of the five Brazilian regions. We analysed data of women with pi-PTB, defined as childbirth occurring at less than 37 weeks, medically indicated for maternal/fetal compromise or both; and women with term birth, childbirth at or after 37 weeks. Maternal, sociodemographic, obstetric, prenatal care, delivery, and postnatal characteristics were assessed as possible factors associated with pi-PTB, compared to term births. The overall prevalence of preterm births was 12.3%. Of these, approximately one-third of cases were initiated by the provider. Hypertensive disorders, placental abruption, and diabetes were the main maternal conditions leading to pi-PTB. Caesarean section was the most common mode of delivery. Chronic hypertension (OR 7.47; 95%CI 4.02–13.88), preeclampsia/eclampsia/HELLP syndrome (OR 15.35; 6.57–35.88), multiple pregnancy (OR 12.49; 4.86–32.05), and chronic diabetes (OR 5.24; 2.68–10.25) were the most significant factors independently associated with pi-PTB.

Conclusions

pi-PTB is responsible for about one-third of all preterm births, requiring special attention. The decision-making process relative to the choice of provider-initiated birth is complex, and many factors should be elucidated to improve strategies for its prevention, including evidence-based guidelines on proper management of the corresponding clinical conditions.