Effect of mode of delivery in nulliparous women on neonatal intracranial injury

BACKGROUND

Infants delivered by vacuum extraction or other operative techniques may be more likely to sustain major injuries than those delivered spontaneously, but the extent of the risk is unknown.

METHODS

From a California data base, we identified 583,340 live-born singleton infants born to nulliparous women between 1992 and 1994 and weighing between 2500 and 4000 g. One third of the infants were delivered by operative techniques. We evaluated the relation between the mode of delivery and morbidity in the infants.

RESULTS

Intracranial hemorrhage occurred in 1 of 860 infants delivered by vacuum extraction, 1 of 664 delivered with the use of forceps, 1 of 907 delivered by cesarean section during labor, 1 of 2750 delivered by cesarean section with no labor, and 1 of 1900 delivered spontaneously. As compared with the infants delivered spontaneously, those delivered by vacuum extraction had a significantly higher rate of subdural or cerebral hemorrhage (odds ratio, 2.7; 95 percent confidence interval, 1.9 to 3.9), as did the infants delivered with the use of forceps (odds ratio, 3.4; 95 percent confidence interval, 1.9 to 5.9) or cesarean section during labor (odds ratio, 2.5; 95 percent confidence interval, 1.8 to 3.4), but the rate of subdural or cerebral hemorrhage associated with vacuum extraction did not differ significantly from that associated with forceps use (odds ratio for the comparison with vacuum extraction, 1.2; 95 percent confidence interval, 0.7 to 2.2) or cesarean section during labor (odds ratio, 0.9; 95 percent confidence interval, 0.6 to 1.4).

CONCLUSIONS

The rate of intracranial hemorrhage is higher among infants delivered by vacuum extraction, forceps, or cesarean section during labor than among infants delivered spontaneously, but the rate among infants delivered by cesarean section before labor is not higher, suggesting that the common risk factor for hemorrhage is abnormal labor.

Shoulder dystocia: an obstetric emergency

Shoulder dystocia is one of the most dreaded complications of vaginal delivery encountered by the obstetrician. Although risk factors for shoulder dystocia exist, approximately 50% of cases do not demonstrate the classic predisposing signs. Obstetricians can help patients decrease their risk for fetal macrosomia by frequent attention to weight gain, nutrition, and exercise during pregnancy and by aggressive management of diabetes. All obstetricians must be familiar with the maneuvers used to effect delivery of impacted shoulders and must be prepared to institute these maneuvers immediately in a crisis situation.

Prenatal pressure necrosis of the scalp

A case of full-thickness pressure necrosis of the scalp in a newborn is reported. This is a rare injury, with only four similar prior reports found in the literature. The presumed mechanism of injury is pressure of the infant's head against the mother's bony pelvis. A spectrum of injury can be seen, from temporary alopecia to complete scalp necrosis. Risk factors include prolonged ruptured membranes and prolonged labor.

Calving chain fractures. Radiographic assessment of healing

Calving chain fractures are highly characteristic injuries that when treated by casting, exhibit a predictable healing pattern. By knowing how such fractures appear radiographically at 1, 2, and 3 months following injury, it is much easier to decide when the fracture has become strong enough to bear weight, thus avoiding recasting the leg. This article describes the appearance of calving chain fractures as they heal over time, and how they appear when they do not.

Brachial plexus palsy: an in utero injury?

Acquired brachial plexus injury historically has been linked with excessive lateral traction applied to the fetal head, usually in association with shoulder dystocia. Recent reports in the obstetric literature, however, have suggested that in utero forces may underlie a significant portion of these injuries. Brachial plexus palsies may therefore precede the delivery itself and may occur independent of the actions of the accoucheur. Thus we propose that the long-held notions of a traction-mediated pathophysiologic mechanism for all brachial plexus injuries warrant critical reappraisal.

Effects of twinning on gestation length, retained placenta, and dystocia

Constraints to maximal productivity from twinning in beef cattle include increased incidence of dystocia and retained placenta, longer postpartum interval, and lower conception rate. Incidence and cause(s) of the shorter gestation length and of the increased retained placenta and dystocia associated with twinning were evaluated for 3,370 single and 1,014 twin births produced in a population of cattle selected for natural twin births. Gestation length was shorter for twin than for single pregnancies (275.6 vs. 281.3 d, P<.01) and likely contributed to the higher incidence of retained placenta associated with twin births (27.9 vs. 1.9%; P<.01). Incidence of retained placenta was also higher in the spring (March-April) than in the fall (August-September) calving season (18.3 vs. 11.4%; P<.01). The higher incidence of dystocia with twins than with singles (46.9 vs. 20.6%, P<.01) was primarily due to abnormal presentation (37.0 vs. 4.5%, respectively) of one or both twin calves at parturition. First- (40.5%) and second- (22.7%) parity dams with a single birth had more (P<.01) dystocia than older dams (13.4%), whereas dystocia was not affected (P>.10) by parity with twin births. Because of the shorter gestation length and the increased incidence of retained placenta and(or) dystocia, achievement of increased productivity with twinning in cattle necessitates intensive management of twin-producing dams and their calves during the calving season. Management of the increased dystocia can be facilitated by preparturient diagnosis of twin pregnancies, enabling timely administration of obstetrical assistance to facilitate delivery of twin calves and to increase their neonatal survival.

Surgical management of rectal and jejunal tears associated with dystocia in a cow

The rectal and jejunal tears associated with dystocia in a cow were treated surgically. The cow developed peritonitis which was treated medically. It recovered, was successfully rebred and delivered a live calf.

Lower thoracic spinal cord injury--a severe complication of shoulder dystocia

Fundal pressure as a maneuver for the relief of shoulder dystocia is associated with up to a 77% fetal injury rate. The usual injuries involve the brachial plexus or orthopedic injuries. We now report a severe lower thoracic spinal cord injury with permanent neurological injury when fundal pressure was applied in an attempt to relieve shoulder dystocia. Shoulder dystocia occurred in a 28-year-old nulliparous woman. A series of manual maneuvers to include episiotomy extension, McRoberts, suprapubic pressure, Woods screw, and extraction of the posterior arm all failed to achieve delivery. During these maneuvers, but not coordinated with them, fundal pressure was applied by multiple individuals. The Zavanelli maneuver and cesarean delivery ultimately allowed delivery. On Day 2 of life marked decrease in lower extremity motor function, over-flow urinary incontinence, and rectal incontinence led to imaging studies that revealed focal spinal cord injury at T-9 through T-12. Compressive forces applied to the fetal spine during fundal pressure is the likely cause of the lower thoracic spinal cord injury manifest by this newborn.

The timing of congenital brachial plexus injury: a study of electromyography findings in the newborn piglet

OBJECTIVE

Permanent congenital brachial plexus palsy is a recognized serious complication associated with shoulder dystocia. The timing and etiology of this injury remains controversial. Previous authorities have used adult-derived, non-brachial plexus data to extrapolate the anticipated timing for electromyographic denervation changes to date such injuries in the newborn. With use of a domestic swine model, this investigation tests the hypothesis that electromyographic evidence of brachial plexus denervation in the newborn is temporally different than that in the adult.

STUDY DESIGN

Five healthy 2-day-old and two adult pigs underwent unilateral sharp transection of the brachial plexus. Daily electromyographic studies were performed in brachial plexus innervated muscle groups on the involved and contralateral (control) front limbs. Postmortem measurements of the transected nerve segments were obtained in one piglet and one adult animal. Representative hard copy recordings of individual electromyographic studies were collected.

RESULTS

Immediately after surgical transection of the brachial plexus, no electromyographic evidence of denervation was observed. Uniformly in the newborn piglets, at 24 hours after transection, denervation in the form of fibrillation potentials, positive sharp waves, and complex repetitive discharges was seen. Serial testing demonstrated proximal to distal gradients of denervation over the next 24 to 48 hours. A delay in electromyographic evidence of denervation was observed in the two adult pigs until days 5 and 8, respectively. Control limb studies remained normal throughout the study period. Nerve length measurements for individual muscle groups were as follows for the adult and newborn pigs, respectively: deltoid 11.4 cm, 2.5 cm; cleidobrachialis 16.0 cm, 4.0 cm; triceps 15.5 cm, 4.5 cm; forelimb flexors 26.0 cm, 6.5 cm; and extensor carpi radialis 31.0 cm, 9.0 cm.

CONCLUSION

Electromyographic evidence of brachial plexus denervation after surgical transection differs between the newborn and the adult pig. Consistent with wallerian degeneration, a correlation exists between length of the distal nerve segment and timing for electromyographic signs of denervation. These findings suggest it would be inappropriate to extrapolate the anticipated timing for electromyographic changes in the newborn on the basis of previously established adult non-brachial plexus data.

Evaluation of prostaglandin F2 alpha treatment in dairy cows at risk for low fertility after parturition

OBJECTIVE

To evaluate the effect of 2 postpartum prostaglandin F2 alpha (PGF 2 alpha) treatment protocols on reproductive performance of dairy cows at risk for low fertility. In addition, various medical conditions in cows that are recognized as having adverse effects on fertility were evaluated as criteria for fertility treatment.

DESIGN

Prospective study.

ANIMALS

291 cows with, and 271 cows without, risk factors for low fertility.

PROCEDURE

Cows at risk for low fertility were randomly assigned to 2 treatment groups. Group-1 cows received 3 i.m. injections of PGF2 alpha at weekly intervals after parturition, and group-2 cows received 1 i.m. injection of PGF2 alpha 17 to 24 days after parturition.

RESULTS

Compared with a single PGF2 alpha treatment 17 to 24 days after parturition, there was no added benefit of 3 treatments with PGF2 alpha 3 to 10, 10 to 17, and 17 to 24 days after parturition in cows at risk for low fertility. Cows without risk factors for low fertility had 20% higher pregnancy rates, compared with cows with risk factors for low fertility. Twinning had a negative effect on future fertility.

CLINICAL IMPLICATIONS

Results of this study indicate that further consideration should be given to the timing and intervals of PGF2 alpha administration after parturition. Risk factors for low fertility, such as retained placenta, twins, and assisted calvings, are valid criteria to evaluate different treatment options to improve fertility in dairy cows.

Spontaneous vaginal delivery: a risk factor for Erb's palsy?

OBJECTIVE

Our purpose was to determine whether Erb's palsies occurring in the absence of shoulder dystocia differ from those occurring after shoulder dystocia.

STUDY DESIGN

We compared the time course of resolution and incidence of persistent injury at 1 year of age in 17 cases of Erb's palsy without shoulder dystocia and 23 cases associated with shoulder dystocia.

RESULTS

The rate of persistence at 1 year was significantly higher in those Erb's cases without identified shoulder dystocia, 7 of 17 (41.2%) versus 2 of 23 (8.7%), p = 0.04. These cases of Erb's palsies also took longer to resolve (6.4 +/- 0.9 vs 2.6 +/- 0.7 months, p = 0.002), had a higher rate of associated clavicular fracture (12 of 17 vs 5 of 23, p = 0.006), and were more likely to occur in the posterior arm (10 of 15 vs 4 of 21, p = 0.009).

CONCLUSIONS

Erb's palsy occurring without shoulder dystocia may be a qualitatively different injury than that occurring with shoulder dystocia.

Evaluation of extradural xylazine injection for caesarean operation in ovine dystocia cases

Twenty-eight sheep suffering from dystocia, with complications including vaginal prolapse and emphysematous foetuses, were treated by caesarean operation. When tested by needle prick 30-40 min after injection, analgesia of the flank was present in 12 of 13 ewes and eight of nine ewes following either sacrococcygeal or lumbosacral extradural xylazine, respectively at a dose rate of 0.07 mg kg-1. Twelve of 13 ewes, which were ambulatory at the time of extradural injection, exhibited pelvic paresis in the interval before surgery. Vaginal prolapses associated with the dystocia in seven of 22 ewes which were replaced during surgery but not retained by suture, did not recur.

Brachial plexus palsy: an old problem revisited again. II. Cases in point

OBJECTIVES

In spite of mounting evidence to the contrary, plaintiffs' expert witnesses continue to maintain that brachial plexus impairment is almost always the result of excessive lateral traction on the head during the last phase of delivery. Case studies are presented to challenge this concept.

STUDY DESIGN

Examples encountered in medicolegal consultations were analyzed with this purpose as our focus.

RESULTS

Cases of brachial plexus impairment were encountered in which there was no evidence of shoulder dystocia or extreme lateral traction on the fetal head. In one in which shoulder dystocia was recorded, there was also incontrovertible evidence of intrauterine maladaptation. In another, the posterior shoulder was involved.

CONCLUSION

To propose that shoulder dystocia with extreme lateral traction on the fetal head after its delivery is not a factor in some cases of brachial plexus impairment would be insupportable. Conversely, to maintain a posteriori that brachial plexus impairment in itself is evidence that such pressure must have been used is untenable.

Laparoscopic diagnosis of ischemic necrosis of the descending colon after rectal prolapse and rupture of the mesocolon in two postpartum mares

Two mares were referred for evaluation after dystocia and rectal prolapse. Diagnostic laparoscopy, performed while the horses were standing, was used to evaluate the condition of the distal portion of the colon, rectum, uterus, and mesocolon. In both horses, laparoscopic observation revealed tears in the mesocolon of the descending colon. Exploration from the left or right flank was adequate. Because of the poor prognosis associated with the findings, euthanasia was elected at completion of laparoscopy. Tears in the mesocolon are not easily detected by use of traditional tests. Laparoscopy proved to be a more thorough means of evaluating the caudal portion of the abdomen including the digestive and urogenital tracts in these horses. As a less invasive diagnostic tool, laparoscopy can be performed earlier in the course of disease than alternative approaches for direct viewing. Furthermore, laparoscopy can be used to access the viability of tissues as well as the location and severity of lesions for prognostic purposes. The distal portion of the descending colon can also be evaluated to determine whether celiotomy with anastomosis or colostomy may be the surgical procedure of choice.