Kraayenbrink et al. July 1993 Am J Obstet Gynecol in the obstetrical encounter. Soc Sci Med 1983; 17: 139-46. 9. Cranston CS. The important first trimester: an educational approach. J Nurse Midwifery 1980;25:40-2. 10. Giblin P, Poland M, Sachs B. Pregnant adolescents health information needs. J Adolesc Health 1986;7:168-72. 15. Freda MC, Andersen HF, Damus K, Merkatz IR. What do pregnant women really want to know? A comparison of client and provider perceptions. J Obstet Gynecol Neona- tal Nurs 1993;22:237-44. 11. Bliss-Holtz VJ. Primiparas prenatal concern for learning infant care. Nurs Res 1988;37:20-4. 12. Copeland DZ. Unwed adolescent primigravidas identifY subject matter for prenatal classes. J Obstet Gynecol Neontal Nurs July 1979;248-53. 13. Slager-Earnest SE, Hoffman SJ, Beckman CJA. Effects of a specialized prenatal adolescent program on maternal and infant outcomes. J Obstet Gynecol Neonatal Nurs 1987; 16:422-9. 14. Smoke J, Grace MC. Effectiveness of prenatal care and education for pregnant adolescents. J Nurse Midwifery 1988;33: 178-84. 16. Levenson PM, Smith PB, Morrow JR. A comparison of physician-patient views of teen prenatal information needs. J Adolesc Health Care 1986;7:6-11. 17. The American College of Obstetricians and Gynecologists. The battered woman. Washington: The American College of Obstetricians and Gynecologists, 1989 Jan; technical bulletin no 124. 18. The American College of Obstetricians and Gynecologists. Human immunodeficiency virus infections. Washington: The American College of Obstetricians and Gynecologists, 1992 June; technical bulletin no 169. Endothelial vasoactive mediators in preeclampsia Atjan A. Kraayenbrink, MD; Gustaaf A. Dekker, MD, PhD; Gerard J. van Kamp, PhD,b and Herman P. van Geijn, MD, PhD" Amsterdam, The Netherlands OBJECTIVE: In recent years an increasing amount of evidence supports the concept that preeclampsia is an endothelial disease. The purpose of our study was to evaluate the extent to which endothelial cell dysfunction is involved in the pathophysiology of preeclampsia. STUDY DESIGN: We studied the urinary excretion of thromboxane 6 2 and 6-keto-prostaglandin Fin and the venous plasma endothelin levels in 23 preeclamptic patients and in control subjects. In six of these patients and in six controls arterial plasma endothelin levels were also measured. In addition, plasma levels of calcitonin gene-related peptide and plasma fibronectin levels were measured. Results were analyzed by Wilcoxon's rank-sum test or Signed-rank test. RESULTS: In preeclampsia the urinary thromboxane 6 2 /6-keto-prostaglandin Fin ratio (p < 0.001), venous plasma endothelin levels (p < 0.001), and plasma fibronectin levels (p < 0.001) were significantly elevated compared with normotensive pregnancy. Arterial plasma endothelin levels were significantly higher than venous plasma endothelin levels in normotensive and hypertensive patients (p < 0.05). Calcitonin gene-related peptide levels showed a wide range in normotensive pregnancy and in preeclampsia, but the difference was not significant. CONCLUSIONS: These results confirm the extensive involvement of the endothelium in the pathophysiology of preeclampsia. Preeclamptic vasoconstriction seems to be mediated by an increase in the vasoconstrictor autocoids thromboxane and endothelin. Production of prostacyclin by the vessel wall and endovascular trophoblast might be just a pivotal escape mechanism of the uteroplacental circulation. Calcitonin gene-related peptide appears not to be involved in the pathophysiology of preeclampsia. (AM J OSSTET GYNECOL 1993;169:160-5.) Key words: Preeclampsia, endothelin, calcitonin gene-related peptide, thromboxane A 2 /prostacyclin balance, endothelium, fibronectin From the Departments of Obstetrics and Gynecology" and Clinical Chemistry, b Free University Hospital. Supported by grants from Organon International. Presented at the Twelfth Annual Meeting of the Society of Perinatal Obstetricians, Orlando, Florida, February 3-8, 1992. Received for publication August 18, 1992; revised December 28, 1992; accepted December 31, 1992. 160 Reprint requests: Arjan A. Kraayenbrink, MD, Department of Ob- stetrics and Gynecology, Free University Hospital, room L355, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands. Copyright © 1993 by Mosby-Year Book, Inc. 0002-9378193 $1.00 + .20 6/1/45232