Critical analysis of risk factors for shoulder dystocia

Predictors of maternal and neonatal outcomes in labors complicated by shoulder dystocia: a comparative analysis

INTRODUCTION

Studies investigating the risk factors associated with unfavorable maternal/neonatal outcomes in cases of shoulder dystocia are scarce. This study aims to uncover the predictive factors that give rise to unfavorable outcomes within the context of shoulder dystocia.

MATERIALS AND METHODS

Medical records of pregnancies complicated by shoulder dystocia was obtained between 2008-2022 from a single tertiary center. This study involved the comparison of sociodemographic, sonographic, and delivery characteristics among pregnancies complicated by shoulder dystocia resulting in favorable vs. unfavorable maternal/neonatal outcomes.

RESULTS

A total of 275 pregnancies were analyzed, with 111 (40.3%) classified as unfavorable outcomes and 164 (59.7%) as favorable outcomes. Employing a multivariable regression analysis, several independent associations were identified with unfavorable maternal/neonatal outcomes. Specifically, short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia merged as significant predictors of unfavorable maternal/neonatal outcomes.

CONCLUSION

Short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia may all contribute to poor maternal/neonatal outcomes in shoulder dystocia cases. This knowledge allows clinicians to improve their decision-making, patient care, and counseling.

Maternal adiposity and perinatal and offspring outcomes: an umbrella review

Maternal adiposity deleteriously affects obstetrical health and has been associated with long-term adverse consequences in offspring. Here we conducted an umbrella review encompassing 194 observational meta-analyses, 10 Mendelian randomization studies and 748 interventional meta-analyses to appraise the published evidence on the associations between maternal adiposity and perinatal and offspring outcomes. Evidence grading suggested that 17 (8.8%) observational meta-analyses were supported by convincing evidence for 12 outcomes: maternal adiposity was associated with an increased risk of caesarean delivery following labour induction, infant mortality, Apgar score <7 at 1 min, antenatal depression, offspring overweight and obesity, early timing of puberty onset in daughters, attention deficit hyperactivity disorder, cerebral palsy, congenital heart disease and spina bifida (OR/RR ranging from 1.14 to 2.31), as well as increased offspring body fat percent and fat mass (SMD 0.31 and 0.35, respectively). Among these outcomes, interventional meta-analyses supported that maternal weight loss interventions significantly reduced the risk of antenatal depression but not low Apgar scores; these interventions also could not reduce offspring fat mass or body fat percent. Evidence from Mendelian randomization studies supported a causal relationship between maternal adiposity and gestational diabetes mellitus, preeclampsia, birth size and offspring adiposity. Our findings highlight that while observational meta-analyses reveal associations between maternal adiposity and various adverse perinatal and offspring outcomes, convincing, unbiased evidence or support from Mendelian randomization studies is limited. Maternal pre-conceptional and prenatal weight loss interventions can reduce some, but not all, of these adverse effects.

Shoulder dystocia by severity in families: A nationwide population study

INTRODUCTION

Previous studies have established a history of shoulder dystocia as an important risk factor for shoulder dystocia, but studies on shoulder dystocia by severity are scarce. It is unknown if shoulder dystocia tends to be passed on between generations. We aimed to assess the recurrence risk of shoulder dystocia by severity in the same woman and between generations on both the maternal and paternal side. We also assessed the likelihood of a second delivery and planned cesarean section after shoulder dystocia.

MATERIAL AND METHODS

This was a population-based cohort study, using data from the Medical Birth Registry of Norway. To study recurrence in the same mother, we identified 1 091 067 pairs of first and second, second and third, and third and fourth births in the same mother. To study intergenerational recurrence, we identified an individual both as a newborn and as a mother or father in 824 323 mother-offspring pairs and 614 663 father-offspring pairs. We used Bayesian log-binomial multilevel regression to calculate relative risks (RR) with 95% credible intervals.

RESULTS

In subsequent deliveries in the same woman the unadjusted RR of recurrence was 7.05 (95% credible interval 6.39-7.79) and 2.99 (2.71-3.31) after adjusting for possible confounders, including current birthweight. The RRs were higher with severe shoulder dystocia as exposure or outcome. With severe shoulder dystocia as both exposure and outcome, unadjusted and adjusted RR was 20.42 (14.25-29.26) and 6.29 (4.41-8.99), respectively. Women with severe and mild shoulder dystocia and those without had subsequent delivery rates of 71.1, 68.9 and 69.0%, respectively. However, the rates of planned cesarean section in subsequent deliveries for those without shoulder dystocia, mild and severe were 1.3, 5.2 and 16.0%, respectively. On the maternal side the unadjusted inter-generational RR of recurrence was 2.82 (2.25-3.54) and 1.41 (1.05-1.90) on the paternal side. Corresponding adjusted RRs were 1.90 (1.51-2.40) and 1.19 (0.88-1.61), respectively.

CONCLUSIONS

We found a strong recurrence risk of shoulder dystocia, especially severe, in subsequent deliveries in the same woman. The inter-generational recurrence risk was higher on the maternal than paternal side. Women with a history of shoulder dystocia had more often planned cesarean section.

Obstetric and perinatal outcome in short-stature patients

OBJECTIVE

Scarce data exist regarding obstetric complications of short-stature patients. This study aimed to investigate obstetric and perinatal outcomes in women with short stature; specifically, to investigate whether short-stature patients are at an increased risk for cesarean delivery.

METHODS

A population-based cohort study was conducted, including all singletons born between the years 1991 and 2021 at a tertiary medical center. Obstetric and perinatal outcomes of short-stature patients were compared with those of non-short patients. A generalized estimation equation binary logistic model was constructed to adjust for confounders and maternal recurrence in the cohort.

RESULTS

The study population included 356 356 parturient; among them, 14 035 (3.9%) were short-stature patients. Short-stature patients had significantly higher rates of cesarean delivery (20.7% vs 13.7%, odds ratio = 1.64, 95% confidence interval 1.57-1.71, P < 0.001), induction of labor, pathologic presentations, prolonged second stage of labor, non-reassuring fetal monitoring, and meconium-stained amniotic fluid. Newborns of short-stature patients had a significantly higher risk of being small for gestational age as compared with those of non-short patients. In the generalized estimation equation models, the association between short stature and risk of cesarean delivery remained significant (adjusted odds ratio = 1.32, 95% confidence interval 1.27-1.38, P < 0.001), as well as the risk of small for gestational age newborns (adjusted odds ratio = 1.51, 95% confidence interval 1.40-1.63, P < 0.001), but not for the other adverse outcomes.

CONCLUSIONS

Maternal short stature is an independent risk factor for cesarean delivery and is associated with small for gestational age newborns.

Predictors of shoulder dystocia at the time of operative vaginal delivery: a prospective cohort study

Our aim was to identify factors associated with shoulder dystocia following an attempted operative vaginal delivery (aOVD) in a prospective cohort study and to evaluate whether these factors can be used to accurately predict shoulder dystocia by building a score of shoulder dystocia risk. This was a planned secondary analysis of a prospective cohort study of deliveries with aOVD at term from 2008-2013. Cases were defined as women with shoulder dystocia following an aOVD defined as a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders. Multivariate logistic regression analyses were performed to determine risk factors for shoulder dystocia. Shoulder dystocia occurred in 57 (2.7%) of the 2118 women included. In the whole cohort, women with shoulder dystocia more often had a history of shoulder dystocia (3.5% vs. 0.2%, p = 0.01), and there was a significant interaction between aOVD and gestational age and the duration of the second stage of labor: women with shoulder dystocia more often had a gestational age > 40 weeks and a second stage of labor longer than 3 h specifically for midpelvic aOVD. In multivariable analysis, a history of shoulder dystocia was the only factor independently associated with shoulder dystocia following aOVD (aOR 27.00, 95% CI 4.10-178.00). The AUC for the receiver operating characteristic curve generated using a multivariate model with term interaction with head station was 0.70 (95% CI 0.62-0.77). The model failed to accurately predict shoulder dystocia.

Antenatal risk score for prediction of shoulder dystocia with focus on fetal ultrasound data

BACKGROUND

Shoulder dystocia is one of the most threatening complications during delivery, and although it is difficult to predict, individual risk should be considered when counseling for mode of delivery.

OBJECTIVE

This study aimed to develop and validate a risk score for shoulder dystocia based on fetal ultrasound and maternal data from 15,000 deliveries.

STUDY DESIGN

Data were retrospectively obtained of deliveries in 3 tertiary centers between 2014 and 2017 for the derivation cohort and between 2018 and 2020 for the validation cohort. Inclusion criteria were singleton pregnancy, vaginal delivery in cephalic presentation at ≥37+0 weeks' gestation, and fetal biometry data available within 2 weeks of delivery. Independent predictors were determined by multivariate regression analysis in the derivation cohort, and a score was developed on the basis of the effect of the predictors.

RESULTS

The derivation cohort consisted of 7396 deliveries with a 0.91% rate of shoulder dystocia, and the validation cohort of 7965 deliveries with a 1.0% rate of shoulder dystocia. Among all women, 13.8% had diabetes mellitus, and 12.1% were obese (body mass index ≥30 kg/m2). Independent risk factors in the derivation cohort were: estimated fetal weight ≥4250 g (odds ratio, 4.27; P=.002), abdominal-head-circumference ≥2.5 cm (odds ratio, 3.96; P<.001), and diabetes mellitus (odds ratio, 2.18; P=.009). On the basis of the strength of effect, a risk score was developed: estimated fetal weight ≥4250 g=2, abdominal-head-circumference ≥2.5 cm=2, and diabetes mellitus=1. The risk score predicted shoulder dystocia with moderate discriminatory ability (area under the receiver-operating characteristic curve, 0.69; P<.001; area under the receiver-operating characteristic curve, 0.71; P<.001) and good calibration (Hosmer-Lemeshow goodness-of-fit; P=.466; P=.167) for the derivation and validation cohorts, respectively. With 1 score point, 16 shoulder dystocia cases occurred in 1764 deliveries, with 0.6% shoulder dystocia incidence and a number needed to treat with cesarean delivery to avoid 1 case of shoulder dystocia of 172 (2 points: 38/1809, 2.1%, 48; 3 points: 18/336, 5.4%, 19; 4 points: 10/96, 10.5%, 10; and 5 points: 5/20, 25%, 4); 40.8% of the shoulder dystocia cases occurred without risk factors.

CONCLUSION

The presented risk score for shoulder dystocia may act as a supplemental tool for the clinical decision-making regarding mode of delivery. According to our score model, in pregnancies with a score ≤2, meaning having solely estimated fetal weight ≥4250 g, or abdominal-head-circumference ≥2.5, or diabetes mellitus, cesarean delivery for prevention of shoulder dystocia should not be recommended because of the high number needed to treat to avoid 1 case of shoulder dystocia. Conversely, in patients with a score of ≥4 with or without diabetes mellitus, cesarean delivery may be considered. However, in 40% of the shoulder dystocia cases, no risk factors had been present.

Food taboos during pregnancy: meta-analysis on cross cultural differences suggests specific, diet-related pressures on childbirth among agriculturalists

Pregnancy is the most delicate stage of human life history as well as a common target of food taboos across cultures. Despite puzzling evidence that many pregnant women across the world reduce their intake of nutritious foods to accomplish cultural norms, no study has provided statistical analysis of cross-cultural variation in food taboos during pregnancy. Moreover, antenatal practices among forager and agriculturalists have never been compared, despite subsistence mode being known to affect staple foods and lifestyle directly. This gap hinders to us from understanding the overall threats attributed to pregnancy, and their perceived nutritional causes around the world. The present study constitutes the first cross-cultural meta-analysis on food taboos during pregnancy. We examined thirty-two articles on dietary antenatal restrictions among agricultural and non-agricultural societies, in order to: (i) identify cross-culturally targeted animal, plant and miscellaneous foods; (ii) define major clusters of taboo focus; (iii) test the hypothesis that food types and clusters of focus distribute differently between agricultural and non-agricultural taboos; and (iv) test the hypothesis that food types distribute differently across the clusters of taboo focus. All data were analysed in SPSS and RStudio using chi-squared tests and Fisher's exact tests. We detected a gradient in taboo focus that ranged from no direct physiological interest to the fear of varied physiological complications to a very specific concern over increased birth weight and difficult delivery. Non-agricultural taboos were more likely to target non-domesticated animal foods and to be justified by concerns not directly linked to the physiological sphere, whereas agricultural taboos tended to targed more cultivated and processed products and showed a stronger association with concerns over increased birth weight. Despite some methodological discrepancies in the existing literature on food taboos during pregnancy, our results illustrate that such cultural traits are useful for detecting perception of biological pressures on reproduction across cultures. Indeed, the widespread concern over birth weight and carbohydrate rich foods overlaps with clinical evidence that obstructed labor is a major threat to maternal life in Africa, Asia and Eurasia. Furthermore, asymmetry in the frequency of such concern across subsistence modes aligns with the evolutionary perspective that agriculture may have exacerbated delivery complications. This study highlights the need for the improved understanding of dietary behaviors during pregnancy across the world, addressing the role of obstructed labor as a key point of convergence between clinical, evolutionary and cultural issues in human behavior.

Macrosomia and its predictors in pregnant women with diabetes in Ethiopia

BACKGROUND

To estimate the prevalence of macrosomia and contributing factors among pregnant women with diabetes in Ethiopia.

METHODS

The Cochrane, PubMed, Google Scholar, SCOPUS, Web of Science electronic databases and grey literature found in online university repositories were searched for primary studies reporting the prevalence of macrosomia (birth weight ≥4 kg, irrespective of gestational age) and/or at least one determinant factor using WHO diabetes diagnosis criteria were involved. Variations across the studies were checked using the I²  statistic; funnel plot and Egger's test were used to assess publication bias. A weighted inverse random effect model was used to estimate the overall prevalence of macrosomia.

RESULTS

The overall prevalence of macrosomic newborns among pregnant women with diabetes [15.1% (95% CI: 9.0%, 21.2%)] was higher than the prevalence among non-diabetic mothers (3.9%). Maternal blood glucose level >100 mg/dl [AOR = 10.5: 95% CI: 5.9, 15.1] and >120 mg/dl [AOR = 8.8: 95% CI: 4.5, 13.0], lack of Antenatal Care (ANC) visit [AOR = 10.8: 95% CI: 6.0, 15.0], previous adverse birth outcomes and advanced maternal age [AOR = 3.5: 95% CI: 1.0, 5.9] were significantly associated with the prevalence of macrosomia at 95% CI.

CONCLUSION

The pooled prevalence of macrosomia among pregnant women with diabetes was higher than the prevalence among non-diabetic pregnant women (3.9%). Advanced maternal age, previous adverse birth outcomes, lack of ANC and uncontrolled maternal plasma glucose level were independent predictors of macrosomia.

Antenatal risk prediction of shoulder dystocia: influence of diabetes and obesity: a multicenter study

PURPOSE

To estimate the risk of shoulder dystocia (SD) in pregnancies with/without maternal diabetes or obesity; to identify antenatal maternal and fetal ultrasound-derived risk factors and calculate their contributions.

METHODS

A multicenter retrospective analysis of 13,428 deliveries in three tertiary hospitals (2014-2017) with fetal ultrasound data ≤ 14 days prior to delivery (n = 7396).

INCLUSION CRITERIA

singleton pregnancies in women ≥ 18 years old; vertex presentation; vaginal delivery at ≥ 37 weeks of gestation. Estimated fetal weight (EFW) and birth weight (BW) were categorized by steps of 250 g. To evaluate risk factors, a model was performed using ultrasound data with SD as the dependent variable.

RESULTS

Diabetes was present in 9.3%; BMI ≥ 30 kg/m² in 10.4% and excessive weight gain in 39.8%. The total SD rate was 0.9%, with diabetes 2.0% and with obesity 1.9%. These increased with BW 4250-4499 g compared to 4000-4249 g in women with diabetes (12.1% vs 1.9%, P = 0.010) and without (6.1% vs 1.6%, P < 0.001) and at the same BW threshold for women with obesity (9.6% vs 0.6%, P = 0.002) or without (6.4% vs 1.8%, P < 0.001). Rates increased similarly for EFW at 4250 g and for AC-HC at 2.5 cm. Independent risk factors for SD were EFW ≥ 4250 g (OR 3.8, 95% CI 1.5-9.4), AC-HC ≥ 2.5 cm (OR 3.1, 95% CI 1.3-7.5) and diabetes (OR 2.2, 95% CI 1.2-4.0). HC/AC ratio, obesity, excessive weight gain and labor induction were not significant.

CONCLUSION

Independent of diabetes, which remains a risk factor for SD, a significant increase may be expected if the EFW is ≥ 4250 g and AC-HC is ≥ 2.5 cm.

Risk of major labour-related complications for pregnancies progressing to 42 weeks or beyond

BACKGROUND

Post-term gestation beyond 41⁺⁶ completed weeks of gestation is known to be associated with a sharp increase in the risk of stillbirth and perinatal mortality. However, the risk of common adverse outcomes related to labour, such as shoulder dystocia and post-partum haemorrhage for those delivering at this advanced gestation, remains poorly characterised. The objective of this study was to examine the risk of adverse, labour-related outcomes for women progressing to 42 weeks gestation or beyond, compared with those giving birth at 39 completed weeks.

METHODS

We performed a state-wide cohort study using routinely collected perinatal data in Australia. Comparing the two gestation cohorts, we examined the adjusted relative risk of clinically significant labour-related adverse outcomes, including macrosomia (≥ 4500 at birth), post-partum haemorrhage (≥1000 ml), shoulder dystocia, 3rd or 4th degree perineal tear and unplanned caesarean section. Parity, maternal age and mode of birth were adjusted for using logistic regression.

RESULTS

The study cohort included 91,314 women who birthed at 39 completed weeks and 4317 at ≥42 completed weeks. Compared to 39 weeks gestation, those giving birth ≥42 weeks gestation had an adjusted relative risk (aRR) of 1.85 (95% CI 1.55-2.20) for post-partum haemorrhage following vaginal birth, 2.29 (95% CI 1.89-2.78) following instrumental birth and 1.44 (95% CI 1.17-1.78) following emergency caesarean section; 1.43 (95% CI 1.16-1.77) for shoulder dystocia (for non-macrosomic babies); and 1.22 (95% CI 1.03-1.45) for 3rd or 4th degree perineal tear (all women). The adjusted relative risk of giving birth to a macrosomic baby was 10.19 (95% CI 8.26-12.57) among nulliparous women and 4.71 (95% CI 3.90-5.68) among multiparous women. The risk of unplanned caesarean section was 1.96 (95% CI 1.86-2.06) following any labour and 1.47 (95% CI 1.38-1.56) following induction of labour.

CONCLUSIONS

Giving birth at ≥42 weeks gestation may be an under-recognised risk factor for several important, labour-related adverse outcomes. Clinicians should be aware that labour at this advanced gestation incurs a higher risk of adverse outcomes. In addition to known perinatal risks, the risk of obstetric complications should be considered in the counselling of women labouring at post-term gestation.

Shoulder Dystocia during Delivery and Long-Term Neurological Morbidity of the Offspring

OBJECTIVE

The study aimed to evaluate risk factors and implications of shoulder dystocia (SD) on the neurological outcome of successfully delivered offspring.

STUDY DESIGN

This is a cohort analysis including 207,571 deliveries. Risk factors for SD were evaluated using general estimation equation multivariable analyses. Offspring hospitalization incidence up to age 18 years due to neurological conditions was compared between both groups. Kaplan-Meyer curve was used to assess the cumulative hospitalization incidence. Cox proportional hazards model was used to control for confounders.

RESULTS

SD complicated 0.2% (n = 353) of deliveries included in the study (n = 207,571). Risk factors for SD were fetal macrosomia, maternal diabetes mellitus, male gender, and advanced maternal age (p < 0.05 for all). Higher perinatal mortality was observed among SD cases (2.8 vs. 0.4%, p < 0.001). In most of the investigated neurological conditions no significant differences were found between the groups. Comparable rates of cumulative neurological-related hospitalization were observed (log rank p-value = 0.342) as well as lack of association between SD and neurological hospitalization (adjusted HR = 0.73; 95% CI 0.36-1.47; p = 0.381) when controlled for gestational age.

CONCLUSION

Risk factors for SD are macrosomia, diabetes mellitus, male gender, and advanced maternal age. SD is not associated with long-term neurological morbidity of the offspring.

Developing a core outcome set for the treatment of pregnant women with pregestational diabetes-a study protocol

BACKGROUND

Pregestational diabetes mellitus (PGDM) is associated with adverse pregnancy outcomes including increased rates of caesarean section birth, macrosomia, congenital malformation, prematurity, admission to the neonatal intensive care unit and stillbirth. As a result, there has been an increase in interventions to improve outcomes in both mother and infant. To date, meaningful comparisons between these studies are limited due to heterogeneity in outcome selection and reporting. The aim of this study is to develop a core outcome set (COS) for randomised controlled trials evaluating the effectiveness of interventions for the treatment of pregnant women with PGDM.

METHODS

The study consists of three steps. The first step is a systematic review of the literature to assess outcomes reported in randomised controlled trials assessing the effectiveness of interventions for the treatment of pregnant women with PGDM. The second step is a three round, online Delphi survey to prioritise these outcomes. In this step, stakeholders (including women with PGDM, healthcare workers, researchers and policymakers) will be asked to rank the importance of outcomes for inclusion in the COS using a 9-point Likert type scale. Outcomes that meet the inclusion criteria after completion of the Delphi surveys will be brought to the consensus meeting. The consensus meeting will be the third and final step, where the COS will be finalised. The consensus meeting will include members from each stakeholder group.

DISCUSSION

This paper describes the process used to develop a COS for the reporting of studies evaluating the effectiveness of interventions in pregnant women with PGDM. The COS will enable greater comparison between and information synthesis across RCTs in the treatment of PGDM. In addition, this COS will also help improve trial reporting and minimise research waste by prioritising the collection and reporting of outcomes that matter to all relevant stakeholder groups.

TRIAL REGISTRATION

This COS has been registered with the Core Outcome Measures in Effectiveness Trials (COMET) initiative ( http://www.comet-initiative.org/studies/details/1425 ) on the 4th of November 2019. The systematic review component of this study has also been registered with the International Prospective Register of Systematic Reviews (PROSPERO) ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020173549 ).

Fetal overgrowth in pregnancies complicated by diabetes: validation of a predictive index in an external cohort

PURPOSE

To assess validity of a fetal overgrowth index in an external cohort of women with diabetes in pregnancy METHODS: We performed a retrospective analysis of data derived from women with singleton gestations complicated by diabetes who delivered January 2015-June 2018. The following index variables were used to calculate risk of fetal overgrowth as defined by a customized birthweight ≥ 90th centile: age, history of fetal overgrowth in a prior pregnancy, gestational weight gain, fetal abdominal circumference measurement and fasting glucose between 24 and 30 weeks.

RESULTS

In our validation cohort, 21% of 477 pregnancies were complicated by fetal overgrowth. The predictive index had a bias-corrected bootstrapped area under receiver operating characteristic curve of 0.90 (95% CI 0.86-0.93). 55% of the cohort had a low-risk index (≤ 3) which had a negative predictive value of 97% (95% CI 94-98%), while 18% had a high-risk index (≥ 8) that had a positive predictive value of 74% (95% CI 66-81%).

CONCLUSION

The fetal overgrowth index incorporates five factors that are widely available in daily clinical practice prior to the period of maximum fetal growth velocity in the third trimester. Despite substantial differences between our cohort and the one studied for model development, we found the performance of the index was strong. This finding lends support for the general use of this tool that may aid counseling and allow for targeted allocation of healthcare resources among women with pregnancies complicated by diabetes.

Pregnancy after bariatric surgery: a narrative literature review and discussion of impact on pregnancy management and outcome

Bariatric surgery (BS) is regarded to be the most effective treatment of obesity with long lasting beneficial effects including weight loss and improvement of metabolic disorders. A considerable number of women undergoing BS are at childbearing age.Although the surgery mediated weight loss has a positive effect on pregnancy outcome, the procedures might be associated with adverse outcomes as well, for example micronutrient deficiencies, iron or B12 deficiency anemia, dumping syndrome, surgical complications such as internal hernias, and small for gestational age (SGA) offspring, possibly due to maternal undernutrition. Also, there is no international consensus concerning the ideal time to conception after BS. Hence, the present narrative review intents to summarize the available literature concerning the most common challenges which arise before and during pregnancy after BS, such as fertility related considerations, vitamin and nutritional deficiencies and their adequate compensation through supplementation, altered glucose metabolism and its implications for gestational diabetes screening, the symptoms and treatment of dumping syndrome, surgical complications and the impact of BS on pregnancy outcome. The impact of different bariatric procedures on pregnancy and fetal outcome will also be discussed, as well as general considerations concerning the monitoring and management of pregnancies after BS.Whereas BS leads to the mitigation of many obesity-related pregnancy complications, such as gestational diabetes mellitus (GDM), pregnancy induced hypertension and fetal macrosomia; those procedures pose new risks which might lead to adverse outcomes for mothers and offspring, for example nutritional deficiencies, anemia, altered maternal glucose metabolism and small for gestational age children.

Simulation in shoulder dystocia: does it change outcomes?

Background

Shoulder dystocia is an obstetrical emergency that requires immediate and appropriate provider response to decrease neonatal morbidity.

Objective

To determine whether institution of shoulder dystocia simulation training improves maternal and neonatal outcomes at delivery.

Study design

This retrospective cohort study compared maternal and neonatal outcomes before (1 September 2008–31 December 2009) and after (1 January 2010–31 December 2014) a mandatory shoulder dystocia simulation curriculum was instituted. Χ2 and Fisher’s exact tests along with multivariate logistic regression models were conducted to adjust for potential confounding.

Results

Of 8930 vaginal deliveries that met eligibility criteria over the 6-year period, 299 (3.3%) deliveries were complicated by a shoulder dystocia. The adjusted frequency of shoulder dystocia was approximately two times higher after training implementation (1.9% vs 3.8%; adjusted OR=1.80 (1.23 to 2.65), p=0.003). Neonatal outcomes such as brachial plexus injury (5.0% vs 7.7%; p=0.75), clavicle fracture (5.0% vs 4.6%; p=1.00) and humerus fracture (0.0% vs 1.9%; p=1.00) were not statistically different after training. Additionally, no significant differences in episiotomy (5.0% vs 4.6%; p=1.00), postpartum haemorrhage (10.0% vs 12.4%; p=0.80) and severe perineal laceration (10.0% vs 6.6%; p=0.50) were observed.

Conclusions

The overall frequency of shoulder dystocia reportedly doubled after training despite stable operative vaginal delivery and caesarean delivery rates. No significant improvements were seen in maternal or neonatal outcomes after simulation training. As shoulder dystocias are rare events, simulation training may not necessarily improve neonatal outcomes, but it may increase overall provider awareness and intervention.

Population-Based Risk Factors for Shoulder Dystocia

OBJECTIVE

To re-examine the risk factors for shoulder dystocia given the increasing rates of obesity and diabetes in pregnant women.

DESIGN

Retrospective observational study.

SETTING

Five hospitals located in Wisconsin, Florida, Maryland, Michigan, and Alabama.

PARTICIPANTS

We evaluated 19,236 births that occurred between April 1, 2011, and July 25, 2013.

METHODS

Data were collected from electronic medical records and used to evaluate the risk of shoulder dystocia. Data were analyzed using a generalized linear mixed model, which controlled for clustering due to site.

RESULTS

When insulin was prescribed, gestational diabetes was associated with an increased risk of shoulder dystocia (odds ratio = 2.10, 95% confidence interval [1.01, 4.37]); however, no similar association was found with regard to gestational diabetes treated with glycemic agents or through diet. Use of epidural anesthesia was associated with an increased risk for shoulder dystocia (odds ratio = 3.47, 95% confidence interval [2.72, 4.42]). Being Black or Hispanic, being covered by Medicaid or having no insurance, infant gestational age of 41 weeks or greater, and chronic diabetes were other significant risk factors.

CONCLUSION

With the changing characteristics of pregnant women, labor and birth clinicians care for more pregnant women who have an increased risk for shoulder dystocia. Our findings may help prospectively identify women with the greatest risk.

Obesity and gynaecological and obstetric conditions: umbrella review of the literature

Objective To study the strength and validity of associations between adiposity and risk of any type of obstetric or gynaecological conditions.Design An umbrella review of meta-analyses.Data sources PubMed, Cochrane database of systematic reviews, manual screening of references for systematic reviews or meta-analyses of observational and interventional studies evaluating the association between adiposity and risk of any obstetrical or gynaecological outcome.Main outcomes Meta-analyses of cohort studies on associations between indices of adiposity and obstetric and gynaecological outcomes.Data synthesis Evidence from observational studies was graded into strong, highly suggestive, suggestive, or weak based on the significance of the random effects summary estimate and the largest study in the included meta-analysis, the number of cases, heterogeneity between studies, 95% prediction intervals, small study effects, excess significance bias, and sensitivity analysis with credibility ceilings. Interventional meta-analyses were assessed separately.Results 156 meta-analyses of observational studies were included, investigating associations between adiposity and risk of 84 obstetric or gynaecological outcomes. Of the 144 meta-analyses that included cohort studies, only 11 (8%) had strong evidence for eight outcomes: adiposity was associated with a higher risk of endometrial cancer, ovarian cancer, antenatal depression, total and emergency caesarean section, pre-eclampsia, fetal macrosomia, and low Apgar score. The summary effect estimates ranged from 1.21 (95% confidence interval 1.13 to 1.29) for an association between a 0.1 unit increase in waist to hip ratio and risk endometrial cancer up to 4.14 (3.61 to 4.75) for risk of pre-eclampsia for BMI >35 compared with <25. Only three out of these eight outcomes were also assessed in meta-analyses of trials evaluating weight loss interventions. These interventions significantly reduced the risk of caesarean section and pre-eclampsia, whereas there was no evidence of association with fetal macrosomia.Conclusions Although the associations between adiposity and obstetric and gynaecological outcomes have been extensively studied, only a minority were considered strong and without hints of bias.

Risk Factors for Shoulder Dystocia: the Impact of Mother's Race and Ethnicity

Shoulder dystocia is a rare but severe birth trauma where the neonate's shoulders fail to deliver after delivery of the head. Failure to deliver the shoulders quickly can lead to severe, long-term injury to the infant, including nerve injury, skeletal fractures, and potentially death. This observational study examined shoulder dystocia risk factors by race and ethnicity using a sample of 19,236 pregnant women who presented for labor and delivery from July 1, 2010 until June 30, 2013 at five locations. Multivariate analyses were used to identify risk factors associated with shoulder dystocia occurrence in racial/ethnic groups with high incidence rates. For White non-Hispanic mothers, the strongest risk factors were delivering past 40 weeks' gestation (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.5, 3.9; p < .01) and use of epidural anesthesia during delivery (OR = 4.4; 95% CI = 3.0, 6.4; p < .01). Among Black non-Hispanic mothers, the risk factors with the greatest impact were use of epidural (OR = 5.3; 95% CI = 3.2, 8.7; p < .01) and having gestational diabetes and controlling the condition with insulin (OR = 4.6; 95% CI = 1.5, 13.8; p < .01). Additionally, among Hispanic mothers, having Spanish as primary language increased shoulder dystocia likelihood compared to those who did not cite it as their primary language (OR = 2.3; 95% CI = 1.1, 4.6; p < .05). This study provides evidence that risk factors for a labor and delivery condition can vary significantly across racial and ethnic subgroups. These differences emphasize the importance of evaluating risk by population subgroups and might provide a basis for labor and delivery clinicians to enhance personalized medicine to reduce adverse events.

[Macrosomia, shoulder dystocia and elongation of the brachial plexus: what is the role of caesarean section?]

The delivery of a macrosomic infant is associated with a higher risk for maternofoetal complications. Shoulder dystocia is the most feared fetal complication, leading sometimes to a disproportionate use of caesarean section. This study aims to evaluate the interest of preventive caesarean section. We conducted a retrospective study of 400 macrosomic births between February 2010 and December 2012. We also identified cases of infants with shoulder dystocia occurred in 2012 as well as their respective birthweight. Macrosomic infants weighed between 4000g and 4500g in 86.25% of cases and between 4500 and 5000 in 12.25% of cases. Vaginal delivery was performed in 68% of cases. Out of 400 macrosomic births, 9 cases with shoulder dystocia were recorded (2.25%). All of these cases occurred during vaginal delivery. The risk for shoulder dystocia invaginal delivery has increased significantly with the increase in birth weight (p <10-4). The risk for elongation of the brachial plexus was 11 per thousand vaginal deliveries of macrosomic infants. This risk was not correlated with birthweight (p = 0.38). The risk for post-traumatic sequelae was 0.71%. Shoulder dystocia affectd macrosoic infants in 58% of cases. Shoulder dystocia is not a complication exclusively associated with macrosomia. Screening for risky deliveries and increasing training of obstetricians on maneuvers in shoulder dystocia seem to be the best way to avoid complications.

Bariatric Surgery and the Pregnancy Complicated by Gestational Diabetes

Gestational diabetes mellitus (GDM) is an increasingly common obstetrical problem. Due to the global escalation in the prevalence of obesity, as many as 15 % of pregnant women may soon be classified as having GDM. While often not diagnosed until late gestation, GDM is now recognized as a disorder of glucose and lipid metabolism, systemic inflammation, and insulin resistance that begins early in pregnancy. Recent large randomized trials have clarified the risk of maternal and neonatal complications caused by GDM, as well as the potential to ameliorate these risks. There is significant interest in the potential to reduce the risk for developing GDM in obese women through the performance of bariatric surgery (BS) before pregnancy. BS significantly reduces the risk for GDM, preeclampsia, and large neonates. However, it seems that the risk for small neonates and preterm delivery is increased. No significant differences are observed in regard to cesarean section, postpartum hemorrhage, or perinatal mortality. In this article, we address the effects of GDM on the mother and child, and explore the risks and benefits of BS in the obstetrical population.

[Neonatal complications related to shoulder dystocia]

OBJECTIVE

To describe neonatal complications related to shoulder dystocia.

METHODS

This systematic evidence review is based on PubMed search, Cochrane library and experts' recommendations.

RESULTS

The risks of brachial plexus birth injury, clavicle and humeral fracture, perinatal asphyxia, hypoxic-ischemic encephalopathy and perinatal mortality are increased after shoulder dystocia. The medical team should be able to provide neonatal resuscitation in the delivery room in case of perinatal asphyxia following shoulder dystocia, according to national and international guidelines. The initial clinical examination should search for complications such as brachial plexus birth injury or clavicle fracture.

CONCLUSION

The risk of perinatal complications is increased in newborn after shoulder dystocia. The medical team should be able to manage these complications.

[Epidemiology of shoulder dystocia]

OBJECTIVES

To synthetize the available evidence regarding the incidence and risk factors of shoulder dystocia (SD).

METHODS

Consultation of the Medline database, and of national guidelines.

RESULTS

Shoulder dystocia is defined as a vaginal delivery that requires additional obstetric manoeuvres to deliver the foetus after the head has delivered and gentle traction has failed. With this definition, the incidence of SD in population-based studies is about 0.5-1% of vaginal deliveries. Many risk factors have been described but most associations are not independent, or have not been constantly found. The 2 characteristics consistently found as independent risk factors for SD in the literature are previous SD (incidence of SD of about 10% in parturients with previous SD) and foetal macrosomia. Maternal diabetes and obesity also are associated with a higher risk of SD (2 to 4 folds) but these associations may be completely explained by foetal macrosomia. However, even factors independently and constantly associated with SD do not allow a valid prediction of SD because they are not discriminant; 50 to 70% of SD cases occur in their absence, and the great majority of deliveries when they are present is not associated with SD.

CONCLUSION

Shoulder dystocia is defined by the need for additional obstetric manoeuvres to deliver the foetus after the head has delivered and gentle traction has failed, and complicates 0.5-1% of vaginal deliveries. Its main risk factors are previous SD and macrosomia, but they are poorly predictive. SD remains a non-predictable obstetrics emergency. Knowledge of SD risk factors should increase the vigilance of clinicians in at-risk contexts.

[Assessment of shoulder dystocia related knowledge among French obstetrics and gynecology residents]

OBJECTIVE

To study the related knowledge of French residents in obstetrics concerning maneuvers for shoulder dystocia (SD).

MATERIALS AND METHODS

Multicenter descriptive transversal study conducted from June to September 2014. Data collection was performed through questionnaires sent by email to French resident in obstetrics.

RESULTS

Among the 1080 questionnaires sent, 366 responses were obtained with a response rate of 33.9%. One hundred and forty-three residents (39.1%) were in the first part of their training (≤5th semester) and 60.9% (n=223) were in the second part of their training. Theoretical training on the SD was provided to 88.2% of resident (n=323). In total, 38.8% (n=142) obtained their French degree in mechanical and technical obstetric and among them 77.5% (n=110) had the opportunity to train on simulators and dummies. Concerning their practical experiences, 31.5% (n=45) residents ≤5th semester reported having experienced SD during their residency vs 58.3% (n=130) amongst oldest residents (P<0.001). In the second part of residency, 40% of residents (n=89) expressed to feel able to manage shoulder dystocia. Only 19.1% (n=70) were satisfied with their residency training program vs 39.1% (n=143) who were unsatisfied.

CONCLUSION

Our study showed that less than one resident out of two (40%) felt able to perform maneuvers for SD in the second part of residency. We think that simulation activities should be mandatory for residency training programs in Obstetrics and Gynecology, which have to develop dependable measures to assess resident competencies to execute practical maneuvers for clinical emergencies in obstetrics.

Risk factors for clavicle fracture concurrent with brachial plexus injury

PURPOSE

The aim of this study was to evaluate the risk factors for clavicle fracture concurrent with brachial plexus injuries.

METHODS

A retrospective study was conducted at a tertiary centre. The hospital records of 62,288 vaginal deliveries were evaluated retrospectively. There were 35 cases of brachial plexus injury. Of these patients, nine had brachial plexus injuries with clavicle fracture and 26 without clavicle fracture. The analysed risk factors for clavicle fracture concurrent with brachial plexus injury were gestational diabetes, labour induction and augmentation, prolonged second stage of labour, estimated foetal weight above 4000 g, birth weight above 4000 g, risky working hours, and the requirement of manoeuvres to free the impacted shoulder from behind the symphysis pubis.

RESULTS

Labour augmentation with oxytocin increased the risk of clavicle fracture in cases of brachial plexus injury (OR 6.67; 95% CI 1.26-35.03). A birth weight higher than 4000 g also increased the risk of clavicle fracture. Risky working hours, gestational diabetes, estimated foetal weight higher than 4000 g, and requirement of shoulder dystocia manoeuvres did not increase the risk of clavicle fracture.

CONCLUSIONS

Labour augmentation and actual birth weight higher than 4000 g were identified as risk factors for clavicle fracture in cases of brachial plexus injury.

Fetal sonographic characteristics associated with shoulder dystocia in pregnancies of women with type 1 diabetes

INTRODUCTION

Shoulder dystocia is a rare but severe complication of vaginal delivery and diabetic women are at high risk. The aim of this study was to identify fetal sonographic and maternal glycemic characteristics associated with shoulder dystocia in pregnant women with type 1 diabetes.

MATERIAL AND METHODS

Twelve cases (5%) of shoulder dystocia among 241 consecutive vaginal deliveries in women with type 1 diabetes followed at Rigshospitalet University Hospital in 2009-2013 were retrospectively identified in a local database. Fetal sonographic and clinical data were compared with 69 women with type 1 diabetes and uncomplicated vaginal deliveries.

RESULTS

Women experiencing shoulder dystocia compared with women with uncomplicated deliveries had a higher glycated hemoglobin (HbA1c) in early pregnancy [median 7.0% (range 5.9-8.1) vs. 6.6% (range 5.4-10.0, P = 0.04)], whereas in late pregnancy, HbA1c in the two groups of women was comparable [6.1% (range 5.5-6.9) vs. 6.0% (range 4.7-8.4, P = 0.30)]. Fetal biometry at 36 weeks showed a higher estimated fetal weight of 3597 g (range 3051-4069) vs. 2989 g (range 2165-4025), P < 0.001, corresponding to 20% (4-41%) vs. 5% (-20 to 44%) above the mean estimated fetal weight for gestational age (P = 0.002) and a greater abdominal circumference SD score of 2.51 (range 1.56-4.20) vs. 1.33 (range -1.08 to 4.25), P = 0.001). Head circumference was comparable. Vacuum extraction was more frequent during deliveries with shoulder dystocia (58 vs. 17%, P = 0.005). Seven (58%) newborns with shoulder dystocia had brachial plexus injuries, fractures, intra-abdominal bleeding or needed resuscitation.

CONCLUSIONS

Excessive estimated fetal weight and abdominal circumference at 36 weeks' sonographic examination may help in identifying diabetic women at high risk of later shoulder dystocia.

Cost-effectiveness of the New Zealand diabetes in pregnancy guideline screening recommendations

OBJECTIVE

To compare the cost-effectiveness of 2 possible screening strategies for gestational diabetes mellitus (GDM) from the perspective of the New Zealand health system, developed as part of a gestational diabetes guideline.

DESIGN

A decision analytic model was built comparing 2-step screening (glycated haemoglobin (HbA1c) test at first booking and a 2 h 75 g oral glucose tolerance test (OGTT) as a single test at 24-28 weeks) with 3-step screening (HbA1c test at first booking and a 1 h glucose challenge test (GCT) followed by a 2 h 75 g OGTT when indicated from 24-28 weeks) using a 9-month time horizon.

SETTING

A hypothetical cohort of 62,000 pregnant women in New Zealand.

METHODS

Probabilities, costs and benefits were derived from the literature, and supplementary data was obtained from National Women's Annual Clinical Reports. Main outcome measures, screening and treatment costs (NZ$2013) and effect on health outcomes (incidence of complications).

RESULTS

The total cost for both strategies under baseline assumptions shows that the 2-step screening strategy would cost NZ$1.38 m more than the 3-step screening strategy overall. The additional cost per case detected was NZ$12,460 per case. The model found that the 2-step screening strategy identifies 12 more women with diabetes and 111 more women with GDM when compared against the 3-step screening strategy. We assessed the effect of changing the sensitivity and specificity of the OGTT. The baseline model assumed that the 2 h 75 g OGTT has a sensitivity and specificity of 95%. The 2-step strategy becomes more cost-effective when the diagnostic accuracy measures are improved.

CONCLUSIONS

Adopting a 2-step strategy would moderately increase the number of GDM cases detected at the same time as moderately increasing the number of women with false negatives at a significant cost to the health system. Further evidence on the benefits of the 2 different approaches would be welcome.

Complications of shoulder dystocia

Complications of shoulder dystocia are divided into fetal and maternal. Fetal brachial plexus injury (BPI) is the most common fetal complication occurring in 4-40% of cases. BPI has also been reported in abdominal deliveries and in deliveries not complicated by shoulder dystocia. Fractures of the fetal humerus and clavicle occur in about 10.6% of cases of shoulder dystocia and usually heal with no sequel. Hypoxic ischemic brain injury is reported in 0.5-23% of cases of shoulder dystocia. The risk correlates with the duration of head-to-body delivery and is especially increased when the duration is >5 min. Fetal death is rare and is reported in 0.4% of cases. Maternal complications of shoulder dystocia include post-partum hemorrhage, vaginal lacerations, anal tears, and uterine rupture. The psychological stress impact of shoulder dystocia is under-recognized and deserves counseling prior to home discharge.

Shoulder dystocia: definitions and incidence

Though subjective in nature, both the American College of Obstetricians and Gynecologists practice bulletin and the Royal College of Obstetricians and Gynaecologists green guideline are in agreement on the descriptor of shoulder dystocia: requirement of additional obstetric maneuvers when gentle downward traction has failed to affect the delivery of the shoulders. The rate of shoulder dystocia is about 1.4% of all deliveries and 0.7% for vaginal births. Compared to non-diabetics (0.6%), among diabetics, the rate of impacted shoulders is 201% higher (1.9%); newborns delivered by vacuum or forceps have 254% higher likelihood of shoulder dystocia than those born spontaneously (2.0% vs. 0.6%, respectively). When the birthweight is categorized as <4000, 4000-4449, and >4500 g, the likelihood of shoulder dystocia in the US vs. other countries varies significantly. Future studies should focus on lowering the rate of shoulder dystocia and its associated morbidities, without concomitantly increasing the rate of cesarean delivery.

Fetal macrosomia and shoulder dystocia in women with gestational diabetes: risks amenable to treatment?

Fetal macrosomia and maternal diabetes are independent risk factors for shoulder dystocia, an obstetrical emergency that may cause permanent neonatal injury. Randomized trials of glycemic control in pregnancies complicated by gestational diabetes reveal decreased rates of macrosomia and shoulder dystocia among those treated. However, definitions of gestational diabetes vary and a specific glycemic threshold for clinically significant risk reduction remains to be delineated. This review discusses risks associated with gestational diabetes including macrosomia (birth weight above 4000-4500 g) and delivery-related morbidity, specifically, shoulder dystocia. Subsequently, we will review recent randomized trials assessing the impact of glycemic control on these delivery-related morbidities. Finally, we will examine a large observational study that found associations with delivery-related morbidity and hyperglycemia below current diabetic thresholds, observations which may suggest reexamination of current diagnosis guidelines for gestational diabetes.

Risk factors for neonatal brachial plexus paralysis

PURPOSE

The study was aimed to identify risk factors for neonatal brachial plexus paralysis.

METHODS

A retrospective case-control study was designed. A comparison was performed between cases of brachial plexus paralysis, with all consecutive deliveries during the same 5 months period, without brachial plexus paralysis. Statistical analysis was performed using the SPSS package.

RESULTS

The prevalence of brachial plexus paralysis was 1.62/1,000 (9/5,525) vaginal births. Independent risk factors for brachial plexus paralysis were shoulder dystocia (OR = 525; 95% CI 51-4,977, P < 0.001), vacuum delivery (OR = 16.4; 95% CI 3.7-70.5, P < 0.001), macrosomia (birth weight >4,000 g; OR = 16.3; 95% CI 3.7-70.2, P < 0.001), prolonged second stage (OR = 40.8; 95% CI 7.9-188.2, P < 0.001) and vaginal breech delivery (OR = 36.1; 95% CI 4.5-262.5, P = 0.032).

CONCLUSIONS

In our population, shoulder dystocia, macrosomia, labor dystocia, vacuum delivery and vaginal breech deliveries were significant risk factors for neonatal brachial plexus paralysis, while maternal characteristics such as obesity and diabetes were not. Despite our growing knowledge concerning the risk factors associated with brachial plexus paralysis, unfortunately, this condition cannot be predicted or prevented.