Objective: To examine the association between potassium level during the first half of pregnancy and the development of gestational diabetes mellitus (GDM) and hypertensive disorders in the second half of the pregnancy.
Methods: The study population included all registered births between the years 2001-2007. The potassium levels during the first half of pregnancy were sorted by the following groups: K < 3.5 mEq/l; K = 3.5-3.99 mEq/l; and K > or = 4 mEq/l. The linear by linear chi(2)-test was used to determine the association between potassium level during the beginning of pregnancy and pregnancy complications.
Results: The study population included 8114 deliveries. A significant linear association was documented between potassium level in the first half of the pregnancy and the prevalence of GDM in the second half of the pregnancy: 6.3% in the K < 3.5 mEq/l group, 6.6% in the K = 3.5-3.99 mEq/l group and 8.2% in the K > 4 mEq/l group; (p = 0.008). A statistically significant for lower rates of severe pre-eclampsia was noted between the groups: 0.4% in the K < 3.5 mEq/l group, 0.9% in the K = 3.5-3.99 mEq/l group, 1.3% in the K = 4.0-4.99 mEq/l group and 1.5% in the K > or = 5 mEq/l group, (p = 0.027). Indeed, K > 5 mEq/l was noted as a significant risk factor for both, severe pre-eclampsia and for GDM. Using two multiple logistic regression models controlling for maternal age, potassium level was noted as an independent risk factor for both GDM and severe pre-eclampsia.
Conclusions: High potassium levels during the first half of pregnancy are associated with higher risk for the development of GDM and severe pre-eclampsia.