Determining factors associated with shoulder dystocia: a population-based study

Maternal and neonatal complications of shoulder dystocia with a focus on obstetric maneuvers: A case-control study of 1103 deliveries

INTRODUCTION

Shoulder dystocia is a severe obstetric emergency that can cause substantial neonatal and maternal complications. This study aims to assess the performed obstetric maneuvers and their frequency, success, and association with maternal and neonatal complication rates.

MATERIAL AND METHODS

The study population was collected among all deliveries in the Hospital District of Helsinki and Uusimaa between 2006 and 2015 (n = 181 352) by searching for ICD-10 codes for shoulder dystocia, brachial plexus injury and clavicle fracture. Shoulder dystocia cases (n = 537) were identified by reviewing the medical records. Shoulder dystocia cases treated with one or two maneuvers were compared with those treated with at least three. Medical records of a matched control group constituting of 566 parturients without any of the forementioned ICD-10 codes were also scrutinized.

RESULTS

Using the four most common obstetric maneuvers (McRoberts maneuver, suprapubic pressure, rotational maneuvers, the delivery of the posterior arm) significantly increased during the study period with individual success rates of 61.0%, 71.9%, 68.1% and 84.8%, respectively. Concurrently, the rate of brachial plexus injury and combined neonatal morbidity significantly declined from 50% to 24.2% (p = 0.02) and from 91.4% to 48.5% (p < 0.001). Approximately 75% of shoulder dystocia cases treated with maneuvers were resolved by the McRoberts maneuver and/or suprapubic pressure, but each of the four most performed maneuvers significantly increased the cumulative success rate individually and statistically (p < 0.001). The rates of brachial plexus injury and combined neonatal morbidity were at their highest (52.9% and 97.8%) when none of the maneuvers were performed and at their lowest when two maneuvers were performed (43.0% and 65.4%). The increasing number (≥3) of maneuvers did not affect the combined maternal or neonatal morbidity or brachial plexus injury but increased the risk for third- or fourth-degree lacerations (odds ratio 2.91, 95% confidence interval 1.17 to 7.24).

CONCLUSIONS

The increased use of obstetric maneuvers during the study period was associated with decreasing rates of neonatal complications; conversely, the lack of obstetric maneuvers was associated with the highest rate of neonatal complications. These emphasize the importance of education, maneuver training and urgently performing shoulder dystocia maneuvers according to the international protocol guidelines.

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.

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.

Isolated neonatal clavicular fracture is a risk factor for future shoulder dystocia

Objective: Shoulder dystocia (SD) is a risk factor for neonatal clavicular fracture (CF). Previous SD is a known risk factor for subsequent SD. It is unknown whether an isolated neonatal CF (one that is not associated with SD) increases the risk of future SD. We aimed to investigate this question.Methods: A retrospective computerized database study conducted at Shaare Zedek Medical Center, a university-affiliated hospital, between 2005 and 2018. We included in the study all women that had a vaginal delivery without SD and had a subsequent vaginal delivery in our center between 2005 and 2018. Medical records of parturients who had a coded diagnosis of neonatal CF were retrieved. The first delivery with the neonatal diagnosis of an isolated CF was chosen as index delivery. Rates of SD at the subsequent delivery were assessed and compared between parturients with isolated neonatal CF (INCF) and parturients without neonatal CF or SD at the index delivery. To account for dependency between deliveries of the same individual parturient, we used generalized estimating equation (GEE) models.Results: We identified 39,601 parturients that met the inclusion criteria. During the study period, 519 parturients with a diagnosis of INCF that had at least one subsequent delivery were identified (1.3%). Overall, 3.9% of parturients with isolated CF (20/519) had subsequent SD, as compared to 0.5% of parturients without CF or SD at the index delivery (190/39082; p < .01). Previous diagnosis of INCF was found to be independently associated with SD in a subsequent delivery after controlling for known risk factors for SD (aOR = 6.41, 95% CI = 3.92-10.61). Previous diagnosis of an INCF was also found to be independently associated with a subsequent event of SD in all subsequent deliveries of the same individual parturient (aOR = 3.42, 95% CI = 2.26-5.18).Conclusion: Women with previous INCF have an increased risk for SD in subsequent deliveries. Intervention efforts directed at this particular subgroup of women should be applied, with special attention to potentially modifiable risk factors to minimize the risk for future SD.

Obstetric emergencies as antecedents to neonatal hypoxic ischemic encephalopathy, does parity matter?

INTRODUCTION

Our aim was to investigate the risk of moderate to severe hypoxic ischemic encephalopathy (HIE) by obstetric emergencies, with focus on the distribution of obstetric emergencies by parity, taking the history of a previous cesarean into account.

MATERIAL AND METHODS

Population-based cohort study of 692 428 live births at ≥ 36 weeks of gestation in Sweden, 2009-2015. Data were retrieved by linking the Swedish Medical Birth Register with the Swedish Neonatal Quality Register. Therapeutic hypothermia served as surrogate for moderate to severe HIE. Logistic regression analysis was used to estimate associations between HIE and placental abruption, eclampsia, cord prolapse, uterine rupture, and shoulder dystocia, presented as adjusted odds ratios (aORs) with 95% CI.

RESULTS

An obstetric emergency occurred in 133/464 (29%) of all HIE cases, more commonly in the parous (overall 37%; 48% with and 31% without a previous cesarean) than in the nulliparous (21%). Among nulliparas, shoulder dystocia was the most common obstetric emergency with the strongest association with HIE (aOR 48.2; 95% CI 28.2-82.6). In parous women without a previous cesarean, shoulder dystocia was most common, but placental abruption had the strongest association with HIE. Among parous women with a previous cesarean, uterine rupture was the most prevalent obstetric emergency with the strongest association with HIE (aOR 45.6; 95% CI 24.5-84.6).

CONCLUSIONS

Obstetric emergencies are common among cases of moderate to severe HIE. The strong association with shoulder dystocia in nullipara, and with uterine rupture in women with previous cesarean deliveries, implies an opportunity for reducing the incidence of HIE.

Maternal gestational diabetes mellitus: is it associated with long-term pediatric ophthalmic morbidity of the offspring?

PURPOSE

To determine whether children born to mothers with gestational diabetes mellitus (GDM) are at increased risk to develop of pediatric ophthalmic morbidity.

MATERIALS AND METHODS

In this population based cohort study, all deliveries between 1991 and 2014 were included. Congenital malformations, multiple gestations, and patients lacking prenatal care were excluded from analysis. Mothers were defined as either having no GDM, having diet-treated GDM, or medically treated GDM. Outcomes were defined as different ophthalmic morbidities of the offspring until the age of 18. Kaplan-Meier curves were used to compare the cumulative morbidity in each group, and a Cox proportional hazard model was used to control for possible confounders.

RESULTS

During the study period, 238,622 deliveries met the inclusion criteria, of those 4.0% (n = 9601) of mothers were diagnosed with GDM treated by diet, and an additional 1.0% (n = 2398) were diagnosed with GDM treated by medication. Offsprings of patients with GDM treated by medication had a higher cumulative incidence of ophthalmic morbidity when compared to the other groups (Kaplan-Meier log rank test p = .038). GDM treated by medication was found to be an independent risk factor for long-term ophthalmic morbidity, in a cox multivariable model (adjusted HR: 1.5, 95%CI: 1.05-2.1, p = .025).

CONCLUSIONS

Gestational diabetes mellitus treated by medication is associated with an increased risk for long-term pediatric ophthalmic morbidity.

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.

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.

Predictors of shoulder dystocia at the time of operative vaginal delivery

BACKGROUND

It remains uncertain whether clinical factors known prior to delivery can predict which women are more likely to experience shoulder dystocia in the setting of operative vaginal delivery.

OBJECTIVE

We sought to identify whether shoulder dystocia can be accurately predicted among women undergoing an operative vaginal delivery.

STUDY DESIGN

This was a case-control study of women undergoing a low or outlet operative vaginal delivery from 2005 through 2014 in a single tertiary care center. Cases were defined as women who experienced a shoulder dystocia at the time of operative vaginal delivery. Controls consisted of women without a shoulder dystocia at the time of operative vaginal delivery. Variables previously identified to be associated with shoulder dystocia that could be known prior to delivery were abstracted from the medical records. Bivariable analyses and multivariable logistic regression were used to identify factors independently associated with shoulder dystocia. A receiver operating characteristic curve was created to evaluate the predictive value of the model for shoulder dystocia.

RESULTS

Of the 4080 women who met inclusion criteria, shoulder dystocia occurred in 162 (4.0%) women. In bivariable analysis, maternal age, parity, body mass index, diabetes, chorioamnionitis, arrest disorder as an indication for an operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg were significantly associated with shoulder dystocia. In multivariable analysis, parity, diabetes, chorioamnionitis, arrest disorder as an indication for operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg remained independently associated with shoulder dystocia. The area under the curve for the generated receiver operating characteristic curve was 0.73 (95% confidence interval, 0.69-0.77), demonstrating only a modest ability to predict shoulder dystocia before performing an operative vaginal delivery.

CONCLUSION

While risk factors for shoulder dystocia at the time of operative vaginal delivery can be identified, reliable prediction of shoulder dystocia in this setting cannot be attained.

Shoulder dystocia in primary midwifery care in the Netherlands

INTRODUCTION

In the Netherlands, low-risk pregnancies are managed by midwives in primary care. Despite strict definitions of low risk, obstetric complications can occur. Midwives seldom encounter uncommon labour complications, but are sufficiently trained to manage these. We assessed neonatal and maternal outcome after management of shoulder dystocia in primary midwifery care.

MATERIALS AND METHODS

In this 2-year prospective cohort study from April 2008 to April 2010, primary-care midwives, who participated in an obstetric emergency course, reported all obstetric complications. Main outcome was neonatal and maternal outcome.

RESULTS

In sixty-four cases of shoulder dystocia McRoberts was the first maneuver in 42/64 (65.6%) cases with a success rate of 23.8%. All-fours maneuver was most frequently used as the second maneuver (24/45; 53.3%). No neonatal mortality occurred, none of the infants suffered from hypoxic ischemic injury, two (3.1%) had transient brachial plexus injuries, two (3.1%) had fractured clavicles and one (1.6%) had a fractured humerus. Eight (12.5%) neonates were successfully resuscitated because of birth asphyxia. All infants fully recovered. In neonates with immediate adverse outcome significantly more maneuvers were used compared with those without adverse neonatal outcome (p = 0.02). Postpartum hemorrhage occurred in 2/64 (3.1%) women, deep vaginal lacerations in 2/64 (3.1%), perineal tears in 23/64 (35.9%). No anal sphincter injuries occurred.

CONCLUSIONS

McRoberts and all-fours maneuvers are widely used by primary-care midwives in the management of shoulder dystocia. Low rates of adverse neonatal and maternal outcomes were observed in cases of shoulder dystocia up to 6 weeks postpartum.

[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.

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.

Planned hospital birth versus planned home birth

BACKGROUND

Observational studies of increasingly better quality and in different settings suggest that planned home birth in many places can be as safe as planned hospital birth and with less intervention and fewer complications. This is an update of a Cochrane review first published in 1998.

OBJECTIVES

To assess the effects of planned hospital birth compared with planned home birth in selected low-risk women, assisted by an experienced midwife with collaborative medical back up in case transfer should be necessary.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 March 2012) and contacted editors and authors involved with possible trials.

SELECTION CRITERIA

Randomised controlled trials comparing planned hospital birth with planned home birth in low-risk women as described in the objectives.

DATA COLLECTION AND ANALYSIS

The two review authors as independently as possible assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Two trials met the inclusion criteria but only one trial involving 11 women provided some outcome data and was included. The evidence from this trial was of moderate quality and too small to allow conclusions to be drawn.

AUTHORS' CONCLUSIONS

There is no strong evidence from randomised trials to favour either planned hospital birth or planned home birth for low-risk pregnant women. However, the trials show that women living in areas where they are not well informed about home birth may welcome ethically well-designed trials that would ensure an informed choice. As the quality of evidence in favour of home birth from observational studies seems to be steadily increasing, it might be as important to prepare a regularly updated systematic review including observational studies as described in the Cochrane Handbook for Systematic Reviews of Interventions as to attempt to set up new randomised controlled trials.

Critical analysis of risk factors for shoulder dystocia

OBJECTIVE

The study was aimed to define trends, risk factors and perinatal outcome associated with shoulder dystocia (SD).

METHODS

A population-based study comparing all singleton deliveries with and without SD was conducted. Statistical analysis was performed using multiple logistic regression analysis.

RESULTS

Shoulder dystocia complicated 0.2% (n = 451) of all deliveries included in the study (n = 240,189). The rate of SD declined from 0.4% in 1988 to 0.13% in 2009. Independent risk factors for SD in a multivariable analysis were fetal macrosomia (birth-weight ≥ 4 kg; OR = 16.1; 95% CI 13.2-19.6, P < 0.001), failure of labor to progress during the second stage (OR = 2.4; 95% CI 1.5-3.7, P < 0.001), diabetes mellitus (OR = 1.8; 95% CI 1.4-2.3, P < 0.001) and advanced maternal age (years, OR = 1.02; 95% CI 1.001-1.03, P = 0.029). Perinatal mortality was significantly higher after SD as compared to the comparison group (6.2 vs. 1.4%, P <0.001). Another multivariable analysis, with perinatal mortality as the outcome variable, controlling for confounders such as maternal age, gestational age, diabetes mellitus, etc. was constructed; SD was noted as an independent risk factor for perinatal mortality (adjusted OR = 11.1; 95% CI 7.2-17.1, P < 0.001).

CONCLUSIONS

Shoulder dystocia, associated with macrosomia, labor dystocia, diabetes mellitus, and advanced maternal age, is an independent risk factor for perinatal mortality. In an era of increased rate of cesarean deliveries, and perhaps increased accuracy of birth weight estimation, the rate of shoulder dystocia gradually declines.

Reducing the risk of shoulder dystocia and associated brachial plexus injury

Despite persisting controversy over shoulder dystocia prediction, prevention, and injury causation, the authors find considerable evidence in recent research in the field to recommend additional guidelines beyond the current American College of Obstetricians and Gynecologists and Royal College of Obstetricians and Gynecologists guidelines to improve clinical practice in managing patients at risk for experiencing shoulder dystocia. In this article, the authors offer health care providers information, practical direction, and advice on how to limit shoulder dystocia risk and, more importantly, to reduce adverse outcome risk.

Shoulder dystocia and the next delivery: Outcomes and management

OBJECTIVE

To evaluate delivery mode management decisions and the rate of shoulder dystocia recurrence for women with a prior delivery complicated by shoulder dystocia.

STUDY DESIGN

We used a computerized perinatal database and ICD-9 codes to identify all vaginal deliveries complicated by shoulder dystocia from 1996 to 2001. Subsequent deliveries over the next three years were identified and reviewed for relevant clinical, obstetric, and delivery outcomes. Management including use of labor induction, labor augmentation, operative vaginal delivery, and delivery mode (elective cesarean section (CS) vs. trial of labor (TOL)) were reviewed. The recurrence rate of shoulder dystocia was calculated and the characteristics of these cases further described.

RESULTS

Over the initial 5-year study, there were 25 995 vaginal deliveries, 205 shoulder dystocia cases (0.8%), 36 (17.5%) with neonatal injury. Of the 205 initial shoulder dystocia cases, 39 patients had 48 subsequent deliveries at our institution (a subsequent delivery rate of 23% at our institution, significantly less than the overall population (42%, p < 0.001)). Complete data were available for 47 deliveries. Four women had elective CS without labor (one due to prior shoulder dystocia), 43 (91.5%) had a TOL, and 42 (88%) achieved vaginal delivery. Recurrent shoulder dystocia complicated 9.5% (4/42) of deliveries; one case included neonatal brachial plexus injury that resolved prior to hospital discharge. Of the four recurrent shoulder dystocia cases, none were complicated by maternal diabetes, macrosomia, prolonged second stage of labor, or underwent an operative vaginal delivery. No statistically significant univariate differences were seen between the recurrence group and the no-shoulder dystocia vaginal delivery group; however birth weight and nulliparity at initial shoulder dystocia pregnancy jointly demonstrated a relationship of recurrence (p = 0.048).

CONCLUSION

In TOL cases that result in a vaginal delivery, the rate of recurrence of shoulder dystocia is high--approximately 10 times higher than the rate for the general population. Often the only identifiable risk factor is the prior history itself, which may influence delivery management in subsequent pregnancies. Birth weight and nulliparity at initial shoulder dystocia pregnancy may influence clinical decision-making in cases of prior shoulder dystocia.

Sense of coherence predicts uncomplicated delivery: a prospective observational study

The present study aimed to investigate factors predicting uncomplicated deliveries and specifically whether a sense of coherence (SOC) and perceived stress can predict such deliveries. A prospective observational study was conducted employing self-administered SOC and perceived stress scale (PSS) questionnaires with pregnant women attending the outpatient clinic for routine surveillance. Following delivery, data regarding maternal and fetal delivery complications were collected from the participants' medical records. Of one hundred forty-five women completing the study, 43.4% completed the delivery process without complications. Women experiencing delivery complications, on average, had lower SOC scores (67.7 +/- 1.19 vs. 72.2 +/- 1.32, p = 0.014). Maternal complications (as opposed to fetal complications) accounted for this divergence and were related to lower SOC scores (67.74 +/- 1.19 vs. 72.18 +/- 1.32, p = 0.01). PSS was not associated with uncomplicated delivery (18.82 +/- 0.59 vs. 17.98 +/- 0.62, p = 0.341). Nulliparity, however, was associated with higher occurrence of complicated delivery (31.9% of complicated vs. 13.2% of uncomplicated deliveries, p = 0.007). Multivariable analysis demonstrated that high SOC (OR = 1.042; 95% CI = 1.004-1.08; p = 0.03) and nulliparity (OR = 0.293; 95% CI = 0.113-0.758; p = 0.011) both were independent predictors of uncomplicated delivery, directly and inversely, respectively. In conclusion, higher SOC scores are an independent protective factor for the prediction of uncomplicated delivery.

The influence of meteorological factors on the emergence of preterm delivery and preterm premature rupture of membrane

OBJECTIVE

To evaluate the influence of changes in the atmospheric state on the incidence of preterm delivery (PTD) and preterm premature rupture of membrane (PPROM).

STUDY DESIGN

The hospital records of PTD and/or PPROM over the year 1999 were reviewed. The current meteorological state was described by a set of parameters and their diurnal and seasonal variations. Multivariate analysis, time series approach and Poisson regression were used.

RESULT

PTD occurrence was correlated with humidity and maximum temperature (P<0.01), its rise preceded their sharp variations by 3 days (P<0.01). PPROM was influenced by the variations in the weather state: desert heat wave arrival (P=0.093), strong winds, overall daily differences of humidity and temperature (all with P<0.05).

CONCLUSION

The rates of PTD and PPROM are affected by an ensemble of meteorological variables, specific for each disorder. Obstetricians should be aware of the influence of unstable weather on PTD and PPROM rates, especially in the spring and autumn.

[Severe shoulder dystocia: study of 14 cases treated by Jacquemier's maneuver]

OBJECTIVE

Shoulder dystocia is a dreadful complication of vaginal deliveries since it can be responsible of brachial plexus palsies and even neonatal deaths. Unlike most studies, we defined shoulder dystocia as the enclosing of fetal shoulders above the superior strait (cavity station of 1cm) and situations being resolved only by delivery of the posterior arm (Jacquemier's maneuver). The purpose of this study was to analyze cases of shoulder dystocia in terms of maternal and neonatal complications and to compare risk factors with those identified in the literature.

MATERIAL AND METHODS

We conducted a retrospective study of 14 cases of severe shoulder dystocia (SSD) which occurred at our hospital between January 1995 and January 2007. TSD was diagnosed in the absence of engagement of both fetal shoulders requiring recourse to Jacquemier's maneuver for delivery. Any gestational diabetes, abnormal progression of labour, suspicion or existence of fetal macrosomia, instrumental delivery, and neonatal complications were noted.

RESULTS

The incidence of SSD was around 1 per thousand. Multiparity, weight gain greater than 15kg and gestational diabetes were moderately present in our study group. Only 20% of neonates were macrosomic and 50% had a birth-weight of less than 4000g. In 80% of cases, an instrumental extraction was practised. Brachial plexus injuries affected 20% of neonates, no fracture was observed, one child died following an unresolved SSD.

CONCLUSION

This series shows that the incidence of SSD is rare and difficultly predictable even though identified risk factors exist. However, an instrumental extraction seems frequently associated with SSD and any extraction should take into account the presence of known risk factors. In spite of the severity of our cases of shoulder dystocia, complications found seemed to be similar to those observed in the literature.

The relationship between fetal gender and pregnancy outcome

BACKGROUND

Genesis 3:16 is the passage usually quoted by those who believe women have been cursed to give birth in pain. God punished Eve that she will have increased (painful) labor, after she was beguiled by the serpent and ate the forbidden fruit of knowledge. The Lord God said "I will greatly multiply your pain in childbearing; in pain you shall bring forth children". Nevertheless, the word translated as "children" is the Hebrew word "banim" which means "boys". Indeed, most interpreters translated boys as children. Yet, there is gaining scientific evidence that the gender does matter.

OBJECTIVE

The present Editorial will discuss gender differences in perinatal medicine.

CONCLUSIONS

Male gender is an independent risk factor for adverse pregnancy outcome. Further research including endocrine and immunological tests is needed to clarify gender differences in birth outcome.

Shoulder dystocia: a comparison of patients with and without diabetes mellitus

BACKGROUND

The study was aimed to compare pregnancies complicated with shoulder dystocia, of patients with and without diabetes mellitus.

METHODS

A comparison of all singleton, vertex, term deliveries between the years 1988-1999, complicated with shoulder dystocia with and without diabetes mellitus was performed. Statistical analysis was done using receiver operating characteristic curve analysis.

RESULTS

Using a receiver operating characteristic curve analysis, the area under the curve for birth weight was 0.92 (95% CI 0.90-0.93). However, for birth weight of 4,000 g the sensitivity was only 56% with specificity of 95%. While comparing shoulder dystocia between patients with (n=38) and without diabetes mellitus (n=207), neonates of the diabetic patients were significantly heavier (mean birth weight 4,244.2+/-515.1 vs. 4,051.6+/-389.5; P=0.008) and had higher rate of Apgar scores lower than 7 at 1 min (50.0% vs. 25.9%; P=0.030), but not at 5 min (2.6% vs. 2.0%; P=0.083) when compared to the non-diabetic group. No significant differences were noted regarding perinatal mortality between the groups (0% vs. 4.3%; P=0.362).

CONCLUSIONS

The newborn of the diabetic mother complicated with shoulder dystocia does not appear to be at an increased risk for perinatal morbidity compared with the newborn of the non-diabetic mother.