Low sodium diet and pregnancy-induced hypertension: a multi-centre randomised controlled trial
Article first published online: 19 AUG 2005
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 105, Issue 4, pages 430–434, April 1998
How to Cite
Knuist, M., Bonsel, G. J., Zondervan, H. A. and Treffers, P. E. (1998), Low sodium diet and pregnancy-induced hypertension: a multi-centre randomised controlled trial. BJOG: An International Journal of Obstetrics & Gynaecology, 105: 430–434. doi: 10.1111/j.1471-0528.1998.tb10129.x
- Issue published online: 19 AUG 2005
- Article first published online: 19 AUG 2005
- Received 26 March 1997 Returned for revision 25 September 1997 Accepted 3 December 1997
Objective To examine the effectiveness of the standard policy in the Netherlands to prescribe a sodium restricted diet to prevent or to treat mild pregnancy-induced hypertension.
Design Multi-centre randomised controlled trial between April 1992 and April 1994.
Setting Seven practices of independent midwives and one university hospital.
Participants The experimental group comprised 184 women given a low sodium diet (≤ 50 mmol sodium/day) and a control group of 177 women given a normal diet. Eligible women for inclusion had had a rise of blood pressure, or excessive weight gain or oedema during the antenatal period. The 361 women in the trial were recruited from 2020 nulliparae, of whom 1512 (75%) gave informed consent at the beginning of their pregnancy to participate in the study.
Main outcome measures The difference between highest diastolic blood pressure after randomization and diastolic blood pressure at the moment of randomisation; referral and admission to hospital for hypertension.
Results There was no difference in increase of diastolic blood pressure after randomisation, the percentage of referral and admission to hospital for hypertension, or in obstetric outcome between the two groups. Urinary sodium excretion after randomisation in the normal diet group was significantly higher than in the low sodium group.
Conclusion Prescribing a sodium-restricted diet to prevent or to treat mild pregnancy-induced hypertension is not effective. Therefore there is no need to introduce a salt restricted diet in prenatal care, although increasing evidence shows that a low sodium diet prevents hypertension in non pregnant individuals.