Association of Recorded Estimated Fetal Weight and Cesarean Delivery in Attempted Vaginal Delivery at Term

Quantitative Approach to Quality Review of Prenatal Ultrasound Examinations: Fetal Biometry

Background/Objectives: To evaluate the quality of an ultrasound practice, both large-scale and focused audits are recommended by professional organizations, but such audits can be time-consuming, inefficient, and expensive. Our objective was to develop a time-efficient, quantitative, objective, large-scale method to evaluate fetal biometry measurements for an entire practice, combined with a process for focused image review for personnel whose measurements are outliers. Methods: Ultrasound exam data for a full year are exported from commercial ultrasound reporting software to a statistical package. Fetal biometry measurements are converted to z-scores to standardize across gestational ages. For a large-scale audit, sonographer mean z-scores are compared using analysis of variance (ANOVA) with Scheffe multiple comparisons test. A focused image review is performed on a random sample of exams for sonographers whose mean z-scores differ significantly from the practice mean. A similar large-scale audit is performed, comparing physician mean z-scores. Results: Using fetal abdominal circumference measurements as an example, significant differences between sonographer mean z-scores are readily identified by the ANOVA and Scheffe test. A method is described for the blinded image audit of sonographers with outlier mean z-scores. Examples are also given for the identification and interpretation of several types of systematic errors that are unlikely to be detectable by image review, including z-scores with large or small standard deviations and physicians with outlier mean z-scores. Conclusions: The large-scale quantitative analysis provides an overview of the biometry measurements of all the sonographers and physicians in a practice, so that image audits can be focused on those whose measurements are outliers. The analysis takes little time to perform after initial development and avoids the time, complexity, and expense of auditing providers whose measurements fall within the expected range. We encourage commercial software developers to include tools in their ultrasound reporting software to facilitate such quantitative reviews.

Ensemble learning for fetal ultrasound and maternal-fetal data to predict mode of delivery after labor induction

Providing adequate counseling on mode of delivery after induction of labor (IOL) is of utmost importance. Various AI algorithms have been developed for this purpose, but rely on maternal-fetal data, not including ultrasound (US) imaging. We used retrospectively collected clinical data from 808 subjects submitted to IOL, totaling 2024 US images, to train AI models to predict vaginal delivery (VD) and cesarean section (CS) outcomes after IOL. The best overall model used only clinical data (F1-score: 0.736; positive predictive value (PPV): 0.734). The imaging models employed fetal head, abdomen and femur US images, showing limited discriminative results. The best model used femur images (F1-score: 0.594; PPV: 0.580). Consequently, we constructed ensemble models to test whether US imaging could enhance the clinical data model. The best ensemble model included clinical data and US femur images (F1-score: 0.689; PPV: 0.693), presenting a false positive and false negative interesting trade-off. The model accurately predicted CS on 4 additional cases, despite misclassifying 20 additional VD, resulting in a 6.0% decrease in average accuracy compared to the clinical data model. Hence, integrating US imaging into the latter model can be a new development in assisting mode of delivery counseling.

A model to predict delivery time following induction of labor at term with a dinoprostone vaginal insert: a retrospective study

BACKGROUND

Dinoprostone vaginal insert is the most common pharmacological method for induction of labor (IOL); however, studies on assessing the time to vaginal delivery (DT) following dinoprostone administration are limited.

AIMS

We sought to identify the primary factors influencing DT in women from central China, at or beyond term, who underwent IOL with dinoprostone vaginal inserts.

METHODS

In this retrospective observational study, we analyzed the data of 1562 women at 37 weeks 0 days to 41 weeks 6 days of gestation who underwent dinoprostone-induced labor between January 1st, 2019, and December 31st, 2021. The outcomes of interest were vaginal or cesarean delivery and factors influencing DT, including maternal complications and neonatal characteristics.

RESULTS

Among the enrolled women, 71% (1109/1562) delivered vaginally, with median DT of 740.50 min (interquartile range 443.25 to 1264.50 min). Of the remaining 29% (453/1562), who delivered by cesarean section, 11.9% (54/453) were multiparous. Multiple linear regression analysis showed that multiparity, advanced maternal age, fetal macrosomia, premature rupture of membranes (PROM), and daytime insertion of dinoprostone were the factors that significantly influenced DT. Time to vaginal delivery increased with advanced maternal age and fetal macrosomia and decreased with multiparity, PROM, and daytime insertion of dinoprostone. A mathematical model was developed to integrate these factors for predicting DT: Y = 804.478 - 125.284 × multiparity + 765.637 × advanced maternal age + 411.511 × fetal macrosomia-593.358 × daytime insertion of dinoprostone - 125.284 × PROM.

CONCLUSIONS

Our findings may help obstetricians estimate the DT before placing a dinoprostone insert, which may improve patient management in busy maternity wards and minimize potential risks.

The Rate of Intrapartum Cesarean Delivery Based on Estimated Fetal Weight in Comparison to Previous Child's Birth Weight

OBJECTIVE

The aim of the study is to examine whether an estimated fetal weight of the current pregnancy greater than previous birth weight is associated with increased odds of intrapartum cesarean delivery.

STUDY DESIGN

We conducted a retrospective cohort study of all women who had more than one singleton pregnancy at 23 weeks' gestation or greater at a single labor and delivery unit. We only analyzed the second pregnancy in the dataset. We excluded women who had preterm birth in the second pregnancy. Women were categorized according to the difference between estimated fetal weight and previous birth weight-estimated fetal weight close to previous birth weight within 500 g (similar weight group); estimated fetal weight significantly (more than 500 g) greater than previous birth weight (larger weight group); and estimated fetal weight significantly (more than 500 g) lower than previous birth weight (smaller weight group). The primary outcome was intrapartum cesarean delivery. Multivariable logistic regression was performed to calculate adjusted odds ratios (aORs) with 95% confidence interval (95% confidence interval [CI]) after adjusting for predefined covariates.

RESULTS

Of 1,887 women, there were 1,415 (75%) in the similar weight group, 384 (20%) in the greater weight group, and 88 (5%) in the smaller weight group. Individuals in the larger weight group compared with those in the similar weight group had higher odds of undergoing intrapartum cesarean delivery (11.2 vs. 4.5%; aOR 2.91; 95% CI 1.91-4.45). The odds of intrapartum cesarean delivery in the smaller weight group compared with those in the similar weight group were not increased (3.4 vs. 4.5%; crude OR 0.75; 95%CI 0.23-2.42).

CONCLUSION

The difference between current estimated fetal weight and previous birth weight plays an important role in assessing the risk of intrapartum cesarean delivery.

KEY POINTS

· Estimated fetal weight compared with previous birth weight is an important factor.. · Cesarean delivery is infrequent if estimated fetal weight is similar to previous birth weight.. · Larger estimated fetal weight greater than the previous birth weight is associated with cesarean delivery..

Predicting primary cesarean delivery in pregnancies complicated by gestational diabetes mellitus

BACKGROUND

Prediction models have shown promise in helping clinicians and patients engage in shared decision-making by providing quantitative estimates of individual risk of important clinical outcomes. Gestational diabetes mellitus is a common complication of pregnancy, which places patients at higher risk of primary CD. Suspected fetal macrosomia diagnosed on prenatal ultrasound is a well-known risk factor for primary CD in patients with gestational diabetes mellitus, but tools incorporating multiple risk factors to provide more accurate CD risk are lacking. Such tools could help facilitate shared decision-making and risk reduction by identifying patients with both high and low chances of intrapartum primary CD.

OBJECTIVE

This study aimed to develop and internally validate a multivariable model to estimate the risk of intrapartum primary CD in pregnancies complicated by gestational diabetes mellitus undergoing a trial of labor.

STUDY DESIGN

This study identified a cohort of patients with gestational diabetes mellitus derived from a large, National Institutes of Health-funded medical record abstraction study who delivered singleton live-born infants at ≥34 weeks of gestation at a large tertiary care center between January 2002 and March 2013. The exclusion criteria included previous CD, contraindications to vaginal delivery, scheduled primary CD, and known fetal anomalies. Candidate predictors were clinical variables routinely available to a practitioner in the third trimester of pregnancy found to be associated with an increased risk of CD in gestational diabetes mellitus. Stepwise backward elimination was used to build the logistic regression model. The Hosmer-Lemeshow test was used to demonstrate goodness of fit. Model discrimination was evaluated via the concordance index and displayed as the area under the receiver operating characteristic curve. Internal model validation was performed with bootstrapping of the original dataset. Random resampling with replacement was performed for 1000 replications to assess predictive ability. An additional analysis was performed in which the population was stratified by parity to evaluate the model's predictive ability among nulliparous and multiparous individuals.

RESULTS

Of the 3570 pregnancies meeting the study criteria, 987 (28%) had a primary CD. Of note, 8 variables were included in the final model, all significantly associated with CD. They included large for gestational age, polyhydramnios, older maternal age, early pregnancy body mass index, first hemoglobin A1C recorded in pregnancy, nulliparity, insulin treatment, and preeclampsia. Model calibration and discrimination were satisfactory with the Hosmer-Lemeshow test (P=.862) and an area under the receiver operating characteristic curve of 0.75 (95% confidence interval, 0.74-0.77). Internal validation demonstrated similar discriminatory ability. Stratification by parity demonstrated that the model worked well among both nulliparous and multiparous patients.

CONCLUSION

Using information routinely available in the third trimester of pregnancy, a clinically pragmatic model can predict intrapartum primary CD risk with reasonable reliability in pregnancies complicated by gestational diabetes mellitus and may provide quantitative data to guide patients in understanding their individual primary CD risk based on preexisting and acquired risk factors.

Vaginal delivery rate by near delivery sonographic weight estimation and maternal stature among nulliparous women

BACKGROUND

We evaluated the risk for cesarean delivery among term nulliparous women, categorized by maternal stature and recent sonographic estimated fetal weight (EFW).

METHODS

A retrospective study including singleton deliveries of nulliparous women between 2011 and 2020, with sonographic EFW within 1 week of delivery. We categorized maternal height into five groups: ≤150, 151-155, 156-160, 161-165, and ≥166 cm. Fetal weight estimation was categorized into five groups as well: ≤2500 g, 2501-2999, 3000-3499, 3500-3999, and ≥4000 g.

RESULTS

Overall, 13 107 deliveries were included. The cesarean delivery rate was inversely correlated with maternal height, ranging from 41.0% in group 1 to 13.1% in group 5. The vaginal delivery rate ranged from 33.3% in maternal height group 1 with EFW of ≥4000 g to 85% in maternal height group 5 with EFW of ≤2500 g. In weight categories above 2500 g, maternal height correlated significantly with vaginal delivery rate, except in weight category ≥4000 g in which vaginal delivery rate ranged around 30% in maternal height categories 1-3 and increased significantly in groups 4-5 to 50-60%. In multivariable logistic regression analysis, EFW was independently associated with CD for EFW categories 3500-3999 and ≥4000 g [aOR 95% CI 1.49 (1.08-2.06) and 4.39 (2.97-6.50), respectively]. Maternal height was negatively associated with CD [aOR 95% CI 0.67 (0.64-0.70)] for each increase in maternal height group.

CONCLUSIONS

Cesarean delivery rate was inversely correlated with maternal height, ranging from 41.0% among women ≤150 cm to 13.1% among women ≥166 cm. Maternal height and EFW of ≥3500 g are independently associated with CD rates among term nulliparous women.

Influence of Sonographic Fetal Weight Estimation Inaccuracies in Macrosomia on Perinatal Outcome

OBJECTIVE

 To evaluate the influence of inaccurate sonographic fetal weight estimation in macrosomia on the mode of delivery and neonatal outcome (NO).

METHODS

 In 14 633 pregnancies between 2002 and 2016, this retrospective study evaluated the association between sonographic fetal weight estimation, true birth weight (BW), mode of delivery (primary cesarean section [pCS], secondary cesarean section, vaginal delivery, and operative vaginal delivery rates) and NO parameters (5-min Apgar < 7, pH < 7.1, neonatal intensive care unit [NICU] admission, shoulder dystocia). Singleton pregnancies > 37 + 0 weeks with ultrasound-estimated fetal weight (EFW) within 7 days before delivery were included. The study population was divided into four groups: Group 1 (false-negative): EFW < 4000 g/BW ≥ 4000 g; Group 2 (true-positive): EFW ≥ 4000 g/BW ≥ 4000 g; Group 3 (false-positive): EFW ≥ 4000 g/BW < 4000 g; and Group 4 (true-negative): EFW < 4000 g/BW < 4000 g.

RESULTS

 As expected, the highest secondary cesarean section (sCS) rate was found in Group 2 (true-positive) (30.62 %), compared with only 17.68 % in Group 4 (true-negative). The sCS rate in the false-positive Group 3 was significantly higher (28.48 %) in comparison with the false-negative Group 1 (21.22 %; OR 1.48; 95 % CI, 1.16 to 1.89; P = 0.002). In comparison with the true-negative Group 4, univariate analyses showed significantly higher rates for sCS in all other groups: odds ratio (OR) 2.06 for Group 2 (95 % CI, 1.74 to 2.42; P < 0.001), 1.85 for Group 3 (95 % CI, 1.54 to 2.22, P < 0.001), and 1.25 for Group 1 (95 % CI, 1.05 to 1.49; P < 0.01). No significant differences were found for NO between Groups 1 and 3 for the parameters 5-min Apgar < 7 (P = 0.75), pH < 7.1 (P = 0.28), or NICU admission (P = 0.54). However, there was a significantly higher chance for shoulder dystocia in Group 1 compared with Group 3 (OR 4.58; 95 % CI, 1.34 to 24.30; P = 0.008).

CONCLUSION

 Sonographic EFW inaccuracies in fetal macrosomia appear to have a greater impact on the mode of delivery than birth weight itself. Underestimation of fetal weight may be associated with a higher probability of shoulder dystocia.

HbA1c at term delivery and adverse pregnancy outcome

Background

There are no obvious thresholds at which the risk of adverse pregnancy outcomes increases as a result of maternal hyperglycemia. HbA1c level which is representative of average blood glucose levels over the last 2–3 months is not as strongly predictive of adverse outcome compared to blood glucose values of oral glucose tolerance test. Data is sparse on the predictive value of HbA1c at term just prior to delivery on adverse outcome. We sought to evaluate HbA1c taken on admission for delivery at term on adverse outcomes of Cesarean delivery and large (≥ 90^th centile) for gestational age (LGA) infants.

Methods

A prospective cross-sectional study was conducted in a university hospital in Malaysia from December 2017-August 2018. 1000 women at term whose deliveries were imminent were enrolled. Blood were drawn and immediately sent for HbA1c analysis at our hospital laboratory. Primary outcomes were Cesarean delivery and LGA.

Results

On crude analyses, Cesarean births (vs. vaginal births) were associated with significantly higher HbA1c (%) levels 5.4[5.2–5.7] vs. 5.3[5.1–5.6] P =  < 0.001 but not for LGA vs. non-LGA 5.4[5.1–5.6] vs. 5.3[5.1–5.6] P = 0.17. After controlling for significant confounders identified on crude analysis (diabetes in pregnancy, parity, ethnicity, body mass index (BMI), previous cesarean, labor induction, Group B streptococcus (GBS) carriage and birth weight), HbA1c is independently predictive of Cesarean birth, adjusted odds ratio (AOR) 1.47 95% CI 1.06–2.06 P = 0.023 per HbA1c 1% increase. Following adjustment for significant confounders (BMI, predelivery anemia [hemoglobin < 11 g/dl] and GBS carriage), the impact of raised HbA1c level on LGA is AOR 1.43 95% CI 0.93–2.18 P = 0.101 per HbA1c 1% increase and non-significant.

Conclusion

Raised HbA1c level at term births in the general pregnant population is independently predictive of Cesarean delivery after adjustment for potential confounders including diabetes in pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05000-7.

Prediction of Emergency Cesarean Section Using Machine Learning Methods: Development and External Validation of a Nationwide Multicenter Dataset in Republic of Korea

This study was a multicenter retrospective cohort study of term nulliparous women who underwent labor, and was conducted to develop an automated machine learning model for prediction of emergent cesarean section (CS) before onset of labor. Nine machine learning methods of logistic regression, random forest, Support Vector Machine (SVM), gradient boosting, extreme gradient boosting (XGBoost), light gradient boosting machine (LGBM), k-nearest neighbors (KNN), Voting, and Stacking were applied and compared for prediction of emergent CS during active labor. External validation was performed using a nationwide multicenter dataset for Korean fetal growth. A total of 6549 term nulliparous women was included in the analysis, and the emergent CS rate was 16.1%. The C-statistics values for KNN, Voting, XGBoost, Stacking, gradient boosting, random forest, LGBM, logistic regression, and SVM were 0.6, 0.69, 0.64, 0.59, 0.66, 0.68, 0.68, 0.7, and 0.69, respectively. The logistic regression model showed the best predictive performance with an accuracy of 0.78. The machine learning model identified nine significant variables of maternal age, height, weight at pre-pregnancy, pregnancy-associated hypertension, gestational age, and fetal sonographic findings. The C-statistic value for the logistic regression machine learning model in the external validation set (1391 term nulliparous women) was 0.69, with an overall accuracy of 0.68, a specificity of 0.83, and a sensitivity of 0.41. Machine learning algorithms with clinical and sonographic parameters at near term could be useful tools to predict individual risk of emergent CS during active labor in nulliparous women.

Adverse Outcomes among Low-Risk Pregnancies at 39 to 41 Weeks: Stratified by Birth Weight Percentile

OBJECTIVE

This study aimed to assess the risk of adverse outcomes among low-risk pregnancies at 39 to 41 weeks, stratified by birth weight percentile.

STUDY DESIGN

This retrospective cohort study utilized the U.S. vital statistics datasets (2013-2017) and evaluated low-risk women with nonanomalous cephalic singleton gestations who labored and delivered at 39 to 41 weeks, regardless of ultimate mode of delivery. Newborns were categorized as small (<10th percentile), large (>90th percentile), or appropriate (10-90th percentile) for gestational ages (SGA, LGA, and AGA, respectively). The primary outcome, composite neonatal adverse outcome (CNAO), included Apgar's score <5 at 5 minutes, assisted ventilation >6 hours, seizure, or neonatal death. The secondary outcome, composite maternal adverse outcome (CMAO), included intensive care unit admission, blood transfusion, uterine rupture, or unplanned hysterectomy. Multivariable Poisson's regression was used to estimate the association (using adjusted relative risk [aRR] and 95% confidence interval [CI]).

RESULTS

Of 19.8 million live births during the study interval, approximately 8.9 million (44.9%) met the inclusion criteria, with 9.9% being SGA, 9.2% being LGA, and 80.9% being AGA. SGA newborns delivered at 40 (aRR = 1.17; 95% CI: 1.12-1.23) and at 41 weeks (aRR = 1.55; 95% CI: 1.45-1.66) had a higher risk of CNAO than at 39 weeks. Similarly, LGA newborns delivered at 40 (aRR = 1.13; 95% CI: 1.07-1.19) and 41 weeks (aRR = 1.44; 95% CI: 1.35-1.54) and AGA newborns delivered at 40 (aRR = 1.24; 95% CI: 1.21-1.26) and 41 weeks (aRR = 1.57; 95% CI: 1.53-1.61) also had a higher risk of CNAO than at 39 weeks. CMAO was also significantly higher at 40 and 41 weeks than at 39 weeks, regardless of whether the mothers delivered SGA, LGA, or AGA newborns.

CONCLUSION

Among low-risk pregnancies, the risks of composite neonatal and maternal adverse outcomes increase from 39 through 41 weeks' gestation, irrespective of whether newborns are SGA, LGA, or AGA.

Shoulder dystocia and composite adverse outcomes for the maternal-neonatal dyad

BACKGROUND

Although the neonatal morbidity associated with shoulder dystocia are well known, the maternal morbidity caused by this obstetrical emergency is infrequently reported.

OBJECTIVE

This study aimed to assess the composite adverse maternal and neonatal outcomes among vaginal deliveries (at 34 weeks or later) with and without shoulder dystocia.

STUDY DESIGN

This is a secondary analysis of the Consortium of Safe Labor, an observational obstetrical cohort of all vaginal deliveries occurring at 19 hospitals (from 2002-2008) and for which data on the occurrence of shoulder dystocia were available. The composite adverse maternal outcome included third- or fourth-degree perineal laceration, postpartum hemorrhage (>500 cc blood loss for a vaginal delivery and >1000 cc blood loss for cesarean delivery), blood transfusion, chorioamnionitis, endometritis, thromboembolism, admission to intensive care unit, or maternal death. The composite adverse neonatal outcome included an Apgar score of <7 at 5 minutes, a birth injury, neonatal seizure, hypoxic ischemic encephalopathy, or neonatal death. A multivariable Poisson regression was used to estimate the adjusted relative risks with 95% confidence intervals. The area under the receiver operating characteristic curve was constructed to determine if clinical factors would identify shoulder dystocia.

RESULTS

Of the 228,438 women in the overall cohort, 130,008 (59.6%) met the inclusion criteria, and among them, shoulder dystocia was documented in 2159 (1.7%) cases. The rate of composite maternal morbidity was significantly higher among deliveries with shoulder dystocia (14.7%) than without (8.6%; adjusted relative risk, 1.71; 95% confidence interval, 1.64-2.01). The most common maternal morbidity with shoulder dystocia was a third- or fourth-degree laceration (adjusted relative risk, 2.82; 95% confidence interval, 2.39-3.31). The risk of composite neonatal morbidity with shoulder dystocia (12.2%) was also significantly higher than without shoulder dystocia (2.4%) (adjusted relative risk, 5.18; 95% confidence interval, 4.60-5.84). The most common neonatal morbidity was birth injury (adjusted relative risk, 5.39; 95% confidence interval, 4.71-6.17). The area under the curve for maternal characteristics to identify shoulder dystocia was 0.66 and it was 0.67 for intrapartum factors.

CONCLUSION

Although shoulder dystocia is unpredictable, the associated morbidity affects both mothers and newborns. The focus should be on concurrently averting the composite morbidity for the maternal-neonatal dyad with shoulder dystocia.

Ultrasound for the Pregnant Person With Diabesity

Diabetes and obesity increase the risk of congenital anomalies, but the putative mechanisms of this increased risk are not fully elucidated. In this chapter, we delve into sonographic characteristics associated with diabetes and obesity, including fetal structural anomalies, functional cardiac alterations, and growth abnormalities. We will also discuss the technical challenges of imaging in the patient with diabesity and propose methodologies for optimizing imaging. Lastly, we will address the prevention of workplace-associated musculoskeletal disorders injury for sonographers.

Maternal and fetal characteristics to predict c-section delivery: A scoring system for pregnant women

INTRODUCTION

Cesarean section is one of the most common obstetrical interventions that has been performed at an increasing rate globally, due to both medical and non-medical reasons. This study aims to develop a prediction tool for pregnant women potentially needing c-section, such that necessary preparations from the mothers, families, and health providers can be made.

METHODS

A total of 603 pregnant women were recruited in the first phase of c-section prediction tool development. The association between the maternal and fetal factors on the risk of c-section were analyzed, followed by a stepwise multivariate regression analysis. In the next phase, 61 pregnant women were enrolled for external validation. Discrimination was assessed using area under the curve. The calibration plot was then made and assessed using the Hosmer-Lemeshow test.

RESULTS

There were 251 (41.6%) cases of vaginal delivery and 352 (58.4%) of c-section assessed. Multivariate analysis showed that gestational age < 37 wg (OR: 1.66, 95% CI: 1.10-2.51), pre-pregnancy body mass index (underweight) (OR: 0.40, 95% CI: 0.22-0.76), no history of vaginal delivery (OR: 2.66, 95% CI: 1.76-4.02), history of uterine surgery (OR: 8.34, 95% CI: 4.54-15.30), obstetrical complications (OR: 5.61, 95% CI: 3.53-8.90), birthweight ⩾ 3500 g (OR: 4.28, 95% CI: 2.16-8.47), and non-cephalic presentation (OR: 2.74, 95% CI: 1.53-4.89) were independently associated with c-section delivery. Those parameters were included in a 7-item scoring tool, with consecutive predictive scores of 1,-1,2,3,3,2,2,1. The area under the curve result was 0.813 (95% CI: 0.779-0.847), indicating a good predictive ability. The external validation showed AUC: 0.806, 95% CI: 0.694-0.917, Hosmer-Lemeshow test p = 0.666 and calibration plot coefficient of r = 0.939.

CONCLUSION

A total of 7 maternal-fetal factors were found to be strongly associated with c-section delivery, including gestational age < 37, maternal underweight body mass index, previous uterine surgery, obstetrical complications, birthweight ⩾ 3500, history of vaginal delivery, and non-cephalic presentation. Using these factors, a prediction tool was developed and validated with good quality.

Macrosomic Newborns Delivered at Term after Labor among Nondiabetic Women: Maternal and Neonatal Morbidities

OBJECTIVE

This study aimed to compare morbidities among nonmacrosomic versus macrosomic singleton live births of nondiabetic women who labored.

STUDY DESIGN

This retrospective study utilized the 2003 revision of U.S. birth certificate data of singleton live births (2011-2013) at 37 to 41 weeks who labored. The primary outcomes were composite maternal and neonatal morbidities (CMM and CNM, respectively). We compared these outcomes by birth weight, 2,500 to 3,999 g (group 1; reference), 4,000 to 4,449 g (group 2), and 4,500 to 5,999 g (group 3). We used multivariable Poisson regression analyses to examine the association between birth weight groups and the outcomes.

RESULTS

Among 6,691,338 live births, 92.0% were in group 1, 7.1% in group 2, and 0.9% in group 3. The overall CMM and CNM rates were 4.4 and 6.8 per 1,000 live births, respectively. Compared with group 1, the risk of CMM was significantly higher in group 2 (adjusted risk ratio [aRR] = 1.50; 95% confidence interval [CI]: 1.44-1.56) and group 3 (aRR = 2.00; 95% CI: 1.82-2.19). Likewise, the risk of CNM was significantly higher in group 2 (aRR = 1.38; 95% CI: 1.33-1.43) and group 3 (aRR = 2.57; 95% CI: 2.40-2.75) than in group 1.

CONCLUSION

Nondiabetic women who labor with a macrosomic newborns have a significantly higher rate of adverse outcomes than nonmacrosomic.

Maternal and Neonatal Morbidity Associated With Early Term Delivery of Large-for-Gestational-Age But Nonmacrosomic Neonates

OBJECTIVE

To evaluate whether, at 37-39 weeks of gestation, delivery of a neonate with a birth weight that is 90% or greater for gestational age but less than 4,000 g is associated with increased composite maternal and neonatal morbidity.

METHODS

This retrospective cohort study used U.S. Vital Statistics datasets for the years 2011-2013. Inclusion criteria were singleton pregnancies delivered at 37-39 weeks of gestation after labor in which the neonates were nonanomalous, and either appropriate for gestational age or large for gestational age (LGA) neonates with birth weights of less than 4,000 g (our threshold for macrosomia). The coprimary outcomes were composite maternal morbidity (any of the following: maternal transfusion, ruptured uterus, unplanned hysterectomy, admission to intensive care unit, or unplanned procedure) and composite neonatal morbidity (any of the following: Apgar score less than 5 at 5 minutes, assisted ventilation for more than 6 hours, seizure or serious neurologic dysfunction, significant birth injury or neonatal mortality). Multivariable Poisson regression models were used to calculate adjusted relative risk (aRR) and 95% CI.

RESULTS

Among the 3.9 million women who met inclusion criteria, 1.3% delivered neonates who were LGA but nonmacrosomic. The rate of composite maternal morbidity was 53% higher women who delivered nonmacrosomic LGA neonate (6.27 vs 4.09/1,000 live births; aRR 1.40, 95% CI 1.25-1.56). This increased risk of composite maternal morbidity persisted in analyses stratified by diabetes. The rate of composite neonatal morbidity was 83% higher for nonmacrosomic LGA neonates (11.09 vs 6.07/1,000 live births; aRR 1.47, 95% CI 1.35-1.60) and persisted in analyses stratified by diabetes.

CONCLUSION

At 37-39 weeks of gestation, delivery of a neonate with a birth weight that is 90% or greater for gestational age but less than 4,000 g is associated with increased composite maternal and neonatal morbidity.

Sonographic Estimated Fetal Weight and Cesarean Delivery among Nulliparous Women with Obesity

Objective  This study was aimed to examine the association between having an ultrasound estimate of fetal weight (US-EFW) and mode of delivery among obese women. Study Design  A retrospective cohort study of nulliparous women with a body mass index of ≥ 35 kg/m ² who delivered term singleton gestations. We examined whether having had an US-EFW within 35 days of delivery, or an US-EFW ≥ 90th percentile for gestational age, was associated with intrapartum cesarean delivery. Results  Of 2,826 women, 22.5% ( n  = 636) had an US-EFW within 35 days of delivery. Having an US-EFW was associated with increased frequency of cesarean (43.1% for those with an US-EFW versus 30.0% for those without, p  < 0.001); this finding persisted when controlling for confounders (adjusted odds ratio [aOR] 1.48, 95% confidence interval [CI] 1.21-1.81). Of the 636 women with an US-EFW, 22.5% ( n  = 143) had an US-EFW ≥ 90th percentile for gestational age, which was associated with increased frequency of an intrapartum cesarean (60.8% for those with an US-EFW ≥ 90th percentile vs. 37.9% for those with an US-EFW of < 90th percentile, p  < 0.001), even when accounting for confounders (aOR = 1.78, 95% CI: 1.10-2.87). Conclusion  The presence of an US-EFW among nulliparous obese women was associated with undergoing intrapartum cesarean delivery.

Are selection criteria for healthy pregnancies responsible for the gap between fetal growth in the French national Elfe birth cohort and the Intergrowth-21st fetal growth standards?

BACKGROUND

The Intergrowth-21st (IG) project proposed prescriptive fetal growth standards for global use based on ultrasound measurements from a multicounty study of low-risk pregnancies selected using strict criteria. We examined whether the IG standards are appropriate for fetal growth monitoring in France and whether potential differences could be due to IG criteria for "healthy" pregnancies.

METHOD

We analysed data on femur length and abdominal circumference at the second and/or the third recommended ultrasound examination from 14 607 singleton pregnancies from the Elfe national birth cohort. We compared concordance of centile thresholds using the IG standards and current French references and used restricted cubic splines to plot z-scores by gestational age. A "healthy pregnancy" sub-sample was created based on maternal and pregnancy selection criteria, as specified by IG.

RESULTS

Mean gestational age-specific z-scores for femur length and abdominal circumference using French references fluctuated around 0 (-0.2 to 0.1), while those based on IG standards were higher (0.3-0.8). Using IG standards, 2.5% and 5.2% of fetuses at the third ultrasound were <10th centile for femur length and abdominal circumference, respectively, and 31.5% and 16.7% were >90th. Only 34% of pregnancies fulfilled IG low-risk criteria, but sub-analyses yielded very similar results.

CONCLUSION

Intergrowth standards differed from fetal biometric measures in France, including among low-risk pregnancies selected to replicate IG's healthy pregnancy sample. These results challenge the project's assumption that careful constitution of a low-risk population makes it possible to describe normative fetal growth across populations.

A Mediterranean Diet with an Enhanced Consumption of Extra Virgin Olive Oil and Pistachios Improves Pregnancy Outcomes in Women Without Gestational Diabetes Mellitus: A Sub-Analysis of the St. Carlos Gestational Diabetes Mellitus Prevention Study

AIMS

The aim of the study was to evaluate the effect of a Mediterranean diet (MedDiet), enhanced with extra virgin olive oil (EVOO) and nuts, on a composite of adverse maternofoetal outcomes of women with normoglycemia during pregnancy.

METHODS

This was a sub-analysis of the St Carlos gestational diabetes mellitus Prevention Study. Only normoglycemic women were analysed (697). They were randomized (at 8-12th gestational weeks) to: standard-care control group (337), where fat consumption was limited to 30% of total caloric intake; or intervention group (360), where a MedDiet, enhanced with EVOO and pistachios (40-42% fats of total caloric intake) was recommended. The primary outcome was a composite of maternofoetal outcomes (CMFOs): at least having 1 event of emergency C-section, perineal trauma, pregnancy-induced hypertension and preeclampsia, prematurity, large-for-gestational-age and small-for gestational-age.

RESULTS

Crude relative risk showed that the intervention was associated with a significant reduction in the risk of CMFOs (0.48 [0.37-0.63]; p = 0.0001), with a number-needed-to-treat = 5. Risk of urinary tract infections, emergency C-sections, perineal trauma, large-for-gestational-age and small-for gestational age new-borns were also significantly reduced.

CONCLUSION

A MedDiet, enhanced with EVOO and nuts, was associated with a risk reduction of CMFOs in over 50% in normoglycemic pregnant women. Therefore, it might be a potentially adequate diet for pregnant women.

TRIAL REGISTRATION

Identifier ISRCTN84389045. The study was registered on September 27, 2013. Last edited on September 26, 2018.

Association between Sonographic Estimated Fetal Weight and the Risk of Cesarean Delivery among Nulliparous Women with Diabetes in Pregnancy

OBJECTIVE

The objective of this study was to examine the association between an ultrasound-estimated fetal weight (US-EFW) and mode of delivery among nulliparous diabetic women.

STUDY DESIGN

This is a retrospective cohort study of nulliparous women with medication-requiring gestational or pregestational diabetes who delivered term, singleton gestations following a trial of labor. We determined whether having had an US-EFW within 35 days of delivery was associated with cesarean delivery.

RESULTS

Of 304 women who met the eligibility criteria, 231 (76.0%) had an US-EFW within 35 days of delivery. An US-EFW was associated with increased likelihood of intrapartum cesarean (51.5% for those with an ultrasound vs. 27.4% for those without, p < 0.001); this finding persisted even when controlling for birth weight and other confounding factors (adjusted odds ratio: 2.23, 95% confidence interval: 1.16-4.28). Among women with a recent US-EFW, a diagnosis of a large-for-gestational-age (LGA) fetus was associated with overall intrapartum cesarean frequency (65.2% for women with an LGA fetus vs. 46.1% for those without, p = 0.009), but this association did not remain significant in multivariable models.

CONCLUSION

An US-EFW within 35 days of delivery among nulliparous women with medication-requiring diabetes was positively associated with intrapartum cesarean delivery.

Does maternity care decision-making conform to shared decision- making standards for repeat cesarean and labor induction after suspected macrosomia?

BACKGROUND

In a national United States survey, we investigated whether crucial shared decision-making standards were met for 2 common maternity care decisions.

METHODS

Secondary analysis of Listening to Mothers III. A sequence of validated questions concerning shared decision-making was adapted to 2 maternity care decisions: to induce labor or wait for spontaneous onset of labor among women who were told their baby may be "getting quite large" (N = 349); and for women with 1 or 2 prior cesareans (N = 393), the decision to have a repeat cesarean.

RESULTS

Almost half (N = 163; 47%) of women who were told their baby might be large reported engaging in a discussion concerning possible labor induction vs waiting for labor, while a large majority (N = 321; 82%) of women with a prior cesarean discussed the option of a repeat cesarean or a planned vaginal birth after cesarean (VBAC). Women who engaged in discussions received disproportionate information about having the interventions and were more likely to experience the interventions (68% induction, 87% repeat cesarean) than women who did not. After adjustment, women who reported that their provider recommended scheduling a repeat cesarean were 14 times more likely to give birth via cesarean compared with those whose providers recommended planning VBAC (AOR 14.2; 95% CI: 3.2, 63.0).

CONCLUSION

Our findings suggest that, for the decisions in question, established standards of shared decision-making are not being reliably implemented in maternity care despite opportunities to do so. Provider recommendations and the disproportionate conveyance of reasons for an intervention appear to be related to higher levels of intervention.

Accuracy of immediate antepartum ultrasound estimated fetal weight and its impact on mode of delivery and outcome - a cohort analysis

Background

The aim of the study was to investigate the accuracy of ultrasound-derived estimated fetal weight (EFW) and to determine its impact on management and outcome of delivery.

Methods

In this single-center cohort analysis, women with a singleton term pregnancy in the beginning stages of labor were included. Women with immediately antepartum EFW (N = 492) were compared to women without ultrasound (N = 515).

Results

EFW was correct (deviation from birth weight ≤ 10%) in 72.2% (355/492) of patients with fetal biometry; 19.7% (97/492) were underestimated, and 8.1% (40/492) were overestimated. Newborns with a lower birth weight were more frequently overestimated, and newborns with higher birth weight were more frequently underestimated. The mean difference between EFW and real birth weight was − 114.5 g (standard deviation ±313 g, 95% confidence interval 87.1–142.0). The rate of non-reassuring fetal heart tracing (9.8% vs. 1.9%, P < 0.001) and of caesarean delivery (9.1% vs. 5.0%, P = 0.013) was higher in women with EFW. Overestimation was associated with an increased risk for delivery by caesarean section (odds ratio 2.80; 95% confidence interval 1.2–6.5, P = 0.017). After adjustment, EFW remained associated with increased non-reassuring fetal heart tracing (odds ratio 4.73; 95% confidence interval 2.3–9.6) and caesarean delivery (odds ratio 1.86; 95% confidence interval 1.1–3.1). The incidence of perineal tears of grade 3/4, shoulder dystocia, postnatal depression and neonatal acidosis did not differ between groups.

Conclusions

Antepartum ultrasound-derived EFW does not improve maternal and fetal outcome and is therefore not recommended.

Sonographic Estimated Fetal Weight among Diabetics at ≥ 34 Weeks and Composite Neonatal Morbidity

Objectives  The objective was to assess the composite neonatal morbidity (CNM) among diabetic women with sonographic estimated fetal weight (SEFW) at 10 to 90th versus >90th percentile for gestational age (GA). Study Design  The inclusion criteria for this retrospective study were singleton pregnancies at 34 to 41 weeks, complicated by diabetes, and that had SEFW within 4 weeks of delivery. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated. Results  Among the 140 cohorts that met the inclusion criteria, 72% had SEFW at 10th to 90th percentile for GA, and 28% at >90th percentile. Compared with women with diabetes with last SEFW at 10th to 90th percentile, those with estimate > 90th percentile for GA had a significantly higher rate of CNM (13 vs. 28%; OR, 2.65; 95% CI, 1.07-6.59). Among 109 diabetic women who labored, the rate of shoulder dystocia was significantly higher with SEFW at >90th percentile for GA than those at 10th to 90th percentile (25 vs. 2%; p  = 0.002); the corresponding rate of CNM was 29 versus 10% ( p  = 0.02). Conclusion  Among diabetic women with SEFW > 90th percentile for GA, CNM was significantly higher than in women with estimate at 10 to 90th percentile. Despite the increased risk of CNM, these newborns did not have long-term morbid sequela.