Dietary acid load and blood pressure development in pregnancy: The Generation R Study

Background & aims: Dietary intake could induce a mild maternal metabolic acidosis that might lead to a higher level of blood pressure. Because studies in pregnancy are scarce, we evaluated the association between maternal dietary acid load and changes in blood pressure during pregnancy, pregnancy-induced hypertension and pre-eclampsia. Methods: We included 3411 pregnant women of Dutch ancestry from a prospective population-based cohort (Rotterdam, The Netherlands). Dietary data was self-reported via a food-frequency questionnaire in early pregnancy. Four dietary acid load measurements were calculated: dietary potential renal acid load (dPRAL), net endogenous acid production (NEAP), animal protein/potassium ratio, and vegetable protein/potassium ratio. Diastolic blood pressure (DBP) and systolic blood pressure (SBP) were measured three times during pregnancy. Information on pregnancy-induced hypertension and pre-eclampsia was obtained from medical records. Linear mixed models and logistic regression were used and adjusted for sociodemographic and lifestyle factors. Results: The results indicated that dPRAL, NEAP and animal protein/potassium ratio were not associated with DBP or SBP in pregnancy. One standard deviation higher vegetable protein/potassium ratio was associated with lower DBP (−0.30 mmHg [95% CI −0.54; −0.06]) but not with SBP (−0.29 mmHg [95% CI −0.60; 0.01]). Dietary acid load measurement was neither associated with the prevalence of pregnancy-induced hypertension nor with pre-eclampsia. Conclusions: Dietary acid load was not associated with changes in DBP or SBP during pregnancy, although women with a higher vegetable protein/potassium ratio had a slightly lower DBP. Dietary acid load was not associated with pregnancy-induced hypertension or pre-eclampsia.