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. 1997 Nov 1;157(9):1245–1254.

Report of the Canadian Hypertension Society Consensus Conference: 3. Pharmacologic treatment of hypertensive disorders in pregnancy

E Rey 1, J LeLorier 1, E Burgess 1, I R Lange 1, L Leduc 1
PMCID: PMC1228354  PMID: 9361646

Abstract

OBJECTIVE: To provide Canadian physicians with evidence-based guidelines for the pharmacologic treatment of hypertensive disorders in pregnancy. OPTIONS: No medication, or treatment with antihypertensive or anticonvulsant drugs. OUTCOMES: Prevention of maternal complications, and prevention of perinatal complications and death. EVIDENCE: Pertinent articles published from 1962 to September 1996 retrieved from the Pregnancy and Childbirth Module of the Cochrane Database of Systematic Reviews and from MEDLINE; additional articles retrieved through a manual search of bibliographies; and expert opinion. Recommendations were graded according to levels of evidence. VALUES: Maternal and fetal well-being were equally valued, with the belief that treatment side effects should be minimized. BENEFITS, HARMS AND COSTS: Reduction in the rate of adverse perinatal outcomes, including death. Potential side effects of antihypertensive drugs include placental hypoperfusion, intrauterine growth retardation and long-term effects on the infant. RECOMMENDATIONS: A systolic blood pressure greater than 169 mm Hg or a diastolic pressure greater than 109 mm Hg in a pregnant woman should be considered an emergency and pharmacologic treatment with hydralazine, labetalol or nifedipine started. Otherwise, the thresholds at which to start antihypertensive treatment are a systolic pressure of 140 mm Hg or a diastolic pressure of 90 mm Hg in women with gestational hypertension without proteinuria or pre-existing hypertension before 28 weeks' gestation, those with gestational hypertension and proteinuria or symptoms at any time during the pregnancy, those with pre-existing hypertension and underlying conditions or target-organ damage, and those with pre-existing hypertension and superimposed gestational hypertension. The thresholds in other circumstances are a systolic pressure of 150 mm Hg or a diastolic pressure of 95 mm Hg. For nonsevere hypertension, methyldopa is the first-line drug; labetalol, pindolol, oxprenolol and nifedipine are second-line drugs. Fetal distress attributed to placental hypoperfusion is rare, and long-term effects on the infant are unknown. Magnesium sulfate is recommended for the prevention and treatment of seizures. VALIDATION: The guidelines are more precise but compatible with those from the US and Australia.

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Selected References

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  1. Appleton M. P., Kuehl T. J., Raebel M. A., Adams H. R., Knight A. B., Gold W. R. Magnesium sulfate versus phenytoin for seizure prophylaxis in pregnancy-induced hypertension. Am J Obstet Gynecol. 1991 Oct;165(4 Pt 1):907–913. doi: 10.1016/0002-9378(91)90437-v. [DOI] [PubMed] [Google Scholar]
  2. Barton J. R., Hiett A. K., Conover W. B. The use of nifedipine during the postpartum period in patients with severe preeclampsia. Am J Obstet Gynecol. 1990 Mar;162(3):788–792. doi: 10.1016/0002-9378(90)91011-z. [DOI] [PubMed] [Google Scholar]
  3. Ben-Ami M., Giladi Y., Shalev E. The combination of magnesium sulphate and nifedipine: a cause of neuromuscular blockade. Br J Obstet Gynaecol. 1994 Mar;101(3):262–263. doi: 10.1111/j.1471-0528.1994.tb13126.x. [DOI] [PubMed] [Google Scholar]
  4. Brent R. L., Beckman D. A. Angiotensin-converting enzyme inhibitors, an embryopathic class of drugs with unique properties: information for clinical teratology counselors. Teratology. 1991 Jun;43(6):543–546. doi: 10.1002/tera.1420430602. [DOI] [PubMed] [Google Scholar]
  5. Burrows R. F., Burrows E. A. The feasibility of a control population for a randomized control trial of seizure prophylaxis in the hypertensive disorders of pregnancy. Am J Obstet Gynecol. 1995 Sep;173(3 Pt 1):929–935. doi: 10.1016/0002-9378(95)90368-2. [DOI] [PubMed] [Google Scholar]
  6. Butters L., Kennedy S., Rubin P. C. Atenolol in essential hypertension during pregnancy. BMJ. 1990 Sep 22;301(6752):587–589. doi: 10.1136/bmj.301.6752.587. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. CUADROS A., TATUM H. J. THE PROPHYLACTIC AND THERAPEUTIC USE OF BENDROFLUMETHIAZIDE IN PREGNANCY. Am J Obstet Gynecol. 1964 Aug 1;89:891–897. doi: 10.1016/0002-9378(64)90058-4. [DOI] [PubMed] [Google Scholar]
  8. Campbell D. M., MacGillivray I. The effect of a low calorie diet or a thiazide diuretic on the incidence of pre-eclampsia and on birth weight. Br J Obstet Gynaecol. 1975 Jul;82(7):572–577. doi: 10.1111/j.1471-0528.1975.tb00689.x. [DOI] [PubMed] [Google Scholar]
  9. Cockburn J., Moar V. A., Ounsted M., Redman C. W. Final report of study on hypertension during pregnancy: the effects of specific treatment on the growth and development of the children. Lancet. 1982 Mar 20;1(8273):647–649. doi: 10.1016/s0140-6736(82)92202-4. [DOI] [PubMed] [Google Scholar]
  10. Collins R., Yusuf S., Peto R. Overview of randomised trials of diuretics in pregnancy. Br Med J (Clin Res Ed) 1985 Jan 5;290(6461):17–23. doi: 10.1136/bmj.290.6461.17. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Crowther C. Magnesium sulphate versus diazepam in the management of eclampsia: a randomized controlled trial. Br J Obstet Gynaecol. 1990 Feb;97(2):110–117. doi: 10.1111/j.1471-0528.1990.tb01735.x. [DOI] [PubMed] [Google Scholar]
  12. Cruickshank D. J., Robertson A. A., Campbell D. M., MacGillivray I. Does labetalol influence the development of proteinuria in pregnancy hypertension? A randomised controlled study. Eur J Obstet Gynecol Reprod Biol. 1992 Jun 16;45(1):47–51. doi: 10.1016/0028-2243(92)90192-2. [DOI] [PubMed] [Google Scholar]
  13. Danielsson B. R., Reiland S., Rundqvist E., Danielson M. Digital defects induced by vasodilating agents: relationship to reduction in uteroplacental blood flow. Teratology. 1989 Oct;40(4):351–358. doi: 10.1002/tera.1420400407. [DOI] [PubMed] [Google Scholar]
  14. Dommisse J. Phenytoin sodium and magnesium sulphate in the management of eclampsia. Br J Obstet Gynaecol. 1990 Feb;97(2):104–109. doi: 10.1111/j.1471-0528.1990.tb01734.x. [DOI] [PubMed] [Google Scholar]
  15. Dubois D., Petitcolas J., Temperville B., Klepper A., Catherine P. Treatment of hypertension in pregnancy with beta-adrenoceptor antagonists. Br J Clin Pharmacol. 1982;13(Suppl 2):375S–378S. doi: 10.1111/j.1365-2125.1982.tb01944.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Dumez Y., Tchobroutsky C., Hornych H., Amiel-Tison C. Neonatal effects of maternal administration of acebutolol. Br Med J (Clin Res Ed) 1981 Oct 24;283(6299):1077–1079. doi: 10.1136/bmj.283.6299.1077. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Ellenbogen A., Jaschevatzky O., Davidson A., Anderman S., Grunstein S. Management of pregnancy-induced hypertension with pindolol--comparative study with methyldopa. Int J Gynaecol Obstet. 1986 Feb;24(1):3–7. doi: 10.1016/0020-7292(86)90015-9. [DOI] [PubMed] [Google Scholar]
  18. FLOWERS C. E., Jr, GRIZZLE J. E., EASTERLING W. E., BONNER O. B. Chlorothiazide as a prophylaxis against toxemia of pregnancy. A double-blind study. Am J Obstet Gynecol. 1962 Oct 1;84:919–929. doi: 10.1016/0002-9378(62)90069-8. [DOI] [PubMed] [Google Scholar]
  19. Fenakel K., Fenakel G., Appelman Z., Lurie S., Katz Z., Shoham Z. Nifedipine in the treatment of severe preeclampsia. Obstet Gynecol. 1991 Mar;77(3):331–337. [PubMed] [Google Scholar]
  20. Fidler J., Smith V., De Swiet M. A randomized study comparing timolol and methyldopa in hospital treatment of puerperal hypertension. Br J Obstet Gynaecol. 1982 Dec;89(12):1031–1034. doi: 10.1111/j.1471-0528.1982.tb04659.x. [DOI] [PubMed] [Google Scholar]
  21. Fidler J., Smith V., Fayers P., De Swiet M. Randomised controlled comparative study of methyldopa and oxprenolol in treatment of hypertension in pregnancy. Br Med J (Clin Res Ed) 1983 Jun 18;286(6382):1927–1930. doi: 10.1136/bmj.286.6382.1927. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Friedman S. A., Lim K. H., Baker C. A., Repke J. T. Phenytoin versus magnesium sulfate in preeclampsia: a pilot study. Am J Perinatol. 1993 May;10(3):233–238. doi: 10.1055/s-2007-994727. [DOI] [PubMed] [Google Scholar]
  23. Gallery E. D., Ross M. R., Gyory A. Z. Antihypertensive treatment in pregnancy: analysis of different responses to oxprenolol and methyldopa. Br Med J (Clin Res Ed) 1985 Aug 31;291(6495):563–566. doi: 10.1136/bmj.291.6495.563. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Garden A., Davey D. A., Dommisse J. Intravenous labetalol and intravenous dihydralazine in severe hypertension in pregnancy. Clin Exp Hypertens B. 1982;1(2-3):371–383. doi: 10.3109/10641958209139860. [DOI] [PubMed] [Google Scholar]
  25. Griffis K. R., Jr, Martin J. N., Jr, Palmer S. M., Martin R. W., Morrison J. C. Utilization of hydralazine or alpha-methyldopa for the management of early puerperal hypertension. Am J Perinatol. 1989 Oct;6(4):437–441. doi: 10.1055/s-2007-999634. [DOI] [PubMed] [Google Scholar]
  26. Guzman E. R., Conley M., Stewart R., Ivan J., Pitter M., Kappy K. Phenytoin and magnesium sulfate effects on fetal heart rate tracings assessed by computer analysis. Obstet Gynecol. 1993 Sep;82(3):375–379. [PubMed] [Google Scholar]
  27. Hanssens M., Keirse M. J., Vankelecom F., Van Assche F. A. Fetal and neonatal effects of treatment with angiotensin-converting enzyme inhibitors in pregnancy. Obstet Gynecol. 1991 Jul;78(1):128–135. [PubMed] [Google Scholar]
  28. Harper A., Murnaghan G. A. Maternal and fetal haemodynamics in hypertensive pregnancies during maternal treatment with intravenous hydralazine or labetalol. Br J Obstet Gynaecol. 1991 May;98(5):453–459. doi: 10.1111/j.1471-0528.1991.tb10339.x. [DOI] [PubMed] [Google Scholar]
  29. Helewa M. E., Burrows R. F., Smith J., Williams K., Brain P., Rabkin S. W. Report of the Canadian Hypertension Society Consensus Conference: 1. Definitions, evaluation and classification of hypertensive disorders in pregnancy. CMAJ. 1997 Sep 15;157(6):715–725. [PMC free article] [PubMed] [Google Scholar]
  30. Horvath J. S., Phippard A., Korda A., Henderson-Smart D. J., Child A., Tiller D. J. Clonidine hydrochloride--a safe and effective antihypertensive agent in pregnancy. Obstet Gynecol. 1985 Nov;66(5):634–638. [PubMed] [Google Scholar]
  31. Högstedt S., Lindeberg S., Axelsson O., Lindmark G., Rane A., Sandström B., Lindberg B. S. A prospective controlled trial of metoprolol-hydralazine treatment in hypertension during pregnancy. Acta Obstet Gynecol Scand. 1985;64(6):505–510. doi: 10.3109/00016348509156729. [DOI] [PubMed] [Google Scholar]
  32. Impey L. Severe hypotension and fetal distress following sublingual administration of nifedipine to a patient with severe pregnancy induced hypertension at 33 weeks. Br J Obstet Gynaecol. 1993 Oct;100(10):959–961. doi: 10.1111/j.1471-0528.1993.tb15120.x. [DOI] [PubMed] [Google Scholar]
  33. Ismail A. A., Medhat I., Tawfic T. A., Kholeif A. Evaluation of calcium-antagonist (Nifedipine) in the treatment of pre-eclampsia. Int J Gynaecol Obstet. 1993 Jan;40(1):39–43. doi: 10.1016/0020-7292(93)90770-w. [DOI] [PubMed] [Google Scholar]
  34. Jannet D., Carbonne B., Sebban E., Milliez J. Nicardipine versus metoprolol in the treatment of hypertension during pregnancy: a randomized comparative trial. Obstet Gynecol. 1994 Sep;84(3):354–359. [PubMed] [Google Scholar]
  35. Jouppila P., Kirkinen P., Koivula A., Ylikorkala O. Labetalol does not alter the placental and fetal blood flow or maternal prostanoids in pre-eclampsia. Br J Obstet Gynaecol. 1986 Jun;93(6):543–547. doi: 10.1111/j.1471-0528.1986.tb07951.x. [DOI] [PubMed] [Google Scholar]
  36. Kumar N., Batra Y. K., Bala I., Gopalan S. Nifedipine attenuates the hypertensive response to tracheal intubation in pregnancy-induced hypertension. Can J Anaesth. 1993 Apr;40(4):329–333. doi: 10.1007/BF03009631. [DOI] [PubMed] [Google Scholar]
  37. Lardoux H., Blazquez G., Leperlier E., Gérard J. Essai ouvert, comparatif, avec tirage au sort pour le traitement de l'HTA gravidique modérée: méthyldopa, acébutolol, labétalol. Arch Mal Coeur Vaiss. 1988 Jun;81(Spec No):137–140. [PubMed] [Google Scholar]
  38. Leather H. M., Humphreys D. M., Baker P., Chadd M. A. A controlled trial of hypotensive agents in hypertension in pregnancy. Lancet. 1968 Aug 31;2(7566):488–490. doi: 10.1016/s0140-6736(68)90650-8. [DOI] [PubMed] [Google Scholar]
  39. Livingstone I., Craswell P. W., Bevan E. B., Smith M. T., Eadie M. J. Propranolol in pregnancy three year prospective study. Clin Exp Hypertens B. 1983;2(2):341–350. doi: 10.3109/10641958309006092. [DOI] [PubMed] [Google Scholar]
  40. Lucas M. J., Leveno K. J., Cunningham F. G. A comparison of magnesium sulfate with phenytoin for the prevention of eclampsia. N Engl J Med. 1995 Jul 27;333(4):201–205. doi: 10.1056/NEJM199507273330401. [DOI] [PubMed] [Google Scholar]
  41. Lurie S., Fenakel K., Friedman A. Effect of nifedipine on fetal heart rate in the treatment of severe pregnancy-induced hypertension. Am J Perinatol. 1990 Jul;7(3):285–286. doi: 10.1055/s-2007-999503. [DOI] [PubMed] [Google Scholar]
  42. Mabie W. C., Gonzalez A. R., Sibai B. M., Amon E. A comparative trial of labetalol and hydralazine in the acute management of severe hypertension complicating pregnancy. Obstet Gynecol. 1987 Sep;70(3 Pt 1):328–333. [PubMed] [Google Scholar]
  43. Mabie W. C., Pernoll M. L., Biswas M. K. Chronic hypertension in pregnancy. Obstet Gynecol. 1986 Feb;67(2):197–205. doi: 10.1097/00006250-198602000-00008. [DOI] [PubMed] [Google Scholar]
  44. Magee L. A., Schick B., Donnenfeld A. E., Sage S. R., Conover B., Cook L., McElhatton P. R., Schmidt M. A., Koren G. The safety of calcium channel blockers in human pregnancy: a prospective, multicenter cohort study. Am J Obstet Gynecol. 1996 Mar;174(3):823–828. doi: 10.1016/s0002-9378(96)70307-1. [DOI] [PubMed] [Google Scholar]
  45. Meizner I., Paran E., Katz M., Holcberg G., Insler V. Flow velocity analysis of umbilical and uterine artery flow in pre-eclampsia treated with propranolol or pindolol. J Clin Ultrasound. 1992 Feb;20(2):115–119. doi: 10.1002/jcu.1870200205. [DOI] [PubMed] [Google Scholar]
  46. Michael C. A. Intravenous labetalol and intravenous diazoxide in severe hypertension complicating pregnancy. Aust N Z J Obstet Gynaecol. 1986 Feb;26(1):26–29. doi: 10.1111/j.1479-828x.1986.tb01523.x. [DOI] [PubMed] [Google Scholar]
  47. Moretti M. M., Fairlie F. M., Akl S., Khoury A. D., Sibai B. M. The effect of nifedipine therapy on fetal and placental Doppler waveforms in preeclampsia remote from term. Am J Obstet Gynecol. 1990 Dec;163(6 Pt 1):1844–1848. doi: 10.1016/0002-9378(90)90762-v. [DOI] [PubMed] [Google Scholar]
  48. Morris J. A., Arce J. J., Hamilton C. J., Davidson E. C., Maidman J. E., Clark J. H., Bloom R. S. The management of severe preeclampsia and eclampsia with intravenous diazoxide. Obstet Gynecol. 1977 Jun;49(6):675–680. [PubMed] [Google Scholar]
  49. Moutquin J. M., Garner P. R., Burrows R. F., Rey E., Helewa M. E., Lange I. R., Rabkin S. W. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. CMAJ. 1997 Oct 1;157(7):907–919. [PMC free article] [PubMed] [Google Scholar]
  50. Neuman J., Weiss B., Rabello Y., Cabal L., Freeman R. K. Diazoxide for the acute control of severe hypertension complicating pregnancy: a pilot study. Obstet Gynecol. 1979 Mar;53(3 Suppl):50S–55S. [PubMed] [Google Scholar]
  51. Page E. W., Christianson R. The impact of mean arterial pressure in the middle trimester upon the outcome of pregnancy. Am J Obstet Gynecol. 1976 Jul 15;125(6):740–746. doi: 10.1016/0002-9378(76)90839-5. [DOI] [PubMed] [Google Scholar]
  52. Paterson-Brown S., Robson S. C., Redfern N., Walkinshaw S. A., de Swiet M. Hydralazine boluses for the treatment of severe hypertension in pre-eclampsia. Br J Obstet Gynaecol. 1994 May;101(5):409–413. doi: 10.1111/j.1471-0528.1994.tb11913.x. [DOI] [PubMed] [Google Scholar]
  53. Phippard A. F., Fischer W. E., Horvath J. S., Child A. G., Korda A. R., Henderson-Smart D., Duggin G. G., Tiller D. J. Early blood pressure control improves pregnancy outcome in primigravid women with mild hypertension. Med J Aust. 1991 Mar 18;154(6):378–382. doi: 10.5694/j.1326-5377.1991.tb121126.x. [DOI] [PubMed] [Google Scholar]
  54. Pickles C. J., Symonds E. M., Broughton Pipkin F. The fetal outcome in a randomized double-blind controlled trial of labetalol versus placebo in pregnancy-induced hypertension. Br J Obstet Gynaecol. 1989 Jan;96(1):38–43. doi: 10.1111/j.1471-0528.1989.tb01574.x. [DOI] [PubMed] [Google Scholar]
  55. Piper J. M., Ray W. A., Rosa F. W. Pregnancy outcome following exposure to angiotensin-converting enzyme inhibitors. Obstet Gynecol. 1992 Sep;80(3 Pt 1):429–432. [PubMed] [Google Scholar]
  56. Plouin P. F., Breart G., Maillard F., Papiernik E., Relier J. P. Comparison of antihypertensive efficacy and perinatal safety of labetalol and methyldopa in the treatment of hypertension in pregnancy: a randomized controlled trial. Br J Obstet Gynaecol. 1988 Sep;95(9):868–876. doi: 10.1111/j.1471-0528.1988.tb06571.x. [DOI] [PubMed] [Google Scholar]
  57. Ramanathan J., Sibai B. M., Mabie W. C., Chauhan D., Ruiz A. G. The use of labetalol for attenuation of the hypertensive response to endotracheal intubation in preeclampsia. Am J Obstet Gynecol. 1988 Sep;159(3):650–654. doi: 10.1016/s0002-9378(88)80027-9. [DOI] [PubMed] [Google Scholar]
  58. Redman C. W. Eclampsia still kills. Br Med J (Clin Res Ed) 1988 Apr 30;296(6631):1209–1210. doi: 10.1136/bmj.296.6631.1209. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Redman C. W. Fetal outcome in trial of antihypertensive treatment in pregnancy. Lancet. 1976 Oct 9;2(7989):753–756. doi: 10.1016/s0140-6736(76)90597-3. [DOI] [PubMed] [Google Scholar]
  60. Rey E. Effects of methyldopa on umbilical and placental artery blood flow velocity waveforms. Obstet Gynecol. 1992 Nov;80(5):783–787. [PubMed] [Google Scholar]
  61. Reynolds B., Butters L., Evans J., Adams T., Rubin P. C. First year of life after the use of atenolol in pregnancy associated hypertension. Arch Dis Child. 1984 Nov;59(11):1061–1063. doi: 10.1136/adc.59.11.1061. [DOI] [PMC free article] [PubMed] [Google Scholar]
  62. Roberts J. M. Magnesium for preeclampsia and eclampsia. N Engl J Med. 1995 Jul 27;333(4):250–251. doi: 10.1056/NEJM199507273330409. [DOI] [PubMed] [Google Scholar]
  63. Robson S. C., Redfern N., Seviour J., Campbell M., Walkinshaw S., Rodeck C., de Swiet M. Phenytoin prophylaxis in severe pre-eclampsia and eclampsia. Br J Obstet Gynaecol. 1993 Jul;100(7):623–628. doi: 10.1111/j.1471-0528.1993.tb14227.x. [DOI] [PubMed] [Google Scholar]
  64. Rubin P. C., Butters L., Clark D. M., Reynolds B., Sumner D. J., Steedman D., Low R. A., Reid J. L. Placebo-controlled trial of atenolol in treatment of pregnancy-associated hypertension. Lancet. 1983 Feb 26;1(8322):431–434. [PubMed] [Google Scholar]
  65. Sackett D. L. Rules of evidence and clinical recommendations on the use of antithrombotic agents. Chest. 1989 Feb;95(2 Suppl):2S–4S. [PubMed] [Google Scholar]
  66. Seabe S. J., Moodley J., Becker P. Nifedipine in acute hypertensive emergencies in pregnancy. S Afr Med J. 1989 Sep 16;76(6):248–250. [PubMed] [Google Scholar]
  67. Shoemaker C. T., Meyers M. Sodium nitroprusside for control of severe hypertensive disease of pregnancy: a case report and discussion of potential toxicity. Am J Obstet Gynecol. 1984 May 15;149(2):171–173. doi: 10.1016/0002-9378(84)90192-3. [DOI] [PubMed] [Google Scholar]
  68. Sibai B. M., Barton J. R., Akl S., Sarinoglu C., Mercer B. M. A randomized prospective comparison of nifedipine and bed rest versus bed rest alone in the management of preeclampsia remote from term. Am J Obstet Gynecol. 1992 Oct;167(4 Pt 1):879–884. doi: 10.1016/s0002-9378(12)80005-6. [DOI] [PubMed] [Google Scholar]
  69. Sibai B. M., Gonzalez A. R., Mabie W. C., Moretti M. A comparison of labetalol plus hospitalization versus hospitalization alone in the management of preeclampsia remote from term. Obstet Gynecol. 1987 Sep;70(3 Pt 1):323–327. [PubMed] [Google Scholar]
  70. Sibai B. M., Grossman R. A., Grossman H. G. Effects of diuretics on plasma volume in pregnancies with long-term hypertension. Am J Obstet Gynecol. 1984 Dec 1;150(7):831–835. doi: 10.1016/0002-9378(84)90458-7. [DOI] [PubMed] [Google Scholar]
  71. Sibai B. M., Mabie W. C., Shamsa F., Villar M. A., Anderson G. D. A comparison of no medication versus methyldopa or labetalol in chronic hypertension during pregnancy. Am J Obstet Gynecol. 1990 Apr;162(4):960–967. doi: 10.1016/0002-9378(90)91297-p. [DOI] [PubMed] [Google Scholar]
  72. Sibai B. M. Magnesium sulfate is the ideal anticonvulsant in preeclampsia-eclampsia. Am J Obstet Gynecol. 1990 May;162(5):1141–1145. doi: 10.1016/0002-9378(90)90002-o. [DOI] [PubMed] [Google Scholar]
  73. Sibai B. M., Mercer B. M., Schiff E., Friedman S. A. Aggressive versus expectant management of severe preeclampsia at 28 to 32 weeks' gestation: a randomized controlled trial. Am J Obstet Gynecol. 1994 Sep;171(3):818–822. doi: 10.1016/0002-9378(94)90104-x. [DOI] [PubMed] [Google Scholar]
  74. Snyder S. W., Cardwell M. S. Neuromuscular blockade with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 1989 Jul;161(1):35–36. doi: 10.1016/0002-9378(89)90226-3. [DOI] [PubMed] [Google Scholar]
  75. Stempel J. E., O'Grady J. P., Morton M. J., Johnson K. A. Use of sodium nitroprusside in complications of gestational hypertension. Obstet Gynecol. 1982 Oct;60(4):533–538. [PubMed] [Google Scholar]
  76. Thorpe-Beeston J. G., Armar N. A., Dancy M., Cochrane G. W., Ryan G., Rodeck C. H. Pregnancy and ACE inhibitors. Br J Obstet Gynaecol. 1993 Jul;100(7):692–693. doi: 10.1111/j.1471-0528.1993.tb14242.x. [DOI] [PubMed] [Google Scholar]
  77. WESELEY A. C., DOUGLAS G. W. Continuous use of chlorothiazide for prevention of toxemia of pregnancy. Obstet Gynecol. 1962 Mar;19:355–358. [PubMed] [Google Scholar]
  78. Waisman G. D., Mayorga L. M., Cámera M. I., Vignolo C. A., Martinotti A. Magnesium plus nifedipine: potentiation of hypotensive effect in preeclampsia? Am J Obstet Gynecol. 1988 Aug;159(2):308–309. doi: 10.1016/s0002-9378(88)80072-3. [DOI] [PubMed] [Google Scholar]
  79. Williams R. E. Sir Ashley Miles. J Hosp Infect. 1994 Jul;27(3):161–166. doi: 10.1016/0195-6701(94)90123-6. [DOI] [PubMed] [Google Scholar]

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