Letters
Volume 166 Number 3
there a missed enterocele? Had the vaginal vault been closed? Prevention is the key that we strive to achieve. This Clinical Opinion was not based solely on my experience. After supportive letters and an invitation to write this Clinical Opinion, I saw the need. Those wishing to learn this procedure should do so from experienced teachers; they should learn the anatomy and the pelvic floor defects in patients with these kinds of problems. I believe that every patient should be thoroughly evaluated for all defects. These should be corrected at the time of hysterectomy, not as a piecemeal procedure whereby the patient will have to undergo several operations. In conclusion, I say that the sacrospinous ligament fixation is a good adjunct procedure in patients who have multiple defects of the vaginal wall. I have described criteria for patients at risk for vaginal vault prolapse as a result of these defects. When learned appropriately, under the right supervision, sacrospinous fixation at the time of hysterectomy can be a perfect adjunct to the surgical armamentarium. Again, I thank Dr. Scotti for his comments. Stephen H. Cruikshank, MD Department of Obstetrics and Gynecology, Hennepin County Medical Center, 701 Park Ave., South, Minneapolis, MN 55415
1023
the umbilical cord level of linoleic acid was at the lower limit of normality. Nevertheless, bearing in mind the significance of linoleic acid as a precursor of more elongated n-6 fatty acids, which are necessary for brain development and prostanoid synthesis,2 we think linoleic acid should receive more attention in the study of the pathophysiologic features of preeclampsia. In accordance with this, the remarkable difference in total polyunsaturated fatty acids reported by Wang et al. depends fundamentally on the difference on linoleic acid. In summary, we think that, without underestimating n-3 fatty acids, the n-6 class should receive more attention. Finally, we would like to put a question to the authors, in the light of their relevant findings and ours: Do they think that reduced fatty acid levels are primarily of maternal origin, with some kind of active transfer to the fetus, or could it be that there is an increased fetal consumption in preeclamptic pregnancies? P. Sanjurjo, MD, PhD, L. Martin Vargas, MD, PhD, and J. Rodriguez-Alarcon, MD, PhD Department of Pediatrics, University of Pais Vasco, Hospital de Cruces, Baracaldo, Vizcaya, Spain
R. Matorras, MD, PhD, and C. Aranguren, MD
Department of Obstetrics and Gynecology, University of Pais Vasco, Hospital de Cruces, Baracaldo, Vizcaya, Spain
Reply Polyunsaturated fatty acids in preeclampsia
To the Editors: The interesting article of Wang et al. (Wang Y, Kay HH, Killam AP. Decreased levels of polyunsaturated fatty acids in preeclampsia. AM J OBSTET GYNECOL 1991;164:812-8) deals with the present problem of polyunsaturated fatty acids and hypertension, in relation to preeclampsia. This is an aspect that has hitherto received little attention. The authors found significantly lower levels of polyunsaturated acids and of linoleic and eicosapentaenoic acids and suggest that the reduced levels of the latter may playa significant pathophysiologic role in preeclampsia. In a study performed in Spain as early as 1979,' in 14 women with preeclampsia and their newborn infants and 14 control women and their newborn infants, we found significantly lower levels of linoleic acid among women with preeclampsia (29.4% vs 23.9%), as Wang et al. report. Unfortunately the laboratory techniques at that time did not permit determination of n-3 eicosapentaenoic and docosahexaenoic fatty acids. However their precursor, linolenic acid (reduced in the work of Wang et al.), showed no differences.' However, our work did present some facts about polyunsaturated fatty acids in newborn infants of preeclamptic mothers that may be worth reporting now. The aforementioned differences in linoleic acid among the mothers were found, but there were no differences in linoleic acid or in the other fatty acids analyzed among newborns from preeclamptic mothers and those from controls. There was only one newborn infant whose mother had a very low level of linoleic acid and
To the Editors: Sanjurjo et al. pose an interesting question. It is not known whether the decreased levels of fatty acids we found in the preeclamptic patients in our study are due to maternal factors (i.e., decreased intake, decreased mobilization from body stores, or increased metabolism) or to increased fetal consumption. Since preeclampsia is a pregnancy-related disease, a fetal factor certainly may be important. Essential fatty acids, which include linoleic and linolenic acids, are important for fetal growth and development because they are incorporated into phospholipids that are necessary for cell membrane synthesis. They are known to be transported across the placenta in increasing amounts with advancing gestation. Cord blood levels of linoleic acid are reported to be lower than maternal levels. The relatively lower level of linoleic acid in fetal blood facilitates maternal-fetal transport across the placenta.' The reason for a possible increase in the transport across the placenta or for an increase in fetal requirements for these polyunsaturated fatty acids in preeclampsia is not known and would require further investigation. There is, in fact, another possible drain on these maternal fatty acids and that would be the placenta, which is known to synthesize and metabolize large amounts of eicosanoids. It has been shown that placental production of thromboxane is actually increased in preeclampsia. 2 Since linoleic acid is a precursor of thromboxane, it would be possible to explain the decreased maternal plasma levels of linoleic acid by the enhanced synthesis of this vasoconstrictor in the pla-
Volume 166 Number 3
there a missed enterocele? Had the vaginal vault been closed? Prevention is the key that we strive to achieve. This Clinical Opinion was not based solely on my experience. After supportive letters and an invitation to write this Clinical Opinion, I saw the need. Those wishing to learn this procedure should do so from experienced teachers; they should learn the anatomy and the pelvic floor defects in patients with these kinds of problems. I believe that every patient should be thoroughly evaluated for all defects. These should be corrected at the time of hysterectomy, not as a piecemeal procedure whereby the patient will have to undergo several operations. In conclusion, I say that the sacrospinous ligament fixation is a good adjunct procedure in patients who have multiple defects of the vaginal wall. I have described criteria for patients at risk for vaginal vault prolapse as a result of these defects. When learned appropriately, under the right supervision, sacrospinous fixation at the time of hysterectomy can be a perfect adjunct to the surgical armamentarium. Again, I thank Dr. Scotti for his comments. Stephen H. Cruikshank, MD Department of Obstetrics and Gynecology, Hennepin County Medical Center, 701 Park Ave., South, Minneapolis, MN 55415
1023
the umbilical cord level of linoleic acid was at the lower limit of normality. Nevertheless, bearing in mind the significance of linoleic acid as a precursor of more elongated n-6 fatty acids, which are necessary for brain development and prostanoid synthesis,2 we think linoleic acid should receive more attention in the study of the pathophysiologic features of preeclampsia. In accordance with this, the remarkable difference in total polyunsaturated fatty acids reported by Wang et al. depends fundamentally on the difference on linoleic acid. In summary, we think that, without underestimating n-3 fatty acids, the n-6 class should receive more attention. Finally, we would like to put a question to the authors, in the light of their relevant findings and ours: Do they think that reduced fatty acid levels are primarily of maternal origin, with some kind of active transfer to the fetus, or could it be that there is an increased fetal consumption in preeclamptic pregnancies? P. Sanjurjo, MD, PhD, L. Martin Vargas, MD, PhD, and J. Rodriguez-Alarcon, MD, PhD Department of Pediatrics, University of Pais Vasco, Hospital de Cruces, Baracaldo, Vizcaya, Spain
R. Matorras, MD, PhD, and C. Aranguren, MD
Department of Obstetrics and Gynecology, University of Pais Vasco, Hospital de Cruces, Baracaldo, Vizcaya, Spain
Reply Polyunsaturated fatty acids in preeclampsia
To the Editors: The interesting article of Wang et al. (Wang Y, Kay HH, Killam AP. Decreased levels of polyunsaturated fatty acids in preeclampsia. AM J OBSTET GYNECOL 1991;164:812-8) deals with the present problem of polyunsaturated fatty acids and hypertension, in relation to preeclampsia. This is an aspect that has hitherto received little attention. The authors found significantly lower levels of polyunsaturated acids and of linoleic and eicosapentaenoic acids and suggest that the reduced levels of the latter may playa significant pathophysiologic role in preeclampsia. In a study performed in Spain as early as 1979,' in 14 women with preeclampsia and their newborn infants and 14 control women and their newborn infants, we found significantly lower levels of linoleic acid among women with preeclampsia (29.4% vs 23.9%), as Wang et al. report. Unfortunately the laboratory techniques at that time did not permit determination of n-3 eicosapentaenoic and docosahexaenoic fatty acids. However their precursor, linolenic acid (reduced in the work of Wang et al.), showed no differences.' However, our work did present some facts about polyunsaturated fatty acids in newborn infants of preeclamptic mothers that may be worth reporting now. The aforementioned differences in linoleic acid among the mothers were found, but there were no differences in linoleic acid or in the other fatty acids analyzed among newborns from preeclamptic mothers and those from controls. There was only one newborn infant whose mother had a very low level of linoleic acid and
To the Editors: Sanjurjo et al. pose an interesting question. It is not known whether the decreased levels of fatty acids we found in the preeclamptic patients in our study are due to maternal factors (i.e., decreased intake, decreased mobilization from body stores, or increased metabolism) or to increased fetal consumption. Since preeclampsia is a pregnancy-related disease, a fetal factor certainly may be important. Essential fatty acids, which include linoleic and linolenic acids, are important for fetal growth and development because they are incorporated into phospholipids that are necessary for cell membrane synthesis. They are known to be transported across the placenta in increasing amounts with advancing gestation. Cord blood levels of linoleic acid are reported to be lower than maternal levels. The relatively lower level of linoleic acid in fetal blood facilitates maternal-fetal transport across the placenta.' The reason for a possible increase in the transport across the placenta or for an increase in fetal requirements for these polyunsaturated fatty acids in preeclampsia is not known and would require further investigation. There is, in fact, another possible drain on these maternal fatty acids and that would be the placenta, which is known to synthesize and metabolize large amounts of eicosanoids. It has been shown that placental production of thromboxane is actually increased in preeclampsia. 2 Since linoleic acid is a precursor of thromboxane, it would be possible to explain the decreased maternal plasma levels of linoleic acid by the enhanced synthesis of this vasoconstrictor in the pla-
