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Beta blockers in pregnancy-induced hypertension
Volume Number
143 2
Correspondence
methods, and the difference between groups are nonsignificant at the p > 0.05 level. Additionally, we have used the figures derived from Rubin and Ray’s method of calculation and subjected them to inferential statistical methods, and the results are still nonsignificant at the p > 0.05 level. One formula used was:
5T- ST, ‘=gq Drs. Rubin and Ray have reacted to our question relative to the value of ultrasound in preventing the complications of midtrimester amniocentesis. It is our opinion that the true value of any technique lies in the proper use of that technique. The proper use of a technique obviously requires our knowledge of its benefits as well as its limitations. The authors do not question the value of ultrasound in evaluating midtrimester pregnancies. Instead, we express the belief that its value is great and continually growing. We do question its value in preventing complications of midtrimester amniocentesis, and our study supports our position. George Department of Obstetrics and Gynecology Howard University College of Medicine 2041 Georgia Aue., N. W. Washington, D. C. 20060
H.
Nolan,
M.D.
Beta blockers in pregnancy-induced hypertension To the Editors:
On the basis of the review article “Current concepts: Beta-blockers in pregnancy.” by Rubin (New England Journal of Medicine 305: 123, 1981). our colleagues in internal medicine are urging that we obstetricians use beta blockers for the treatment of pregnancy-induced hypertension. In 1978 and 1979, at the University of California, Davis Medical Center in Sacramento, nine women with apparent pregnancy-induced hypertension were treated with propranolol. Consistent with our they had apparent hyperdynamic myohypothesis,’ cardial function as indicated by the arterial wave veloc-
237
ity (AWV) values. This latter is an easily determined indirect measure of cardiac performance, and AWV is often considerably elevated in women with pregnancyinduced hypertension (PIH). (By contrast, those pregnant women with essential hypertension have relatively normal AWV values.) Of the nine women, normal blood pressure and AWV values were achieved in all, but one newborn infant had severe respiratory distress, and three patients experienced delivery prematurely. Our concept is that most pregnant women with complications are relatively hypovolemic.’ Those in whom cardiac output fails to increase as a compensatory mechanism experience premature delivery, whereas those in whom cardiac output increases maintain their pregnancies but are at risk of developing induced hypertension. Although it may not be of great clinical importance, our past experience would suggest that women with pure PIH who are treated with a beta blocker have their cardiac performance reduced and are at risk of premature labor.” For various medical indications (thyroid disease, idiopathic hypertrophic subaortic stenosis, and essential hypertension), we have managed 19 women who received propranolol throughout their pregnancies. Except for an occasional fetal bradycardia during labor, there was no apparent fetal ill effects other than those expected for their primary disease. The purpose of this letter is just simply to suggest that the use of beta blockers in patients with PIH may have effects different from those in patients with essential hypertension, about which there are considerable clinical experience and literature. Robert Department of Obstetrics and Gynecoloa University of Nebraska Medical Ceute~ 42nd and Dewey Aue. Omaha, Nebraska 68105
C. Good&,
M.D.
REFERENCES
1. Goodlin,
R. C., Quaife, M. A., and Dirksen, W. J.: The significance and the diagnosis of maternal hypovolemia, Semin. Perinatol. 5:228, 1981. 2. Lechner, W., Knapp, E., Hammerle, P., et al.: Bestimmung des Herzminutenvolumens durch Impedanzkardiographie, Arch. Gynecol. 225:339, 1978.
Erratum by Morelock and associates, in the In the article, “Bendectin and fetal development,” January 15, 1982, issue of the JOURNAL, on page 212, second paragraph, line 14, the sentence should read, “Because infant growth parameters are highly influenced by gestational age and the relationship between gestational age and infant size is curvilinear, a log transformation of gestational age as an independent variable was entered into the infant growth regressions.”
143 2
Correspondence
methods, and the difference between groups are nonsignificant at the p > 0.05 level. Additionally, we have used the figures derived from Rubin and Ray’s method of calculation and subjected them to inferential statistical methods, and the results are still nonsignificant at the p > 0.05 level. One formula used was:
5T- ST, ‘=gq Drs. Rubin and Ray have reacted to our question relative to the value of ultrasound in preventing the complications of midtrimester amniocentesis. It is our opinion that the true value of any technique lies in the proper use of that technique. The proper use of a technique obviously requires our knowledge of its benefits as well as its limitations. The authors do not question the value of ultrasound in evaluating midtrimester pregnancies. Instead, we express the belief that its value is great and continually growing. We do question its value in preventing complications of midtrimester amniocentesis, and our study supports our position. George Department of Obstetrics and Gynecology Howard University College of Medicine 2041 Georgia Aue., N. W. Washington, D. C. 20060
H.
Nolan,
M.D.
Beta blockers in pregnancy-induced hypertension To the Editors:
On the basis of the review article “Current concepts: Beta-blockers in pregnancy.” by Rubin (New England Journal of Medicine 305: 123, 1981). our colleagues in internal medicine are urging that we obstetricians use beta blockers for the treatment of pregnancy-induced hypertension. In 1978 and 1979, at the University of California, Davis Medical Center in Sacramento, nine women with apparent pregnancy-induced hypertension were treated with propranolol. Consistent with our they had apparent hyperdynamic myohypothesis,’ cardial function as indicated by the arterial wave veloc-
237
ity (AWV) values. This latter is an easily determined indirect measure of cardiac performance, and AWV is often considerably elevated in women with pregnancyinduced hypertension (PIH). (By contrast, those pregnant women with essential hypertension have relatively normal AWV values.) Of the nine women, normal blood pressure and AWV values were achieved in all, but one newborn infant had severe respiratory distress, and three patients experienced delivery prematurely. Our concept is that most pregnant women with complications are relatively hypovolemic.’ Those in whom cardiac output fails to increase as a compensatory mechanism experience premature delivery, whereas those in whom cardiac output increases maintain their pregnancies but are at risk of developing induced hypertension. Although it may not be of great clinical importance, our past experience would suggest that women with pure PIH who are treated with a beta blocker have their cardiac performance reduced and are at risk of premature labor.” For various medical indications (thyroid disease, idiopathic hypertrophic subaortic stenosis, and essential hypertension), we have managed 19 women who received propranolol throughout their pregnancies. Except for an occasional fetal bradycardia during labor, there was no apparent fetal ill effects other than those expected for their primary disease. The purpose of this letter is just simply to suggest that the use of beta blockers in patients with PIH may have effects different from those in patients with essential hypertension, about which there are considerable clinical experience and literature. Robert Department of Obstetrics and Gynecoloa University of Nebraska Medical Ceute~ 42nd and Dewey Aue. Omaha, Nebraska 68105
C. Good&,
M.D.
REFERENCES
1. Goodlin,
R. C., Quaife, M. A., and Dirksen, W. J.: The significance and the diagnosis of maternal hypovolemia, Semin. Perinatol. 5:228, 1981. 2. Lechner, W., Knapp, E., Hammerle, P., et al.: Bestimmung des Herzminutenvolumens durch Impedanzkardiographie, Arch. Gynecol. 225:339, 1978.
Erratum by Morelock and associates, in the In the article, “Bendectin and fetal development,” January 15, 1982, issue of the JOURNAL, on page 212, second paragraph, line 14, the sentence should read, “Because infant growth parameters are highly influenced by gestational age and the relationship between gestational age and infant size is curvilinear, a log transformation of gestational age as an independent variable was entered into the infant growth regressions.”