Shoulder dystocia related fetal neurological injuries: the predisposing roles of forceps and ventouse extractions.

On the basis of 333 documented cases of permanent perinatal neurological damage, associated with arrest of the shoulders at birth, the authors conducted a retrospective study in order to evaluate the predisposing role, if any, of the utilization of extraction instruments. The investigation revealed that 35% of all injuries occurred in neonates delivered by forceps, ventouse or sequential ventouse-forceps procedures. This frequency was several-fold higher than the prevailing instrument use in the practices of American obstetricians during the same years. A high rate of forceps and ventouse extractions was demonstrable in all birth weight categories. Average weight and moderately large for gestational age fetuses underwent instrumental extractions more often than grossly macrosomic ones. This circumstance indicates that forceps and ventouse are independent risk factors, unrelated to fetal size. Their use entailed central nervous system injuries significantly more often than did spontaneous deliveries. The findings suggest that extraction procedures may be as important as macrosomia among the factors that lead to neurological damage in the child in connection with shoulder dystocia. Because they augment the intrinsic dangers of excessive fetal size exponentially, the authors consider their use in case of > or =4,000 g estimated fetal weight inadvisable. Sequential forceps-ventouse utilization further doubles the risks and is, therefore, to be avoided in all circumstances.

Incidents of catastrophic overhydration (maternal and neonatal) identified through medico-legal reviews.

The authors describe two incidents where a mother postpartum and a neonate in the nursery were grossly overhydrated in tertiary care medical centers. In the first case, while receiving intensive care for HELLP (hemolysis, elevated liver enzymes and low platelets) syndrome, involving the participation of eight specialists and subspecialists, the weight of the mother increased by 54% between the 2nd and 8th postpartum days. In the second case, between the time of his birth and his demise 13 days later, the weight of the newborn child increased by 67%. In neither of these cases, was the significance of grossly excessive hydration recognized as a problem either during the management or in retrospect. Only the subsequent medico-legal reviews drew attention to the fact that, in both instances, the participating consultants had ordered the infusion of large quantities of fluids independently of one another without making an attempt to coordinate their activities. The resident and nursing personnel uncritically implemented all of their instructions.

The risk of shoulder dystocia related permanent fetal injury in relation to birth weight.

OBJECTIVE: To examine birth weight related risks of fetal injury in connection with shoulder dystocia. STUDY DESIGN: The investigation was based on a retrospective analysis of 316 fetal neurological injuries associated with deliveries complicated by arrest of the shoulders that occurred across the United States. RESULTS: The study revealed that the distribution of birthweights for the high risk shoulder dystocia population differs from the standard birthweight distribution. The relative difference per birthweight interval is used to adjust an assumed 1:1000 baseline risk of injury due to shoulder dystocia following vaginal deliveries. These adjusted risks show a need to consider new thresholds for elective cesarean delivery. CONCLUSIONS: Current North American and British guidelines, that set 5000 g as minimum estimated fetal weight limit for elective cesarean section in non-diabetic and 4500 g for diabetic gravidas, may expose some macrosomic fetuses to a high risk of permanent neurological damage. The authors present the opinion that the mother, having been informed of the risks of vaginal versus abdominal delivery, should be allowed to play an active role in the critical management decisions.