Correspondence

Effect of Mode of Delivery on Neonatal Intracranial Injury

N Engl J Med 2000; 342:892-893March 23, 2000

Article

To the Editor:

Towner et al. (Dec. 2 issue)1 report that vacuum extraction, use of forceps, and cesarean section during labor are all associated with an increased rate of subdural or cerebral hemorrhage in neonates. They suggest that an abnormality of labor may be the underlying precipitating cause of the hemorrhage.

We suggest an alternative explanation: some of the neonates may have had a bleeding disorder. The incidence of hemophilia has recently been shown to be 1 per 5000 live births of male infants.2 On the basis of the size of the population in the study by Towner et al. (583,340 infants), assuming one half of the infants were boys, we would expect approximately 58 male infants with hemophilia. It has been shown that approximately one half of neonates with hemophilia who have had a hemorrhage of the central nervous system were delivered by vacuum extraction or with the use of forceps.3 Because of the increased propensity for intracranial hemorrhage with any type of delivery in neonates with hemophilia, Buchanan has suggested that a prophylactic dose of recombinant factor concentrate be administered empirically to all neonates at risk for severe hemophilia on the basis of family history or excessive bleeding.4

The Medical and Scientific Advisory Committee of the National Hemophilia Foundation has recommended that all newborns with unexplained subgaleal or intracranial hemorrhage be evaluated for a bleeding disorder.5 In addition to hemophilia, such an evaluation would include tests for von Willebrand's disease and other, less common coagulation protein deficiencies. Although the mode of delivery may be associated with the frequency of neonatal intracranial hemorrhage, as proposed by Towner et al., we should not forget that a hemostatic evaluation of neonates with central nervous system hemorrhage is warranted. Were the neonates who had an intracranial hemorrhage in the study by Towner et al. evaluated for these disorders?

Rachelle Nuss, M.D.
William E. Hathaway, M.D.
Mountain States Regional Hemophilia and Thrombosis Center, Aurora, CO 80045-0507

5 References

1
Towner D, Castro MA, Eby-Wilkens E, Gilbert WM. Effect of mode of delivery in nulliparous women on neonatal intracranial injury. N Engl J Med 1999;341:1709-1714
Full Text | Web of Science | Medline

2
Soucie JM, Evatt B, Jackson D. The occurrence of hemophilia in the United States. Am J Hematol 1998;59:288-294
CrossRef | Web of Science | Medline

3
Kulkarni R, Lusher JM. Intracranial and extracranial hemorrhages in newborns with hemophilia: a review of the literature. J Pediatr Hematol Oncol 1999;21:289-295
CrossRef | Web of Science | Medline

4
Buchanan G. Factor concentrate prophylaxis for neonates with hemophilia. J Pediatr Hematol Oncol 1999;21:254-256
CrossRef | Web of Science | Medline

5
Medical and Scientific Advisory Council Recommendations: #311. Neonatal intracranial hemorrhage and post-partum hemorrhage. New York: National Hemophilia Foundation, 1998:1-2.

To the Editor:

The report by Towner et al. should be read by all obstetricians who use vacuum extraction. If they are not persuaded to review the practice of vacuum extraction in the face of the evidence of harm to the infants, as presented by Towner et al., I doubt that any form of persuasion will ever be effective. The implications for clinical practice are clear. First, if difficulty arises during vacuum extraction, the procedure should be stopped immediately in favor of cesarean section. Forceps should not be applied to try to achieve vaginal delivery. Second, the likelihood of failure of delivery by both vacuum extraction and forceps should be reduced to the minimal level through structured training and use of correct techniques.

Of some concern, however, is the authors' comment that the rate of intracranial hemorrhage decreased after the introduction of plastic cups in vacuum extraction. There have been increasing numbers of case reports of serious injury associated with vacuum extraction with plastic cups,1 and it was these reports that prompted the issuance of a public health advisory by the Food and Drug Administration (FDA).2 It is time to dispel the attitude that the cause of serious neonatal injury associated with vacuum delivery arises from the material of the cup.

The authors point out that a major limitation of the study was the fact that risk factors for neonatal injury could not be identified because the required information was not available in the data base. This limitation applied also to the most important of all factors that influence the outcome of delivery by vacuum extraction — namely, the experience and skill of the attending practitioner. Vacuum extraction may well be associated with an “irreducible component of morbidity among infants,” but there is still a long way to go before a level that low is achieved.

Aldo Vacca, M.B., B.S.
Redcliffe and Caboolture Hospitals, Caboolture, Queensland 4510, Australia

2 References

1
Fortune PM, Thomas RM. Sub-aponeurotic haemorrhage: a rare but life-threatening neonatal complication associated with ventouse delivery. Br J Obstet Gynaecol 1999;106:868-870
CrossRef | Medline

2
Office of Surveillance and Biometrics. FDA Public Health Advisory: need for CAUTION when using vacuum assisted delivery devices. Rockville, Md.: Food and Drug Administration, May 21, 1998.

Author/Editor Response

Dr. Towner replies:

To the Editor: Another explanation for intracranial hemorrhage in some of the neonates in our study could indeed be the presence of an inherited bleeding disorder. Our study was based on discharge diagnoses reported to the state of California, and there is no way to determine whether any of the infants with intracranial hemorrhage were evaluated for a bleeding disorder. Still, delivery by cesarean section during labor did not change the risk of intracranial hemorrhage. I routinely advise the avoidance of operative vaginal deliveries (especially by vacuum extraction) for fetuses at risk for inherited bleeding disorders or those whose mothers have immune thrombocytopenia, because of the potential for hemorrhage, especially subgaleal hemorrhage.

I agree that all obstetricians should have adequate training in the use of instruments to aid vaginal delivery. Nonetheless, the findings of our study are reassuring in that the incidence of intracranial hemorrhage was not exceedingly high when instruments were used by the average practitioner.

Regarding the role of the type of vacuum cup, the incidence of intracranial hemorrhage with vacuum extraction has decreased from 1 in 286 with the Malmstrom cup, reported in 1979,1 to 1 in 860 with predominantly plastic cups, as reported in our study. Since obstetrical practice has changed in the past 20 to 25 years, the type of vacuum cup may not be an important factor at all. Obstetricians should not be fooled into thinking that the plastic cups are gentler on the fetus and thus not capable of causing injury. The FDA advisory aroused concern about a potential increase in neonatal injuries in association with vacuum extraction. However, in the cases voluntarily reported to the FDA, the plastic vacuum cups were considered to be medical devices. There may have been increased awareness of the reporting of device-related injuries recently, which may explain this apparent increase in neonatal injuries.

Dena Towner, M.D.
University of California Davis Medical Center, Sacramento, CA 95817

1 References