Volume 161 Number 4

mation is enhanced. As can be seen from their article, a full bladder may obscure the diagnosis. The point is that it is better to begin the imaging process with an empty bladder, then enhance it by rapidly filling the bladder, and if necessary re-examine the patient with an empty bladder after examination with a Lasix-filled bladder.

It is also important to note that with vaginal ultra­sonography there should be less of a need for bladder filling in gynecologic ultrasonography.

John D. Stephens, MD Medical Director California Prenatal Diagnosis Institute 1390 S. Winchester Blvd. San Jose, CA 95128

Delivery of fetuses with gastroschisis To the Editors:

Dr. Lenke's emotional response contained in the let­ter entitled "Congenital defects of abdominal wall" (AM J OBSTET GVNECOL 1988; 158: 1015) highlights the con­troversy concerning the delivery route of fetuses with gastroschisis. His call for a randomized trial is not new. In fact, an international trial is underway and open to all concerned physicians. The principal investigators are Dr. Kevin Pringle of Wellington, New Zealand, and Dr. Sidney Bottoms of Wayne State, Detroit. Fetuses with gastroschisis are randomized to either elective ab­dominal delivery or a trial of vaginal delivery. There are three randomization centers worldwide. In the United States, the randomization center is at the Uni­versity of Iowa. The phone number is (319) 356-2305. In Europe, the randomization center is at King's Col­lege, London, and administered by Dr. K. Nicolaides. In Australasia and the Far East, the randomization cen­ter is in Wellington, New Zealand, and administered by Dr. Pringle. I encourage physicians interested in participating to contact the appropriate center for a copy of the protocol.

Carl P. Weiner, MD Department of Obstetrics and Gynecology The University of Iowa Iowa Ctty. IA 52242

Pulmonary artery catheterization in severe eclampsia

To the Editors: I congratulate Drs. Clark and Cotton on a well­

written and timely article (Clinical indications for pul­monary artery catheterization in the patient with severe preeclampsia. AM J OBSTET GVNECOL 1988; 158:453-8) describing the usefulness of pulmonary artery cathe­terization in the patient with severe preeclampsia. As an anesthesiologist, I was particularly pleased to find recommendations occurring in the obstetric literature for the use of epidural anesthesia in these patients.

Correspondence 1089

However, I have one recommendation to add. Al­though I agree that regional anesthesia is the preferred anesthetic, general anesthesia is sometimes required. For example, most anesthesiologists avoid epidural an­esthesia in patients with marked thrombocytopenia to preclude the possibility of epidural hematoma should epidural vein puncture occur during the process of inserting the epidural needle. Also, regional anesthesia will fail in a small number of patients. In these patients general anesthesia will be necessary. Finally, some pa­tients cannot or will not tolerate being awake for a major operation such as cesarean section. In these pa­tients, many investigators feel that general anesthesia is the wiser choice. Thus general anesthesia will be nec­essary in a certain number of patients with severe pre­eclampsia. When it is indicated, many anesthesiologists will use potent intravenous cardiovascular agents to control the marked hypertension and tachycardia as­sociated with intubation and extubation. In these in­stances, radial artery cannulation and pulmonary artery catheterization provide the anesthesiologist with the type of precise information necessary to handle these very sick patients. Thus pulmonary artery catheteriza­tion can also be useful in the management ofthe patient undergoing general anesthesia.

Charles P. Gibbs, MD Department of Anesthesiology University of Colorado Health Science Center 4200 E. Ninth Ave. Denver, CO 80262

Which is better, being small or thin? To the Edttors:

The relationship between birth weight, nutritional status of the fetus, and perinatal outcome has been analyzed in some articles. I. 2 A few researchers have tried to determine neurologic and intellectual sequelae of small-for-date infants." 4

R. M . Patterson and M. R. Pouliot (Neonatal mor­phometrics and perinatal outcome: Who is growth re­tarded? AM J OBSTET GVNECOL 1987;157:691-3) showed us a new approach to intrauterine growth re­tardation. They emphasized that nutritional status helps to identify neonates at increased risk for perinatal morbidity and that the prediction of a thin neonate is more meaningful than the prediction of birth weight.

The authors used three different methods to de­scribe the nutritional status of the neonate. Separately all of them have about the same power to predict poor perinatal outcome (25% of patients with low birth weight, 23% of neonates with low ponderal index, and 36% of infants with low midarm circumference/head circumference ratio, were morbid). So if we join any two of the three classification methods we will recognize more infants with poor perinatal outcome. Patterson and Pouliot chose two measures of symmetry, ponderal index and midarm circumference/head circumference