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.

Severe shoulder dystocia with a small-for-gestationaI-age infant: a case report.

BACKGROUND: Severe shoulder dystocia is disproportionately associated with large-for-gestational-age infants. CASE: A nulliparous patient at 38 weeks' gestation had an uncomplicated antenatal course. Clinical pelvimetry revealed an acute-angle pubic arch but otherwise normal diameters, conjugate and sacral concavity. Pre-pregnancy BMI was 20.8 and she had had a 14-pound (6.4 kg) weight gain. She presented in labor and, with oxytocin augmentation, progressed to full dilation over 6 hours, followed by an 18-minute second stage. Severe shoulder dystocia was encountered, necessitating multiple maneuvers, and was resolved after 2 minutes with delivery of the posterior arm. The healthy infant weighed 2,289 g (< 5th percentile) and exhibited only transient shoulder weakness, which resolved completely within 1 hour of life. With informed consent, CT pelvimetry was performed within 24 hours postpartum for investigative purposes, revealing small pelvic inlet and at-threshold interischial diameter. CONCLUSION: Geometric analysis reveals that borderline adequate pelvimetry likely played a significant role in severe shoulder dystocia etiology, even with a small-for-gestational-age infant. We alert obstetric providers to the possibility of severe shoulder dystocia in patients with borderline adequate pelves on clinical examination, even when estimated fetal weight makes cephalopelvic disproportion unlikely.

Large fetal sacrococcygeal teratomas: could early delivery improve outcome?

OBJECTIVE: To determine if gestational age (GA) at delivery or tumor size impacts outcome in neonates with very large sacrococcygeal teratomas (SCTs). METHODS: Retrospective chart review from 1990 to 2006 of live-born infants with very large SCTs, defined as diameters exceeding 10 cm. Data analyzed using the independent t test and Fisher's exact test, with p values <0.05 considered significant. RESULTS: Nine infants with very large SCTs were identified. Six of the 9 infants survived, 4 of whom had evidence of early hydrops. Mean GA of survivors was 32.2 +/- 3.7 versus 31.7 +/- 0.6 weeks in nonsurvivors (p = 0.85). Infants with the largest SCTs did not survive. CONCLUSION: Risks of preterm delivery must be weighed against complications from further enlargement of very large SCTs and against the risks of in utero intervention.

Fetal responses to induced maternal relaxation during pregnancy.

Fetal responses to induced maternal relaxation during the 32nd week of pregnancy were recorded in 100 maternal-fetal pairs using a digitized data collection system. The 18-min guided imagery relaxation manipulation generated significant changes in maternal heart rate, skin conductance, respiration period, and respiratory sinus arrhythmia. Significant alterations in fetal neurobehavior were observed, including decreased fetal heart rate (FHR), increased FHR variability, suppression of fetal motor activity (FM), and increased FM-FHR coupling. Attribution of the two fetal cardiac responses to the guided imagery procedure itself, as opposed to simple rest or recumbency, is tempered by the observed pattern of response. Evaluation of correspondence between changes within individual maternal-fetal pairs revealed significant associations between maternal autonomic measures and fetal cardiac patterns, lower umbilical and uterine artery resistance and increased FHR variability, and declining salivary cortisol and FM activity. Potential mechanisms that may mediate the observed results are discussed.

Shoulder dystocia.

Using an evidence-based, medical approach, the strengths and pitfalls of the causation- and standard-of-care-based arguments proffered by plaintiff and defense counsel in shoulder dystocia- associated birth injury litigation are reviewed based on medical plausibility. The role of the expert witness as arbiter of the relationship between medical care rendered and the untoward outcome of such care is distinguished from that of other court members. Proposed solutions to the medical malpractice litigation crisis are also examined in light of relevant differences in the pathogenetic bases for birth injuries of various types.

Reproductive implications of bariatric surgery: pre- and postoperative considerations for extremely obese women of childbearing age.

Extreme obesity remains a frustrating and formidable disease, with most sufferers requiring surgical intervention in order to achieve long-term, sustained weight loss. Most bariatric procedures today are performed on women, many of whom are of reproductive age; yet minimal evidence exists to guide clinicians in the care of such women before, during, and after pregnancy. This review outlines the fundamental nutritional and surgical alterations of the most commonly performed bariatric procedures with the aim to elucidate a physiologically sound approach to counseling and management of extremely obese women of childbearing age who are either contemplating or have already undergone bariatric surgery. Preconception, pregnancy, and lactation guidelines are offered based on available evidence. Outstanding questions are highlighted for further investigation.

Comparing mechanical fetal response during descent, crowning, and restitution among deliveries with and without shoulder dystocia.

OBJECTIVE: Previous computer simulations of shoulder dystocia (SD) explored the effect of SD itself on the mechanical response of the fetus. Our objective was to perform a mechanical simulation study to explore the variations in fetal response during routine, unilateral SD (USD), and bilateral SD (BSD) deliveries. STUDY DESIGN: Using a biofidelic birthing simulator, we performed 30 experiments mimicking passage of the fetus through the pelvis. For routine deliveries, we engaged the fetal head and allowed it to progress through cardinal movements using typical uterine contraction forces. Deliveries stopped when the head restituted externally to left occiput anterior (LOA) position. The identical procedure was repeated for USD deliveries, except we obstructed the anterior shoulder on the symphysis pubis; for BSD, the posterior shoulder was also impacted on the sacral promontory. For each delivery we continuously measured head rotation, brachial plexus (BP) stretch and neck extension, selecting peak values for analysis. Maximum rotation, BP stretch, and extension were compared among groups using analysis of variance, with P < .05 considered significant. RESULTS: Among routine, USD, and BSD deliveries, mean peak BP stretch varied between 10% and 21%, rotation varied between 70 degrees and 77 degrees, and extension varied between 6% and 18%. Greatest stretch occurred in the posterior BP during descent in non-SD deliveries, whereas anterior BP stretch, rotation, and extension were similar among the 3 types of deliveries. CONCLUSION: Quantifiable mechanical response occurs in routine and SD deliveries. Posterior BP stretch is significantly longer for routine deliveries than either USD or BSD deliveries. By itself, shoulder dystocia does not pose additional risk of brachial plexus stretch over routine deliveries.

After shoulder dystocia: managing the subsequent pregnancy and delivery.

Among risk factors for shoulder dystocia, a prior history of delivery complicated by shoulder dystocia is the single greatest risk factor for shoulder dystocia occurrence, with odds ratios 7 to 10 times that of the general population. Recurrence rates have been reported to be as high as 16%. Whereas prevention of shoulder dystocia in the general population is neither feasible nor cost-effective, intervention efforts directed at the particular subgroup of women with a prior history of shoulder dystocia can concentrate on potentially modifiable risk factors and individualized management strategies that can minimize recurrence and the associated significant morbidities and mortality.

An analysis of transfusion practice and the role of intraoperative red blood cell salvage during cesarean delivery.

BACKGROUND: We sought to determine to what extent intraoperative salvaged red blood cells (RBC) might theoretically reduce exposure to appropriately transfused allogenic erythrocytes in Cesarean delivery patients. METHODS: Medical records of Cesarean delivery patients requiring blood transfusions from January 1, 1992 to June 30, 1996 and June 1, 1998 to June 30, 2003 were reviewed. For each patient, we calculated the number of allogenic RBC units that could have theoretically been avoided had intraoperative autotransfusion been performed, based upon estimated blood loss, preoperative hematocrit, and the amount of retrieved blood needed to yield a single RBC unit. RBC transfusion appropriateness was determined using the recommended guideline of transfusing RBCs if the hemoglobin is <7 gm/dL in a patient with continuing bleeding. RESULTS: A small percentage of Cesarean delivery patients (1.8%) received blood product transfusions. Of 207 patients receiving blood transfusions, salvaged erythrocytes could have theoretically decreased exposure to allogenic RBCs in 115 (55.6%) patients. Only 75.7% of these 115 patients were appropriately transfused with erythrocytes. CONCLUSION: Theoretically, based on best, average, and worst RBC salvage recovery calculations, 25.1%, 21.2%, or 14.5% of the appropriately transfused patients, respectively, could have completely avoided allogenic RBC transfusion.

Use of topical human amniotic fluid in the treatment of acute ocular alkali injuries in mice.

PURPOSE: To evaluate the efficacy of topical human amniotic fluid (HAF) in the treatment of ocular acute alkali burns in mice. DESIGN: Experimental study. METHODS: A chemical burn with 2 microl of sodium hydroxide 0.15 mol/l was created in one eye of 30 mice. The animals were divided into gender- and age-matched groups according to the topical treatment that was administered: group 1 was treated with preterm HAF (n = 10 mice); group 2 was treated with term HAF (n = 10 mice), and group 3 was treated with saline solution (n = 10 mice). Treatment consisted of one drop that was applied to the burned eye five times per day (week one), and three times per day (week two). The epithelial defect was photographed and measured on days two and four. Ocular burn damage was assessed at days two, seven, and 14 after a pre-established classification. On day 14, both eyes of each mouse were enucleated and assessed histopathologically. RESULTS: Median epithelial defect (interquartile range [IQR], 25th, 75th percentile) at day four was 9.93% (IQR, 8.57, 11.27) for group 1, 7.30% (IQR, 5.96, 8.97) for group 2, and 18.92% (IQR, 11.71, 27.64) for group 3 (P < .0076). The overall change (difference in slope) in ocular burn score between days 2 and 14 was -0.127 (P = .009) in group 1 vs 3, -0.134 (P = .012) in group 2 vs 3, and 0.007 (P = .88) in group 1 vs 2. On histologic examination saline solution-treated corneas had more inflammatory cells and blood vessels than HAF-treated corneas. CONCLUSION: Topical preterm/term HAF was an effective topical therapy for limiting the damage after acute alkali burns of the eye in this animal model.

Risk factors for brachial plexus injury with and without shoulder dystocia.

OBJECTIVE: To ascertain whether brachial plexus palsy (BPP) that occurs without shoulder dystocia (SD) represents a traction injury during unrecognized SD or a natural phenomenon with a different mechanism of injury, we compared risk factors and outcomes between SD-associated and non-SD-associated BPP. STUDY DESIGN: Neonates with BPP after cephalic vaginal delivery were pooled from all deliveries at Johns Hopkins (June, 1993-December, 2004) and a dataset of litigated permanent BPP from multiple institutions (1986-2003), grouped by SD association based on clinician documentation and compared by using Fisher exact and t tests. RESULTS: Thirty percent of 49 non-SD-BPP and 11% of 280 SD-BPP lacked all risk factors for SD (P = .002). Compared with SD-BPP infants, non-SD-BPP infants were average weight (P < .001) and had cord pH less than 7.10 (P = .01) more commonly and exhibited a trend toward posterior shoulder involvement (P = .06). Nearly all non-SD-BPP were temporary, whereas more than 90% of permanent BPP were associated with SD (odds ratio 17, 7.3-39.6). CONCLUSION: Non-SD-BPP is uncommon and likely mechanistically distinct from SD-BPP. Risk factors, birth weight, fetal acidosis, posterior arm involvement, and injury severity distinguish between shoulder dystocia-related brachial plexus injuries and those not recorded as such.

Temporary Erb-Duchenne palsy without shoulder dystocia or traction to the fetal head.

BACKGROUND: Although many retrospective studies report that brachial plexus palsies occur after vaginal delivery in the absence of recorded shoulder dystocia, there are no known prospective reports by a treating clinician (PubMed, English language only, 1952-June 2004, search terms: shoulder dystocia, nonshoulder dystocia, obstetric brachial plexus injury, Erb's palsy, Erb-Duchenne palsy, spontaneous vaginal delivery). CASE: A multiparous patient presented with a birth plan requesting that the baby be allowed to deliver on its own, without traction on the head and without suctioning. Although induced at term for elevated blood pressure, the otherwise healthy patient experienced a normal labor with a 30-minute second stage. At delivery, which was videotaped by the father, the fetal head presented over an intact perineum in a right-occiput-anterior position. Without traction, the anterior shoulder delivered spontaneously with the next contraction and Valsalva, followed by the posterior shoulder. The trunk followed routinely. The average-weight for gestational age neonate exhibited an Erb-Duchenne palsy of the right (posterior) arm that resolved on the fourth day of life. CONCLUSION: Temporary Erb-Duchenne palsy can occur in the posterior arm after normal labor and spontaneous delivery without shoulder dystocia or traction on the fetal head.

Maternal psychophysiological change during the second half of gestation.

This study investigated the trajectory of physiological and psychological functioning during the second half of pregnancy and compared responsiveness to a laboratory stressor between pregnant and non-pregnant women. Monitoring of 137 pregnant women at 20, 24, 28, 32, 36, and 38 weeks of pregnancy included measures of heart period (HP), heart period variability (HPV), skin conductance (SCL), respiratory period (RP), respiratory sinus arrhythmia (RSA), and self-report of mood disturbance. HP and RSA declined during this period; SCL and mood disturbance increased. Parity was a significant moderator. HP and SCL responsiveness to the Stroop color-word task was assessed twice in pregnant participants and compared to a sample of 27 non-pregnant women. Physiologic responsiveness was reduced in pregnant women. Pregnant women perceived the Stroop to be more difficult, but performance was unaffected. Despite buffered responsivity to stressful stimuli during pregnancy, advancing gestation is associated with escalating sympathetic tone and declining parasympathetic tone.

Comparing McRoberts' and Rubin's maneuvers for initial management of shoulder dystocia: an objective evaluation.

OBJECTIVE: This study was undertaken to objectively compare delivery traction force, fetal neck rotation, and brachial plexus elongation after 3 different initial shoulder dystocia maneuvers: McRoberts', anterior Rubin's, and posterior Rubin's. STUDY DESIGN: We developed a laboratory birthing simulator comprised of a maternal model with a 3-dimensional bony pelvis, an instrumented fetal model, a force-sensing glove, and a computer-based data acquisition system. A single operator performed 30 simulated shoulder dystocia deliveries using standard downward traction after 1 maneuver was performed. Ten deliveries simulated McRoberts' maneuver with fetal shoulders in the anteroposterior diameter. Ten deliveries involved approximately 30-degree oblique rotation of the anterior shoulder with the spine oriented anteriorly (anterior Rubin's maneuver). Ten deliveries involved approximately 30-degree rotation of the posterior shoulder to the opposite oblique pelvic diameter, with the spine oriented posteriorly (posterior Rubin's maneuver). Peak traction force, brachial plexus elongation, and neck rotation were compared between groups using analysis of variance, with P < .05 considered significant. RESULTS: Rubin's maneuvers were found to require less traction force than McRoberts': 16.2 +/- 2.1 lbs for McRoberts' compared with 8.8 +/- 2.2 lbs and 6.5 +/- 1.8 lbs for posterior and anterior Rubin's respectively (P < .0001). Brachial plexus extension was significantly lower after anterior Rubin's maneuver compared with McRoberts' or posterior Rubin's maneuvers. CONCLUSION In a laboratory model of initial maneuvers for shoulder dystocia, anterior Rubin's maneuver requires the least traction for delivery and produces the least amount of brachial plexus tension. Further study is needed to validate these results clinically.

Episiotomy versus fetal manipulation in managing severe shoulder dystocia: a comparison of outcomes.

OBJECTIVE: In severe shoulder dystocia, when initial maneuvers fail, either episiotomy or fetal manipulation (Rubin, Woods' screw, or posterior arm release) is recommended. We sought to compare maternal and neonatal outcomes between severe shoulder dystocia deliveries managed with episiotomy versus fetal manipulation. STUDY DESIGN: We identified severe shoulder dystocia deliveries from three databases: all shoulder dystocia deliveries (1993-2003 and 1994-1997) from two teaching institutions and litigated cases of shoulder dystocia-associated permanent brachial plexus palsy from multiple U.S. institutions. Pair-wise comparisons were made among three groups of deliveries: those managed by fetal manipulation without episiotomy (fetal manipulation-only), those managed by episiotomy without fetal manipulation (episiotomy-only), and those managed with both (episiotomy + fetal manipulation). Rates of brachial plexus palsy, neonatal depression, and anal sphincter trauma were compared among groups using chi 2 , with significance at P < .05. RESULTS: Among episiotomy-only, 13 of 22 (59.1%) sustained brachial plexus palsy, compared with 20 of 57 (35.1%) among fetal manipulation-only (P = .05). Twenty-eight of 48 (58.3%) in episiotomy + fetal manipulation had brachial plexus palsy, which did not differ from episiotomy-only (P = .95) but was higher than fetal manipulation-only (P = .02), suggesting that the addition of episiotomy conferred no benefit in averting neonatal injury. Anal sphincter trauma was significantly more common among episiotomy-only and episiotomy + fetal manipulation, compared with fetal manipulation-only. CONCLUSION: In severe shoulder dystocia, if fetal manipulation can be performed without episiotomy, severe perineal trauma can be averted without incurring greater risk of brachial plexus palsy.

The psychophysiology of the maternal-fetal relationship.

The enigmatic quality of the maternal-fetal relationship has been extolled throughout history with little empirical support. We apply time series analysis to data for 137 maternal-fetal pairs collected at 20, 24, 28, 32, 36, and 38 weeks gestation. Maternal heart rate and skin conductance data were digitized in tandem with fetal heart rate and motor activity. No temporal relations between fetal heart rate and either maternal variable were found, although averaged maternal and fetal heart rates were correlated from 32 weeks. Consistent temporal associations between fetal movement and maternal heart rate and skin conductance were detected. Fetal movement stimulated rises in each parameter, peaking at 2 and 3 s, respectively. Associations did not change over gestation, were unaffected by a maternal stressor, and showed within-pair stability. The bidirectional nature of the maternal-fetal relationship is considered.