Volume 159 Number 3

tion data, perhaps even more so. We invite Dr. Katz to continue to study the subject, ideally through prospec­tive random trials.

The Ohio State University Fifth Floor, Means Hall 1654 Upham Drive Columbus, OH 43210

REFERENCES

jay D. lams, MD Francee F.] ohnson, RN

Richard O'Shaughnessy, MD

1. Katz M, Gill PJ, Newman RB. Detection of preterm labor by ambulatory monitoring of uterine activity: a preliminary report. Obstet Gynecol 1986;68:773.

2. MorrisonJC, MartinJN Jr, Martin RW, Gookin KS, Wiser WL. Prevention of preterm birth by ambulatory assessment of uterine activity: a randomized study. AM J 0BSTET GY­NECOL 1987;156:536.

3. lams JD, Johnson FF, O'Shaughnessy RW. A prospective random trial of home uterine activity monitoring in preg­nancies at increased risk of preterm labor. Part II. AM J 0BSTET GYNECOL 1988; 159:595-603.

Neonatal seizures after cesarean delivery: Higher risk with labor

To the Editors: We read with great interest the article by Spellacy

et al., entitled "Neonatal seizures after cesarean deliv­ery: Higher risk with labor" (AM 1 OBSTET GYNECOL 1987; 157:377-9). However, we would like to draw their attention to the following points.

1. The authors suggested that brain function as in­dexed by neonatal seizures can be adversely affected during labor. Their study was designed to determine if there was significant difference between the inci­dence of neonatal seizures in infants delivered by elec­tive cesarean section (without labor) and infants deliv­ered by primary cesarean section (with labor). The au­thors did not elaborate on the course and events of labor, i.e., indication for cesarean section in those pre­ceded by labor, fetal heart rate pattern, acid-base status, or Apgar scores. Seizure disorder in this group of in­fants could simply have been caused by fetal acidosis or asphyxia. Therefore, in the absence of acid-base analysis and careful observation of intrapartum events, it is very difficult to suggest that "labor" is a risk factor for development of neonatal seizure and presumably central nervous system damage. It is reasonable to sug­gest that "abnormal labor" could be a risk factor for seizure disorders. In the authors' study of the total8783 infants delivered by primary cesarean section, only 116 were diagnosed as having seizure disorder. In regard to seizure or brain damage in an infant, distinction between normal and abnormal labor is crucial.

2. The authors' data indicated that the incidence of seizure disorder was similar between primary and re­peat cesarean section for infants whose birth weight

Correspondence 789

was <2500 gm. Considering prematurity as a risk factor1 and their suggestion that labor is also a risk factor, infants <2500 gm should have had a higher frequency of seizure after primary cesarean section. The authors' data do not support this concept.

Hamid A. Hadi, MD julius Q. Mallette, MD

Department of Obstetrics and Gynecology East Carolina University School of Medicine Greenville, NC 27858-4354

REFERENCE l. Spellacy WN, MillerS. Neonatal seizures: an obstetrician's

concern. J Perinat 1986;6:157-60.

Reply To the Editors:

I would like to thank Drs. Hadi and Mallette for their interest in our article, but I believe they missed the point. I hope to clarify it now.

The theory behind the study was that infant brain damage, as demonstrated by neonatal seizures, occurs in two groups of neonates and probably for different reasons. It is most frequent in the premature (birth weight <2500 gm) and seems to reflect intracranial bleeding resulting from the immaturity of the blood vessels. Thus labor has little effect on the frequency of the problem in the small infant and this is supported by our data. For term infants there are many causes of brain damage, but one is insults occurring during labor. Our data demonstrate, as Drs. Hadi and Mallette point out, that something occurs during the labor process to increase the frequency of seizures in this group. While we believe it is related to fetal hypoxia, this cannot be proved with the study. However, it does suggest an error in the concept that most brain damage in term infants occurs before labor begins and again focuses obstetric evaluation and intervention on the intrapar­tum time period.

We thank the authors for their letter. William N. Spellacy, MD

Department of Obstetrics and Gynecology The University of Illinois College of Medicine 840 South Wood Street Chicago, IL 60612

Preterm cervical examination To the Editors:

We appreciate the delineation and analysis by Drs. Main and Gabbe of three possibilities for reducing the incidence of preterm birth (Risk scoring for preterm labor: Where do we go from here? AM 1 0BSTET Gv­NECOL 1987;157:789-93). Our own data have also sug­gested that preterm cervical examination can help iden­tify risk for preterm labor, but we suggest an important

790 Correspondence

caveat regarding the internal os.' Numerous studies suggest that subclinical infection may play a role in preterm labor and rupture of the membranes, and it seems plausible to us that an examining finger could carry agents up through the mucous plug to the mem­branes and decidua. Dr. Papiernik's program requires repeatedly testing the internal os for admission of a fingertip! and Dr. Leveno's patients were examined as high as the "level of the membranes if palpable."3 We also assessed the internal os, but the low positive pre­dictive value (many false-positive results) in our data may not be enough to justify possible inoculation of the decidua and membranes in patients who should usually go on to term. Because of (1) the potential risk of sub­clinical infection relative to the predictive value of the test, (2) our opinion that useful information can be obtained without penetrating the upper endocervical canal, and (3) the danger of unrecognized placenta previa, we are no longer evaluating the internal os.

In addition to identifying patients at increased risk for preterm labor, preterm cervical assessment has the advantages of being quick, inexpensive, and applicable to all pregnant patients.

Thomas M. Stubbs, MD Section of Maternal-Fetal Medicine Department of Obstetrics and Gynecology Medical University of South Carolina 171 Ashley A venue Charleston, SC 29425

]. Peter Van Dorsten, MD Section of Maternal-Fetal Medicine Department of Obstetrics and Gynecology Medical College of Virginia 1200 East Broad Street Richmond, VA 23 219

REFERENCES I. Stubbs TM, Van Dorsten JP, Miller CM. The pre term cervix

and preterm labor: relative risks, predictive values, and change over time. AM J 0BSTET GYNECOL 1986;155:829-34.

2. Bouyer J, Papiernik E, Dreyfus J, eta!. Maturation signs of the cervix and prediction of preterm birth. Obstet Gy­necol 1986;68:209-14.

3. Leveno KJ, Cox K, Roark ML. Cervical dilatation and pre­maturity revisited. Obstet Gynecol 1986;68:434-5.

Biophysical profile after premature rupture of membranes

To the Editors: In the article "The use of fetal biophysical profile

improves pregnancy outcome in premature rupture of the membranes" (AMj 0BSTET GYNECOL 1987;157: 236-40), Dr. Vintzileos and co-workers suggest that the fetal biophysical profile should be part of the manage­ment of patients with premature rupture of the mem­branes because they feel that they were able to reduce the neonatal infection rate by using this evaluation tool. I am still a bit confused about how these patients should

September 1988 Am J Obstet Gvnecol

best be managed because it would seem that any test that resulted in earlier delivery of patients with pre­mature rupture of the membranes would reduce the infection rate because of the relationship between in­fection and latency. Data from the authors concerning the latency period in the study group, the control group, and amniocentesis group would be most helpful in understanding the significance of their data. Addi­tionally, since they were unable to demonstrate a dif­ference in the neonatal mortality rate, information con­cerning the neonatal length of stay by gestational age might be helpful in determining if their protocol ac­tually made a clinical difference. Finally, it is possible, on the basis of their methods, that some patients not actually in labor, only suspected to be in labor, could have undergone a vaginal examination. If this did oc­cur, was there a difference in the number of vaginal examinations performed in the three groups?

It continues to be my prejudice that a randomized prospective trial of the fetal biophysical profile will be necessary before it can be universally adopted in the management of patients with premature rupture of the membranes.

David A. Nagey, MD, PhD Division of Maternal-Fetal Medicine Department of Obstetrics and Gynecology The University of Maryland School of Medicine 22 South Greene Street Baltimore, MD 21201

Reply

To the Editors We thank Dr. Nagey for his interest in our work.

Regarding the comment about the latency period in the study group, control group, and amniocentesis group, we have to point out that there were no differences in the latency periods between the three groups. The mean latency was 8.5, 7.6, and 8.1 days, respectively, for the control, study, and amniocentesis groups. The latency period was ;:.7 days in 18 (24.6%) patients of the control group, 15 (20.5%) of the study group, and 16 (21.9%) of the amniocentesis group. Latency periods ;:.2 days were observed in 50 (68.4%) patients of the control group, 44 (60.2%) of the study group, and 46 (63%) of the amniocentesis group. Eight patients de­veloped infection in our study group, and seven of them were delivered because of low biophysical scores (~7). Our findings imply that our method selects only a small group of patients (approximately 25% of pa­tients with premature rupture of the membranes) who already have subclinical infection and therefore are destined to develop clinical infection if not delivered. Therefore our management will possibly shorten the latency period of only 25% of the patients, and this may be the reason for the inability to show statistical dif­ference in the overall latency periods between the three groups. Information concerning the neonatal length of stay will be meaningless because in our institution the