Host Status of Ornamental Shade Trees and Shrubs to Plant Parasitic Nematodes.

Oregon leads the United States in nursery production of shade trees and is third in deciduous and broadleaf evergreen shrub production. Plant-parasitic nematodes have been implicated in problems with the growth of plants in nurseries and are also of phytosanitary risk. A greenhouse experiment was conducted to evaluate the host status of four trees (Quercus alba, Quercus garryana, Acer campestre, Thuja occidentalis) and two shrubs (Buxus sempervirens, Rhododendron catawbiense) to Meloidogyne incognita, Meloidogyne hapla, and Pratylenchus neglectus. Each plant/nematode treatment was replicated five times, and the experiment was conducted twice. Plants were inoculated with 3,000 eggs of M. incognita or M. hapla and 2,500 individuals of P. neglectus two weeks after planting. After three months, the plants were harvested, and the total density of nematodes in soil and roots for P. neglectus and the total density of second-stage juveniles (J2) in soil and eggs on roots for M. hapla and M. incognita were determined. The final nematode population (Pf) and reproductive factor (RF = Pf/initial population density) were calculated. For M. incognita and M. hapla, all of the ornamental trees and shrubs would be considered as fair to good hosts with RF values > 1. Meloidogyne incognita had the highest Pf (5,234 total J2 and eggs/pot) and RF value (28.4) on A. campestre. For P. neglectus, all of the ornamental trees and shrubs were fair to good hosts, except for B. sempervirens. Buxus sermpervirens was not a host for P. neglectus, with an RF value of almost 0. This is the first report of Q. alba, Q. garryana, and A. campestre as hosts for M. incognita, M. hapla, and P. penetrans. This is also the first report of T. occidentalis and R. catawbiense as hosts for P. penetrans and the non-host status of B. sermpervirens for P. penetrans.

A multicentre study on epidemiology and prevention of needle stick injuries among students of nursing schools.

INTRODUCTION: Among the health professions with a long period of training, the students of the Nursing Bachelor's Degree are the most exposed to biological risk resulting from accidents, in particular with needles and cutting edges. The aim of the study was to estimate the frequency and the circumstances for the occurrence of needle stick injuries, as a knowledge base for targeted prevention interventions. METHODS: The study was carried out between May and July 2017 in 11 Universities in Italy and 1 in Albania (associated with the "Tor Vergata" University of Rome). An anonymous semi-structured questionnaire was proposed to 1st (second semester), 2nd and 3rd year students of Nursing Bachelor's Degree. RESULTS: A total of 2742 questionnaires were collected. The average age of participants was 22.9 years (median 22, range 19-60 years), 73% of whom were females. A total of 381 injuries were reported. Three hundred and sixteen students (11.8%) underwent at least 1 injury (12.7% among females, 9.7% among males); 41 students declared two or more injuries; four students did not report the number of injuries occurred. The first injury occurred, as an average, 17 days after the start of the internship (median 15 days) and, in 25% of the cases, during the first 9 days. The highest percentage of accidents occurred during the first internship (25.3% of the total) and decreased with the progress of the training path. The injuries occurred in 38% of cases during drug preparation, 24% when disposing of sharp devices, 15% while re-capping needles, 13% during blood sampling and 10% in other circumstances. In 51.2% of cases, the needle was not sterile. Among the nursing students who suffered a needle stick injury, 58.1% declared that they had performed the post-exposure prophylaxis. 96% of students stated to be vaccinated against Hepatitis B virus. Amongst the students who had their serological status checked (74%), 18% stated the antibody titre was not protective. 49.8% of students answered to have been trained in advance on the correct procedures to avoid needle stick and cutting edges injuries in each clinical ward attended, 41.2% referred that this occurred only in some wards and 10% in no ward at all. CONCLUSION: The results of this study show a high percentage of needle stick injuries in students of the Nursing Bachelor's Degree. Therefore, there is a need for careful reflection on the most effective methods of targeted training acquisition of knowledge, skills and behavioural models useful for the exercise of the profession.

Metabolic effects of 1200-kcal diet in obese pregnant women with gestational diabetes.

Calorie restriction is widely used as a primary therapy for obese pregnant women with gestational diabetes. To better understand the metabolic consequences of marked calorie restriction, we performed a randomized prospective trial under metabolic ward conditions. Obese gestationally diabetic women were randomized to control (n = 5) and calorie-restricted (n = 7) groups. All patients consumed an approximately 2400-kcal/day diet during the 1st wk of the study, and at the end of the 1st wk, metabolic features of the two groups were statistically indistinguishable. During the 2nd wk, the control group continued to consume approximately 2400 kcal/day, whereas the calorie-restricted group consumed approximately 1200 kcal/day. Twenty-four-hour mean glucose levels remained unchanged in the control group (6.7 +/- 0.8 mM wk 1 vs. 6.8 +/- 0.8 mM wk 2), although they dropped dramatically in the calorie-restricted group (6.7 +/- 1.0 mM wk 1 vs. 5.4 +/- 0.5 mM wk 2, P less than 0.01). Fasting plasma insulin also declined in the calorie-restricted group (265 +/- 165 pM wk 1 vs. 145 +/- 130 pM wk 2), resulting in a significant change between groups (P less than 0.02). Surprisingly, fasting plasma glucose and glucose tolerance measured by the 3-h oral glucose tolerance test did not change within or between groups. Fasting levels of beta-hydroxybutyrate rose in the calorie-restricted group (290 +/- 240 microM wk 1 vs. 780 +/- 30 microM wk 2) but not in the control group (P less than 0.01). Finally, urine ketones increased significantly (P less than 0.02) in the calorie-restricted group, whereas they remained absent in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic effects of hypocaloric diets in management of gestational diabetes.

Although hypocaloric diets have been advocated for the management of the obese gravida and the obese mother with gestational diabetes, there is no general agreement on how severely calories should be restricted or on how this therapeutic approach compares with insulin therapy. The lack of consensus is in part because of the lack of studies comparing insulin management with the effects of different degrees of hypocaloric feeding and its effects on metabolism and glycemic status. We review the effects of 50 and 33% calorie restriction on glycemic status and intermediary fuel status in obese gestational diabetic subjects and compare the results with the administration of 20 U NPH and 10 U regular insulin every morning, a therapy of proven value in reducing macrosomia in gestational diabetes. When the two calorie-restriction regimens were compared after a 9-h overnight fast, glycemic status improved 10-20% on both. Ketonuria increased about twofold with 50% calorie restriction, but on average no increase in ketonuria was seen on the 33% calorie-restriction regimen. Both calorie-restriction programs led to a reduction in levels of plasma triglyceride, a correlate of infant birth weight. In contrast, the insulin regimen diminished ketonuria, but glycemic status improved little, and plasma triglyceride concentrations did not decline. Although more studies are needed to confirm these trends, the beneficial effect of 33% calorie restriction, which occurred without marked ketonuria, is consistent with previous studies in gestational diabetes. In addition, the simultaneous improvements observed in plasma glucose and triglyceride concentrations suggest that moderate calorie restriction may be valuable in preventing macrosomia in the offspring of the obese subject with gestational diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance and impaired insulin secretion in subjects with histories of gestational diabetes mellitus.

NIDDM is characterized by decreased insulin secretory responses to glucose and to nonglucose stimuli, hyperglucagonemia, and decreased tissue sensitivity to insulin. However, it has been unclear which of these abnormalities, if any, precedes the others. Since women with histories of gestational diabetes mellitus (GDM) are at high risk for eventual development of NIDDM, we measured B- and A-cell function and tissue sensitivity to insulin in eight normoglycemic, postpartum women with recent histories of GDM and in eight control subjects pair-matched for age and percent of ideal body weight. Fasting plasma glucose levels in subjects with former GDM tended to be slightly higher than in matched controls (98 +/- 3 versus 92 +/- 2 mg/dl, P = 0.07). Basal plasma insulin in subjects with former GDM was significantly higher than in controls (22 +/- 4 versus 14 +/- 2 microU/ml, P = 0.05). During an intravenous glucose tolerance test (IVGTT), relative first- and second-phase insulin responses to glucose were decreased in subjects with former GDM (2316 +/- 560 versus 7798 +/- 1036% of basal X min, P = 0.004; and 8340 +/- 946 versus 14,509 +/- 2556, P = 0.04). An index of sensitivity to insulin, SI, calculated from the IVGTT, was also lower in former GDM (1.23 +/- 0.69 X 10(-4) versus 3.58 +/- 0.78 X 10(-4) min-1/microU/ml, P = 0.001). Acute insulin responses to 5 g i.v. arginine were measured at plasma glucose levels of approximately 95, 215, and 600 mg/dl. The response at 600 mg/dl is termed the AIRmax and is used as an index of glucose-regulated insulin secretory capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of infant birth weight by GDM screening tests. Importance of plasma triglyceride.

OBJECTIVE: We measured plasma glucose, GHb, GPro, IRI and TG at 24-28-wk gestation to determine the extent of elevations in GDM and relationships to glucose intolerance and infant macrosomia. RESEARCH DESIGN AND METHODS: Plasma samples were obtained 1 h after ingestion of 50 g glucose after an overnight fast in 521 randomly selected negative screenees, 264 positive screenees with GTT-, and 96 positive screenees with GTT+ (GDM). RESULTS: Screening test values in GDM subjects exceeded the GTT- group, whose values exceeded those of negative screenees: glucose, 9.6*, 8.7*, 6.3 mM; GHb, 5.2*, 4.9*, 4.7%; GPro, 3.1*, 3.0*, 2.8%; IRI, 791*, 662*, 410 pM; and TG, 2.3*, 1.9, 1.9 mM, (*P < 0.005 vs. negative screenees). TG was the only test elevated in the GDM but not in the GTT- groups. Screening test values correlated with GTT values in the following order (strongest to weakest): glucose* > TG* > GHb* > IRI > GPro (*statistical significance). Plasma TG was the only screening test significantly associated with birth weight corrected for gestational age (birth-weight ratio) (r = 0.09-0.16) (P < 0.05 to < 0.01) and was of the same order as 1- and 2-h GTT associations with birth weight (r = 0.13 and 0.14, respectively) (P < 0.05 to < 0.01). Plots of TG/birth-weight ratio increased linearly to the 80-90th TG percentile in negative screenees and GTT- subjects. GDM subjects followed this trend but with more variation. Above the 90th percentile for TGs, birth-weight ratio trended lower, significantly so when the groups were combined (P < 0.05). In multivariate analysis, TG was associated with birth-weight ratio even when maternal prepregnancy weight and pregnancy weight gain associations with TG and birth-weight ratio were controlled (P < 0.019). CONCLUSIONS: Of the five screening tests evaluated, all were elevated in GDM, but TG is the best discriminator of GDM from the GTT- group, and it is the only test significantly related to birth-weight ratio--and to glucose intolerance besides glucose itself. The TG association with birth weight is not explained fully by maternal weight. The results suggest that plasma TG may be a physiological contributor to infant birth weight. Further evaluation of plasma TG in GDM screening is justified, but GHb, GPro, and IRI appear to hold less promise.

Abnormalities of islet B-cell function, insulin action, and fat distribution in women with histories of gestational diabetes: relationship to obesity.

Although obese women with histories of gestational diabetes mellitus (former GDM) are highly predisposed to develop noninsulin-dependent diabetes mellitus (NIDDM), lean former GDM women are less predisposed. To explore reasons for this difference, we performed measures of islet B-cell function and insulin action in eight lean former GDM women [ideal body weight (IBW), 107 +/- 2% (mean +/- SEM)], 11 obese former GDM (IBW, 161 +/- 11%), and 19 normal women subjects who were individually pair-matched to former GDM for % IBW and age. The first phase (0-10 min) insulin secretory response to iv glucose was significantly lower in both lean and obese former GDM compared to that in normal women (3,480 +/- 548% vs. 8,234 +/- 1,337% basal . min and 3,444 +/- 682 vs. 10,251 +/- 2,465). The second phase (10-60 min) insulin response to glucose was also significantly lower in lean former GDM women and tended to be lower in obese former GDM women compared to that in their respective controls. Insulin action was assessed by the insulin sensitivity index (SI) using Bergman's minimal modeling technique. SI values in lean former GDM women were similar to those in their controls (4.42 +/- 1.3 X 10(-4) ml min-1 microU-1 vs. 5.19 +/- 1.2 X 10(-4). In contrast, SI values in obese former GDM women were significantly lower than those in their controls (0.77 +/- 0.28 X 10(-4) vs. 2.04 +/- 0.43 X 10(-4). To assess whether differences in fat distribution and fat cell size were associated with these differences in insulin sensitivity, the waist to thigh circumference ratio, the waist to hip ratio, and abdominal fat cell diameter were measured. All three were significantly greater in the obese former GDM women than in controls. Thus, an abnormal central distribution of adiposity appears to be associated with the insulin action defect in obese former GDM women. We conclude that both lean and obese former GDM women have insulin secretion defects. Although a modest insulin action defect in lean former GDM women may have been missed by this technique, only in the obese former GDM women, who have a higher risk for future NIDDM, was an insulin action defect demonstrable. Thus, impairments of both insulin secretion and insulin action may be necessary to cause a marked predisposition toward NIDDM.

Age and gender effects on ondansetron pharmacokinetics: evaluation of healthy aged volunteers.

Modest differences in the clearance of the 5HT3 antagonist, ondansetron, among different age groups were detected in two groups of healthy elderly volunteers, one group aged 61 to 74 years ("elderly") and the other 75 to 82 ("aged") years, in addition to young healthy subjects. Both a single 0.15 mg/kg intravenous dose and a single 8 mg oral dose were administered according to a randomized crossover design with a minimum 3-day washout period between treatments. Mean plasma clearance decreased (young, 0.349 L/hr/kg; elderly, 0.279 L/hr/kg; aged, 0.214 L/hr/kg; p less than 0.05) with increasing age. Volume of distribution at steady state was unaffected by age (young, 1.81 L/kg; elderly, 1.94 L/kg; aged, 1.71 L/kg), resulting in increases in mean plasma half-life (young, 3.4 hours; elderly, 4.5 hours; aged, 5.4 hours) and mean absolute bioavailability (young, 57%; elderly, 61%; aged, 69%) with increasing age. Female subjects cleared ondansetron more slowly than males (p less than 0.05), resulting in higher absolute bioavailability. Ondansetron was well tolerated by all age groups with no increase in the number of adverse events observed in older volunteers.

Antiepileptics and the development of congenital anomalies.

We are conducting a prospective cohort study of epilepsy and pregnancy to determine the nature and extent of adverse pregnancy outcomes in infants of mothers with epilepsy (IME). Women with epilepsy were enrolled no later than the first trimester and were matched with controls; their infants were examined at 8 weeks by pediatricians blinded to maternal status. A number of variables were compared between case and control infants: birth weight, length, gestational age, head circumference, Apgar scores, feeding difficulties, neonatal irritability, and presence of major malformations and minor anomalies. The number of minor anomalies per infant was greater for IME than for controls (mean, 5.05 and 3.65, p less than 0.0001 per infant, respectively). Prominent occiput was the only anomaly seen significantly more often in IME than in controls (p less than 0.05).

Use of the Swan-Ganz catheter in obstetrics and gynecology.

Improved cardiovascular hemodynamic monitoring techniques now provide us with a more complete knowledge of disease states and of the effectiveness of our therapeutic modalities. The authors believe that certain areas in obstetric and gynecologic care would benefit from the use of these techniques, including 1) hypovolemic shock unresponsive to initial fluid therapy, 2) septic shock requiring volume resuscitation or vasopressor therapy, 3) surgery and/or labor and delivery of class 3 or 4 cardiac patients, 4) severe preeclampsia or eclampsia complicated by marked oliguria, hypovolemia, or pulmonary edema, and 5) fluid therapy in gynecologic oncologic patients undergoing radical surgery. The Swan-Ganz catheter is a significant advance in hemodynamic monitoring, and a review of the possible measurements, interpretations, and complications is presented.

Shoulder dystocia. A complication of fetal macrosomia and prolonged second stage of labor with midpelvic delivery.

Shoulder dystocia is an infrequently encountered obstetric emergency varying in incidence from 0.15 to 0.60% of all deliveries. Previously identified risk factors include maternal obesity, previous infants weighing greater than 4 kg, maternal diabetes, and fetal macrosomia (greater than 4 kg). To evaluate the role of prolonged second stage of labor (PSS) as a warning sign for shoulder dystocia, 9864 deliveries at LAC-USC Women's Hospital were retrospectively reviewed. Ninety percent delivered vaginally and 4.89% had PSS with midpelvic delivery. Shoulder dystocia occurred in 0.37% of all vertex vaginal deliveries. In the absence of PSS and midpelvic delivery, the incidence of shoulder dystocia was 0.16%. However, with PSS and midpelvic delivery, the incidence of shoulder dystocia was 4.57% (P less than 0.01). Infants weighing in excess of 4 kg were at increased risk of shoulder dystocia compared with infants weighing less than 4 kg. When PSS occurred and midpelvic delivery was attempted, the incidence of shoulder dystocia was 21% in infants weighing in excess of 4 kg; 8% had had failed vaginal delivery. All shoulder dystocias and failed vaginal deliveries occurred after use of the vacuum extractor. Immediate neonatal injury was apparent in 47% of infants with shoulder dystocia after PSS with midpelvic delivery. There were no maternal or fetal deaths related to shoulder dystocia during the study period.

Intrauterine pressure in acute iatrogenic hydramnios.

Amnioinfusion has become a common intrapartum procedure for the relief of cord compression. We report a case of acutely increased intrauterine pressure during amnioinfusion with maternal but not fetal distress. An important decrease in pressure and symptomatology occurred with withdrawal of only a small amount of fluid. Further study is needed of pressure-volume relationships in the uterus and effects on uteroplacental perfusion. Careful attention must be paid to infusion volumes and intrauterine pressure during amnioinfusion.

Fetal heart rate acceleration with fetal blood sampling.

One hundred three fetal heart rate (FHR) tracings in term fetuses with simultaneous fetal blood pH sampling were reviewed. In 71 fetuses accelerations were present in direct response to blood sampling or within 30 minutes of the sampling procedure, and in 70 of these the pH was above 7.20. Of 32 fetuses without FHR acceleration during fetal blood sampling, seven had pH values below 7.20, and in five of these the values were confirmed by cord pH measurement.

Chronic fetal stress and the risk of infant respiratory distress syndrome.

The relationship between five conditions of chronic fetal stress and the incidence of infant respiratory distress syndrome (RDS) was investigated among 614 premature (less than or equal to 36 weeks) infants delivered at the University of Washington Hospital from 1977 to 1980. The strongest association found was a protective effect of abnormal antepartum testing (nonreactive nonstress test, positive contraction stress test, or low or falling maternal urinary estriols). Among the 45 infants with abnormal antepartum testing, the probability of RDS was 15.0 versus 33.8% for the infants without the complication (odds ratio = 0.35, P less than or equal to .01, adjusted for gestational age and mode of delivery). Rupture of the membranes for greater than 24 hours (N = 151), amnionitis (N = 63), and vaginal bleeding beginning more than 24 hours before delivery (N = 108) were each associated with a reduced risk of RDS (adjusted odds ratios = 0.63, 0.51, and 0.58, respectively, P less than or equal to .05). Hypertensive disease of pregnancy was not associated with a decreased risk of RDS; in fact, the opposite trend occurred (N = 96, odds ratio = 1.67, P = .07). The associations with RDS were not explained by differences between births with and without each complication in terms of gestational age, mode of delivery, absence of labor, administration of antenatal steroids, and other complications of pregnancy. This study adds support to the hypothesis that certain conditions associated with chronic fetal stress lead to an acceleration in pulmonary maturity.

Ectopic pregnancy following tubal sterilization surgery.

In a consecutive study of 100 women with the surgical diagnosis of ectopic pregnancy confirmed by histologic examination, 7 women were found to have had prior tubal sterilization surgery. In 3 of these cases the sterilization procedure was bilateral tubal fulguration. The diagnosis of ectopic pregnancy must be given careful consideration if patients conceive after a tubal sterilization procedure of any type.

PIP: From 6 to 10% of all maternal deaths continue to be attributed to ectopic pregnancy, usually the result of hemorrhage. The failure rate of tubal sterilization has been reported to be .25-2% for the Pomeroy procedure and .4-1.7% for bilateral tubal fulguration. The ratio of ectopic to intrauterine pregnancy is higher among pregnancies occurring after sterilizatitn failure than among the general population. The spermatozoa can get past the diminished diameter of a recanalized oviduct but the fertilized ovum cannot pass. During each year about 250 women with ectopic pregnancy are treated at the Los Angeles County-University of Southern California Medical Center. In a review of 100 consecutive cases with a confirmed diagnosis of ectopic pregnancy, 7 were found to have had tubal sterilizaiton surgery 17 months to 8 years previously. In 3 cases, bilateral tubal fulguration had been done and in 4 cases bilateral tubal ligation was performed. Ruptured extrauterine pregnancy had occurred in the distal segment of the tube in 4 and a cornual pregnancy in 1. There was 1 case of aborting tubal gestation and 1 of unruptured tubal pregnancy. In 1 case the tube containing the ectopic pregnancy had not been ligated but the round ligament was by mistake. It is thought the refulguration, as is now done, following transection of the tubes will reduce the incidence of ectopic pregnancies. The diagnosis of ectopic pregnancy should not be excluded because of a patient's history of bilateral tubal ligation or fulguration.

Maternal deaths in Washington state.

The completeness of maternal death reporting in Washington state was determined by comparing death certificates to the birth and fetal death records for women, age 15 to 45, dying from selected causes. From 1977 to 1981 there was 112% underreporting of maternal deaths. Only 17 of 36 maternal deaths were able to be identified on death certificates as being pregnancy related. Of the 36 deaths, two major causes of death were identified: Hypertensive disorders of pregnancy (13 deaths) and pulmonary embolism (six deaths).

The hemodynamic effects of orthostatic stress during pregnancy.

The effects of orthostatic stress on cardiac output and systemic vascular resistance have not been previously studied in pregnancy. A Doppler technique of measuring cardiac output was used to study 15 nonpregnant women, 14 pregnant women in the first trimester, and 16 pregnant women in the third trimester. Subjects were studied in recumbent, sitting, and standing positions. In each group, the change from recumbent to standing positions resulted in a fall in cardiac output of 1.7-1.8 L/minute (P = .001). Systemic vascular resistance rose in each group (P = .001). The magnitude of the rise was greatest in nonpregnant women and smallest in the third trimester (P = .005). The observed fall in cardiac output and rise in systemic vascular resistance may be clinically significant in pregnancies complicated by uteroplacental insufficiency.

Risks associated with pregnancy in spinal cord-injured women.

We reviewed the experience with pregnancy in spinal cord-injured women at the University of Washington over the past 10 years. During that time, 11 women with spinal cord injury had 13 pregnancies. Infant outcome was uniformly good. No major obstetric complication occurred. The mothers experienced medical problems including urinary tract infection in ten and pyelonephritis in three. Autonomic hyperreflexia occurred in three of five subjects with lesions at or above the sixth thoracic vertebra. Pregnancy in the spinal cord-injured patient involves medical risk for the mother, but with careful management, an excellent outcome for both mother and infant may be anticipated.

Face presentation at term.

A retrospective study was conducted of 50,300 consecutive deliveries between July of 1973 and January of 1978. There were 40 instances of face presentation with gestational age greater than 36 weeks and fetal weight greater than 2500 g for an incidence of 1 per 1250 deliveries. Cesarean section was performed in 50% of cases. Spontaneous vaginal delivery occurred with mentum anterior presentation 88% of the time, with mentum transverse presentation 45% of the time, and with mentum posterior presentation 25% of the time. Fetal heart rate (FHR) monitoring was available for review in 29 of the 38 (76%) live births. Internal techniques were used in 79% and external techniques in 21% of the cases. The FHR patterns were classified according to the predominant pattern seen in the first stage of labor. In 59% (17 of 29), variable decelerations were noted, and severe variable decelerations were present in 29% (8 of 29). Late decelerations were noted in 24% (7 of 29) of cases. Only 4 patients completed labor without variable or late decelerations. There were 38 live births and 2 stillbirths. Both of the stillborns were noted to have tight nuchal cords which were believed to be the cause of death. One death occurred intrapartum. Of the 38 live births, there were 14 (37%) with 1-minute Apgar scores of 6 or less and 5 (13%) with 5-minute Apgar scores less than 7. Four of the 5 low 5-minute Apgar scores occurred in babies with mentum posterior position. Of the 23 patients monitored by internal electrodes, no serious trauma was noted as a result of the electrode placement.

Erb/Duchenne's palsy: a consequence of fetal macrosomia and method of delivery.

Methods of delivery, maternal and neonatal characteristics were examined to determine their role in the occurrence of Erb/Duchenne's palsy. Data from 210,947 Washington state birth certificates from 1980 through 1982 were examined. The incidence was 50.2 cases of Erb's palsy per 100,000 live births. A case control study design was used to analyze 106 cases and 386 controls by both univariable and multivariable analysis. Birth weight was shown to be a significant risk factor regardless of which method of delivery was used. A high birth weight infant (4001-4500 g) had 2.5 times the risk of incurring an upper brachial plexus injury compared with normal size infants (2501-4000 g). The risk for infants greater than 4500 g increased another tenfold (OR = 21.0). When birth weight was controlled for in the analysis, midforceps (OR = 18.3), vacuum extraction (OR = 17.2), and low forceps (OR = 3.7) remained significantly associated with the Erb's palsy. Delivery by cesarean section was associated with a significant protective effect (OR = 0.5) compared with instrumental vaginal delivery. These data demonstrate a high risk for serious birth injury associated with instrumental midpelvic delivery.